Introduction:
Pulmonary Arterial Hypertension (PAH) is a rapidly progressive disease with high mortality. We reviewed randomized controlled trials (RCTs) to evaluate the effect of pulmonary vasodilators on mortality in PAH.
Hypothesis:
Our objective was to determine the effect of PAH medicines on survival, and the impact of trial design on outcomes.
Methods:
We conducted a meta-analysis using MEDLINE, EMBASE, Cochrane Library, Web of Science, and Scopus (inceptions-May 2014) of all RCTs treating PAH with pulmonary vasodilators. Data on all-cause mortality and hemodynamics were abstracted. Summary relative risks (RR) and 95% confidence intervals (CI) for outcomes were calculated using a random effects model comparing various pulmonary vasodilators with control.
Results:
The analysis included 31 RCTs (6,271 patients, 77% female, range of mean age 30-57 years). Median follow up was 12 weeks (18 trials had ≤ 12 weeks follow up, and only 5 followed patients ≥ 6 months). When analyzed together (n = 14), FDA-approved pulmonary vasodilators demonstrated a mortality benefit with RR = 0.77 (95% CI = 0.60 - 099, I
2
= 0%). When analyzed by vasodilator type, prostacyclins were the only class of agents with significant mortality benefit, RR = 0.61 (95% CI 0.38-0.98, I
2
= 1%). Oral pulmonary vasodilators demonstrated no significant benefit on PAH mortality, RR = 0.85 (95% CI 0.65-1.12, I
2
= 0.0%), but we could not exclude a clinically meaningful benefit or harm. Many studies reported ≤1 death in at least one treatment arm. When we limited the analysis to only studies with at least 2 deaths in both treatment arms (n=9), the mortality benefit for pulmonary vasodilators was no longer significant (RR 0.86, CI 0.66-1.12, I
2
=0%), but the point estimate was below 1 and we could not exclude a reduction or increase in risk. For studies with the shorter follow up of ≤ 12 weeks, the RR of mortality for active treatment arm was 0.54 (95% CI 0.35-0.83), compared to trials with > 12 weeks of follow up where the RR of mortality was not significant at 0.91 (95% CI 0.67-1.22).
Conclusion:
There is an observed mortality benefit for prostacyclins in PAH. For the oral pulmonary vasodilators, there is no observed mortality benefit based on either design of trials, length of follow up or efficacy of the agents studied.
Long‐Term Outcomes in Patients With Connective Tissue Disease–Associated Pulmonary Arterial Hypertension in the Modern Treatment Era: Meta‐Analyses of Randomized, Controlled Trials and Observational Registries