P1344Balloon pulmonary angioplasty ameliorates long-term survival of patients with inoperable chronic thromboembolic pulmonary hypertension

Abstract

Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by chronic and mechanical thromboembolic obstruction of pulmonary arteries with high mortality without intervention. Although pulmonary endarterectomy (PEA) is the established treatment for CTEPH, approximately 50% of patients are deemed inoperable and 25% have persistent pulmonary hypertension even after PEA. Recently, balloon pulmonary angioplasty (BPA) has been shown to markedly improve both exercise capacity and pulmonary hemodynamics in patients with inoperable CETPH. The aim of this study was to evaluate the long-term efficacy of BPA in patients with inoperable CTEPH. Methods and results: From January 1995 to December 2014, 99 CTEPH patients were admitted to our hospital. Since BPA was instituted as the first-line therapy for inoperable CTEPH in mid-2009 in our hospital, we divided them into 2 groups based on their diagnostic era; the historical control (HC) group diagnosed and treated before July 2009 (N=35; mean age, 62 years; M/F = 30/5) and the BPA group diagnosed and treated after August 2009 (N=64; mean age, 64 years; M/F= 49/15). Both groups were routinely treated with conventional and specific pulmonary vasodilators. We compared baseline characteristics, hemodynamics and long-term survival between the 2 groups. There was no significant difference in baseline parameters, including age, sex, WHO functional class or serum BNP levels between the 2 groups. In the BPA group, 51/64 patients underwent BPA, with a mean BPA session number of 4.6 (range, 1-10). BPA dramatically improved pulmonary hemodynamics including mean pulmonary arterial pressure, mean right atrial pressure, cardiac index, and pulmonary vascular resistance in those patients. BPA also improved WHO functional class and exercise capacity. In the HC group, 12 patients died during the follow-up period [median, 53 months, interquartile range (IQR), 26-80)], whereas only one patient died in the PTPA group [median, 23 months; IQR, 13-39]. Kaplan-Meier analysis showed that the survival rate was significantly better in the BPA group compared with the HC group (log-rank P=0.02) (Figure). Estimated 3- and 5-year survival rates were both 98% in the BPA group, and 86% and 77%, respectively, in the HC group. Univariate Cox hazard analysis revealed that mortality was significantly associated with advanced WHO functional class, CKD ≥ stage 3, elevated mRAP, and BPA therapy. The multiple Cox hazard analysis showed that both age (hazard ratio 1.07, P=0.02) and the HC group (hazard ratio 9.2, P=0.01) were independent predictor of mortality. Conclusions: These results indicate that BPA has a beneficial impact on longterm survival in patients with inoperable CTEPH. (Figure Presented).