Comparison of treatment response in idiopathic and connective tissue disease-associated pulmonary arterial hypertension

Rennie L. Rhee, Nicole B. Gabler, Sapna Sangani, Amy Praestgaard, Peter A. Merkel, Steven M. Kawut

Research output: Contribution to journalArticlepeer-review

72 Scopus citations


Rationale: Studies suggest that patients with connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH) have a poorer treatment response to therapies for PAH compared with patients with idiopathic PAH (IPAH), but individual randomized controlled trials (RCTs) have been underpowered to examine differences within these subgroups. Objectives: To compare the effect of therapy for PAH in CTD-PAH versus IPAH. Methods: We obtained individual participant data from phase III placebo-controlled RCTs of therapies for PAH submitted to the U.S. Food and Drug Administration for drug approval. A treatment-bydiagnosis interaction term evaluated differences in treatment response between CTD-PAH and IPAH. Outcomes included change in 6-minute-walk distance (Δ6MWD) from baseline to 12 weeks, clinical worsening, and all-cause mortality. Measurements and Main Results: The study sample included 827 participants with CTD-PAH and 1,935 with IPAH from 11 RCTs. Patients with CTD-PAH had less improvement in 6MWD when assigned to active treatment versus placebo compared with patients with IPAH (difference in treatment effect on Δ6MWD in CTD-PAH vs. IPAH, 217.3 m; 90% confidence interval, 231.3 to 23.3; P for interaction = 0.043). Treatment was less effective in reducing the occurrence of clinical worsening in CTD-PAH versus IPAH (P for interaction = 0.012), but there was no difference in the placebo-adjusted effect of treatment on mortality (P for interaction = 0.65). Conclusions: Treatment for PAH was less effective in CTD-PAH compared with IPAH in terms of increasing 6MWD and preventing clinical worsening. The heterogeneity of treatment response supports the need for identifying therapies that are more effective for CTDPAH.

Original languageEnglish (US)
Pages (from-to)1111-1117
Number of pages7
JournalAmerican journal of respiratory and critical care medicine
Issue number9
StatePublished - Nov 1 2015
Externally publishedYes


  • Clinical trial
  • Meta-analysis
  • Pulmonary hypertension

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine
  • Critical Care and Intensive Care Medicine


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