The utility of hereditary thrombophilia testing among patients with unprovoked venous thromboembolism.

Abstract

Hereditary-thrombophilia (HT) testing is often sent during the evaluation of patients with unprovoked venous thromboembolism (VTE). This remains a frequent practice even though the results of such testing are often of unclear practical significance. We conducted a multicenter retrospective study to assess whether HT is associated with risk of recurrent VTE among patients who discontinue anticoagulation (AC) following an unprovoked VTE. A total of 528 adult patients were included, 28% of whom (N=110) tested positive for HT. Median follow-up was 55months (IQR 40-66months) following AC discontinuation. One hundred and twenty-four patients (23%) had a recurrent VTE during follow-up, including 29/110 with HT (26%) and 95/418 without HT (23%). Risk of recurrent VTE over time was similar between the two groups (logrank P=.47). The HR for recurrence among patients with HT was 1.17 (95% CI 0.76 to 1.81). On multivariable analysis, HT was not associated with recurrence of VTE (HR with HT=1.07 (95% CI 0.69-1.65), P=.74). The only factor significantly associated with risk of VTE recurrence on multivariable analysis was presence of PE (as opposed to DVT alone) (HR=1.54, 95% CI 1.02-2.30, P=.035). The presence of HT was not associated with risk of recurrent VTE in this cohort of patients. These findings underscore the questionable clinical utility of routine thrombophilia testing among patient with unprovoked VTE and suggest that such testing should not be routinely pursued.