Which subgroup of patients with dilated cardiomyopathy would benefit from long-term beta-blocker therapy ? A histologic viewpoint

Abstract Objectives . The purpose of this study was to elucidate whether the effectiveness of long-term beta-blocker therapy could be predicted before this therapy is started. Background . Long-term beta-blocker therapy has recently been reported to provide a favorable effect in treatment of congestive heart failure due to dilated cardiomyopathy. Methods . Several measurements including histologie variables before administration of metoprolo'. were retrospectively compared among 18 good responders (showing improvement of at least one New York Heart Association functional class or an increase in ejection fraction ≥0.10 12 months after drug administration) and 12 poor responders without such improvement. Results . Although there were no significant differences between the two groups in age, gender, functional class, heart rate, blood pressure, pulmonary capillary wedge pressure, cardiac index, left ventricular end-diastolic dimension and ejection fraction, percent fibrosis estimated by the point-counting method in endomyocardial biopsy specimens was significantly lower in good than in poor responders (7.6 ± 5.7 vs. 14.2 ± 9.7%, p Conclusions . The extent and type of fibrosis may be important factors in the prediction of the effectiveness of long-term betablocker therapy for dilated cardiomyopathy.