Clinical profile and outcomes of young patients treated with implantable cardioverter defibrillators at a South African tertiary hospital: a review of two decades of implantable cardioverter defibrillator implantation and follow up.

AIM: In young patients without atherosclerotic coronary artery disease, the aetiology of sudden cardiac death (SCD) has been described in Europe and North America. However, there are important regional variations and there are limited data on the aetiology and outcome of SCD in South Africa. The objective of this study was to determine the profile and outcomes of young patients treated with implantable cardioverter defibrillators (ICDs) at a South African tertiary hospital. METHODS: This study was designed as a retrospective review of patients aged 35 years or younger implanted with ICDs at Groote Schuur Hospital. RESULTS: During the study period, 38 patients younger than 35 years were implanted with ICDs. The mean (standard deviation) age at ICD implantation was 25.1 (7.6) years and 63.2% were male. A secondary-prevention ICD was implanted in 57.9% of the patient population, and primary prevention in the remaining 42.1%. Patients with secondary-prevention ICDs presented with ventricular tachycardia (59.1%), ventricular fibrillation (31.8%) and receipt of cardiopulmonary resuscitation but no recorded electrocardiograms (9.1%). Arrhythmogenic right ventricular cardiomyopathy (ARVC) was the leading cause of SCD in the secondary-prevention patient population (36.4%). Idiopathic dilated cardiomyopathy accounted for 50% of the primary-prevention patient population. After a median (interquartile range) follow up 32 (14-90) months, 7.9% died and 5.2% received a heart transplant; 42.1% of the study population received appropriate ICD shock therapies and 18.4% received inappropriate shock therapies. CONCLUSIONS: In this single-centre study from South Africa, ARVC and repaired congenital heart disease were the leading causes of SCD in patients younger than 35 years treated with secondary-prevention ICDs. Primary-prevention ICDs were frequently implanted for idiopathic dilated cardiomyopathy.

Feasibility and safety of interventional electrophysiology and catheter ablation in the South African public sector: Challenges and opportunities for comprehensive cardiac electrophysiology in South Africa.

Aims: The spectrum and outcomes of catheter ablation procedures performed in South Africa are unknown, and therefore, the feasibility of interventional electrophysiology in the South African public sector is undetermined. Methods and Results: This study was a retrospective review of all patients that underwent invasive electrophysiology procedures and catheter ablation at Groote Schuur Hospital (GSH) and the University of Cape Town Private Academic Hospital (UCTPAH) between 01 January 2013 and 31 December 2020.One thousand one hundred eighty-six invasive electrophysiology procedures were performed during the study period. Of these were 1102 catheter ablation procedures. There were 76 redo catheter ablation procedures, predominantly for atrial fibrillation (AF), which accounted for 39% (30/76) of the repeat procedures. There were only 0.8% (9/1102) catheter ablation related complications which were mostly access related. Atrial fibrillation accounted for most of the ablation procedures, 28.9% (318/1102); these were mainly performed at UCTPAH than at GSH, 300 vs 18 p < .0001. Cavotricuspid isthmus (CTI) dependent atrial flutter ablation was the second most commonly performed catheter ablation procedure, accounting for 21.6% (238/1102) of the catheter ablation procedures. More CTI dependent atrial flutter ablations were performed at GSH than a UCTPAH, 156 vs 82 p < .0001. The overall success rate of catheter ablation was 92%. Conclusion: A broad spectrum of catheter ablation procedures was performed with a high success rate and limited complications, thus demonstrating the feasibility of safe cardiac electrophysiology and catheter ablation in the South African public sector.

Two decades of implantable cardioverter defibrillator implantation and follow-up at a South African referral centre: trends, indications and long-term outcomes in a resource-limited setting.

Background: More than two-thirds of cardiovascular deaths occur in low- and middle-income countries. Sudden cardiac deaths (SCD) from ventricular arrhythmias are an important cause of cardiovascular deaths. Implantable cardioverter defibrillators (ICD) are an important therapeutic strategy for detecting and terminating ventricular arrhythmias in patients at risk of SCD. The profile of patients treated with ICDs in South Africa is unknown. Further, with changing lines of evidence, the implantation trends are undetermined. The objectives of this study were to determine the profile of ICD recipients and implantation trends in a South African quaternary hospital. Methods: This was a retrospective review of all patients implanted with ICDs at Groote Schuur Hospital from 01 January 1998 to 31 December 2020. A standardised data collection form was used to collect baseline demographic data, information on clinical presentation and ICD follow-up data for the history of ICD shock therapies. Results: A total of 253 ICDs were implanted; 75% for secondary prevention and 25% for primary prevention. 67.2% of the implanted ICDs were single-chamber ICDs, dual-chamber ICDs were implanted in 12.3% and Cardiac resynchronisation with a defibrillator (CRT-D) in 20.6%. There was an upward trajectory of ICD implantations during the study period. Increasing numbers of dual-chamber devices and CRT-D were implanted over time. ICD recipients had a mean (standard deviation) age of 50 (14) years and were predominantly male (69%). Primary prevention ICD recipients were younger than secondary prevention recipients, with a mean (SD) age of 46 (14) years versus 51 (14) years, p = 0.019. The secondary prevention group presented with ventricular tachycardia in 81%, ventricular fibrillation in 13% and cardiopulmonary resuscitation without documented heart rhythm in 5.3% (10/190). After a median (interquartile range) follow-up of 44 (15; 93) months, there was an overall mortality rate of 16.2%, with no mortality difference between the primary and secondary prevention patient groups. Conclusion: There is an increase in the annual number of ICDs implanted at a South African referral centre. ICDs are predominantly implanted for secondary prevention. However, over time the number of devices implanted for primary prevention is steadily increased. During follow-up, there was no mortality difference between the primary prevention and the secondary prevention groups.