Elevated pulmonary arterial elastance and right ventricular uncoupling are associated with greater mortality in...

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.

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.

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.

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.