Publications by authors named "Laurence D Sterns"

36 Publications

Remote-only monitoring for patients with cardiac implantable electronic devices: a before-and-after pilot study.

CMAJ Open 2021 Jan-Mar;9(1):E53-E61. Epub 2021 Jan 25.

QEII Health Sciences Centre, Dalhousie University (Sapp, AbdelWahab, Parkash), Halifax, NS; Department of Cardiac Sciences (Gillis, Raj), University of Calgary, Calgary, Alta.; Institut universitaire de cardiologie and pneumologie de Quebec (Nault, Philippon), Université Laval, Québec, Que.; University of Ottawa Heart Institute (Nery, Wells), Ottawa, Ont.; Hamilton Health Sciences (Healey), McMaster University, Hamilton, Ont.; CK Hui Heart Centre (Lockwood), Edmonton, Alta.; Vancouver Island Health Authority (Sterns), Victoria, BC; East Carolina University (Sears), Greenville, NC; London Health Sciences Centre (Yee, Tang), University of Western Ontario, London, Ont.

Background: Outcomes for patients with cardiac implantable electronic devices are better when follow-up incorporates remote monitoring technology in addition to in-clinic visits. For patients with implantable devices, we sought to determine the feasibility, safety and associated health care utilization of remote-only follow-up, along with its effects on patients' quality of life and costs.

Methods: This multicentre before-and-after pilot study involved patients with new or existing pacemakers or implantable cardioverter defibrillators. The "before" phase of the study spanned the period October 2015 to February 2017; the "after" phase spanned the period October 2016 to February 2018. The exposure was remote-only follow-up in combination with Remote View, a service that facilitates access to device data, allowing device settings to be viewed remotely to facilitate remote programming. Outcomes at 12 months were feasibility (adherence to remote monitoring), safety (rate of adverse events) and health care utilization (remote and in-clinic appointments). We also assessed quality of life, using 3 validated scales, and costs, taking into account both health care system and patient costs.

Results: A total of 176 patients were enrolled. Adherence (defined as at least 1 successful remote transmission during follow-up) was 87% over a mean follow-up of 11.7 (standard deviation 2.2) months. There was a reduction in in-clinic visits at specialized sites among patients with both implantable defibrillators (26 v. 5, < 0.001, = 48) and pacemakers (42 v. 10, < 0.001, = 51). There was no significant change in visits to community sites for patients with defibrillators (13 v. 17, = 0.3, = 48). The composite rate of death, stroke, cardiovascular hospitalization and device-related hospitalization was 7% ( = 164). No adverse events were linked to the intervention. There was no change in quality-of-life scales between baseline and 12 months. Health care costs were reduced by 31% for patients with defibrillators and by 44% for those with pacemakers.

Interpretation: This pilot study showed the feasibility of remote-only follow-up, with no increase in adverse clinical outcomes and no effect on quality of life, but with reductions in costs and health care utilization. These results support progression to a larger-scale study of whether superior effectiveness and reduced cost can be achieved, with preservation of safety, through use of remote-only follow-up.

Trial Registration: ClinicalTrials.gov, no. NCT02585817.
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http://dx.doi.org/10.9778/cmajo.20200041DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7843075PMC
January 2021

Efficacy and Safety of Same-Day Discharge for Atrial Fibrillation Ablation.

JACC Clin Electrophysiol 2020 06 29;6(6):609-619. Epub 2020 Apr 29.

Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, British Columbia, Canada.

Objectives: The purpose of this study was to evaluate the efficacy, health care utilization, and safety of a same-day discharge protocol.

Background: Catheter ablation of atrial fibrillation (AF) is the most common ablation performed. Increasing volumes of AF ablation are placing demands on hospital resources. In response, our institutions developed a same-day discharge protocol for AF ablation.

Methods: This was a multicenter cohort study of all patients undergoing AF ablation from 2010 to 2014 at 2 major centers. The primary efficacy outcome was the proportion of successful same-day discharges. The primary health care utilization outcome was 30-day hospital readmission for any reason. The primary safety outcome was a composite of 30-day death, stroke/transient ischemic attack or embolism, or bleeding requiring hospitalization.

Results: A total of 3,054 patients underwent AF ablation from 2010 to 2014 and met inclusion criteria. Same-day discharge was achieved in 79.2% (2,418 of 3,054). Hospital readmission at 30 days was 7.7% for the same-day discharge group, 10.2% for those who remained in the hospital overnight without complications (p = 0.055 for comparison with same-day discharge), and 19.5% (p < 0.001) for those who remained in the hospital with procedural complications (7.7%). Complication rates from discharge to 30 days (excluding immediate procedural complications) were 0.37% for the same-day discharge group, 0.36% (p = 0.999) for those kept overnight without complications, and 2.5% (p = 0.044) for those with initial procedural complications.

Conclusions: Same-day discharge after AF ablation is feasible in the majority of patients with use of a standardized protocol. This approach was not associated with higher hospital readmission or complication rates after discharge.
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http://dx.doi.org/10.1016/j.jacep.2020.02.009DOI Listing
June 2020

SVT discrimination algorithms significantly reduce the rate of inappropriate therapy in the setting of modern-day delayed high-rate detection programming.

J Cardiovasc Electrophysiol 2019 12 5;30(12):2877-2884. Epub 2019 Nov 5.

Division of Cardiology, Virginia Commonwealth University, Richmond, Virginia.

Background: Contemporary implantable cardioverter-defibrillator (ICD) programming involving delayed high-rate detection and use of supraventricular tachycardia (SVT) discriminators has significantly reduced the rate of inappropriate shocks. The extent to which SVT algorithms alone reduce inappropriate therapies is poorly understood.

Methods And Results: PainFree SST enrolled 2770 patients with a single- or dual-chamber ICD or cardiac resynchronization defibrillator. Patients were followed for 22 ± 9 months with SVT discriminators on in 96% of patients. Sustained ventricular tachyarrhythmias and SVT episodes were adjudicated by an independent physician committee. For this analysis, all episodes were subjected to postprocessing computer simulation with SVT discriminators off with and without delayed high-rate detection criteria (ventricular fibrillation zone only, 30/40 at 320 ms). There were 3282 adjudicated SVT episodes of which 115 resulted in an ICD shock and 113 received only ATP (2-year inappropriate shock and therapy rates of 3.1% and 4.1%). Therapy was appropriately withheld for the remaining 3054 SVT episodes. With both SVT discriminators and delayed high-rate detection simulated off, the 2-year inappropriate therapy rate would have been 22.9% (hazard ratio [HR] = 6.24; 95% confidence interval [CI]: 5.20-7.49). With SVT discriminators simulated off and delayed high-rate detection simulated on in all patients, the 2-year rate would have been 6.4% (HR = 1.63; CI: 1.44-1.85).

