Impact of preoperative body mass index on long-term survival, quality of life, and functional outcomes after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension: Results from the UK National Cohort

Abstract

Background: Previous studies have demonstrated the safety of pulmonary endarterectomy (PEA) across body mass index (BMI) strata. However, long-term survival and patient-reported outcome measures by BMI strata remain unknown. We examined the impact of preoperative BMI on long-term survival, QOL, and functional outcomes for patients undergoing PEA for chronic thromboembolic pulmonary hypertension (CTEPH).

Methods: Retrospective review of 2,004 patients from the UK National Cohort between 2007 and 2021 undergoing PEA for CTEPH (mean pulmonary artery pressure >20 mm Hg and pulmonary vascular resistance >160 dynes). Patients were stratified into BMI<20, 20 to 29, 30 to 39, 40 to 49, and 50+. All-cause mortality was the primary outcome measure. Secondary outcome measures were 3- to 6-month postoperative hemodynamics, 6-minute walk distance (6MWD), New York Heart Association (NYHA) class, and Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) scores.

Results: Hemodynamics and 6MWD at 3 to 6 months were similar across BMI strata. Patients with BMI 50+ reported the highest incidence of postoperative NYHA III/IV limitation (53.3%, p < 0.001) and the highest residual symptom burden by CAMPHOR (p < 0.001). Five-year survival was lowest in patients with BMI 50+ (70.2%) and BMI<20 (73.4%), while highest in BMI 30 to 39 (88.2%, p = 0.008). Ten-year Kaplan-Meier estimates predicted the lowest survival in BMI 50+ and BMI<20.

Conclusions: PEA remains safe and effective for all patients regardless of BMI. Despite similar hemodynamic outcomes, patients with BMI 50+ are at the greatest risk of long-term all-cause mortality, and patients with BMI 50+ experience residual symptomatic limitation.

Keywords: body mass index; chronic thromboembolic pulmonary hypertension; obesity; patient-reported outcomes; pulmonary endarterectomy.