RESUMO
BACKGROUND: Fatty acid is a main source of cardiac energy in aerobic conditions. We used iodine-123-beta-methyl-iodophenyl pentadecanoic acid ((123)I-BMIPP) myocardial scintigraphy to study the efficacy of the angiotensin-converting enzyme inhibitor (ACEI) enalapril in the treatment of chronic heart failure (CHF) by evaluating its therapeutic effects on myocardial fatty acid metabolism. METHODS AND RESULTS: New York Heart Association functional class status, left ventricular end-diastolic diameter, percent fractional shortening, the ratio between early and late peaks of flow velocity, (123)I-BMIPP myocardial-to-mediastinal uptake ratio, and mean washout rate were measured in 42 patients (31 men and 11 women; mean age, 58 +/- 3 years) with CHF before treatment and 3 months after treatment. There was a significant correlation between myocardial fatty acid metabolism and other variables as well as between the degree of improvement in myocardial fatty acid metabolism and the degree of improvement in other variables. CONCLUSIONS: Enalapril improved symptoms and cardiac function in patients with CHF. These improvements significantly correlated with improvement of (123)I-BMIPP metabolism in the myocardium. (123)I-BMIPP scintigraphy is useful for evaluating the efficacy of drug therapy for CHF based on myocardial fatty acid metabolism.