Correlation of Right Ventricular Wall Stress With Plasma B-Type Natriuretic Peptide Levels in Patients With Pulmonary Hypertension.

BACKGROUND: This study was designed to investigate the relationship between right ventricular wall stress (RVWS) and plasma B-type natriuretic peptide (BNP) levels in patients with pulmonary hypertension (PH). Methods and Results: The 57 consecutive PH patients and 8 control subjects were enrolled. Right heart catheterization (RHC), echocardiography, and BNP measurements were performed, and RVWS and left ventricular wall stress (LVWS) were calculated with the formula based on Laplace's law. Systolic RVWS and end-diastolic RVWS were higher in PH patients compared with controls (systolic RVWS: 77±41 vs. 17±5 kdynes/cm2 (P<0.0001), end-diastolic RVWS: 15±12 vs. 8±2 kdynes/cm2 (P<0.0005)). Univariate analyses showed that logBNP at baseline correlated with systolic RVWS (r=0.58, P<0.0001) and end-diastolic RVWS (r=0.61, P<0.0001). We performed multivariate regression analysis and determined that end-diastolic RVWS was an independent determinant of logBNP in patients with PH. In addition, change in plasma BNP levels after treatment correlated with change in systolic RVWS (r=0.70, P<0.0001) and change in end-diastolic RVWS (r=0.68, P<0.0001).

CONCLUSIONS: Both systolic and end-diastolic RVWS were elevated in patients with PH, and correlated with the symptoms of PH. End-diastolic RVWS was an independent determinant of plasma BNP levels in PH patients.