The University of Auckland
Auckland | New Zealand
Main Specialties: Cardiovascular Disease
Additional Specialties: Cardiothoracic Surgery
Navneet Singh is a medical student at the University of Auckland in New Zealand. He has a strong desire to pursue a career in cardiothoracic surgery. Navneet is passionate about surgical research, and regularly presents academic work at conferences both locally and internationally. Of note, Navneet was awarded the Best Registrar Prize for his research presentation at the Tongariro New Zealand National Cardiac Surgery Meeting 2018. Furthermore, Navneet won this Best Research Prize again at the 2019 Tongariro New Zealand Cardiac Surgery Meeting as well! Navneet has also authored multiple peer-reviewed publications in reputable journals, including the European Journal of Cardio-Thoracic Surgery. He is the President of the Auckland University Surgical Society, and convened the inaugural Auckland University Surgical Conference 2018. He is also the New Zealand Ambassador and Co-Founder of the Global Cardiac Surgery Network.
Please visit his ResearchGate profile to view his complete comprehensive list of publications, presentations, awards, prizes, scholarships, grants and professional research and teaching experience: https://www.researchgate.net/profile/Navneet_Singh56
You can watch Navneet explain his research to the media here: https://vimeo.com/261201667
Primary Affiliation: The University of Auckland - Auckland , New Zealand
Heart Lung Circ 2019 Nov 27;28(11):1670-1676. Epub 2018 Sep 27.
Waikato Cardiothoracic Unit, Waikato Hospital, Hamilton, New Zealand; The University of Waikato, Hamilton, New Zealand.
Download full-text PDF
BMJ Open. 2019 Aug 18;9(8):e029966
To evaluate the importance of the frequency and duration of lifestyle interventions for achieving weight loss over ≥1 year and associations with all-cause mortality.
Meta-analysis of randomised trials using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and RevMan software version 5·2 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen).
MEDLINE, CENTRAL, Google and Science Direct databases alongside reference lists of appropriate articles and meta-analyses.
Randomised studies published in English-language journals from 1980 to June 2018 that assessed lifestyle compared with control interventions on weight loss and that included ≥100 subjects and reported weight change and mortality for ≥1 year.
Two independent reviewers extracted data and assessed risk of bias. Data were pooled using the generic inverse-variance method and expressed as mean differences (MDs) with 95% CI and OR with 95% CI as appropriate. Heterogeneity was assessed (Cochran Q statistic) and quantified (I2 statistic). The Grading of Recommendations Assessment, Development, and Evaluation score was used to assess the certainty of the evidence.
31 randomised trials with a total of 20 816 overweight or obese participants were included. 70% of participants had cardiometabolic risk factors. Body weight was lower for lifestyle intervention compared with the control at 1 year (3.63 kg, 95% CI 2.58 to 4.67) and at 3 years (2.45 kg, 95% CI 1.17 to 3.73). Weight loss at 1 year was greater in studies with >28 compared with ≤28 interventions per year (4.50 kg, 95% CI 3.03, 5.97 vs 2.38, 95% CI 0.78 to 3.98 kg, p=0.001). In all studies, there were 593 deaths (~0.3%/year). The ORs for mortality for weight loss interventions compared with the controls was 0.86 (95% CI 0.73 to 1.02), p=0.09.
In predominantly healthy populations with risk factors, there is a dose response with number of lifestyle interventions and weight loss. Frequent and sustained interventions are needed to achieve a clinically significant 5% weight loss. There was insufficient evidence to reliably evaluate the benefits in persons with known cardiovascular disease or cancer.
N Z Med J. 2019 Aug 16;132(1500):59-69
New Zealand Medical Journal
Child restraint practices among New Zealand children have fallen short of best practice recommendations. In 2013, New Zealand child restraint legislation was amended. The aim of the present study was to determine the child restraint practices of a cohort of children admitted to hospital and how practices have changed since the amendment in child restraint legislation.
We conducted interviews with the parents of 300 paediatric inpatients aged 0-13 years. Data were recorded on their child's usual child restraint use, the restraint used during their trip to hospital, and parental knowledge of child restraint law and best practice recommendations. We compared their responses with those of our survey published in 2013, which was performed before the amendment in child restraint legislation.
The median age of the 300 children was three years: 181 (60%) were aged 0-4 years, 65 (22%) 5-9 years and 54 (18%) 10-13 years. One hundred and thirty-six (45%) were girls. Of children <5 years of age, 97% always used a child restraint. Of children 5-9 years of age, 60% always used a child restraint, 12% sometimes and 28% never. A significantly greater proportion of 5-9 year-old children used a child restraint at least some of the time in the present study compared to the 2013 study (47/65 versus 27/53, OR 2.49 [95%CI 1.09-5.81]). Child restraint use declined in children <6 years of age. On their journey to hospital, five children used no restraint, four of whom were held in the arms of a caregiver. Parental knowledge of child restraint recommendations correlated inversely with their compliance with the recommendations (OR 0.33 [95%CI 0.11-0.91]).
