Is Pulmonary Artery Pulsatility Index (PAPi) a Predictor of Outcome After Pulmonary Endarterectomy?

Background: Pulmonary endarterectomy (PEA) is the gold standard therapy for chronic thromboembolic pulmonary hypertension (CTEPH). Traditionally, pulmonary vascular resistance (PVR) represents the main prognostic factor after surgery. The pulmonary artery pulsatility index (PAPi) has been proposed for the assessment of RV in advanced heart failure, but it has never been applied in CTEPH patients. The aim of the present study is to describe PAPi in patients who underwent PEA, before and after surgery, and to define its predictive impact on postoperative outcomes. Methods: We retrospectively reviewed 188 consecutive adult patients who underwent PEA, between December 2003 and December 2021. PAPi was calculated for 186 patients and reported. Patients were partitioned in two groups using median preoperative PAPi as cutoff value: Group 1 with PAPi ≤ 8.6 (n = 94) and Group 2 with PAPi > 8.6 (n = 92). The propensity-score-matched analysis identified 67 pairs: Early outcomes were compared between two groups. Results: Mean preoperative PAPi was 10.3 ± 7.2. Considering matched populations, no differences emerged in terms of postoperative hemodynamics; Group 1 demonstrated higher 90-day mortality significance (10.4% vs. 3.0%, p = 0.082); the need for mechanical circulatory support (MCS) was similar, but successful weaning was unlikely (25% vs. 85.7%, p = 0.032). Conclusions: Mean PAPi in the CTEPH population is higher than in other diseases. Low PAPi (≤8.6) seems to be associated with lower postoperative survival and successful weaning from MCS.