The natural history of acute dilated cardiomyopathy.

INTRODUCTION

Acute dilated cardiomyopathy (ADCM) is a frequent cause for referral for cardiac transplantation yet its prognosis and natural history on contemporary therapy remain uncertain.

METHODS

The Multicenter Intervention in Myocarditis and Acute Cardiomyopathy (IMAC)-2 trial enrolled 373 patients at 12 academic medical centers with left ventricular ejection fraction (LVEF) ≤ 40%, heart failure symptoms < 6 months duration, and a diagnostic evaluation consistent with idiopathic cardiomyopathy or acute myocarditis. The natural history of ADCM in an earlier era (1975-2000) was also examined via a MEDLINE search of published observational studies.

RESULTS

Mean age of the IMAC-2 study cohort was 45 ± 4 years and 38% were female. Mean initial LVEF was 24% ± 8% and increased to 40% ± 12% during treatment with ACE-I/ARB (82%), and a beta-blocker (94%). Transplantation-free survival at 1, 2, and 4 years was 94%, 92%, and 86%, respectively. This survival rate was substantially higher than the prior era. Multivariate predictors of improvement in LVEF were smaller LV dimension and higher systolic blood pressure whereas black race and higher initial New York Heart Association functional class were associated with lower final LVEF. Genotypic variation did not correlate with response to pharmacological therapy.

CONCLUSION

Earlier diagnosis and aggressive pharmacologic and device-based therapy of ADCM has led to improved prognosis.