AIMS: To characterize right ventricular (RV) geometry and function in chronic thromboembolic pulmonary hypertension (CTEPH) patients at rest and during exercise before pulmonary thromboendarterectomy (PEA), and at 3 and 12 months after PEA using two-dimensional and three-dimensional echocardiography with reference to clinical performance and exercise capacity.

METHODS AND RESULTS: Forty subjects (20 CTEPH patients and 20 controls) were enrolled between December 2014 and January 2017. Three-dimensional echocardiography demonstrated a significant reduction and normalization of end-diastolic and end-systolic RV volumes in CTEPH patients 12 months after PEA. RV systolic function improved after PEA; however, tricuspid annular plane systolic excursion (TAPSE) (baseline 18 ± 6 mm vs 15 ± 3 mm at 12 months after PEA, P < .05) and tricuspid lateral annular systolic velocity (RV-S') (baseline -8.3 ± 2.1 cm/s vs -7.2 ± 1.3 cm/s at 12 months after PEA, P < .05) declined significantly after PEA. Tricuspid regurgitation gradient was 64 ± 21 mm Hg at baseline, 40 ± 14 mm Hg at 3 months, and 30 ± 13 at 12 months, P < .00001. RV free-wall longitudinal strain at peak exercise was significantly increased from baseline (-10.6 ± 5.5%) to 12 months of follow-up (-15.8 ± 5.2%), P < .005. Physical exercise capacity, measured as peak oxygen uptake, was significantly increased and correlated directly with improvement of resting and exercise-induced RV-EF.

CONCLUSION: Improvement of RV geometry and systolic function, along with the reduction of systolic pulmonary pressure, can be expected following PEA in CTEPH patients during long-term follow-up. Improvement of RV myocardial contractility after PEA was only revealed at peak exercise over time. Importantly, physical exercise capacity was significantly increased and was found to be directly correlated with improvement of resting and exercise-induced RV-EF.