Risk Factors for Target Vessel Re-intervention After Balloon Pulmonary Angioplasty in Inoperable Chronic...

This study aims to identify the risk factors of re-intervention on targeted vessels after balloon pulmonary angioplasty (BPA) in patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH).

We retrospectively analyzed consecutive patients with inoperable CTEPH undergoing BPA at a single center. Targeted vessels and patients were classified according to whether re-intervention occurred. Mixed-effects logistic regression with a patient-level random intercept was used to identify predictors of re-intervention. The optimal threshold was determined by ROC analysis. Time to re-intervention was described by vessel-level Kaplan-Meier curves, and model performance was evaluated using the C-statistic, bootstrap internal validation, calibration plots, and decision-curve analysis.

We enrolled 62 patients with inoperable CTEPH who underwent 168 BPA sessions and 412 targeted vessels. Re-intervention occurred in 98/412 vessels (23.8%) across 32/62 patients (51.6%). In mixed-effects logistic regression, percent diameter stenosis remained independently associated with re-intervention (OR = 1.38, 95% CI 1.23-1.54, p = 0.023), and pulmonary flow grade showed a strong graded association (p < 0.001). The combined model (percent diameter stenosis + pulmonary flow grade) showed good discrimination for re-intervention (AUC = 0.81, 95% CI 0.75-0.86). Kaplan-Meier curves demonstrated higher re-intervention rates in vessels with higher percent diameter stenosis and in those with pulmonary flow grade 0-1 (both log-rank p < 0.001). The combined model also had acceptable calibration and greater net benefit than percent diameter stenosis or pulmonary flow grade alone.

Baseline pulmonary flow grade and percent diameter stenosis independently predict re-intervention after BPA. Vessels lacking high-grade flow and exhibiting greater stenosis may benefit from closer follow-up and staged dilatation strategies.