Reserve of Right Ventricular-Arterial Coupling in the Setting of Chronic Overload.

BACKGROUND

Right ventricular (RV) maladaptation and failure determine outcome in pulmonary hypertension. The adaptation of RV function to loading (RV-pulmonary arterial coupling) is defined by a ratio of end-systolic to arterial elastances (Ees/Ea). How RV-pulmonary arterial coupling relates to pulmonary hypertension severity and onset of RV failure (defined by excessive volume increase and ejection fraction [EF] decrease) is not exactly known.

METHODS AND RESULTS

We performed cardiac magnetic resonance (CMR) imaging within 24 hours of a diagnostic right heart catheterization and invasive measurement of RV pressure-volume loops in 42 patients with pulmonary hypertension. Median (interquartile range) Ees and Ea were 0.49 (0.35-0.74) and 0.74 (0.45-1.04) mm Hg/mL, respectively; Ees/Ea was 0.73 (0.47-1.07). End-diastolic elastance (Eed) was 0.14 (0.06-0.24) mm Hg/mL. RV EF was 39±13%. End-systolic volume and end-diastolic volume/body surface area (BSA) were 62 (45-101) and 104 (83-143) mL/m

CONCLUSIONS

RV-pulmonary arterial coupling (Ees/Ea) has considerable reserve, from normal values of 1.5-2 to <0.8, and has the ability to detect pending RV failure in patients with pulmonary hypertension. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT03403868.