Sudden cardiac death prevention in the era of novel heart failure medications

Changing Antiarrhythmic Drug Regimen in Patients with Amiodarone and Ablation Refractory Ventricular Tachyarrhythmias Is Associated with Increased Implantable Cardioverter Defibrillator Shocks-A Retrospective Analysis from a Large Tertiary Center

Background and Objective: Implantable Cardioverter Defibrillators (ICDs) are crucial in treating ventricular tachyarrhythmias (VTs) and preventing sudden cardiac death. However, ICD shocks are linked to higher mortality and a lower quality of life. Many patients suffer from recurrent VTs despite concomitant antiarrhythmic drug (AAD) therapy with amiodarone, and it is unclear if changing the AAD while on chronic amiodarone therapy is beneficial. Hence, we investigated the impact of changing the AAD on the incidence of appropriate ICD shocks in patients on chronic amiodarone, impaired LV function, and at least one previous VT ablation. Methods and Results: We retrospectively analyzed 131 ICD patients (LVEF < 40%) from a single-center registry. All were on chronic amiodarone and had undergone VT ablation. The mean age was 66.0 ± 12.8 years; 82.4% were male; and the follow-up period averaged 5.8 ± 0.6 years. Ischemic cardiomyopathy was present in 52.7% of patients. AAD therapy was changed in 49 patients (37.4%), primarily due to inefficacy (40.8%), intolerance (16.3%), or other reasons (42.9%). Of those, 8 received flecainide (≥200 mg) and 41 sotalol (≥240 mg); 82 (62.6%) continued amiodarone. VT re-ablation was performed in 23.7%. During follow-up, 11 patients (8.4%) died and 18 (13.7%) received appropriate ICD shocks-17 with changed AAD vs. 1 with continued amiodarone (p ≤ 0.01). A multivariate regression showed that switching from amiodarone to flecainide or sotalol was significantly associated with increased ICD shock risk (OR 34.9; 95% CI 4.3-283.8; p < 0.01). Conclusions: In patients on chronic amiodarone with severely impaired LV function and at least one previous VT ablation, changing AAD therapy to flecainide or sotalol is associated with an increased incidence of appropriate ICD shocks.

Evaluating the predictive value of late gadolinium enhancement assessed by cardiac magnetic resonance on sudden cardiac death in patients selected for implantable cardioverter defibrillator and cardiac resynchronization therapy implantation: a systematic review and meta-analysis

AIMS

Late gadolinium enhancement (LGE) assessed by cardiovascular magnetic resonance (CMR) can evaluate myocardial scar associated with a higher risk of sudden cardiac death (SCD), which can guide the selection between cardiac resynchronization therapy with or without a defibrillator (CRT-P/CRT-D). Our aim was to investigate the association between LGE and SCD risk in patients with CRT using the LGE-CMR technique.

METHODS AND RESULTS

We performed a systematic literature search using four databases. The target population was CRT candidates. The primary endpoint was SCD. The risk of bias was assessed using the QUIPS tool. Fifteen eligible articles were included with a total of 2494 patients, of whom 27%, 56%, and 19% had an implantable cardioverter defibrillator (ICD), CRT-D, and CRT-P, respectively. Altogether, 54.71% of the cohort was LGE positive, who had a 72% higher risk for SCD (HR 1.72; 95% CI 1.18-2.50) compared to LGE negatives. In non-ischemic patients, the proportion of LGE positivity was 46.6%, with a significantly higher risk for SCD as compared to LGE negatives (HR 2.42; 95% CI 1.99-2.94). The subgroup of CRT-only patients showed no difference between the LGE-positive vs. negative candidates (HR 1.17; 95% CI 0.82-1.68). Comparable SCD risk was observed between articles with short- (OR 7.47; 95% CI 0.54-103.12) vs. long-term (OR 6.15; 95% CI 0.96-39.45) follow-up time.

CONCLUSION

LGE-CMR positivity was associated with an increased SCD risk; however, in CRT candidates, the difference in risk reduction between LGE positive vs. negative patients was statistically not significant, suggesting a role of reverse remodeling. LGE-CMR before device implantation could be crucial in identifying high-risk patients even in non-ischemic etiology.