Survival in biopsy-proven myocarditis: A long-term retrospective analysis of the histopathologic, clinical, and hemodynamic predictors

Objective We hypothesized that histopathology predicts survival without cardiac transplantation in patients with biopsy-proven myocarditis. Background The role of endomyocardial biopsy in diagnosing myocarditis remains controversial. Histopathology has been integrated with clinical and hemodynamic features to predict prognosis. However, the influence of histopathology on survival >5 years has not been explored. Methods We retrospectively identified 112 consecutive patients with histopathologic confirmation of myocarditis. We examined these patientsʹ clinical presentation, hemodynamic assessment, hospital course, and treatment. We selected 14 variables that might influence survival without cardiac transplantation. Results A total of 62 (55%) of 112 patients had lymphocytic myocarditis; 88 (79%) and 63 (56%) were alive without cardiac transplantation at 1 and 5 years, respectively. Median follow-up was a mean 95.5 months and median 74.5 months. Among the 55 with complete data of the 14 candidate predictor variables, age, sex, and clinical presentation with congestive heart failure and ventricular (ventricular tachycardia or fibrillation) or atrial arrhythmias (atrial fibrillation or flutter) did not predict the study end point of death or need for transplantation. In univariate analysis, pulmonary capillary wedge pressure ≥15 mm Hg significantly predicted the study end point. In multivariate analysis, pulmonary capillary wedge pressure ≥15 mm Hg and histopathology of lymphocytic, granulomatous, or giant cell myocarditis each significantly predicted mortality or transplant (P = .047, P = .013, and P = .054, respectively) on cumulative survival without cardiac transplantation. Conclusions Histopathology predicts long-term survival in patients with myocarditis. Clinical presentation, including presentation with congestive heart failure, ventricular tachycardia/ventricular fibrillation, or atrial fibrillation/atrial flutter, does not predict survival without transplantation. Endomyocardial biopsy can play a role in predicting transplant-free survival in patients with myocarditis.