Improve the Prevention of Sudden Cardiac Arrest in Patients With Post-Acute Myocardial Infarction

Risk factors for mortality in post-myocardial infarction patients: insights from the improve SCA bridge study

BACKGROUND

Underutilization of implantable cardioverter defibrillators (ICD) to prevent sudden cardiac death (SCD) in post-myocardial infarction (MI) patients remains an issue across several geographies. A better understanding of risk factors for SCD in post-MI patients from regions with low ICD adoption rates will help identify those who will benefit from an ICD. This analysis assessed risk factors for all-cause and cardiovascular-related mortality in post-MI patients from the Improve Sudden Cardiac Arrest (SCA) Bridge Trial.

RESULTS

For the entire cohort, the overall 1-year mortality rate was 5.9% (88/1491) and 3.4% (51/1491) for all-cause and cardiovascular mortality, respectively, with 76.5% of all cardiac deaths being from SCD. A multivariate model determined increased age, reduced left ventricular ejection fraction (LVEF), increased time from myocardial infarction to hospital admission, being female, being from Southeast Asia (SEA), and having coronary artery disease to be significant risk factors for all-cause mortality. The risk factors for cardiovascular-related mortality revealed increased age, reduced LVEF, and being from SEA as significant risk factors.

CONCLUSIONS

We show several characteristics as being predictors of cardiovascular-related mortality in post-MI patients from the Improve SCA Bridge study. Patients who experience an MI and present with these characteristics would benefit from a referral to an electrophysiologist for further SCD risk stratification and management and possible subsequent ICD implantation to reduce unnecessary death.

Catheter ablation versus antiarrhythmic drug therapy for sustained ventricular tachycardia in patients with hypertrophic cardiomyopathy

BACKGROUND

Ventricular tachycardia (VT) is the primary cause of sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM). However, the strategy for VT treatment in HCM patients remains unclear. This study is aimed to compare the effectiveness of catheter ablation versus antiarrhythmic drug (AAD) therapy for sustained VT in patients with HCM.

METHODS

A total of 28 HCM patients with sustained VT at 4 different centers between December 2012 and December 2021 were enrolled. Twelve underwent catheter ablation (ablation group) and sixteen received AAD therapy (AAD group). The primary outcome was VT recurrence during follow-up.

RESULTS

Baseline characteristics were comparable between two groups. After a mean follow-up of 31.4 ± 17.5 months, the primary outcome occurred in 35.7% of the ablation group and 90.6% of the AAD group (hazard ratio [HR], 0.29 [95%CI, 0.10-0.89]; P = 0.021). No differences in hospital admission due to cardiovascular cause (25.0% vs. 71.0%; P = 0.138) and cardiovascular cause-related mortality/heart transplantation (9.1% vs. 50.6%; P = 0.551) were observed. However, there was a significant reduction in the composite endpoint of VT recurrence, hospital admission due to cardiovascular cause, cardiovascular cause-related mortality, or heart transplantation in ablation group as compared to that of AAD group (42.9% vs. 93.7%; HR, 0.34 [95% CI, 0.12-0.95]; P = 0.029).

CONCLUSIONS

In HCM patients with sustained VT, catheter ablation reduced the VT recurrence, and the composite endpoint of VT recurrence, hospital admission due to cardiovascular cause, cardiovascular cause-related mortality, or heart transplantation as compared to AAD.

Burden of bradycardia and barriers to accessing bradycardia therapy in underserved countries

Bradycardia, a condition characterized by an abnormally slow heart rate, poses significant challenges in terms of diagnosis and treatment. While it is a concern world-wide, low- and middle-income countries (LMICs) face substantial barriers in accessing appropriate bradycardia therapy. This article aims to explore the global aetiology and incidence of bradycardia, compare the prevalence and management of the condition in high-income countries versus LMICs, identify the key reasons behind the disparities in access to bradycardia therapy in LMICs, and emphasize the urgent need to address these disparities to ensure equitable healthcare on a global scale.