Abstract
BACKGROUND: Catheter ablation (CA) is increasingly recognized as an effective treatment for ventricular tachycardia (VT) in myocarditis patients, although current evidence is based on less robust data. OBJECTIVES: The purpose of this study was to confirm CA's efficacy in reducing VT recurrence and to identify arrhythmic risk factors in biopsy-proven myocarditis patients. METHODS: In this dual-center, retrospective study, we included 50 patients with biopsy-proven myocarditis and VT. They were divided into 2 groups: CA (n = 23) and non-CA (n = 27), with the primary endpoint being VT recurrence at 1-year follow-up. RESULTS: The average age of participants was 40.8 ± 14.9 years; 48% were men. Over a median 371-day follow-up, 28 (56%) experienced VT recurrence, with 8 patients (35%) in the CA group and 20 patients (74%) in the non-CA group. Kaplan-Meier analysis showed that the rate of VT recurrence in the CA group was significantly lower than in the non-CA group (log-rank P = 0.009). However, this difference was not found in patients with acute myocarditis. Multivariable analysis revealed a significant correlation between the acute stage of myocarditis and VT recurrence in both the general cohort (HR: 3.02; 95% CI: 1.11-8.21; P = 0.031) and the subset undergoing CA (HR: 11.4; 95% CI: 1.02-127.5; P = 0.048). CONCLUSIONS: CA is significantly associated with reduced VT recurrence in biopsy-proven myocarditis, albeit this association is not observed in cases of acute myocarditis. The acute stage of myocarditis is independently associated with an increased risk of VT recurrence.