ACE and idiopathic pulmonary fibrosis: ACE inhibitor use was associated with improved survival, independent of coexisting comorbidities, in patients with IPF (hazard ratio, 0.82; 95% CI, 0.75-0.91; P ≤ .001), but a similar association was not found in patients with COPD (hazard ratio, 1.09; 95% CI, 0.96-1.23; P = .180).<h4>Interpretation</h4>In this study, ACE inhibitor therapy was independently associated with reduced all-cause mortality in IPF but not in COPD.