Objective

To explore the factors affecting patient outcomes in pulmonary artery thromboendarterectomy (PTE) under deep hypothermic circulatory arrest (DHCA) and cardiopulmonary bypass (CPB) support and to provide a reference for further improving the effect of PTE.

Methods

Eighty-five patients with chronic thromboembolic pulmonary hypertension (CTEPH) who underwent PTE under DHCA and CPB support at Beijing Anzhen Hospital from January 2015 to October 2023 were enrolled, including 56 males (65.88%) and 29 females (31.42%), aged 23–75 years (mean 57.05 ± 15.03 years). The diagnostic criteria for the patients with CTEPH met with the diagnostic criteria described in the 2022 ESC/ERS guidelines for the diagnosis and treatment of pulmonary hypertension. Based on whether major adverse events (MAE) occurred during the hospitalization after PTE (MAE was defined as all-cause death and major complications related to surgery), patients were divided into the MAE group (n = 36) and the non-MAE group (Control group, n = 49). The differences in the preoperative and intraoperative indicators were compared between the two groups. A logistic regression analysis, receiver operating characteristic (ROC) curve and area under the curve (AUC) analysis were performed to identify risk factors affecting the outcomes of PTE.

Results

PTE under DHCA and CPB support was performed in 85 cases. Duration of CPB was 214.84 ± 49.08 min. The duration of aortic cross-clamping (ACC) was 125.88 ± 24.22 min. The duration of DHCA was 24.36 ± 7.25 min, and the number of DHCA episodes was 3.14 ± 1.52. After the PTE 36 patients (42.35%) experienced one or more MAEs, including 7 all-cause deaths (8.24%), 14 cases (16.47%) with reperfusion pulmonary edema, 20 cases (23.53%) with residual pulmonary hypertension (defined as mPAP > 25 mmHg), 6 cases (7.06%) with pulmonary hemorrhage syndrome, 12 cases (14.12%) with pneumonia, 12 cases (14.12%) with delirium, 6 cases (7.06%) with pericardial tamponade, 12 cases (14.12%) with pleural effusion, and 6 cases (7.06%) with acute kidney injury. When compared with the factors affecting the patient outcomes between two groups, significant differences (P < 0.05) were observed in the preoperative factors including gender (female), body mass index, heart failure with New York Heart Association (NYHA) class Ⅲ-Ⅳ, tricuspid valve pressure gradient value, B-type natriuretic peptide (BNP) value, left ventricular ejection fraction (LVEF), 6-minute walking distance, mean pulmonary arterial pressure (mPAP), systolic pulmonary artery pressure (sPAP), pulmonary vascular resistance (PVR), pulmonary artery wedge pressure (PAWP), and cardiac index. Significant intraoperative differences (P < 0.05) were also found in the parameters including CPB time, ACC time, DHCA time, the longest single DHCA time, maximum temperature difference between nasopharynx and bladder, and peak value of lactic acid. However, logistic regression analysis, receiver operating characteristic (ROC) curve, and area under the curve (AUC) analysis revealed that among these factors, only sPAP, PVR, PAWP, CPB time, DHCA time, and the longest single DHCA time were independent risk factors for MAE.

Conclusion

The results of this study indicate that preoperative right heart catheterization parameters—including mPAP, PAWP, and PVR—and intraoperative parameters—such as prolonged CPB time, DHCA time, and the longest single DHCA time—are independent predictors of MAE after PTE. Therefore, careful management of these parameters may further improve patient outcomes.