NEW YORK (Reuters Health) – In patients presenting with acute coronary syndrome, elevated B-type natriuretic peptide (BNP) levels add important prognostic data, independent of echocardiographic findings, according to a report in the American Heart Journal for July.

The report also indicates that repeat BNP testing 7 weeks after the initial presentation further enhances risk prediction.

Although elevated BNP levels had been linked to adverse outcomes in the past, it was unclear whether this finding, independent of left ventricular hypertrophy and other echocardiographic abnormalities, has prognostic value, Dr. Donald S. C. Ang, from Ninewells Hospital and Medical School, Dundee, UK, and colleagues explain.

To investigate, the researchers followed 443 patients with ACS – including 120 (27%) with ST-elevation MI — who had BNP levels measured at presentation and again 7 weeks later. The composite outcome — readmission with acute coronary syndrome, congestive heart failure, and all-cause mortality – was assessed after 10 months’ follow-up.

By 10 months, 90 cardiovascular events had been logged, the report indicates.

After accounting for age, gender, diabetes, hypertension, smoking status, renal impairment, left ventricular ejection fraction, and echocardiographic left ventricular hypertrophy, a baseline BNP level >80 pg/mL increased the odds of a cardiovascular event by 2.63-fold. An elevated BNP level at 7 weeks increased the risk of an event by 4.12-fold.

Patients who had elevated BNP levels at presentation and at 7 weeks were 4.04-times more likely to experience a cardiovascular event than were subjects with elevated levels only at presentation, the report shows.

“Future studies are now required to confirm our suggestion that a second BNP sample might enhance risk prediction in routine ACS patients,” the authors conclude. “In addition, the fact that BNP assesses risk over and above echocardiographic abnormalities in ACS suggests indirectly that some of the high risk in high BNP individuals may be a reflection of the extent of the ischemia.”

Reference:
Am Heart J 2009;158:133-140.