Effect of pulmonary hypertension on exercise tolerance in patients with COPD: a prognostic systematic review and meta-analysis
Rodrigo Torres‐Castro, Elena Gimeno‐Santos, Jordi Vilaró, Marta Roqué i Figuls, Jorge Moisés, Luis Vasconcello‐Castillo, Tanya Orizaga, Joan Albert Barberà, Isabel Blanco
Abstract
Background Pulmonary hypertension (PH) is a frequent complication in patients with COPD. Objective To determine if, in patients with COPD, the presence of PH decreases exercise tolerance. Methods We included studies that analysed exercise tolerance using a cardiopulmonary exercise test (CPET) in patients with COPD with PH (COPD-PH) and without PH (COPD-nonPH). Two independent reviewers analysed the studies, extracted the data and assessed the quality of the evidence. Results Of the 4915 articles initially identified, seven reported 257 patients with COPD-PH and 404 patients with COPD-nonPH. The COPD-PH group showed differences in peak oxygen consumption ( V ′ O 2peak ), −3.09 mL·kg −1 ·min −1 (95% CI −4.74 to −1.43, p=0.0003); maximum workload (W max ), −20.5 W (95% CI −34.4 to −6.5, p=0.004); and oxygen pulse (O 2 pulse), −1.24 mL·beat −1 (95% CI −2.40 to −0.09, p=0.03), in comparison to the group with COPD-nonPH. If we excluded studies with lung transplant candidates, the sensitivity analyses showed even bigger differences: V ′ O 2 , −4.26 mL·min −1 ·kg −1 (95% CI −5.50 to −3.02 mL·kg −1 ·min −1 , p<0.00001); W max , −26.6 W (95% CI −32.1 to −21.1 W, p<0.00001); and O 2 pulse, −2.04 mL·beat −1 (95% CI −2.92 to −1.15 mL·beat −1 , p<0.0001). Conclusion Exercise tolerance was significantly lower in patients with COPD-PH than in patients with COPD-nonPH, particularly in nontransplant candidates.