Marked decrease in BNP levels in 2 related patients with reversible dilated cardiomyopathy

Two male patients, one in his thirties and the other in his fifties, were admitted to different hospitals for congestive heart failure (CHF). In both patients, laboratory findings indicated high plasma B-type natriuretic peptide (BNP) levels (266.0 and 902.7 pg/mL, respectively) and echocardiography showed large left ventricular diastolic dimensions (LVDd) (67 and 73 mm, respectively) and low ejection fractions (EF) (26% and 18%, respectively). Coronary arteriography revealed no organic stenosis in either patient. Following treatment, plasma BNP levels decreased to below the limit of measurement (4 pg/mL) in both patients and echocardiography revealed improved LVDd (61 and 52 mm, respectively) and EF (41% and 45%, respectively). Because these patients are related, genetic factors might have affected low plasma BNP levels. Moreover, these results suggest that marked decrease in plasma BNP during follow up may be an indicator of preserved neurohormonal and organ systems.