Brain natriuretic peptide: is it a predictor of cardiomyopathy in cirrhosis?

Subtle cardiac abnormalities have been described in patients with cirrhosis. Natriuretic peptide hormones have been reported to be sensitive markers of early cardiac disease. We postulate that plasma levels of N-terminal pro-atrial natriuretic peptide and brain natriuretic peptide could be used as markers of cardiac dysfunction in cirrhosis. The aim of the study was to evaluate the levels of N-terminal pro-atrial natriuretic peptide and brain natriuretic peptide and their relationship with cardiac structure and function in patients with cirrhosis. The study population comprised 36 patients with cirrhosis of mixed aetiologies, but with no cardiac symptoms; 19 of the patients had ascites and 17 did not. The subjects underwent (i) trans-thoracic two-dimensional echocardiography, and (ii) radionuclide angiography for measurements of cardiac structural parameters, diastolic and systolic function. Levels of N-terminal pro-atrial natriuretic peptide and brain natriuretic peptide were also measured. The results were compared with those from eight age- and sex-matched healthy volunteers. Compared with the controls, the baseline mean ejection fraction was increased significantly in both patient groups (P=0.02), together with prolonged deceleration times (P=0.03), left atrial enlargement (P=0.03) and interventricular septal thickening (P=0.02), findings that are compatible with diastolic dysfunction. Levels of N-terminal pro-atrial natriuretic peptide and brain natriuretic peptide were significantly higher in all patients with cirrhosis with ascites (P=0.01 and P=0.05 respectively), but in only some of the pre-ascitic cirrhotic patients, compared with controls. All high levels of brain natriuretic peptide were correlated significantly with septal thickness (P<0.01), left ventricular diameter at the end of diastole (P=0.02) and deceleration time (P<0.01). We conclude that elevated levels of brain natriuretic peptide are related to interventricular septal thickness and the impairment of diastolic function in asymptomatic patients with cirrhosis. Levels of brain natriuretic peptide may prove to be useful as a marker for screening patients with cirrhosis for the presence of cirrhotic cardiomyopathy, and thereby identifying such patients for further investigations.