Long-term outcomes of pulmonary thromboendarterectomy: predictors of residual pulmonary hypertension

Introduction. Pulmonary thromboendarterectomy (TEE) is the gold standard of treatment for patients with chronic thromboembolic pulmonary hypertension (CTEPH). Residual pulmonary hypertension (PH) may worsen prognosis of disease after TEE, and incidence reaches 40%. Identification of risk factors of residual PH in long-term period after surgery is an actual issue. Material and methods. A retrospective observational study included 58 patients with CTEPH who underwent TEE in 2016—2020. We studied long-term results and obtained data in 96.6% patients (n=56); median follow-up was 66 (57—78) months. The primary endpoint was residual PH as mPAP ≥25 mmHg according to right heart catheterization (RHC) or sPAP ≥40 mmHg according to echocardiography. Statistical analysis was performed. Sensitivity and specificity of predictors of residual PH were analyzed using ROC analysis (cut-off value was established using Youden index). Results. The 5-year cumulative survival rate was 94.6%. Recurrence of pulmonary embolism was diagnosed in 1 patient (1.7%). Among survivors, residual PH was diagnosed in 12 (22.6%) patients. Patients in this group were older (61.2±8.7 vs. 49.8±13.2 years, p=0.007) and had higher PVR on the first day after TEE (361.8±130.3 vs. 250.7±82.2 dynes/sec/cm-5, p<0.001) with a cut-off PVR 321 dyne/sec/cm-5 (sensitivity 75.0%, specificity 80.5%). Patients with residual PH were treated with balloon angioplasty of pulmonary arteries (n=4, 33.3%) and PAH-specific therapy (n=10, 83.3%). Conclusion. The incidence of residual PH after successful TEE within 5 years was 22.6%. Predictors of residual PH were older age and high PVR in early postoperative period. PVR>321 dynes/sec/cm-5 on the 1st day after surgery is associated with high risk of residual PH.