Exercise-induced changes of B-type natriuretic peptide uncover the unknown coronary artery disease in patients with chest pain and normal left ventricular systolic function

Abstract

The diagnostic and prognostic utility of B-type natriuretic peptide (BNP) has been shown in patients either with heart failure or with known coronary artery disease (CAD). We aimed to investigate the utility of the exercise-induced changes of BNP in patients with chest pain, unknown CAD, and normal left ventricular systolic function. We evaluated 100 consecutive patients (mean age 58.7 ± 9 years) (80% male) with left ventricular ejection fraction of more than 50%. Blood samples were collected and BNP was measured before exercise stress testing, at peak, and 20 min after it. All patients underwent coronary artery angiography. We used univariate and multivariate logistic regression analysis. An increment in BNP values of 1.3 fold (from before to peak exercise BNP values) have 11 times greater odds of having CAD [odds ratio (OR): 11.45 with 95% confidence interval (CI): 3.48–37.66, P < 0.001]. Receiver operating curve analysis revealed a sensitivity of 81.8% and a specificity of 71.8%. Multivariate analysis revealed that BNP increment from before to peak exercise remained statistically significant regardless of the presence of other risk factors for atherosclerosis (OR: 18.59 with 95% CI: 4.14–83.45, P < 0.001). Interestingly, patients showing 1.79 times increment of before to peak exercise BNP values have 19 times greater odds of having multivessel disease (OR: 19.28 with 95% CI: 4.95–75.17, P < 0.001) with a sensitivity of 81% and specificity of 81.8%. The exercise-induced changes of BNP in patients with chest pain, normal left ventricular systolic function, and unknown CAD may uncover patients with CAD and discriminate those with angiographically severe one.