Switching from amiodarone to flecainide or sotalol was associated with a significantly increased risk of appropriate ICD shocks (OR 34.9; 95% CI 4.3-283.8; p<0.01).
Cohort (n=131)
No
Does changing antiarrhythmic drug therapy to flecainide or sotalol increase the incidence of appropriate ICD shocks in patients with impaired LV function and previous VT ablation on chronic amiodarone?
In patients with severely impaired LV function and prior VT ablation on chronic amiodarone, switching to flecainide or sotalol is associated with a significantly increased risk of appropriate ICD shocks compared to continuing amiodarone.
Odds Ratio: 34.9 (95% CI 4.3–283.8)
Absolute Event Rate: 34.7% vs 1.2%
p-value: p=< 0.01
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.
Doldi et al. (Tue,) conducted a cohort in Ventricular tachyarrhythmias (n=131). Changing antiarrhythmic drug therapy (flecainide or sotalol) vs. Continued amiodarone was evaluated on Appropriate ICD shocks (OR 34.9, 95% CI 4.3-283.8, p=< 0.01). Switching from amiodarone to flecainide or sotalol was associated with a significantly increased risk of appropriate ICD shocks (OR 34.9; 95% CI 4.3-283.8; p<0.01).