Determinants of pulmonary hypertension in left ventricular dysfunction

Objectives. This study sought to analyze the determinants of pulmonary hypertension in patients with left ventricular dysfunction. Background. Pulmonary hypertension in patients with left ventricular dysfunction is a predictor of poor outcome. The independent role of cardiac functional abnormalities in the genesis of pulmonary hypertension is unclear. Methods. In 102 consecutive patients with primary left ventricular dysfunction (ejection fraction <50%), systolic pulmonary artery pressure was prospectively measured by Doppler echocardiography (using tricuspid regurgitant velocity), and left ventricular systolic and diastolic function, functional mitral regurgitation, cardiac output and left atrial volume were quantified. Results. Systolic pulmonary artery pressure was elevated in patients with left ventricular dysfunction (51 ± 14 mm Hg [mean ±SD]), but the range was wide (23 to 87 mm Hg). Of the numerous variables correlating significantly with systolic pulmonary artery pressure, the strongest were mitral deceleration time (r = -0.61, p = 0.0001; odds ratio of pulmonary pressure ≤50 mm Hg [95% confidence interval] if <150 ms, 48.8 [14.8 to 161]) and mitral effective regurgitant orifice (r = 0.50, p = 0.0001; odds ratio [95% confidence interval] if ≤20 mm², 5.9 [2.3 to 15.5]). In multivariate analysis, these two variables were the strongest predictors of systolic pulmonary artery pressure in association with age (p = 0.005). Ejection fraction or end-systolic volume was not an independent predictor of pulmonary artery pressure. Conclusions. Pulmonary hypertension is frequent and highly variable in patients with left ventricular dysfunction. It is not independently related to the degree of left ventricular systolic dysfunction but is strongly associated with diastolic dysfunction (shorter mitral deceleration time) and the degree of functional mitral regurgitation (larger effective regurgitant orifice). These results emphasize the importance of assessing diastolic function and quantifying mitral regurgitation in patients with left ventricular dysfunction.