Anticoagulation and Survival in Pulmonary Arterial Hypertension: Results From the COMPERA Registry

Study Questions:

Despite limited evidence, anticoagulation has been recommended for patients with idiopathic pulmonary arterial hypertension (IPAH) since the 1990s. Is anticoagulation justified in IPAH in the modern management era, and should it be extended to patients with other forms of pulmonary arterial hypertension (PAH)?


The authors used COMPERA, an ongoing European pulmonary hypertension registry that began in 2007. Data collected included all standard clinical and measured parameters that were considered to have the potential for predicting outcome. Survival rates of patients with IPAH and other forms of PAH were compared by the use of anticoagulation. The sample consisted of 1,283 consecutively enrolled patients with newly diagnosed PAH. Anticoagulation was used in 66% of 800 patients with IPAH, and in 43% of 483 patients with other forms of PAH.


During the 3-year follow-up period, there were 75 deaths (14.2%) in the anticoagulation group versus 57 deaths (21.0%) in the no anticoagulation group (survival advantage, p = 0.006), despite that the patients in the anticoagulation group were older, and had worse functional class and baseline hemodynamics. The survival difference at 3 years remained statistically significant (p = 0.017) in a matched-pair analysis of n = 336 IPAH patients. The beneficial effect of anticoagulation on survival of IPAH patients was confirmed by Cox multivariable regression analysis (hazard ratio, 0.79; 95% confidence interval, 0.66-0.94). In contrast, the use of anticoagulants was not associated with a survival benefit in patients with other forms of PAH.


The present data suggest that the use of anticoagulation is associated with a survival benefit in patients with IPAH, supporting current treatment recommendations. The evidence remains inconclusive for other forms of PAH.


While a placebo-controlled trial designed to assess the safety and efficacy of anticoagulation in IPAH has been needed, considering the high mortality in IPAH despite modern therapy and the 20% survival advantage in this observation study, it will be difficult to design such a study with appropriate informed consent. Further, trials assessing new therapies for PAH will have to consider anticoagulation as an important variable, and possibly include it as standard therapy.

Clinical Topics: Heart Failure and Cardiomyopathies, Prevention, Pulmonary Hypertension and Venous Thromboembolism, Acute Heart Failure, Pulmonary Hypertension, Hypertension

Keywords: Follow-Up Studies, Standard of Care, Hemodynamics, Heart Diseases, Incidence, Prognosis, Registries, Blood Coagulation, Survival Rate, Heart Failure, Hypertension, Pulmonary, Confidence Intervals, Informed Consent, Regression Analysis, Hypertension

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