A single-centre experience of His bundle pacing without electrophysiological mapping system: implant success rate, safety, pacing characteristics and one-year follow up

INTRODUCTION@#Despite the challenges related to His bundle pacing (HBP), recent data suggest an improved success rate with experience. As a non-university, non-electrophysiology specialised centre in Singapore, we report our experiences in HBP using pacing system analyser alone.@*METHODS@#Data of 28 consecutive patients who underwent HBP from August 2018 to February 2019 was retrospectively obtained. The clinical and technical outcomes of these patients were compared between two timeframes of three months each. Patients were followed up for 12 months.@*RESULTS@#Immediate technical success was achieved in 21 (75.0%) patients (mean age 73.3 ± 10.7 years, 47.6% female). The mean left ventricular ejection fraction was 53.9% ± 12.1%. The indications for HBP were atrioventricular block (n = 13, 61.9%), sinus node dysfunction (n = 7, 33.3%) and upgrade from implantable cardioverter-defibrillator to His-cardiac resynchronisation therapy (n = 1, 4.8%). No significant difference was observed in baseline characteristics between Timeframe 1 and Timeframe 2. Improvements pertaining to mean fluoroscopy time were achieved between the two timeframes. There was one HBP-related complication of lead displacement during Timeframe 1. All patients with successful HBP achieved non-selective His bundle (NSHB) capture, whereas only eight patients had selective His bundle (SHB) capture. NSHB and SHB capture thresholds remained stable at the 12-month follow-up.@*CONCLUSION@#Permanent HBP is feasible and safe, even without the use of an electrophysiology recording system. This was successfully achieved in 75% of patients, with no adverse clinical outcomes during the follow-up period.

Validation of MyDiagnostick tool to identify atrial fibrillation in a multi-ethnic Asian population

INTRODUCTION@#MyDiagnostick is an atrial fibrillation (AF) screening tool that has been validated in the Caucasian population in the primary care setting.@*METHODS@#In our study, we compared MyDiagnostick with manual pulse check for AF screening in the community setting.@*RESULTS@#In our cohort of 671 candidates from a multi-ethnic Asian population, AF prevalence was found to be 1.78%. Of 12 candidates, 6 (50.0%) had a previous history of AF and another 6 (50.0%) were newly diagnosed with AF. Candidates found to have AF during the screening were older (72.0 ± 11.7 years vs. 56.0 ± 13.0 years, P < 0.0001) and had a higher CHADSVASC risk score (2.9 ± 1.5 vs. 1.5 ± 1.1, P = 0.0001). MyDiagnostick had a sensitivity of 100.0% and a specificity of 96.2%. In comparison, manual pulse check had a sensitivity of 83.3% and a specificity of 98.9%.@*CONCLUSION@#MyDiagnostick is a simple AF screening device that can be reliably used by non-specialist professionals in the community setting. Its sensitivity and specificity are comparable and validated across various studies performed in different population cohorts.

Ablation therapies for paroxysmal atrial fibrillation: A systematic review and patient-level network meta-analysis

INTRODUCTION@#Despite promising trials, catheter ablation is still regarded as an adjunct to antiarrhythmic drugs (AADs) in the treatment of paroxysmal atrial fibrillation (PAF). This study aimed to compare the effectiveness of various ablation therapies and AADs.@*METHOD@#Randomised controlled trials or propensity score-matched studies comparing atrial tachyarrhythmia recurrence among any combination of ablation modalities or AAD were retrieved. Kaplan-Meier curves and risk tables for this outcome were graphically reconstructed to extract patient-level data. Frequentist network meta-analysis (NMA) using derived hazard ratios (HRs), as well as 2 restricted mean survival time (RMST) NMAs, were conducted. Treatment strategies were ranked using P-scores.@*RESULTS@#Across 24 studies comparing 6 ablation therapies (5,132 patients), Frequentist NMA-derived HRs of atrial fibrillation recurrence compared to AAD were 0.35 (95% confidence interval [CI]=0.25-0.48) for cryoballoon ablation (CBA), 0.34 (95% CI=0.25-0.47) for radiofrequency ablation (RFA), 0.14 (95% CI=0.07-0.30) for combined CBA and RFA, 0.20 (95% CI=0.10-0.41) for hot-balloon ablation, 0.43 (95% CI=0.15-1.26) for laser-balloon ablation (LBA), and 0.33 (95% CI=0.18-0.62) for pulmonary vein ablation catheter. RMST-based NMAs similarly showed significant benefit of all ablation therapies over AAD. The combination of CBA + RFA showed promising long-term superiority over CBA and RFA, while LBA showed favourable short-term efficacy.@*CONCLUSION@#The advantage of ablation therapies over AAD in preventing atrial tachyarrhythmia recurrence suggests that ablation should be considered as the first-line treatment for PAF in patients fit for the procedure. The promising nature of several specific therapies warrants further trials to elicit their long-term efficacy and perform a cost-benefit analysis.

