The prognostic significance of tricuspid valve regurgitation in pulmonary arterial hypertension

Introduction: Tricuspid valve regurgitation (TR) is a frequent finding in patients with pulmonary arterial hypertension (PAH). However, its prognostic significance and relation to PAH, while suspected, are poorly understood. We assessed 727 consecutive patients with newly diagnosed PAH who underwent transthoracic echocardiographic evaluation of tricuspid valve function. Objectives: The study objective was to determine the association of TR presence and severity with patient characteristics, pulmonary artery hemodynamics and outcome. Methods: Consecutive patients with newly diagnosed PAH (N = 727 with group 1 pulmonary hypertension) underwent transthoracic echocardiographic evaluation of tricuspid valve function at diagnosis. The primary study end point was all-cause mortality or lung transplantation. Results: In this population, 702 patients (96.5%) had TR; in 165 patients (23%), TR was severe. Compared with those with no or mild TR by echocardiography criteria, patients with severe TR had shorter mean (SD) 6-minute walk distances (285 [125] m vs 360 [121] m; P =.02) and higher levels of B-type natriuretic peptide (695 [672] pg/dL vs 328 [300] pg/dL; P <.05). Severe TR was associated with greater right atrial dilatation (91% vs 47%; P =.004) and right ventricular (RV) dilatation (92% vs 51%; P =.008), greater right atrial pressure (mean [SD] 15 [7] mm Hg vs 10 [6] mm Hg; P <.001) and lower cardiac index (mean [SD], 2.2 [0.7] L/min/m2 vs 2.8 [0.9] L/min/m2; P <.001). Severe TR was strongly predictive of greater 5-year mortality risk after adjustment for age, sex, functional class, 6-minute walk distance, diffusing capacity, RV size and pulmonary vascular resistance index (adjusted hazard ratio, 1.83; 95% CI, 1.38-2.41; P <.001). Conclusions: Severe TR was a significant predictor of long-term mortality rate in PAH, and TR severity correlated with PAH severity.