Consideration should be given to extending child restraint legislation to children older than seven years of age. Further studies could explore the barriers parents face to the use of child restraints and the potential effect of extending child restraint laws to older children.
N Z Med J 2019 Aug 16;132(1500):59-69. Epub 2019 Aug 16.
Paediatric Surgeon, Department of Paediatric Surgery, Starship Children's Health, Auckland.
Download full-text PDF
Eur J Cardiothorac Surg. 2019 Jun 1;55(6):1237
European Journal of Cardio-Thoracic Surgery
Image in Cardiothoracic Surgery
J Card Surg 2019 May 1;34(5):367-369. Epub 2019 Apr 1.
Department of Cardiothoracic Surgery, Auckland City Hospital, Auckland, New Zealand.
Download full-text PDF
J Card Surg 2019 May
Journal of Cardiac Surgery
We report a case of a 44-year-old patient presenting with new-onset severe decompensated congestive heart failure, which was refractory to aggressive inpatient medical treatment. Left ventricular ejection fraction was 16%. Radiological investigations revealed the presence of an anomalous subannular origin of the left coronary artery, with an associated 95% ostial stenosis. The artery was supplied by collaterals from the right coronary system. This included a proximal collateral from the right marginal artery, which had its own separate ostium in the right aortic sinus. A diagnosis of ischemic dilated cardiomyopathy was made. The patient successfully underwent urgent coronary artery bypass grafting with a view to improve his left ventricular function and congestive heart failure symptoms.
Journal of Cardiac Surgery
We report a case of severe long‐term failure of an aortic root reduction aortoplasty with external wrapping. The patient presented 13 years after the initial surgery with a large redilatation of the aortic root and major atrophy of the native aortic root wall inside the external wrap. This subsequently necessitated challenging corrective redo surgery with a Bentall procedure. This case highlights the potential long‐term risk of redilatation posed by using reduction aortoplasty with concomitant aortic external wrapping as a technique to treat largely aneurysmal aortic roots.
J Trauma Acute Care Surg 2019 Feb;86(2):374-375
From the School of Medicine (N.S.), The University of Auckland, Auckland; Waikato Cardiothoracic Unit (D.G., P.G.), Waikato Hospital, Hamilton; Faculty of Medical and Health Sciences (D.G.), The University of Auckland, Auckland; Department of Radiology (Z.Z.), and Department of General Surgery (R.F.), Waikato Hospital, Hamilton, New Zealand.
Download full-text PDF
J Trauma Acute Care Surg. 2019 Feb;86(2):374-375
Journal of Trauma and Acute Care Surgery
Case report publication
Heart Lung Circ. 2018 Sep 27. pii: S1443-9506(18)31910-3
Heart, Lung and Circulation
The updated European System for Cardiac Operative Risk Evaluation (EuroSCORE II) is a well-established cardiac surgery risk scoring tool for estimating operative mortality. This risk stratification system was derived from a predominantly European patient cohort. No validation analysis of this risk model has been undertaken for the New Zealand population across all major cardiac surgery procedures. We aim to assess the efficacy (discrimination and calibration) of the EuroSCORE II for predicting mortality in cardiac surgical patients at a large New Zealand tertiary centre.
Data was prospectively collected on patients undergoing cardiac surgery from September 2014 to September 2017 at Waikato Hospital, New Zealand. Patient demographic information, preoperative clinical risk factors and outcome data were entered into a national database. Included patients received either isolated coronary artery bypass grafting (CABG), isolated valve surgery, isolated thoracic aortic surgery, or a combination of these procedures. The primary outcome was the discrimination and calibration of predicted EuroSCORE II risk scores compared with observed 30-day mortality events.
1666 cardiac surgery patients were included during the study period, with an average EuroSCORE II of 2.97% (95% confidence interval (CI): 2.76-3.18). 933 patients underwent isolated CABG, 384 underwent isolated valve surgery, 48 received isolated thoracic aortic surgery and 301 received combination procedures. Thirty-day mortality events in each of these groups was 7, 4, 2 and 13 deaths respectively. There were 26 deaths across the total cohort at 30-days (observed mortality rate 1.56%). Discrimination analysis using receiver operating characteristic curves demonstrated the area under the curve (AUC) of the EuroSCORE II in each of these groups as 93.4% (95% CI: 91.6-94.9, p<0.0001), 66.3% (95% CI: 61.3-71.0, p=0.37), 37.0% (95% CI: 15.7-58.2, p=0.23) and 74.8% (95% CI: 69.5-79.6, p<0.0001) respectively. The total cohort AUC was 83.1% (95% CI: 81.2-84.9, p<0.0001). Calibration analysis using Hosmer-Lemeshow tests for the subgroups revealed p-values of 0.848, 0.114, 0.638 and 0.2 respectively. The total cohort Hosmer-Lemeshow p-value was 0.317.
