['The safety of β-blockers in patients with isolated right ventricular failure because of pulmonary arterial hypertension (PAH) is unclear.', 'We studied 564 PAH patients (total cohort) referred to our center from 1982 to 2013. Propensity score-matching was used to match pairs of PAH patients with and without β-blocker use (matched cohort). We compared all-cause mortality between the groups in the total cohort and the matched cohort using bootstrap validation, Kaplan-Meier, and Cox proportional hazard analyses. Seventy-one of the 564 patients in the total cohort were on β-blockers. They were older, had higher prevalence of comorbidities, and were more often on diuretics, digoxin, and angiotensin converting enzyme inhibitors. The severity of PAH and right ventricular failure was similar between those with and without β-blocker use. After propensity matching, 63 patients with β-blocker use were compared with 51 patients without β-blocker use. During a median follow-up time of 4.8 years, there were 339 (60%) deaths in the total cohort and 70 deaths (61%) in the matched cohort. There was no difference in absolute mortality between those with and without β-blockers (P=0.71). β-Blocker use was not associated with increased all-cause mortality in the total cohort after adjusting for propensity score (adjusted hazard ratio, 1.0; 95% confidence interval, 0.7-1.5) and in the matched cohort (hazard ratio, 1.2; 95% confidence interval, 0.8-2.0).'] Is β-blocker therapy associated with adverse outcomes in patients with pulmonary arterial hypertension : a propensity score analysis?