N-terminal proatrial natriuretic peptide in primary care: relation to echocardiographic indices of cardiac function in mild to moderate cardiac disease

Aims: In patients with chronic heart failure plasma levels of N-terminal proatrial natriuretic peptide (Nt-proANP) correlate to cardiac filling pressures. The aim of the present study was to examine the relation between Nt-proANP plasma levels and echocardiographic indices of cardiac dysfunction in patients recruited from primary care. Methods and results: After clinical examination by the primary care physician, the patients were referred to one of two centres for echocardiography and blood sampling. In patients with mild to moderate symptoms of heart failure (n=52) and in asymptomatic patients with long-standing hypertension (n=46) or previous myocardial infarction (n=97), peptide levels were most closely related to parameters of left atrial wall stress. Patients who according to echocardiographic predefined criteria had diastolic or systolic dysfunction had two- and three-fold higher Nt-proANP than controls. According to receiver operating curve (ROC) analysis, Nt-proANP measurements were helpful in ruling out left ventricular systolic dysfunction, but not diastolic dysfunction. Conclusion: In patients with mild to moderate cardiac disease, Nt-proANP plasma concentration was related to increased atrial wall stress. Peptide measurement could assist in ruling out the presence of LV systolic dysfunction, but was otherwise of limited value when used for diagnostic subgrouping into echocardiographically determined function categories.