Brain natriuretic peptide is not predictive of dilated cardiomyopathy in Becker and Duchenne muscular dystrophy patients and carriers

BACKGROUND: Cardiomyopathy is reported in Duchenne and Becker muscle dystrophy patients and female carriers. Brain Natriuretic peptide (BNP) is a hormone produced mainly by ventricular cardiomyocytes and its production is up regulated in reaction to increased wall stretching. N-terminal-proBNP (NT-proBNP) has been shown to be a robust laboratory parameter to diagnose and monitor cardiac failure, and it may be helpful to screen for asymptomatic left ventricular dysfunction. Therefore we tested whether NT-proBNP can distinguish patients with Duchenne or Becker muscular dystrophy patients and carriers of a dystrophin mutation with a dilated cardiomyopathy from those without. METHODS: In a cohort of Duchenne and Becker muscle dystrophy patients (n = 143) and carriers (n = 219) NT-proBNP was measured, and echocardiography was performed to diagnose dilated cardiomyopathy (DCM). RESULTS: In total sixty-one patients (17%) fulfilled the criteria for DCM, whereas 283 patients (78%) had an elevated NT-pro BNP. The sensitivity of NT-proBNP for DCM in patients or carriers was 85%, the specificity 23%, area under the ROC-curve = 0.56. In the specified subgroups there was also no association. CONCLUSION: Measurement of NT-pro BNP in patients suffering from Duchenne or Becker muscular dystrophy and carriers does not distinguish between those with and without dilated cardiomyopathy.