The use of wearable cardioverter defibrillator among patients suffering from myocarditis: data from a multicenter registry

Abstract Background Data on the use of the wearable cardioverter defibrillator (WCD) among patients suffering from myocarditis in a large cohort remains sparse. Subsequently several guidelines give a different recommendation regarding WCD indication in this cohort. Methods 1596 patients were included in a multicenter registry from ten European centers. Among this cohort 132 (8%) patients received a WCD due to myocarditis. The mean follow-up time of the whole cohort was 620.2±607.8 days. The presence of ventricular tachyarrhythmias and/or WCD shocks during WCD use were evaluated. Results The mean age of patients was 52.5±16.3 years (75% males). 20% of patients suffered from atrial fibrillation, 17% diabetes mellitus, 40% were smoker and 38.9% suffered from arterial hypertension. The body-mass-index (BMI) of the cohort was 27.8±5.7 kg/m². The initial left ventricular ejection fraction (LVEF) was 33.4±14.6% and increased to 45.9±13.2% (p<0.05) over long-term follow-up. Patient were discharged on ACE-inhibitors (62.5%), ARNI (21.2%), aldosterone-antagonist (50%), beta-blockers (89.5%) and amiodarone (13.6%). An improvement of LVEF (LVEF>35%) was documented in 81.2% of patients. The BNP level was at baseline 7401±30584 pg/ml and decreased to 530±803 pg/ml (p<0.05) over long-term follow-up. The wear duration was 78.5±51.5 days and 34% of patients wore the WCD for longer than 90 days. The wear-hours per day were 21.1±4.8 hours. In 3.1% sustained ventricular tachycardia, 0.8% ventricular fibrillation and 9.1% non-sustained ventricular tachycardia were documented. Subsequently 3% of patients suffered from an appropriate WCD shock. The rate of inappropriate WCD shock was 0.8%. Patients suffering from WCD shock were at age 31, 31, 61, 24 and 51 years and suffered a former non-sustained ventricular tachycardia before receiving a WCD. Among these patients suffering from appropriate WCD shock only two patients showed an LVEF<35%. Among the myocarditis patients 48% suffered from a former ventricular tachycardia and/or ventricular fibrillation and therefore received a WCD. Conclusions Myocarditis patients can be effectively protected by WCD and may benefit from its’ use. WCD shock occurred also in patients with an LVEF >35%.