Medical therapy versus balloon angioplasty for CTEPH: a systematic review and meta-analysis

Background: A significant number of chronic thromboembolic pulmonary hypertension (CTEPH) patients will have an inoperable disease. Medical therapy and balloon pulmonary angioplasty (BPA) have provided alternate therapeutic options for patients with inoperable CTEPH, although there are a limited number of published studies examining the outcomes. Thus, our study aims to evaluate and compare the efficacy of medical therapy and BPA in patients with inoperable CTEPH. Methods: An electronic search of six databases was performed and the search results were screened against established criteria for inclusion into this study. Data was extracted and meta-analytical techniques were used to analyse the data. Results: Pooled data from RCTs revealed that medical therapy, compared with a placebo, was associated with a significant improvement of at least one functional class (P = 0.038). With regards to pulmonary haemodynamics, medical therapy also resulted in a significant reduction in both mean pulmonary arterial pressure (mPAP) (P = 0.002) and pulmonary vascular resistance (PVR) (P < 0.001). From the included observational studies, the 6-minute walk distance (6MWD) significantly increased following medical therapy by an average of 22.8% (P < 0.001). The pooled improvement in 6MWD was found to be significantly higher in the BPA group when compared to medical therapy for CTEPH (P = 0.001). Pooled data from available observational studies of medical therapy or BPA all demonstrated significant improvements in mPAP and PVR for pre versus post intervention comparisons. The improvement in mPAP (P = 0.002) and PVR (P = 0.002) were significantly greater for BPA intervention when compared to medical therapy. Conclusions: High-quality evidence supports the use of targeted medical therapy in improving haemodynamics in patients with inoperable CTEPH. There is only moderate-quality evidence from observational studies supporting the efficacy of BPA in improving both haemodynamics and exercise capacity. Further RCTs and prospective observational studies comparing medical therapy and BPA in patients with inoperable CTEPH are required.