Predictors and Outcomes of Acute Kidney Injury After Pulmonary Endarterectomy: A Single-Centre Retrospective Study

Pulmonary endarterectomy (PEA) is the established curative treatment for chronic thromboembolic pulmonary hypertension (CTEPH). Despite favourable haemodynamic outcomes, postoperative acute kidney injury (AKI) is a frequent and clinically relevant complication, reported in 7.1% to 57.5% of PEA series.

This retrospective observational study was conducted at a tertiary referral centre for PEA. Of 126 consecutive adult patients screened between January 2018 and December 2020, 117 were included in the primary analysis after applying predefined exclusion criteria and excluding one patient with insufficient postoperative renal data for KDIGO staging.

AKI was defined according to KDIGO 2012 criteria using both serum creatinine and urine output assessed over 48 hours. Four separate multivariable logistic regression models were constructed: Model A assessed preoperative variables; Model B assessed intraoperative time variables including ECC duration, DHCA duration and ACC time entered simultaneously; Model C assessed clinical and postoperative variables; and Model D was a parsimonious combined model incorporating variables identified as independent determinants across Models A through C.

Model discrimination was evaluated using receiver operating characteristic analysis with 95% confidence intervals estimated by non-parametric bootstrapping. Model calibration was assessed using the Hosmer-Lemeshow test, and bootstrap internal validation with 1000 resamples was used to estimate optimism-corrected AUC for the combined model. Linearity of the association between ECC duration and AKI was examined using restricted cubic spline modelling.

ECC duration, rather than DHCA or aortic cross-clamp duration, was the intraoperative time variable independently associated with AKI. Age was the principal preoperative determinant, and early postoperative albumin was independently associated with lower AKI odds. Despite comparable haemodynamic improvement in both groups, 30-day mortality was significantly higher in patients who developed AKI.