The Role of Medical Therapy Before and After Balloon Pulmonary Angioplasty: CTEPH AC Registry Across Japan

We aimed to evaluate the role of medical therapy before and after balloon pulmonary angioplasty (BPA) for non‐operable chronic thromboembolic pulmonary hypertension (CTEPH) in the modern management era. This Japanese nationwide, multicenter, prospective observational registry, including 37 centers, analyzed data newly registered from August 2018–December 2023. Pretreatment before BPA was analyzed in patients who were treatment naïve or received medical therapy only at registration ( n = 557). De‐escalation or escalation of medical therapy after BPA was analyzed in patients who underwent BPA ( n = 966). The BPA pretreatment analysis in 557 patients showed that approximately 70% of the patients received medical therapy, of which 18% received combination therapy. Patients who received monotherapy or combination therapy had more severe baseline hemodynamics than those who did not. The 3‐year survival did not significantly differ between the no, mono, and combination pretreatment groups (94%, 98%, and 97%, respectively; p = 0.852). The BPA post‐treatment analysis in 966 patients showed that 20% of patients underwent de‐escalation of medical therapy. Patients with de‐escalation of medical therapy had lower mean pulmonary artery pressure (PAP) (20.9 ± 5.8 vs. 24.1 ± 7.3 mmHg, p < 0.01); however, they had a lower cardiac index at last follow‐up compared to patients without de‐escalation (2.66 ± 0.61 vs. 2.84 ± 0.70 L/min/m 2 , p = 0.01). Patients with severe disease tended to undergo pre‐treatment before BPA; however, patient survival did not differ across pretreatment types. De‐escalation of medical therapy after BPA can affect cardiac index. Therefore, de‐escalation or continuation of medical therapy should be carefully considered even after mean PAP normalizes after BPA.