Impact of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers on in-hospital mortality among patients with COVID-19: a systematic review and meta-analysis

INTRODUCTION@#There are concerns that angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) may worsen the outcomes of patients with COVID-19. This systematic review and meta-analysis aimed to study the in-hospital mortality among COVID-19 patients who were on ACEIs/ARBs as compared to those not on ACEIs/ARBs.@*METHODS@#We searched PubMed, EMBASE, clinicaltrials.gov and Google Scholar between 1 January 2020 and 30 May 2020 to identify all studies that evaluated the use of ACEIs/ARBs and reported the in-hospital mortality outcomes of COVID-19 patients. Nine non-randomised studies were eligible for inclusion in the analysis. The primary outcome studied was the in-hospital mortality of COVID-19 patients who were on ACEIs/ARBs compared with those not on ACEIs/ARBs.@*RESULTS@#Of the 8,313 patients in the nine studies, 7,622 (91.7%) were from studies with all-comers, while 691 (8.3%) were from studies involving only patients with hypertension. 577 (14.6%) in-hospital deaths were observed out of a total of 3,949 patients with an outcome in the nine studies. Overall, no significant difference was observed in the in-hospital mortality between patients on ACEIs/ARBs and those not on ACEIs/ARBs (odds ratio [OR] 1.06, 95% confidence interval [CI] 0.75-1.50; p = 0.73). Further sensitivity analysis in the hypertension group and the all-comers group showed similar results (OR 0.88, 95% CI 0.58-1.32; p = 0.53 and OR 1.85, 95% CI 1.00-3.43; p = 0.05, respectively).@*CONCLUSION@#We observed that ACEIs/ARBs had no significant impact on the in-hospital mortality of COVID-19 patients and can be used safely in patients with indications.

A Real-world Experience of the Safety and Efficacy of Non-vitamin K Oral Anticoagulants Versus Warfarin in Patients with Non-valvular Atrial Fibrillation-A Single-centre Retrospective Cohort Study in Singapore

INTRODUCTION@#Non-vitamin K oral anticoagulants (NOACs) were shown to have better outcomes than warfarin for non-valvular atrial fibrillation (NVAF). Given limited local real-world data, this study aims to evaluate the safety and efficacy of NOACs versus warfarin for NVAF in Singapore.@*METHODS@#This single-centre retrospective cohort study included 439 patients ≥ 21 years old that were newly prescribed with oral anticoagulants (OACs) for NVAF in 2015. Follow-ups for patients upon OAC initiation lasted either for 2 years or until the occurrence of bleeding or thromboembolism event or death (whichever was earlier). Primary endpoints included major bleeding and stroke, while secondary endpoints included overall bleeding and thromboembolic events. Time-to-events was evaluated via Kaplan-Meier survival analysis. Data on time in therapeutic range (TTR) and compliance were analysed.@*RESULTS@#Patients were assigned to 4 groups: warfarin (157, 35.8%), rivaroxaban (154, 35.1%), apixaban (98, 22.3%) and dabigatran (30, 6.8%). With a mean age of 70.8 (±10.8) years old, the population were predominantly males (56.5%) and comprised Chinese (73.8%), Malays (18.7%) and others (7.5%). The rates of stroke per year were 0.7%, 1.7%, 2.2% and 0% for warfarin, rivaroxaban, apixaban and dabigatran, respectively (@*CONCLUSION@#NOACs were associated with similar stroke and major bleeding rates as warfarin for NVAF.

Catheter ablation of ventricular fibrillation storm in a long QT syndrome genotype carrier with normal QT interval

Patients with long QT syndrome can sometimes present with a ventricular fibrillation (VF) storm. Catheter ablation of culprit premature ventricular complexes responsible for the triggering of the VF episodes may be required in rare cases of electrical storm that do not respond to conventional measures, and this can be life-saving. We describe a case of emergency catheter ablation in a young woman with a normal corrected QT interval, who presented with malignant VF storm for the first time. We also discuss the diagnostic and management challenges involved, as well as the value of genetic testing in refining the diagnosis.