Clinical Implications of Body Composition and Exercise Capacity Following Pulmonary Endarterectomy

Pulmonary endarterectomy (PEA) is a curative procedure for patients with chronic thromboembolic pulmonary hypertension. Body composition and exercise capacity have been associated with adverse outcomes in patients undergoing cardiothoracic operations, but their significance with PEA is unclear. We evaluated the association of body composition and 6-minute walk distance (6MWD) with disease severity, hospital length of stay, discharge disposition, and postoperative functional recovery.

This was a retrospective, single-center cohort study of patients who underwent PEA (January 2014-December 2017). Body composition (skeletal muscle mass and adiposity cross-sectional area) was quantified using thoracic computed tomography with sliceOmatic (TomoVision, Magog, QC, Canada) software. Body mass index was calculated. Association of body composition measures and 6MWD with clinical outcomes was evaluated using multivariable regression models.

The study included 127 patients (42% men), aged 58 ± 14 years; body mass index was 31 ± 7 kg/m² and 6MWD was 361 ± 165 m). Muscle and 6MWD were associated with disease severity measures. Of those surviving hospitalization (n = 125), a greater 6MWD was associated with a shorter hospital stay (1.9 median days per 100 m; p < .001) and higher likelihood of being discharged directly home from hospital (odds ratio, 2.1 per 100 m; P = .004), independent of age, sex, and body mass index. Those with a lower preoperative 6MWD (per 100 m) had a greater increase in their postoperative 6MWD (52 m; P < .0001), independent of age, sex, and body mass index. Body composition measures were not associated with hospital outcomes or exercise capacity in the first year postoperatively.

Exercise capacity was a more prognostic marker of PEA outcomes compared with body composition. Future research is needed to explore pre-PEA rehabilitation strategies.