Pre-capillary pulmonary hypertension and right ventricular dilation predict clinical outcome in cardiac resynchronization therapy

Abstract

Objectives: This study examined the prognostic significance of pre- and post-capillary components of pulmonary hypertension (PH) in patients receiving cardiac resynchronization therapy (CRT).

Background: PH is common in patients with left ventricular systolic dysfunction (LVSD) receiving CRT. The impact of PH subtype on clinical outcome in CRT is unknown.

Methods: The study population consisted of 101 patients (average age 66 ± 13 years, left ventricular ejection fraction 0.23 ± 0.07, and New York Heart Association functional class 3.2 ± 0.4) who underwent right heart catheterization in the 6 months before CRT. PH was defined as a mean pulmonary artery pressure ≥25 mm Hg; a significant pre-capillary contribution to elevated mean pulmonary artery pressure was defined as a transpulmonary gradient (TPG) ≥12 mm Hg. Clinical endpoints were assessed at 2 years and included all-cause mortality and a composite of death, left ventricular assist device, or cardiac transplantation.

Results: Patients with TPG ≥12 mm Hg were more likely to experience all-cause mortality (hazard ratio [HR]: 3.2; 95% confidence interval [CI]: 1.3 to 7.4; p = 0.009) and the composite outcome (HR: 3.0; 95% CI: 1.4 to 6.3; p = 0.004) compared with patients with TPG <12 mm Hg. After multivariate adjustment for hemodynamic, clinical, and echocardiographic variables, only TPG ≥12 mm Hg and baseline right ventricular (RV) dilation (RV end-diastolic dimension >42 mm) were associated with the composite clinical outcome (p = 0.05 and p = 0.04, respectively).

Conclusions: High TPG PH and RV dilation are independent predictors of adverse outcomes in patients with LVSD who are receiving CRT. RV pulmonary vascular dysfunction may be a therapeutic target in select patients receiving CRT.

Keywords: cardiac resynchronization therapy; pulmonary hypertension; right ventricle.