Do Patients with a Family or Personal History of Venous Thromboembolism have an Increased Risk of Recurrence?

BACKGROUND A family (FH) and personal history (PH) of venous thromboembolism (VTE) are commonly evaluated risk factors for recurrence. We examined the association between FH/PH of VTE and the risk of recurrence and whether a stronger history status (i.e., both FH/PH vs. no FH/PH) carries an increased recurrence risk. METHODS We prospectively followed 813 patients aged ≥ 65 years with acute VTE from 9 Swiss hospitals. We classified patients into four groups: no FH/PH, FH only, PH only, and both FH/PH. The primary outcome was recurrent VTE during the full observation period. We examined the association between FH/PH status and the time to VTE recurrence using competing risk regression, adjusting for confounders and periods of anticoagulation. RESULTS Of 813 patients with VTE, 59% had no FH/PH, 11% a FH only, 24% a PH only, and 7% had both a FH and PH of VTE. Overall, 105 patients had recurrent VTE during the full observation period. After adjustment, patients with a FH only (subhazard ratio [SHR] 0.8, 95% confidence interval [CI] 0.4-1.7), PH only (SHR 1.5, 95% CI 0.9-2.5), and both FH/PH (SHR 1.4, 95% CI 0.6-3.1) did not have an increased risk of recurrent VTE compared with those without FH/PH. When we considered the period after the completion of initial anticoagulation only, the results were similar. CONCLUSION Our findings indicate that in patients with acute VTE, a FH and/or PH of VTE does not convey an increased risk of recurrent VTE. In particular, we did not find a "dose-effect" relationship between FH/PH status and VTE recurrence