B-type natriuretic peptide levels and its correlation with left ventricular functions and heart failure in patients of acute coronary syndromes

Background: This study was designed to measure levels of B-type natriuretic peptide (BNP) across entire spectrum of acute coronary syndrome (ACS) and to find its correlation with left ventricular functions and heart failure.Methods: We measured BNP levels at baseline in 100 consecutive patients between 24-96 hours after the onset of ischemic symptoms in patients of ACS. Echocardiography was performed in all patients between day 2-5 after the index diagnosis and stabilizing the patients.Results: The BNP levels were raised across the entire spectrum of ACS, with levels (>80 pg/ml) in 32.2% of patients with ST segment-elevation myocardial infarction (STEMI), in 24% with non-ST segment-elevation myocardial infarction (NSTEMI), and in 16.6% with unstable angina (UA) respectively. High BNP levels were associated with greater increase in LV end-systolic volumes (r=+0.545, p<0.001) (LVESV) and end-diastolic volumes (LVEDV) (r=+0.336, p<0.001). There was a negative correlation between BNP levels and left ventricular ejection fraction (LVEF) (r=-0.394, p<0.002). BNP levels were significantly raised (156.0±45.1 vs 57.7±18.3 pg/ml, p<0.02) in patients developing symptomatic clinical heart failure, irrespective of LVEF ≤40%.Conclusions: Integrated use of echocardiography and BNP levels provide powerful incremental assessment of cardiac functions, clinical status, and outcome across the entire spectrum of acute coronary syndromes (ACS). Increased BNP levels are associated with progressive ventricular dilatation, LV-dysfunction, development of clinical heart failure and is associated with poor prognosis in patients of ACS.