EuroSCORE II showed a strong discriminative ability for isolated CABG 30-day mortality in a New Zealand patient cohort. However, the scoring system discriminated poorly across valvular, thoracic aortic or complex combination cardiac surgical procedures. Good calibration of the EuroSCORE II was achieved across both the total cohort and subgroups. It is important to consider the performance of other cardiac surgery risk stratification models for the New Zealand population.
New Zealand Medical Journal
Published abstract in the NZMJ.
Heart, Lung and Circulation
Aim: Guidelines recommend lifestyle modification to reduce weight and mortality risk in overweight and obese persons with coronary heart disease (CHD). A meta-analysis of randomised trials of lifestyle interventions aimed at weight reduction in either CHD or in general populations was undertaken to evaluate evidence supporting these guideline recommendations.
Method: Online databases were searched from 1990 to January 2017 for randomised controlled trials comparing lifestyle-modification weight loss interventions with non-weight loss controls in samples with mean BMI 25 kg/ m2. Trials had a minimum of one year follow-up and 100 participants, and reported weight and mortality.
Results: No trials in patients with CHD met inclusion criteria. 30 trials in general populations were included. Compared to controls, the mean weight loss with lifestyle intervention was -3.69 kg (95% CI; -4.74, -2.64, p < 0.00001) at one year follow-up, which decreases to -2.50 kg (95% CI; -4.00, -1.00, p = 0.001) at two years and to -2.45 kg (95% CI; -3.73, -1.17, p = 0.0002) at three years follow-up. Greater intervention intensity (>12 interventions across the first year of a trial with >25% of interventions occurring after six months) was associated with increased weight loss. During an average follow-up of 9.2 years, mortality in weight-loss groups was 13% lower compared to controls (risk ratio = 0.87; 95% CI 0.74, 1.01; p = 0.07).
Conclusion: Weight loss can be achieved and maintained over three years through high intensity lifestyle interventions, and this may result in a modest reduction in mortality risk. However, randomised trials are needed to determine whether weight-loss lifestyle interventions reduce weight and mortality in patients with CHD
European Heart Journal
Background: Guidelines recommend lifestyle modification to reduce weight and mortality risk in overweight and obese persons with coronary heart disease (CHD).
Purpose: A meta-analysis of randomised trials of lifestyle interventions aimed at weight reduction in either CHD or in general populations was undertaken to evaluate evidence supporting these guideline recommendations.
Methods: Online databases of MEDLINE, CENTRAL and Science Direct were searched from 1990 to January 2017 for randomised controlled trials comparing lifestyle-modification interventions with a non-weight loss control. Inclusion criteria included a study population with a mean BMI ≥25kg/m2, at least one year follow-up, ≥100 participants, and reporting of both weight and mortality.
Results: No trials in patients with CHD met inclusion criteria. 30 trials in general populations with a total of 20143 participants were included. Compared to controls, the mean decrease in weight with lifestyle intervention was -3.69kg (95% CI; -4.74, -2.64, p<0.00001) at one year, -2.50kg (95% CI; -4.00, -1.00, p=0.001) at two years, and -2.45kg (95% CI; -3.73, -1.17, p=0.0002) at three years follow-up. Studies with a greater intensity of lifestyle intervention (>12 dietary interventions in the first year of the trial with n=21 studies, versus ≤12 with n=6 studies) resulted in greater weight loss at one year [-4.18kg (95% CI; -5.37, -2.99, p<0.00001) versus -1.27kg (95% CI; -1.79, -0.75, p<0.00001)]. More sustained interventions (>25% of first year dietary interventions occurring after 6 months) were also associated with greater weight loss at one year [-3.95kg (95% CI; -5.34, -2.57, p<0.00001) with n=18 studies, versus -2.86kg (95% CI; -3.96, -1.76, p<0.00001) with n=8 studies]. During an average weighted follow-up of 9.2 years, mortality with weight-loss interventions was 278/10154 and in controls was 319/9989 (Risk ratio=0.87; 0.74, 1.01 95% CI; p=0.07).
Conclusions: Modest weight loss can be achieved and maintained over three years through sustained lifestyle interventions. Available evidence is consistent with a modest favourable effect of lifestyle interventions for weight reduction on mortality, but is insufficient to support a class 1A recommendation on lifestyle intervention to reduce weight for secondary prevention of CHD.