Optimal Endpoint for Balloon Pulmonary Angioplasty Based on Distal Pulmonary Artery Pressure Waveforms

Balloon pulmonary angioplasty (BPA) is an established therapy for chronic thromboembolic pulmonary hypertension (CTEPH), but its optimal lesion-specific endpoint remains unclear. This study aimed to clarify the optimal endpoint for pressure-guided BPA (PG-BPA) based on the distal pulmonary artery pressure waveform (Pd-WF).

We retrospectively analyzed 23 patients with CTEPH who underwent 118 PG-BPA sessions involving 424 lesions. The pressure ratio (PR; i.e., the distal-to-proximal mean pulmonary artery pressure ratio) and Pd-WF were evaluated for each lesion. Complete arterialization of the Pd-WF (Pd-CA), defined as a distal-to-proximal pulse pressure ratio >0.5, was used as the physiological endpoint. PR improved significantly from a median of 0.52 (interquartile range [IQR] 0.39-0.66) to 0.80 (IQR 0.73-0.89) after balloon dilatation (P<0.001), and Pd-CA was achieved in 63.9% of lesions. Significant decreases were seen in both mean pulmonary artery pressure (median 34 [IQR 26-50] to 19 [IQR 18-25] mmHg) and pulmonary vascular resistance (median 8.3 (IQR 5.6-13.6) to 2.7 (IQR 2.1-4.0 Wood units; both P<0.0001). The number of lesions achieving Pd-CA correlated with the percentage reduction in pulmonary vascular resistance (r=-0.52, P=0.011). Receiver operating characteristic analysis identified a PR cut-off value of 0.77 for predicting Pd-CA (area under the curve 0.86; P<0.0001).

Pd-CA may represent an optimal physiological endpoint for PG-BPA and enable lesion-level optimization beyond angiographic assessment alone.