Balloon pulmonary angioplasty for symptomatic chronic thromboembolic disease without pulmonary hypertension at rest

Background: Patients with chronic thromboembolic disease (CTED)have chronic thromboembolic obstructions of the pulmonary arteries with exercise intolerance, but without signs of pulmonary hypertension at rest. We investigated the efficacy of balloon pulmonary angioplasty (BPA)for CTED patients. Methods: Fifteen CTED patients (4 males, 11 females)who underwent BPA were enrolled. The inclusion criteria were 1)chronic thromboembolic obstructions of the pulmonary artery identified on ventilation–perfusion scans and pulmonary angiography, 2)WHO functional class II or greater, and 3)mean PAP of <25 mmHg as measured by right heart catheterization. This study excluded patients with CTEPH at diagnosis. Results: At the 6-month follow-up after the final BPA session, hemodynamics and 6-min walk distance were significantly improved. Although more than half of the patients were prescribed home oxygen therapy before BPA due to O₂ desaturation with exercise, the use ratio of home oxygen therapy was reduced at the time of follow-up (from 53% to 7%; P = 0.01). Furthermore, cardiopulmonary exercise tests during right heart catheterization demonstrated that BPA could ameliorate an abnormal pulmonary vascular response to exercise. Conclusions: BPA can produce favorable outcomes in patients with CTED. Prospective, larger randomized clinical trials are needed to further investigate this treatment strategy.