RT Journal Article
SR Electronic
T1 Warfarin in Systemic Sclerosis-associated and Idiopathic Pulmonary Arterial Hypertension. A Bayesian Approach to Evaluating Treatment for Uncommon Disease
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP 276
OP 285
DO 10.3899/jrheum.110765
VO 39
IS 2
A1 SINDHU R. JOHNSON
A1 JOHN T. GRANTON
A1 GEORGE A. TOMLINSON
A1 HADDAS A. GROSBEIN
A1 THAOLAN LE
A1 PETER LEE
A1 M. ELIZABETH SEARY
A1 GILLIAN A. HAWKER
A1 BRIAN M. FELDMAN
YR 2012
UL http://www.jrheum.org/content/39/2/276.abstract
AB Objective. Warfarin is recommended in systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH) and idiopathic PAH (IPAH) to improve survival. There is no evidence to support this in SSc-PAH and the evidence in IPAH is conflicting. We evaluated the ability of warfarin to improve survival using 2 large SSc-PAH and IPAH cohorts. Methods. The effect of warfarin on all-cause mortality was evaluated. Bayesian propensity scores (PS) were used to adjust for baseline differences between patients exposed and not exposed to warfarin, and to assemble a matched cohort. Bayesian Cox proportional hazards models were constructed using informative priors based on international PAH expert elicitation. Results. Review of 1138 charts identified 275 patients with SSc-PAH (n = 78; 28% treated with warfarin) and 155 patients with IPAH (n = 91; 59% treated with warfarin). Baseline differences in PAH severity and medications were resolved using PS matching. In the matched cohort of 98 patients with SSc-PAH (49 treated with warfarin), the posterior median hazard ratio (HR) was 1.06 [95% credible interval (CrI) 0.70, 1.63]. In the matched cohort of 66 patients with IPAH (33 treated with warfarin), the posterior median HR was 1.07 (95% CrI 0.57, 1.98). The probability that warfarin improves median survival by 6 months or more is 23.5% in SSc-PAH and 27.7% in IPAH. Conversely, there is a > 70% probability that warfarin provides no significant benefit or is harmful. Conclusion. There is a low probability that warfarin improves survival in SSc-PAH and IPAH. Given the availability of other PAH therapies with demonstrable benefits, there is little reason to use warfarin to improve survival for these patients.