Data on the magnitude of benefit of modern therapies for pulmonary arterial hypertension (PAH) in connective tissue disease (CTD)-associated PAH are limited. In this study, we performed meta-analyses of randomized, controlled trials (RCTs) and registries to quantify the benefit of these modern therapies in patients with CTD-PAH.
The PubMed and Embase databases were searched for articles reporting data from RCTs or registries published between January 1, 2000 and November 25, 2019. Eligibility criteria included multicenter studies with ≥30 CTD-PAH patients. For an RCT to be included, the trial had to evaluate an approved PAH therapy, and long-term risks of clinical morbidity and mortality or 6-minute walk distance had to be reported. For a registry to be included, survival rates had to be reported. Random-effects models were used to pool the data.
Eleven RCTs (total of 4,329 patients; 1,267 with CTD-PAH) and 19 registries (total of 9,739 patients; 4,008 with CTD-PAH) were included. Investigational therapy resulted in a 36% reduction in the risk of clinical morbidity/mortality events both in the overall PAH population (hazard ratio [HR] 0.64, 95% confidence interval [95% CI] 0.54, 0.75; P < 0.001) and in CTD-PAH patients (HR 0.64, 95% CI 0.51, 0.81; P < 0.001) as compared to control subjects. The survival rate was lower in CTD-PAH patients compared to all PAH patients (survival rate 62%, 95% CI 57, 67% versus 72%, 95% CI 69, 75% at 3 years). The survival rate in CTD-PAH patients treated primarily after 2010 was higher than that in CTD-PAH patients treated before 2010 (survival rate 73%, 95% CI 62, 81% versus 65%, 95% CI 59, 71% at 3 years).
Modern therapy provides a similar reduction in morbidity/mortality risk in patients with CTD-PAH when compared to the PAH population overall. Risk of death is higher in CTD-PAH patients than in those with PAH overall, but survival has improved in the last 10 years, which may be related to increased screening and/or new treatment approaches. Early detection of PAH in patients with CTD and up-front intensive treatment are warranted.