Conclusions: The use of SVT discriminators has a significant role in reducing the rate of inappropriate ICD therapy even in the setting of delayed high-rate detection settings. Deactivating SVT discriminators would have resulted in an overall increase in the inappropriate ICD therapy rate by 63% and 524% with and without delayed high-rate detection programming, respectively.
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http://dx.doi.org/10.1111/jce.14250DOI Listing
December 2019

Additional antitachycardia pacing programming strategies further reduce unnecessary implantable cardioverter-defibrillator shocks.

Heart Rhythm 2020 01 29;17(1):98-105. Epub 2019 Jul 29.

Medtronic CRHF, Medtronic plc., Mounds View, Minnesota.

Background: Antitachycardia pacing (ATP) is routinely used to terminate ventricular tachyarrhythmias (VTs). However, little guidance exists on the most effective programming of ATP.

Objective: This study evaluated whether additional ATP sequences are more effective in reducing implantable cardioverter-defibrillator shocks.

Methods: In patients from the Shock-Less study, the number of overall shocks were compared between patients programmed to ≤3 ATP sequences (VT zone) and ≤1 ATP sequence (fast ventricular tachycardia [FVT] zone) (nominal group) and patients programmed to receive additional ATP sequences in VT (>3) or FVT (>1) zones.

Results: Of the 4112 patients (15% receiving secondary prevention; 77% men; mean age 65.9 ± 12.6 years), 1532 patients (37%) were programmed with additional ATP sequences (1025 with >3 ATP sequences in the VT zone; 699 patients with >1 ATP sequence in the FVT zone). Over a mean follow-up period of 19.6 ± 10.7 months, 4359 VT/FVT episodes occurred in 591 patients. Compared with the nominal group, in patients with additional ATP programming, there was a 39% reduction in the number of shocked VT episodes (0.46 episodes per patient-year vs 0.28 episodes per patient-year; incidence rate ratio [IRR] 0.61; P < .001) and a 44% reduction in the number of shocked FVT episodes (0.83 episodes per patient-year vs 0.47 episodes per patient-year; IRR 0.56; P < .001). The reduction in shocked VT episodes was observed in both primary (IRR 0.68; 95% confidence interval 0.51-0.90; P = .007) and secondary (IRR 0.51; 95% confidence interval 0.35-0.72; P < .001) prevention patients.

Conclusion: Programming more than the nominal number of ATP sequences in both the VT and FVT zones is associated with a lower occurrence of implantable cardioverter-defibrillator shocks in clinical practice.
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http://dx.doi.org/10.1016/j.hrthm.2019.07.027DOI Listing
January 2020

Optimum lesion set and predictors of outcome in persistent atrial fibrillation ablation: a meta-regression analysis.

Europace 2019 Aug;21(8):1176-1184

International Centre for Circulatory Health, National Heart and Lung Institute, Imperial College London, London, UK.

Aims: Ablation of persistent atrial fibrillation (PsAF) has been performed by many techniques with varying success rates. This may be due to ablation techniques, patient demographics, comorbidities, and trial design. We conducted a meta-regression of studies of PsAF ablation to elucidate the factors affecting atrial fibrillation (AF) recurrence.

Methods And Results : Databases were searched for prospective studies of PsAF ablation. A meta-regression was performed. Fifty-eight studies (6767 patients) were included. Complex fractionated atrial electrogram (CFAE) ablation reduced freedom from AF by 8.9% [95% confidence interval (CI) -15 to -2.3, P = 0.009). Left atrial appendage [LAA isolation (three study arms)] increased freedom from AF by 39.5% (95% CI 9.1-78.4, P = 0.008). Posterior wall isolation (PWI) (eight study arms) increased freedom from AF by 19.4% (95% CI 3.3-38.1, P = 0.017). Linear ablation or ganglionated plexi ablation resulted in no significant effect on freedom from AF. More extensive ablation increased intraprocedural AF termination; however, intraprocedural AF termination was not associated with improved outcomes. Increased left atrial diameter was associated with a reduction in freedom from AF by 4% (95% CI -6.8% to -1.1%, P = 0.007) for every 1 mm increase in diameter.

Conclusion : Linear ablation, PWI, and CFAE ablation improves intraprocedural AF termination, but such termination does not predict better long-term outcomes. Study arms including PWI or LAA isolation in the lesion set were associated with improved outcomes in terms of freedom from AF; however, further randomized trials are required before these can be routinely recommended. Left atrial size is the most important marker of AF chronicity influencing outcomes.
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http://dx.doi.org/10.1093/europace/euz108DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6680367PMC
August 2019

Estimating the incidence of atrial fibrillation in single-chamber implantable cardioverter defibrillator patients.

Pacing Clin Electrophysiol 2019 02 13;42(2):132-138. Epub 2018 Dec 13.

Medtronic plc, Mounds View, Minnesota.

Background: Atrial arrhythmias are associated with major adverse cardiovascular events. Recent reports among implantable cardioverter defibrillator (ICD) patients have demonstrated a high prevalence of atrial fibrillation (AF), predominantly in dual-chamber recipients. AF incidence among patients with single-chamber systems (approximately 50% of all ICDs) is currently unknown. The objective was to estimate the prevalence of new-onset AF among single-chamber ICD patients by observing the rates of new atrial tachycardia (AT)/AF among a propensity scoring matched cohort of dual-chamber ICD patients from the PainFree SmartShock technology study, to better inform screening initiatives.

Methods: Among 2770 patients enrolled, 1862 single-chamber, dual-chamber, and cardiac resynchronization therapy subjects with no prior history of atrial tachyarrhythmias were included. Daily AT/AF burden was estimated using a propensity score weighted model against data from dual-chamber ICDs.

Results: Over 22 ± 9 months of follow-up, the estimated incidence of AT/AF-lasting at least 6 min, 6 h, and 24 h per day -in the single-chamber cohort was 22.0, 9.8, and 6.3%, whereas among dual-chamber patients, the prevalence was 26.6, 13.1, and 7.1%, respectively. Initiation of oral anticoagulation was estimated to occur in 9.8% of the propensity matched single-chamber cohort, which was higher than the actual observed rate of 6.0%. Stroke and transient ischemic attack occurred at low rates in all device subgroups.

Conclusions: Atrial arrhythmias occur frequently, and significant underutilization of anticoagulation is suggested in single-chamber ICD recipients. Routine screening for AF should be considered among single-chamber ICD recipients.
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http://dx.doi.org/10.1111/pace.13555DOI Listing
February 2019

Pacemaker lead surveillance and failure: Is there a signal in the noise?

Heart Rhythm 2019 04 9;16(4):579-580. Epub 2018 Nov 9.

Pacemaker and ICD Clinic, Vancouver Island Health Authority, Victoria, British Columbia, Canada. Electronic address:

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http://dx.doi.org/10.1016/j.hrthm.2018.11.011DOI Listing
April 2019

Outcomes of paroxysmal atrial fibrillation ablation studies are affected more by study design and patient mix than ablation technique.

