Background: Pulmonary hypertension (PH) patients are at higher risk of postoperative complications. We analyzed the association of PH with 30-day postoperative pulmonary complications (PPC). Methods: A single-center propensity score overlap weighting (OW) retrospective cohort study of 164 patients with mean pulmonary artery pressure (mPAP) of >20 mmHg within 24 months of procedure and a control cohort (N=1981), undergoing elective inpatient abdominal surgery or endoscopic procedures under general anesthesia. The primary outcome was PPC, and the secondary outcomes were PPC sub-composites; respiratory failure (RF), pneumonia (PNA), aspiration pneumonia/pneumonitis (ASP), pulmonary embolism (PE), length of stay (LOS), and 30-day mortality. Results: PPC was higher in the PH cohort (29.9% vs. 11.2%, p<0.001). When sub-composites were analyzed, higher rates of RF (19.3% vs. 6.6%, p<0.001) and PNA (11.2% vs. 5.7%, p=0.01) were observed. After OW, PH was still associated with higher PPC [RR 1.66, 95% CI (1.05 - 2.71), p=0.036] and increased LOS (median 8.0 days vs. 4.9 days) but not 30-day mortality. Sub-cohort analysis showed no difference in PPC between pre- and post-capillary PH patients. Conclusions: After covariate balancing, PH was associated with a higher risk for PPC and pro-longed LOS. This elevated PPC risk should be considered during preoperative risk assessment.

We have not received any external funding specifically for this research, but the following authors have external fundings for their other research projects. Z.C. reported receiving study grants from Shape Medical Systems, Inc. P.H. reported receiving research support grants from Edwards Lifesciences and consulting and royalty fees from Baudax Bio, Fire1Foundry, Cardiage LLC and Edwards Lifesciences.

We have not received any external funding specifically for this research, but the following authors have external fundings for their other research projects. Z.C. reported receiving study grants from Shape Medical Systems, Inc. P.H. reported receiving research support grants from Edwards Lifesciences and consulting and royalty fees from Baudax Bio, Fire1Foundry, Cardiage LLC and Edwards Lifesciences.

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The study was conducted in accordance with the Declaration of Helsinki, and approved by the Institutional Review Board of Yale University (protocol code 2000032516 and date of approval 3/19/2022).

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