Comparison of Hemodynamic Responses to Balloon Pulmonary Angioplasty in Chronic Thromboembolic Pulmonary Hypertension in Japan and the Netherlands: a multicenter study

BACKGROUND: Mean pulmonary arterial pressures (mPAP) following balloon pulmonary angioplasty (BPA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) had consistently been lower in Japan than in non-Japanese cohorts. RESEARCH QUESTION: What factors are associated with higher mPAP following BPA? STUDY DESIGN AND METHODS: This retrospective multicenter study screened 200 consecutive patients with CTEPH who underwent BPA at two centers in the Netherlands and two in Japan. After excluding patients with prior pulmonary endarterectomy or lacking follow-up hemodynamic data, 138 patients were analyzed. Comorbidities, lesion distribution and morphology, PH medication, procedural details, and hemodynamic parameters were compared between the two countries. Multivariable regression analysis was performed to identify factors associated with high mPAP at follow-up. RESULTS: = 0.03), with a lower mPAP at follow-up (22 ± 1 vs. 30 ± 1 mmHg, p < 0.01). Independent factors associated with higher follow-up mPAP included lower DLCO, higher right atrial pressure, higher pulmonary arterial wedge pressure at follow-up, a greater number of BPA sessions, and less frequent use of intermediate-sized balloons. INTERPRETATION: Higher mPAP following BPA was associated with impaired lung and left heart function, and procedural parameters, rather than nationality or lesion distribution. These findings suggest that occult cardiopulmonary comorbidities are important contributors to international differences in BPA outcomes, while differences in procedural practice may play a role.