Letter by Nikpour et al Regarding Article, “Effect of Warfarin Treatment on Survival of Patients With Pulmonary Arterial Hypertension (PAH) in the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL)”

Abstract

We thank Nikpour et al for highlighting their observational, retrospective study, which suggested, in a multivariate analysis, that anticoagulation of at least 6 months was associated with improved survival in connective disease–associated pulmonary arterial hypertension (PAH).1 Their results, indeed, are contrary to our US-based (Registry to Evaluate Early and Long-Term PAH Disease Management [REVEAL]) and the EU-based (Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension [COMPERA]) databases,2,3 both of which suggested lack of (or even possible harm with) anticoagulation in this high-risk population. Acknowledging that these analyses are limited by the lack of randomization, the study by Ngian et al also suffers from several flaws: lack of definition of survival analysis (start at entry in the …