Association Between Body Mass Index and 30-Day Mortality in Patients with Pulmonary Hypertension Undergoing Non-cardiothoracic, Non-obstetric Surgery

Introduction Evidence regarding the association between body mass index (BMI) and outcomes in non-cardiothoracic, non-obstetric surgery patients with pulmonary hypertension (PHTN) is limited. We aimed to investigate the association between BMI and 30-day mortality in non-cardiothoracic, non-obstetric surgery patients with pulmonary hypertension. Material and Methods We performed a secondary analysis of non-cardiothoracic, non-obstetric procedures on patients with PHTN between 2007 and 2013 at a single institution. Multivariable logistic regression models were used to estimate the association between BMI and 30-day mortality. Interaction and stratified analyses were conducted according to age, sex, PHTN medical therapy, anticipated inpatient or outpatient post-procedure status, procedure length > 2 h, open surgical approach, and PHTN severity class. Results A total of 513 participants were included, with men accounting for 55.8% of the sample; the 30-day mortality was 1.9%. In the multivariate regression models, BMI was significantly associated with 30-day mortality after adjusting for potential covariates. A 1 kg/m 2 increase in BMI was associated with a 15% decrease in 30-day mortality (adjusted OR = 0.85, 95% CI: 0.73–0.98, P = 0.03). Stratified analyses indicated that this negative correlation was robust. Conclusions In this study, we found that low BMI is associated with increased risk of death in patients undergoing non-cardiothoracic, non-obstetric surgery requiring general anesthesia. Further studies are needed to confirm our findings. Graphical abstract