J Cardiovasc Electrophysiol 2018 11 30;29(11):1471-1479. Epub 2018 Oct 30.

Department of Medicine, Royal Jubilee Hospital, Victoria, Canada.

Objective: We tested whether ablation methodology and study design can explain the varying outcomes in terms of atrial fibrillation (AF)-free survival at 1 year.

Background: There have been numerous paroxysmal AF ablation trials, which are heterogeneous in their use of different ablation techniques and study design. A useful approach to understanding how these factors influence outcome is to dismantle the trials into individual arms and reconstitute them as a large meta-regression.

Methods: Data were collected from 66 studies (6941 patients). With freedom from AF as the dependent variable, we performed meta-regression using the individual study arm as the unit.

Results: Success rates did not change regardless of the technique used to produce pulmonary vein isolation (PVI). Neither was adjunctive lesion sets associated with any improvement in outcome. Studies that included more males and fewer hypertensive patients were found more likely to report better outcomes. The electrocardiography method selected to assess outcome also plays an important role. Outcomes were worse in studies that used regular telemonitoring (by 23%; P < 0.001) or in patients who had implantable loop recorders (by 21%; P = 0.006), rather than those with the less thorough periodic Holter monitoring.

Conclusions: Outcomes of AF ablation studies involving PVI are not affected by the technologies used to produce PVI. Neither do adjunctive lesion sets change the outcome. Achieving high success rates in these studies appears to be dependent more on patient mix and on the thoroughness of AF detection protocols. These should be carefully considered when quoting the success rates of AF ablation procedures that are derived from such studies.
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http://dx.doi.org/10.1111/jce.13745DOI Listing
November 2018

Comparison of ICD shock rates in Japanese and non-Japanese patients in the PainFree SST study.

Pacing Clin Electrophysiol 2018 09 13;41(9):1185-1191. Epub 2018 Aug 13.

Division of Cardiology, Saiseikai Kumamoto Hospital Cardiovascular Center, Kumamoto, Japan.

Background: The PainFree Smart Shock Technology (SST) study showed a low implantable cardioverter-defibrillator (ICD) inappropriate shock rate. However, the majority of patients were from Western countries with patient characteristics different from those in Japan. ICD shock rates using the novel SST algorithms in Japanese patients are still unknown.

Methods: All 2,770 patients in the PainFree SST study (Japan [JPN]: N = 181, other geographies [OJPN]: N = 2,589) were included in this analysis.

Results: Japanese patients had higher average left ventricular ejection fraction (P < 0.0001), higher prevalence of secondary prevention indications (P < 0.0001), nonischemic cardiomyopathy (P < 0.0001), and permanent atrial fibrillation (P < 0.0001). The appropriate shock rate at 12 months was not different between JPN and OJPN: 6.4% and 6.3%, respectively (P = 0.95). The inappropriate shock rate at 12 months was significantly higher in Japanese patients (2.9% vs 1.7%, P = 0.017). However, after propensity score matching to adjust for the difference in baseline characteristics, the difference in inappropriate shock rate was not statistically significant (P = 0.51).

Conclusions: There was no difference in the appropriate shock rate between Japan and other geographies. The inappropriate shock rate in Japan was low, although it was slightly higher compared to other geographies due to baseline characteristics, including a higher prevalence of permanent AF. There was not a statistically significant difference after adjusting for baseline characteristics.
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http://dx.doi.org/10.1111/pace.13427DOI Listing
September 2018

Cost Effectiveness of Ventricular Tachycardia Ablation Versus Escalation of Antiarrhythmic Drug Therapy: The VANISH Trial.

JACC Clin Electrophysiol 2018 05 28;4(5):660-668. Epub 2018 Mar 28.

Department of Medicine, Queen Elizabeth II Health Sciences Centre, Dalhousie University, Halifax, Canada. Electronic address:

Objectives: This analysis uses the data from the randomized controlled trial to assess the cost effectiveness of catheter ablation (n = 132) versus escalated antiarrhythmic therapy (n = 127).

Background: For survivors of myocardial infarction with implantable cardioverter-defibrillator shocks despite antiarrhythmic drugs, the VANISH (Ventricular Tachycardia Ablation Versus Escalated Antiarrhythmic Drug Therapy in Ischemic Heart Disease) trial demonstrated improved clinical outcomes with catheter ablation compared with more aggressive antiarrhythmic pharmacotherapy.

Methods: Health care resource use and quality-of-life data were used to determine the cost effectiveness of catheter ablation. Published references were used to estimate costs (in 2015 Canadian dollars). The analysis was over 3 years, with a 5% discount rate. Adjustment was made for censoring and baseline utilities.

Results: Ablation resulted in greater quality-adjusted life-years (QALYs) than escalated drug therapy did (1.63 vs. 1.49; difference: 0.14; 95% confidence interval [CI]: -0.20 to 0.46) and higher cost ($65,126 vs. $60,269; difference: $4,857; 95% CI: -$19,757 to $27,106); with an incremental cost per QALY gained for ablation versus escalated drug therapy of $34,057 primarily due to the initial costs of ablation, which were partially offset by the costs of subsequent ablations and adverse outcomes in the escalated drug therapy arm. For patients with amiodarone-refractory ventricular tachycardia, ablation dominated escalated drug therapy, with greater QALYs (1.48 vs. 1.26; difference: 0.22; 95% CI: -0.19 to 0.59) and lower costs ($67,614 vs. $68,383; difference: -$769; 95% CI: -$35,330 to $27,092). For those with sotalol-refractory ventricular tachycardia, ablation resulted in similar QALYs (1.90 vs. 1.90; difference: -0.00; 95% CI: -0.59 to 0.62) and higher costs ($60,455 vs. $45,033; difference: $15,422; 95% CI: -$10,968 to $48,555).

Conclusions: For the total trial population, results are suggestive that ablation is cost effective compared with escalation of drug therapy. This result was only manifest for the subgroup of patients whose qualifying arrhythmia occurred despite amiodarone.
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http://dx.doi.org/10.1016/j.jacep.2018.01.007DOI Listing
May 2018

Mexiletine or catheter ablation after amiodarone failure in the VANISH trial.

J Cardiovasc Electrophysiol 2018 04 1;29(4):603-608. Epub 2018 Feb 1.

Department of Medicine, QEII Health Sciences Centre and Dalhousie University, Halifax, Nova Scotia, Canada.

Introduction: In patients with ischemic heart disease and ventricular tachycardia (VT) refractory to high dose amiodarone, the two most common therapeutic options are adjunctive mexiletine therapy or catheter ablation. There are little existing data on the efficacy of these strategies. We examined the relative efficacy of adjunctive mexiletine and catheter ablation among patients enrolled in the VANISH trial.

Methods: All subjects enrolled in the VANISH trial who had VT refractory to high dose (≥ 300 mg daily) amiodarone at baseline were included. Per protocol, subjects randomized to escalated drug therapy received adjunctive mexiletine.

