J Cardiovasc Electrophysiol 2014 Jan 24;25(1):52-9. Epub 2013 Sep 24.
Texas Heart Institute, St. Luke's Episcopal Hospital, Houston, Texas.
Background: Shock therapy delivery by implantable cardioverter-defibrillators (ICD) can be painful and may have adverse consequences. Reducing shock burden for patients with ICDs would be beneficial.
Methods: PROVIDE was a prospective, randomized study of primary prevention ICD patients. Patients in the experimental group received a combination of programmed parameters with higher detection rates, longer detection intervals, empiric antitachycardia pacing (ATP), and optimized supraventricular tachycardia (SVT) discriminators, while those in the control group were programmed with conventional parameters. Shock therapy and arrhythmic syncope were compared.
Results: Of 1,670 patients enrolled (846 in the experimental group, 824 in the control group) and monitored over a follow-up of 530 ± 241 days, 202 patients received shock therapy for any cause (82 in the experimental group and 120 in the control group). The median time to first shock was significantly prolonged (13.1 vs 7.8 months, hazard ratio [HR]: 0.62, 95% confidence interval [CI]: 0.47 to 0.82, P = 0.0005) and the 2-year shock rate significantly reduced (12.4% vs 19.4%, P < 0.001) in the experimental group compared to the control group. There was no increase in arrhythmic syncope (HR: 1.64, 95% CI: 0.69 to 3.90, P = 0.26), while the overall mortality was reduced (HR: 0.7, 95% CI: 0.50 to 0.98, P = 0.036) in the experimental group compared to the control group.
Conclusion: A combination of programmed parameters utilizing higher detection rate, longer detection intervals, empiric ATP, and optimized SVT discriminators reduced ICD therapies without increasing arrhythmic syncope and was associated with reduction in all-cause mortality among ICD patients.