Age at First Venous Thromboembolism and Risk of Recurrence

Risk of first venous thromboembolism (VTE) increases with age. We investigated whether age is related to the risk of recurrent VTE. We followed 694 patients for a mean of 40 months after first unprovoked proximal deep vein thrombosis (DVT) and/or pulmonary embolism (PE) and withdrawal of anticoagulants. We excluded patients with natural inhibitor deficiency, lupus anticoagulant, or cancer; patients who required indefinite anticoagulation; pregnant women; and women who had VTE related to female hormone use. The endpoint was symptomatic recurrent VTE.VTE recurred in 152 patients (22%). The adjusted hazard ratio (HR) of recurrence for a 10-year increase in age was 0.94 (95% confidence interval [CI], 0.82-1.08; p = 0.4). Compared with patients aged younger than 47 years (1st tercile of patient population) no significant increase in the risk of recurrent VTE was found among patients 47-61 years old (2nd tercile) or patients older than 61 years (3rd tercile) ([HR, 1.25; 95% CI, 0.78-2.01] and [HR, 0.93l; 95% CI, 0.56-1.53], respectively). Compared to patients older than 80 years, the HR of recurrence among patients younger than 50 years was 1.11 (95% CI, 0.11-10.3; p = 0.9). After 5 years, probability of recurrence was 32% (95% CI, 24%-40%) among patients aged less than 47 years; 21% (95% CI, 15%-28%) among patients 47-61 years old; and 33% (95% CI, 24%-42%) among patients older than 61 years (p = 0.5).Our results show that in patients with first unprovoked proximal DVT and/or PE, risk of recurrence is not related to age at first VTE. Regardless of age, these patients have a high risk of recurrence.