Long-term outcome of fulminant myocarditis as compared with acute (nonfulminant) myocarditis.

Background: Lymphocytic myocarditis causes left ventricular dysfunction tha t may be persistent or reversible. There are no clinical criteria that pred ict which patients will recover ventricular function and which cases will p rogress to dilated cardiomyopathy. We hypothesized that patients with fulmi nant myocarditis may have a better long-term prognosis than those with acut e (nonfulminant) myocarditis. Methods: We identified 147 patients considered to have myocarditis accordin g to the findings on endomyocardial biopsy and the Dallas histopathological criteria. Fulminant myocarditis was diagnosed on the basis of clinical fea tures at presentation, including the presence of severe hemodynamic comprom ise, rapid onset of symptoms, and fever. Patients with acute myocarditis di d not have these features. The incidence of the end point of this study, de ath or heart transplantation, was ascertained by contact with the patient o r the patient's family or by a search of the National Death Index. The aver age period of follow-up was 5.6 years. Results: A total of 15 patients met the criteria for fulminant myocarditis, and 132 met the criteria for acute myocarditis. Among the patients with fu lminant myocarditis, 93 percent were alive without having received a heart transplant 11 years after biopsy (95 percent confidence interval, 59 to 99 percent), as compared with only 45 percent of those with acute myocarditis (95 percent confidence interval, 30 to 58 percent; P=0.05 by the log-rank t est). Fulminant myocarditis was an independent predictor of survival after adjustments were made for age, histopathological findings, and hemodynamic variables. The rate of transplantation-free survival did not differ signifi cantly between the patients considered to have borderline myocarditis and t hose considered to have active myocarditis according to the Dallas histopat hological criteria. Conclusions: Fulminant myocarditis is a distinct clinical entity with an ex cellent long-term prognosis. Aggressive hemodynamic support is warranted fo r patients with this condition. (N Engl J Med 2000;342:690-5.) (C)2000, Mas sachusetts Medical Society.