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/m2, 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.