Background: Acute myocarditis carries a variable prognosis. We examined the short and long-term mortality rate in patients with acute myocarditis and admission electrocardiographic predictors of outcome.
Methods: Patients admitted to a tertiary hospital with acute myocarditis during a period of 20 years were evaluated for mortality.
Results: 220 patients were evaluated. Median follow-up was 5.8 years; 77% were males, mean age 34±18 years. Median (interquartile range) CRP was 6.5 (2.7-15), Troponin-T 1.0 (0.4-1.7). 30-day survival rate was 96%. Overall survival during follow-up was 90%. The most common abnormalities on ECG were T wave changes (36% of the cohort), ST changes (30%) and either or both abnormalities (52%). Less frequent changes included abnormal T axis (>105° or <-15°, 16%), QTc>460 (14%), QRS interval≥120ms (9%) and left axis deviation (5%). Univariable electrographic predictors of short and long-term outcome were QRS interval>120ms, QRS-T angle, abnormal T wave axis and a prolonged QTc>460. Independent predictors of long-term outcome after adjustment for age and gender were QRS interval>120ms (HR 3.87 per, 95% CI 1.35-11.05, P=0.01), QRS-T angle>100° (HR 5.17, 95% CI 2.12-12.58, P<0.001) and abnormal T wave axis (HR 2.91, 95% CI 1.20-7.02, P=0.02).
Conclusions: T wave abnormalities and the QRS interval are predictors of reduced survival in patients with acute myocarditis.