Results: Nineteen of the 259 patients were receiving high-dose amiodarone at baseline and 11 were randomized to escalated therapy with mexiletine and 8 to ablation. The adjunctive mexiletine group had a higher rate of the primary composite outcome (death, VT storm, or appropriate shock) in comparison to catheter ablation (HR 6.87 [2.08-22.8]). Over 90% of the patients in the adjunctive mexiletine/group experienced a primary endpoint during a median 9.2 months' follow-up. There was no difference in the rate of adverse events between the two groups.

Conclusions: Mexiletine has limited efficacy in the treatment of recurrent VT despite high-dose amiodarone therapy, in patients with ischemic heart disease. Catheter ablation is a superior strategy in this population.
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http://dx.doi.org/10.1111/jce.13431DOI Listing
April 2018

Defibrillator shocks and their effect on objective and subjective patient outcomes: Results of the PainFree SST clinical trial.

Heart Rhythm 2018 05 24;15(5):734-740. Epub 2017 Dec 24.

Fondazione Cardiocentro Ticino, Lugano, Switzerland.

Background: The effect of implantable cardioverter-defibrillator (ICD) shock on device-measured activity and patient-reported outcomes is unknown.

Objective: The purpose of this study was to analyze the acute and long-term effects of ICD shock on objective behavioral data (ie, device-based physical activity) and subjective patient-reported outcomes (eg, quality of life and shock anxiety).

Methods: The PainFree Smart Shock Technology (SST) clinical trial included 2770 patients with a single- or dual-chamber ICD or cardiac resynchronization therapy - defibrillator device who were followed for 22 ± 9 months. Participants completed measures of quality of life (EuroQol-5D [EQ-5D] questionnaire) and shock anxiety (Florida Shock Anxiety Scale) at baseline, biannual visits, and monthly for 6 months after an ICD shock. Daily physical activity data were obtained from a built-in device accelerometer.

Results: The average daily activity was 185.3 ± 119.4 min/d. Activity was significantly reduced after an ICD shock (P < .0001) and recovered to a normal level after ∼90 days. An ICD shock was also associated with decreased quality of life (EQ5-D health score) and increased EQ-5D anxiety scores, but it did not affect mobility, self-care, activity, or pain. Similarly, shock anxiety (Florida Shock Anxiety Scale) increased in shocked patients and remained significantly elevated at 24 months, regardless of appropriate or inappropriate shock delivery.

Conclusion: ICD shocks have a long-lasting adverse effect on both objective, device-measured physical activity and subjective patient-reported outcomes of quality of life and shock anxiety. Successful management of patients with an ICD requires attention to clinically relevant behavioral and psychological outcomes to expedite recovery and return to activities of daily living.
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http://dx.doi.org/10.1016/j.hrthm.2017.12.026DOI Listing
May 2018

Management of Implantable Cardioverter Defibrillator Recipients: Care Beyond Guidelines.

Can J Cardiol 2017 08 26;33(8):977-990. Epub 2017 May 26.

University of British Columbia, Vancouver, British Columbia, Canada.

This companion article is intended to address common clinical scenarios in patients with implantable defibrillators that were not addressed in the 2016 Canadian Cardiovascular Society/Canadian Heart Rhythm Society implantable cardioverter defibrillator guidelines including recommendations for device programming to improve detection, to minimize shocks (appropriate and inappropriate), and to minimize ventricular pacing. Important issues at the time of replacement such as device prescription, technical aspects (vascular access, extraction), and management of components on advisories are also discussed. Finally, common clinical scenarios such as management of patients with terminal illnesses, recurrent ventricular tachycardia, electrical storms, catheter ablation for ventricular tachycardia, and system infection management are considered. The management of these patients requires a team approach and comprehensive knowledge surrounding these common clinical scenarios.
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http://dx.doi.org/10.1016/j.cjca.2017.05.012DOI Listing
August 2017

Inappropriate shocks in single-chamber and subcutaneous implantable cardioverter-defibrillators: a systematic review and meta-analysis.

Europace 2017 Dec;19(12):1973-1980

NAMSA, Inc., Minneapolis, MN, USA.

Aims: Single-chamber (VR-ICD) and subcutaneous (S-ICD) implantable cardioverter-defibrillators are effective to protect patients against sudden death but expose them to higher risk of inappropriate shock (IS). We sought to quantify the annual rate and influencing factors of ISs in VR- and S-ICDs from the literature.

Methods And Results: PubMed, Embase, and Cochrane Library were searched for full text articles with IS rates. Poisson distribution estimated proportion of patients with ISs; rates were annualized based on follow-up duration. Random effects meta-analysis accounted for study-to-study variation. Out of 3264 articles, 16 qualified for the meta-analysis. Across studies, 6.4% [95% confidence interval (CI) 5.1-7.9%] of patients received an IS per year. Meta-regression analyses demonstrated that IS rates were lower in more recent studies [rate ratio (RR) per year: 0.93, 95% CI: 0.87-0.98; P = 0.01] and trended lower in studies with longer follow-up (RR per year: 0.78, 95% CI: 0.60-1.01; P = 0.06). Use of S-ICDs (RR: 1.81, 95% CI: 0.86-3.81; P = 0.12) and ventricular tachycardia zone programmed on (RR: 1.13, 95% CI: 0.65-1.97; P = 0.66) were not associated with a significantly increased change in risk. The IS rate observed in one of the more recent studies was significantly lower than predicted after accounting for covariates (RR: 0.29, 95% CI: 0.14-0.60; P < 0.001).

Conclusions: A comprehensive review of the literature shows that 6.4% of patients with ICDs experienced their first IS annually. One of the 16 studies was better than predicted with the lowest reported rate (1.9%) and could not be explained by timing of the study or other covariates.
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http://dx.doi.org/10.1093/europace/euw415DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5834016PMC
December 2017

Cardiac Resynchronization Therapy Reduces Ventricular Arrhythmias in Primary but Not Secondary Prophylactic Implantable Cardioverter Defibrillator Patients: Insight From the Resynchronization in Ambulatory Heart Failure Trial.

Circ Arrhythm Electrophysiol 2017 Mar;10(3)

From the Department of Medicine, Division of Cardiology, Dalhousie University, Halifax, NS, Canada (J.L.S., R.P., M.J.G.); Department of Medicine (G.A.W.), Cardiovascular Research Methods Centre (E.Y.), and Department of Medicine, Division of Cardiology (D.B., P.B.N.), University of Ottawa Heart Institute, ON, Canada; Department of Medicine, Division of Cardiology, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Department of Medicine, Montreal Heart Institute, QC, Canada (B.T.); Department of Medicine, Division of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada (L.D.S.); Department of Medicine, Division of Cardiology, University of Alberta, Edmonton, Canada (S.S.); Department of Medicine, Division of Cardiology, McGill University Health Centre and Hopital Sacre Coeur de Montreal, Quebec, Canada (V.E.); Department of Medicine, Division of Cardiology, University of Toronto, ON, Canada (P.D.); and Division of Cardiology, Department of Medicine, Western University, London, Canada (A.S.L.T.).

