Thrombophilia testing in patients with venous thromboembolism. Findings from the RIETE registry

Abstract

Background: There is scarce information on the management habits with regard to thrombophilia testing in patients with venous thromboembolism (VTE).

Patients and methods: RIETE is an ongoing registry of consecutive patients with symptomatic VTE. Aimed to estimate the extent to which thrombophilia test ordering patterns are consistent with the recommendations by a 2005 international consensus statement, we retrospectively compared the clinical characteristics of all patients tested for thrombophilia and those who were not tested.

Results: Of 21367 patients enrolled, 4494 (21%) were tested for thrombophilia: 1456 (32%) tested positive, 3038 (68%) negative. The most common abnormalities were: Factor V Leiden (N=376), antiphospholipid syndrome (N=289), and prothrombin G20210A (N=263). Overall, 12740 (60%) patients met one or more criteria of the consensus statement: 7894 (37%) had a first episode of idiopathic VTE; 4013 (19%) were aged <50 years; 133 (0.6%) were pregnant women; 758 (3.5%) were using estrogens; 3375 (16%) had recurrent VTE. Of them, 3618 (28%) underwent thrombophilia tests, 34% of whom tested positive. The percentage of patients testing positive was significantly higher in those aged <50 years, with no differences between idiopathic or secondary, first episode or recurrent VTE. Finally, 876 (10%) of the 8627 (40%) patients meeting no criteria were tested. Of these, 208 (24%) tested positive.

Conclusions: Twenty-eight percent of patients meeting one or more criteria for thrombophilia testing, and 10% of those with no criteria were actually tested. Thus, a substantial proportion of thrombophilia ordering is not consistent with the recommendations made by the consensus statement.