Association between congenital thrombophilia and outcomes in pulmonary embolism patients

The prevalence and distribution of congenital thrombophilia is still unclear in patients with pulmonary embolism (PE). We aimed to determine the prevalence and clinical characteristics of congenital thrombophilia in PE patients and their subsequent outcomes. A prospective observational study was conducted from May 2013 to June 2018. A total of 436 consecutive patients with PE were enrolled. All patients were tested for protein C, protein S, antithrombin III (ATIII), factor V Leiden, and prothrombin G20210A mutations. The median follow-up duration was ∼800 days (range, 11-1872 days). Congenital thrombophilia was diagnosed in 31 of 436 (7.1%) patients; 12 patients had protein C deficiency (2.8%), 13 had protein S deficiency (3.0%), 5 had ATIII deficiency (1.1%), and 1 had (0.2%) factor V Leiden. Age ≤50 years at the first episode (odds ratio [OR], 5.43; 95% confidence interval [CI], 2.35-13.52; P < .001) and male sex (OR, 2.67; 95% CI, 1.15-6.78; P = .03) were 2 independent predictors of congenital thrombophilia in PE patients. There was no statistically significant difference in the prevalence of congenital thrombophilia between PE patients with and without risk factors (P = .58). We also found no significant difference in the risk of having a composite outcome of death or recurrent venous thromboembolism between patients with and without congenital thrombophilia (hazard ratio, 0.18; 95% CI, 0.02-5.69; P = .08). These results suggest that age and male sex are independently associated with the occurrence of congenital thrombophilia in PE patients but that congenital thrombophilia is not associated with the risk of recurrence or death with anticoagulation therapy.