Elevated pulmonary arterial elastance and right ventricular uncoupling are associated with greater mortality in advanced heart failure

Abstract

Background: The objectives of this study were to describe right ventricular-pulmonary arterial elastance coupling hemodynamic phenotypes and their frequency in patients with advanced heart failure and to evaluate the association of elastance-based indices with all-cause mortality, cardiac transplantation, and left ventricular assist device therapy.

Methods: This study included 175 patients with heart failure undergoing right heart catheterization to evaluate candidacy for advanced therapies and 21 healthy controls. We modified a single-beat approach to elastance to account for the magnitude of pulmonary arterial pressure and estimated right ventricular end-systolic elastance (E_es), pulmonary arterial elastance (E_a), and the E_es:E_a ratio. We defined elevated pulmonary arterial load as an E_a > 0.5 mm Hg/ml, and ventriculo-arterial uncoupling as an E_es:E_a < 0.8. We evaluated associations between E_es, E_a, and E_es:E_a with all-cause mortality and composite event-free survival using multivariable Cox proportional-hazard models, adjusted for age and sex.

Results: All 21 controls had E_a ≤ 0.5 mm Hg/ml and E_es:E_a ≥ 0.8. Of 175 patients with heart failure, 63% had E_a > 0.5 mm Hg/ml. E_es:E_a was lower in patients than in controls (p < 0.001), and 47% of the patients demonstrated E_es:E_a < 0.8, including 8% with normal E_a. In median follow-up of 2.2 (0.8-4.6) years, 53 died, 37 received cardiac transplantation, and 33 received a left ventricular assist device. By multivariable analysis, E_a (hazard ratios [HR]: 2.01, 95% CI 1.18-3.41) and E_es:E_a (HR: 0.46, 95% CI: 0.26-0.82) were independently associated with mortality, whereas E_es was not.

Conclusions: Right ventricular-pulmonary vascular coupling is frequently impaired in heart failure and associated with greater mortality. Elevated pulmonary arterial elastance is associated with greater mortality even when coupling is preserved.

Keywords: Elastance; Heart Failure; Pulmonary Hypertension; Right Ventricle; Ventricular-Vascular Coupling.