Background: The RAFT (Resynchronization in Ambulatory Heart Failure Trial) demonstrated that cardiac resynchronization therapy (CRT) reduced both mortality and heart failure hospitalizations in patients with functional class II or III heart failure and widened QRS. We examined the influence of CRT on ventricular arrhythmias in patients with primary versus secondary prophylaxis defibrillator indications.

Methods And Results: All ventricular arrhythmias among RAFT study participants were downloaded and adjudicated by 2 blinded reviewers with an overreader for disagreements and committee review for remaining discrepancies. Incidence of ventricular arrhythmias among patients randomized to CRT-D versus implantable cardioverter defibrillator (ICD) were compared within the groups of patients treated for primary prophylaxis and for secondary prophylaxis. Of 1798 enrolled patients, 1764 had data available for adjudication and were included. Of these, 1531 patients were implanted for primary prophylaxis, while 233 patients were implanted for secondary prophylaxis; 884 patients were randomized to ICD and 880 to CRT-D. During 5953.6 patient-years of follow-up, there were 11 278 appropriate ICD detections of ventricular arrhythmias. In the primary prophylaxis group, CRT-D significantly reduced incidence ventricular arrhythmias in comparison to ICD (hazard ratio, 0.86; 95% confidence interval, 0.74-0.99; =0.044). This effect was not seen in the secondary prophylaxis group (hazard ratio, 1.14; 95% confidence interval, 0.82-1.58; =0.45). CRT-D was not associated with significant differences in overall ventricular arrhythmia burden in either group.

Conclusions: CRT reduced the rate of onset of new ventricular arrhythmias detected by ICDs in patients without a history of prior ventricular arrhythmias. This effect was not observed among patients who had prior ventricular arrhythmias.

Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00251251.
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http://dx.doi.org/10.1161/CIRCEP.116.004875DOI Listing
March 2017

Canadian Cardiovascular Society/Canadian Heart Rhythm Society 2016 Implantable Cardioverter-Defibrillator Guidelines.

Can J Cardiol 2017 02 6;33(2):174-188. Epub 2016 Oct 6.

Montreal Heart Institute, University of Montreal, Montreal, Quebec, Canada.

Sudden cardiac death is a major public health issue in Canada. However, despite the overwhelming evidence to support the use of implantable cardioverter defibrillators (ICDs) in the prevention of cardiac death there remains significant variability in implantation rates across Canada. Since the most recent Canadian Cardiovascular Society position statement on ICD use in Canada in 2005, there has been a plethora of new scientific information to assist physicians in their discussions with patients considered for ICD implantation to prevent sudden cardiac death due to ventricular arrhythmias. We have reviewed, critically appraised, and synthesized the pertinent evidence to develop recommendations regarding: (1) ICD implantation in the primary and secondary prevention of sudden cardiac death in patients with and without ischemic heart disease; (2) when it is reasonable to withhold ICD implantation on the basis of comorbidities; (3) ICD implantation in patients listed for heart transplantation; (4) implantation of a single- vs dual-chamber ICD; (5) implantation of single- vs dual-coil ICD leads; (6) the role of subcutaneous ICDs; and (7) ICD implantation infection prevention strategies. We expect that this document, in combination with the companion article that addresses the implementation of these guidelines, will assist all medical professionals with the care of patients who have had or at risk of sudden cardiac death.
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http://dx.doi.org/10.1016/j.cjca.2016.09.009DOI Listing
February 2017

Atrioventricular Nodal Non Re-Entrant Tachycardia (AVNNT).

Heart Lung Circ 2017 May 30;26(5):524-525. Epub 2016 Aug 30.

Royal Jubilee Hospital, Victoria, BC, Canada; Victoria Cardiac Arrhythmia Trials (VCAT), Victoria BC, Canada.

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http://dx.doi.org/10.1016/j.hlc.2016.07.014DOI Listing
May 2017

Ejectable loop recorders?

Heart Rhythm 2016 10 31;13(10):2105. Epub 2016 May 31.

Royal Jubilee Hospital and Victoria Cardiac Arrhythmia Trials, Victoria, British Columbia, Canada.

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http://dx.doi.org/10.1016/j.hrthm.2016.05.027DOI Listing
October 2016

Ventricular Tachycardia Ablation versus Escalation of Antiarrhythmic Drugs.

N Engl J Med 2016 Jul 5;375(2):111-21. Epub 2016 May 5.

From the Department of Medicine, QEII Health Sciences Centre and Dalhousie University, Halifax, NS (J.L.S., R.P.), University of Ottawa Heart Institute, Ottawa (G.A.W., P.B.N.), Institut Universitaire de Cardiologie et de Pneumologie de Québec, Quebec, QC (L.B., J.-F.S.), Institut de Cardiologie de Montréal (B.T., L.R.), McGill University Health Center and Hôpital Sacré-Coeur de Montréal (V.E.), and Centre Hospitalier de L'Universite de Montréal (J.-M.R.), Montreal, Western University, London, ON (L.G., P.L.-S., A.S.L.T.), the Division of Cardiology, Royal Columbian Hospital, New Westminster, BC (S.K.T.), Royal Jubilee Hospital, Victoria, BC (L.D.S.), Libin Cardiovascular Institute of Alberta, Calgary (G.D.V.), Population Health Research Institute, Hamilton, ON (J.S.H.), Kingston General Hospital, Kingston, ON (D.R.), and Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC (J.-F.R.) - all in Canada; and the Cardiovascular Division, Brigham and Women's Hospital, Boston (W.G.S.).

Background: Recurrent ventricular tachycardia among survivors of myocardial infarction with an implantable cardioverter-defibrillator (ICD) is frequent despite antiarrhythmic drug therapy. The most effective approach to management of this problem is uncertain.

Methods: We conducted a multicenter, randomized, controlled trial involving patients with ischemic cardiomyopathy and an ICD who had ventricular tachycardia despite the use of antiarrhythmic drugs. Patients were randomly assigned to receive either catheter ablation (ablation group) with continuation of baseline antiarrhythmic medications or escalated antiarrhythmic drug therapy (escalated-therapy group). In the escalated-therapy group, amiodarone was initiated if another agent had been used previously. The dose of amiodarone was increased if it had been less than 300 mg per day or mexiletine was added if the dose was already at least 300 mg per day. The primary outcome was a composite of death, three or more documented episodes of ventricular tachycardia within 24 hours (ventricular tachycardia storm), or appropriate ICD shock.

Results: Of the 259 patients who were enrolled, 132 were assigned to the ablation group and 127 to the escalated-therapy group. During a mean (±SD) of 27.9±17.1 months of follow-up, the primary outcome occurred in 59.1% of patients in the ablation group and 68.5% of those in the escalated-therapy group (hazard ratio in the ablation group, 0.72; 95% confidence interval, 0.53 to 0.98; P=0.04). There was no significant between-group difference in mortality. There were two cardiac perforations and three cases of major bleeding in the ablation group and two deaths from pulmonary toxic effects and one from hepatic dysfunction in the escalated-therapy group.

