Utility of B-type natriuretic peptide (BNP) as a screen for left ventricular dysfunction in patients with diabetes

Routine screening of diabetic patients with echocardiography is not feasible due to its limited availability and high cost. B-type natriuretic peptide (BNP) is secreted from the left ventricle in response to pressure overload and is elevated in both systolic and diastolic dysfunction.

BNP levels were compared to echocardiographic findings in 263 patients. Patients were divided into two groups: clinical indication for echocardiography (CIE) (n = 172) and those without clinical indication for echocardiography (no-CIE) (n = 91). Cardiologists making the assessment of left ventricular function were blinded when measuring plasma levels of BNP.

The 91 patients with no-CIE with echoes had similar BNP levels (83 +/- 16 pg/ml) to the 215 patients with no-CIE without echoes (63 +/- 10, P = 0.10). Patients with CIE and subsequent abnormal left ventricular function (n = 112) had a mean BNP concentration of 435 +/- 41 pg/ml, compared with those with no-CIE, but had abnormal left ventricular function on echo (n = 32) (161 +/- 40 pg/ml). Twenty-one of 32 patients with no-CIE but with abnormal left ventricular function had diastolic dysfunction (BNP 190 +/- 60 pg/ml). A receiver-operating characteristic (ROC) curve revealed that the area under the curve was 0.91 for CIE patients and 0.81 for no-CIE patients (P < 0.001). For those with no congestive heart failure (CHF) symptoms, BNP levels showed a high negative predictive value (91% for BNP values <39 pg/ml), while in those patients who had a CIE, BNP levels showed a high positive predictive value for the detection of left ventricular dysfunction (96% with BNP levels >90 pg/ml).

BNP can reliably screen diabetic patients for the presence or absence of left ventricular dysfunction.