Clinical characteristics and predictors for sustained ventricular arrhythmia in acute myocarditis: a multicenter case-control study

Clinical characteristics of acute myocarditis (AM) patients with sustained ventricular arrhythmia (sVA) during acute-phase myocarditis and clinical predictors for these acute-phase sVA are not established.1-6

Evaluate clinical characteristics and predictors for acute-phase sVA during AM hospitalization.

Case-control study of patients with a definite diagnosis of AM who were hospitalized in two large tertiary centers, in Israel and USA, during the years 2000-2020. Patients with documented sVA during AM hospitalization (cases) were compared with AM patients without VA (controls). Patients with history of myocardial infarction, heart failure, or VA were excluded. Univariate and multivariable analyses were used to evaluate possible predictors for occurrence of sVA during AM hospitalization.

Study included 178 AM patients; 41 with sVA (cases) and 137 without VA (controls). VAs included monomorphic VT and polymorphic VT/VF in 24/41 (58.5%) and 17/41 (41.5%) cases, respectively. Older age, syncope, palpitations, hemodynamic instability, abnormal ECG conduction, and reduced LV function (LVF) on admission were associated with increased sVA occurrence, while chest pain was associated with reduced sVA on univariate analysis. Multivariable model including age, sex, admission ECG, and LVF revealed age (OR 1.027/year, 95%, CI [1.015, 1.052]; p =0.038), abnormal ECG conduction (OR 5.55, 95% CI [2.237, 8.346]; p<0.001), and reduced LVF (OR 4.38, 95% CI [1.783, 9.081]; p=0.002) to be independently associated with sVA. Applying these possible predictors we could delineate AM patients with differing prevalence of sVA during AM hospitalization.

Few simple clinical parameters, found on AM admission, may assist prediction of sVA during hospitalization. Thus, delineating patients who may benefit from vigilant ECG monitoring during hospitalization.