Conclusions: In patients with ischemic cardiomyopathy and an ICD who had ventricular tachycardia despite antiarrhythmic drug therapy, there was a significantly lower rate of the composite primary outcome of death, ventricular tachycardia storm, or appropriate ICD shock among patients undergoing catheter ablation than among those receiving an escalation in antiarrhythmic drug therapy. (Funded by the Canadian Institutes of Health Research and others; VANISH ClinicalTrials.gov number, NCT00905853.).
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http://dx.doi.org/10.1056/NEJMoa1513614DOI Listing
July 2016

Extended detection time to reduce shocks is safe in secondary prevention patients: The secondary prevention substudy of PainFree SST.

Heart Rhythm 2016 07 14;13(7):1489-96. Epub 2016 Mar 14.

The Christ Hospital/The Ohio Heart & Vascular Center, Cincinnati, Ohio.

Background: Prolonged ventricular fibrillation (VF) detection has been shown to reduce implantable cardioverter-defibrillator (ICD) therapies and improve prognosis in primary prevention ICD patients. Data in secondary prevention patients are limited.

Objective: The PainFree SST secondary prevention study is the largest trial of secondary prevention patients randomized between standard and prolonged detection to assess the safety of this strategy in these patients.

Methods: A total of 705 secondary prevention patients implanted with an ICD in the PainFree SST trial were enrolled in this substudy; 353 patients were randomized to VF detection of 18/24 intervals and 352 patients to 30/40. All other VF parameters were standardized by protocol.

Results: The 1-year arrhythmic syncope-free rates in the standard and prolonged groups were 97.7% vs 96.9%, respectively, (P = .0034 for noninferiority). Freedom from all-cause syncope was 96% in both arms (P = .0013 for noninferiority). There was no difference in the time to first appropriate or inappropriate VF therapy. However, the rates of treated VF episodes were lower in the prolonged arm (1.48 per patient per year vs 0.44 per patient per year, P = .0001). A trend toward lower mortality in the prolonged group was not statistically different (5.6% 1 year, 12% 2 years vs 3.8% 1 year, 7.7% 2 years, adjusted hazard ratio = 0.60, P = .061).

Conclusion: This large prospective randomized study shows that prolonged detection can safely be programmed in secondary prevention ICD patients with new or existing devices. This programming strategy decreases the rate of treated events and is not associated with an increased risk of syncope or mortality.
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http://dx.doi.org/10.1016/j.hrthm.2016.03.022DOI Listing
July 2016

Low inappropriate shock rates in patients with single- and dual/triple-chamber implantable cardioverter-defibrillators using a novel suite of detection algorithms: PainFree SST trial primary results.

Heart Rhythm 2015 May 28;12(5):926-36. Epub 2015 Jan 28.

Royal Jubilee Hospital, Victoria, Canada.

Background: The benefits of implantable cardioverter-defibrillators (ICDs) have been well demonstrated in many clinical trials, and ICD shocks for ventricular tachyarrhythmias save lives. However, inappropriate and unnecessary shock delivery remains a significant clinical issue with considerable consequences for patients and the healthcare system.

Objective: The purpose of the PainFree SmartShock Technology (SST) study was to investigate new-generation ICDs to reduce inappropriate and unnecessary shocks through novel discrimination algorithms with modern programming strategies.

Methods: This prospective, multicenter clinical trial enrolled 2790 patients with approved indication for ICD implantation (79% male, mean age 65 years; 69% primary prevention indication, 27% single-chamber ICD, 33% replacement or upgrade). Patients were followed for a minimum of 12 months, and mean follow-up was 22 months. The primary end-point of the study was the percentage of patients remaining free of inappropriate shocks at 1 year postimplant, analyzed separately for dual/triple-chamber ICDs (N = 2019) and single-chamber ICDs (N = 751).

Results: The inappropriate shock rate at 1 year was 1.5% for patients with dual/triple-chamber ICDs and 2.5% for patients with single-chamber devices. Two years postimplant, the inappropriate shock rate was 2.8% for patients with dual-/triple chamber ICDs and 3.7% for those with single-chamber ICDs. The most common cause of an inappropriate shock in both groups was atrial fibrillation or flutter.

Conclusion: In a large patient cohort receiving ICDs for primary or secondary prevention, the adoption of novel enhanced detection algorithms in conjunction with routine implementation of modern programming strategies led to a very low inappropriate shock rate.
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http://dx.doi.org/10.1016/j.hrthm.2015.01.017DOI Listing
May 2015

Feedback to providers improves evidence-based implantable cardioverter-defibrillator programming and reduces shocks.

Heart Rhythm 2015 Mar 7;12(3):545-553. Epub 2014 Nov 7.

Medtronic Inc, Minneapolis, Minnesota.

Background: Implantable cardioverter-defibrillator (ICD) shocks are associated with increased anxiety, health care utilization, and potentially mortality.

Objective: The purpose of the Shock-Less Study was to determine if providing feedback reports to physicians on their adherence to evidence-based shock reduction programming could improve their programming behavior and reduce shocks.

Methods: Shock-Less enrolled primary prevention (PP) and secondary prevention (SP) ICD patients between 2009 and 2012 at 118 study centers worldwide and followed patients longitudinally after their ICD implant. Center-specific therapy programming reports (TPRs) were delivered to each center 9 to 12 months after their first enrollment. The reports detailed adherence to evidence-based programming targets: number of intervals to detect ventricular fibrillation (VF NID), longest treatment interval (LTI), supraventricular tachycardia (SVT) discriminators (Wavelet, PR Logic), SVT limit, Lead Integrity Alert (LIA), and antitachycardia pacing (ATP). Clinicians programmed ICDs at their discretion. The primary outcome measure was the change in utilization of evidence-based shock reduction programming before (phase I, n = 2694 patients) and after initiation of the TPR (phase II, n = 1438 patients).

Results: Patients implanted after feedback reports (phase II) were up to 20% more likely to have their ICDs programmed in line with evidence-based shock reduction programming (eg, VF NID in PP patients 30/40 in 33.5% vs 18.6%, P < .0001). Patients implanted in phase II had a lower risk of all-cause shock (adjusted hazard ratio 0.72, 95% confidence interval 0.58-0.90, P = .003).

Conclusion: Providing programming feedback reports improves adherence to evidence-based shock reduction programming and is associated with lower risk of ICD shocks.
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http://dx.doi.org/10.1016/j.hrthm.2014.11.002DOI Listing
March 2015

Incidence, predictors, and procedural results of upgrade to resynchronization therapy: the RAFT upgrade substudy.

Circ Arrhythm Electrophysiol 2015 Feb 23;8(1):152-8. Epub 2014 Nov 23.

