Plasma BNP Level Is a Strong Parameter for Detecting Increased Pulmonary Capillary Wedge Pressure in Patients with Severe Aortic Stenosis

Background: An increased pulmonary capillary wedge pressure (PCWP) is a strong risk factor for the development of congestive heart failure in patients with aortic stenosis (AS). We investigated whether conventional parameters are useful to detect the elevation of PCWP in AS patients. Methods: Ninety-six patients with severe AS (aortic valve area <1.0 cm²) were analyzed in this study. Cardiac catheterization, echocardiography, and plasma B-type natriuretic peptide (BNP) analysis were performed in all patients. Results: PCWP positively correlated with log BNP (r = 0.563) and left ventricular (LV) end-systolic volume index (LVESVI, r = 0.484), but weakly correlated with E/A ratio (r = 0.284), E/E' ratio (r = 0.243), LV ejection fraction (r = 0.384) and left atrial volume index (LAVI, r = 0.386). Multivariate logistic regression analysis revealed that both log BNP (OR 9.94, 95% CI 2.349–103.565, P = .013) and LAVI (OR 1.063, 95% CI 1.010–1.137, P = .035) were independent predictors of increased PCWP (>18 mmHg). Receiver operating characteristic curve analysis revealed that log BNP showed larger area under the curve for detecting increased PCWP compared to LAVI (0.897 vs. 0.753, P = .07). When the cutoff value of BNP was determined as 757 pg/ml, diagnostic accuracy for increased PCWP was as follows: sensitivity 0.889, specificity 0.867, positive predictive value 0.973, negative predictive value 0.591. Conclusion: Compared to conventional echocardiographic parameters, BNP is more useful to predict the increase of PCWP in AS patients.