Subclassification of dilated cardiomyopathy and interferon treatment.

Seventy-seven consecutive patients with dilated cardiomyopathy underwent left ventricular endomyocardial biopsy. In 20 biopsies (26%) enteroviral RNA was detected by in-situ hybridization. After an average observation period of more than 2 years only one patient had died in the enterovirus positive (ev+) group compared with 11 deaths and four heart transplantations in the enterovirus negative (ev-) group. After a mean follow-up of 16 +/- 9 months haemodynamic evaluation of the surviving ev+ patients showed significantly better results with respect to left ventricular ejection fraction and left ventricular end-diastolic diameter. The four ev+ patients with haemodynamic deterioration were given interferon-alpha, 3 million units subcutaneously every other day for six months. No severe side effects were seen and all four patients improved according to their haemodynamic and clinical parameters. In two of the four patients enteroviral RNA was not detectable in a subsequent biopsy.