From the Division of Cardiology, McGill University Health Centre, Montreal, QC, Canada (V.E., J.J., M.S.); Division of Cardiology, University of Ottawa Heart Institute, Ottawa, ON, Canada (D.H.B., E.Y., G.W., A.S.L.T.); Division of Cardiology, Queen Elizabeth II Health Sciences Centre, Halifax, Nova Scotia, Canada (J.L.S.); Division of Cardiology, Victoria Cardiac Arrhythmia Trials, Victoria, BC, Canada (L.D.S.); Division of Cardiology, Quebec Heart and Lung Institute, Quebec City, QC, Canada (F.P.); Division of Cardiology, London Health Sciences Centre, London, ON, Canada (R.Y., A.S.L.T.); Division of Cardiology, Sunnybrook Health Sciences Centre, Toronto, ON, Canada (E.C.); Division of Cardiology, Hôpital du Sacré-Coeur de Montréal, Montreal, QC, Canada (V.E., T.K.); Division of Cardiology, St. Mary's General Hospital, Kitchener, ON, Canada (C.R.); Division of Cardiology, Population Health Research Institute, Hamilton, ON, Canada (J.S.H.); Division of Cardiology, Montreal Heart Institute, Montreal, QC, Canada (B.T.); Division of Cardiology, Libin Cardiovascular Institute of Alberta, Calgary, AB, Canada (D.V.E.); Division of Cardiology, Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada (B.C.); Division of Cardiology, Kingston General Hospital, Kingston, ON, Canada (C.S.S.); and Division of Cardiology, Southlake Regional Health Centre, Newmarket, ON, Canada (Z.W.).

Background: The resynchronization-defibrillation for ambulatory heart failure trial (RAFT) study demonstrated that adding cardiac resynchronization therapy (CRT) in selected patients requiring de novo implantable cardiac defibrillators (ICD) reduced mortality as compared with ICD therapy alone, despite an increase in procedure-related adverse events. Data are lacking regarding the management of patients with ICD therapy who develop an indication for CRT upgrade.

Methods And Results: Participating RAFT centers provided data regarding de novo CRT-D (CRT with ICD) implant, upgrade to CRT-D during RAFT (study upgrade), and upgrade within 6 months after presentation of study results (substudy). Substudy centers enrolled 1346 (74.9%) patients in RAFT, including 644 de novo, 80 study upgrade, and 60 substudy CRT attempts. The success rate (initial plus repeat attempts) was 95.2% for de novo versus 96.3% for study upgrade and 90.0% for substudy CRT attempts (P=0.402). Acute complications occurred among 26.2% of de novo versus 18.8% of study upgrade and 3.4% of substudy CRT implantation attempts (P<0.001). The most common complication was left ventricular lead dislodgement. The principal reasons for not yet attempting upgrade in the substudy were patient preference (31.9%), New York Heart Association Class I (17.0%), and a QRS<150 ms (13.1%).

Conclusions: Among a broad group of implant physicians, CRT upgrades were performed in patients with an ICD in situ with no difference in implant success rate and a reduced acute complication rate as compared with a de novo CRT implant. Decisions to upgrade were influenced by predictors of benefit in subgroup analyses of the RAFT study and other trials.
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http://dx.doi.org/10.1161/CIRCEP.114.001997DOI Listing
February 2015

Esophageal perforation after radiofrequency ablation for atrial fibrillation.

Asian Cardiovasc Thorac Ann 2014 Nov 12;22(9):1116-8. Epub 2013 Nov 12.

Department of Surgery, Royal Alexandra Hospital, University of Alberta, Edmonton, Canada

A 69-year-old man underwent left atrial radiofrequency ablation for atrial fibrillation. After 10 minutes, the procedure was terminated due to pericardial tamponade secondary to perforation during mapping. Pericardiocentesis resolved the tamponade. Ablation was completed one week later, and the patient was discharged. Two days later, he presented with odynophagia. Computed tomography demonstrated small bilateral pleural effusions. He was judged to be stable and was discharged again, but returned 2 days later with chest pain. He was found to have esophageal perforation with empyema, which was repaired using a muscle patch and esophageal stenting, successfully treating the lesion with minimal morbidity.
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http://dx.doi.org/10.1177/0218492313504767DOI Listing
November 2014

Radiofrequency ablation vs antiarrhythmic drugs as first-line treatment of paroxysmal atrial fibrillation (RAAFT-2): a randomized trial.

JAMA 2014 Feb;311(7):692-700

St Davids Medical Center, Austin, Texas.

Importance: Atrial fibrillation (AF) is the most common rhythm disorder seen in clinical practice. Antiarrhythmic drugs are effective for reduction of recurrence in patients with symptomatic paroxysmal AF. Radiofrequency ablation is an accepted therapy in patients for whom antiarrhythmic drugs have failed; however, its role as a first-line therapy needs further investigation.

Objective: To compare radiofrequency ablation with antiarrhythmic drugs (standard therapy) in treating patients with paroxysmal AF as a first-line therapy.

Design, Setting, And Patients: A randomized clinical trial involving 127 treatment-naive patients with paroxysmal AF were randomized at 16 centers in Europe and North America to received either antiarrhythmic therapy or ablation. The first patient was enrolled July 27, 2006; the last patient, January 29, 2010. The last follow-up was February 16, 2012.

Interventions: Sixty-one patients in the antiarrhythmic drug group and 66 in the radiofrequency ablation group were followed up for 24 months.

Main Outcomes And Measures: The time to the first documented atrial tachyarrhythmia of more than 30 seconds (symptomatic or asymptomatic AF, atrial flutter, or atrial tachycardia), detected by either scheduled or unscheduled electrocardiogram, Holter, transtelephonic monitor, or rhythm strip, was the primary outcome. Secondary outcomes included symptomatic recurrences of atrial tachyarrhythmias and quality of life measures assessed by the EQ-5D tool.

Results: Forty-four patients (72.1%) in the antiarrhythmic group and in 36 patients (54.5%) in the ablation group experienced the primary efficacy outcome (hazard ratio [HR], 0.56 [95% CI, 0.35-0.90]; P = .02). For the secondary outcomes, 59% in the drug group and 47% in the ablation group experienced the first recurrence of symptomatic AF, atrial flutter, atrial tachycardia (HR, 0.56 [95% CI, 0.33-0.95]; P = .03). No deaths or strokes were reported in either group; 4 cases of cardiac tamponade were reported in the ablation group. In the standard treatment group, 26 patients (43%) underwent ablation after 1-year. Quality of life was moderately impaired at baseline in both groups and improved at the 1 year follow-up. However, improvement was not significantly different among groups.

Conclusions And Relevance: Among patients with paroxysmal AF without previous antiarrhythmic drug treatment, radiofrequency ablation compared with antiarrhythmic drugs resulted in a lower rate of recurrent atrial tachyarrhythmias at 2 years. However, recurrence was frequent in both groups.

