Background: Little is known about the association between left ventricular (LV) diastolic dysfunction and outcomes in patients with idiopathic or heritable pulmonary arterial hypertension (PAH). Our rationale was to investigate the prevalence of LV diastolic dysfunction, and its association with disease severity and outcomes, in patients with idiopathic or heritable PAH.
Methods: Using the Cleveland Clinic Pulmonary Hypertension Registry, we identified subjects with heritable or idiopathic PAH who underwent Doppler echocardiography and right-sided heart catheterization. Echocardiographic diastolic parameters were assessed in each patient.
Results: A total of 61 patients met the inclusion criteria (idiopathic 85%, heritable 15%). The age at the time of echocardiography was 48.3 ± 18 years, 84% of the subjects were women, and 48% were on PAH-targeted therapies. Normal LV diastolic function, impaired relaxation, and pseudonormalization were seen in 10%, 88%, and 2% of the patients, respectively. Peak early diastolic (peak E) velocity was directly associated with LV end-diastolic volume and cardiac index and inversely associated with the degree of right ventricular dilation, right atrial pressure, and pulmonary vascular resistance. Peak E velocity was associated with mortality adjusted for age and sex (hazard ratio [HR], 1.5; 95% CI, 1.1-2 per 10 cm/s decrease; P = .015) and age, sex, 6-min walk distance, and cardiac output (HR, 1.8; 95% CI, 1.2-2.9 per 10 cm/s decrease; P = .01).
Conclusions: LV diastolic dysfunction of the impaired relaxation type is observed in the majority of patients with advanced idiopathic or heritable PAH. A decrease in transmitral flow peak E velocity is associated with worse hemodynamics and outcome.