Trial Registration: clinicaltrials.gov Identifier: NCT00392054.
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http://dx.doi.org/10.1001/jama.2014.467DOI Listing
February 2014

Do patients at high risk of nonsudden cardiac death benefit from prophylactic ICD therapy?

Curr Opin Cardiol 2012 Jan;27(1):1-7

Island Medical Program, University of British Columbia, Victoria, British Columbia, Canada.

Purpose Of Review: Randomized controlled trials have established that prophylactic implantable cardioverter defibrillator (ICD) therapy improves survival in patients with reduced left ventricular ejection fraction (LVEF). However, mortality reduction is not uniform across the implanted population and recent data have highlighted the importance of nonsudden cardiac death (non-SCD) risk in predicting benefit from ICD therapy. This review explores the importance of non-SCD risk in patient selection for prophylactic ICD therapy, as well as the proposed approaches to identify potential ICD recipients at high risk of non-SCD.

Recent Findings: Data from randomized controlled trials have demonstrated that patients at high risk of non-SCD do not gain significant survival benefit from prophylactic ICD therapy irrespective of their risk of SCD. A variety of strategies to identify low LVEF patients at high risk of non-SCD have been proposed. These include the use of individual risk markers, such as advanced age and renal dysfunction, the presence of cardiac and noncardiac comorbidities, and the use of more complex risk scores.

Summary: Non-SCD risk is an important issue in patient selection for prophylactic ICD therapy. However, the optimal strategy to identify patients at high non-SCD risk is unclear and further research is needed.
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http://dx.doi.org/10.1097/HCO.0b013e32834d84bfDOI Listing
January 2012

The role of device diagnostic algorithms in the assessment and management of patients with systolic heart failure: a review.

Cardiol Res Pract 2011 Apr 7;2011:908921. Epub 2011 Apr 7.

Division of Cardiology, Royal Jubilee Hospital, 1952 Bay Street, Victoria, Canada V8R 1J8.

Hospitalization due to heart failure (HF) exacerbation represents a major burden in health care and portends a poor long-term prognosis for patients. As a result, there is considerable interest to develop novel tools and strategies to better detect onset of volume overload, as HF hospitalizations may be reduced if appropriate interventions can be promptly delivered. One such innovation is the use of device-based diagnostic parameters in HF patients with implantable cardioverter defibrillators (ICD) and/or cardiac resynchronization therapy (CRT) devices. These diagnostic algorithms can effectively monitor and detect changes in patients' HF status, as well as predict one's risk of HF hospitalization. This paper will review the role of these device diagnostics parameters in the assessment and management of HF patients in ambulatory settings. In addition, the integration of these novel algorithms in existing HF disease management models will be discussed.
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http://dx.doi.org/10.4061/2011/908921DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3088115PMC
April 2011

A wide complex tachycardia with changing atrial activation sequence.

Pacing Clin Electrophysiol 2013 Jan 16;36(1):e23-6. Epub 2011 Mar 16.

Department of Electrophysiology, Royal Jubilee Hospital, Victoria, British Columbia, Canada.

Change of the retrograde atrial activation sequence during radiofrequency (RF) ablation of left-side accessory pathway can be due to another accessory pathway, another mechanism for the tachycardia, or due to intraatrial conduction block, partial or complete, caused by RF delivery to a site proximal to the site of insertion of the accessory pathway. In this case report, a temporary complete intraatrial conduction block was created by RF delivery proximal to the site of accessory pathway insertion, causing a change in the retrograde atrial activation sequence during ongoing tachycardia that was terminated by ablation at the insertion site of accessory pathway.
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http://dx.doi.org/10.1111/j.1540-8159.2011.03050.xDOI Listing
January 2013

Double transseptal puncture for catheter ablation of atrial fibrillation: safety of the technique and its use in the outpatient setting.

Cardiol Res Pract 2010 Dec 13;2010:295297. Epub 2010 Dec 13.

Department of Cardiology, Royal Jubilee Hospital, Victoria, BC, Canada V8R1J8.

Introduction. For pulmonary vein isolation in patients with atrial fibrillation (AF), some centers use the double transseptal puncture technique for catheter access in order to facilitate catheter manipulation within the left atrium. However, no safety data has so far been published using this approach. Method. 269 ablation procedures were performed in 243 patients (mean age 56.6 ± 9.3 years, 75% men) using the double transseptal puncture for catheter access in all cases. Patients were considered for ablation of paroxysmal (80%), persistent (19%), and permanent (1%) AF. 230 procedures were performed on an outpatient basis (85.5%), and 26 were repeat procedures (9.7%). Results. The double transseptal puncture catheter access was successfully achieved in all patients. The procedural success with the endpoint of pulmonary vein isolation was reached in 255 procedures (95%). A total of 1048 out of 1062 pulmonary veins (99%) were successfully isolated. Major complications occurred in eight patients (3.0%). Of these, seven patients (2.6%) had pericardial effusion requiring percutaneous drainage, and one patient (0.4%) suffered a minor reversible stroke. One patient (0.4%) had a minor air embolism with transient symptoms. Conclusion. The double transseptal puncture catheterization technique allows easy catheter manipulation within the left atrium to reach the goal of acute procedural success in AF ablation. Procedure-related complications are rare, and the technique can be used safely for AF ablation in the outpatient setting.
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http://dx.doi.org/10.4061/2010/295297DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3004379PMC
December 2010

Feasibility and safety of outpatient radiofrequency catheter ablation procedures for atrial fibrillation.

Postgrad Med J 2010 Jul;86(1017):395-8

Department of Cardiology, Royal Jubilee Hospital, Victoria, British Columbia, Canada.

Introduction: Percutaneous catheter ablation for atrial fibrillation (AF) is a procedure performed typically in an inpatient setting. The feasibility and safety of catheter ablation in patients with paroxysmal and persistent AF were evaluated on an outpatient basis.

Methods: 230 AF ablation procedures were performed in 206 patients (74% male; mean age 56+/-9 years). Patients were admitted to the hospital outpatient facility in the morning for the AF ablation procedure on the same day. The ablation strategy consisted of wide area circumferential lines around both ipsilateral pulmonary veins. After monitoring in the outpatient service, patients were discharged on the same day, if they were clinically stable.

Results: Mean procedure time was 201+/-31 min. Major complications occurred in seven patients (3%). One patient (0.4%) suffered a minor stroke and six patients had pericardial tamponade requiring percutaneous drainage. Patients could be discharged on the same day following 205 (89%) procedures. Among the 148 patients whose clinical outcome was assessed at 6 months, 127 (86%) had a reduction of the total symptomatic AF episodes, compared to pre-ablation, with a complete lack of symptoms in 101 patients (68%).

Conclusion: Catheter ablation of AF on the day of admission is feasible and safe with a low risk of complications. The vast majority of the patients can be discharged on the same day.
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http://dx.doi.org/10.1136/pgmj.2009.092510DOI Listing
July 2010