Factors affecting the recurrence in patients with venous thromboembolism: A retrospective cohort study.

Background: The aim of the study was to evaluate the frequency of recurrence and the risk factors for recurrence in patients who were diagnosed with venous thromboembolism.

Methods: Between January 2005 and January 2015, a total of 412 venous thromboembolism patients (164 males, 248 females; mean age: 53.5±16.6 years; range: 19 to 95 years) were retrospectively analyzed. The demographics, underlying risk factors, comorbidities, imaging findings, and treatment data of the patients were recorded.

Results: At least one transient/permanent risk factor was found in 341 (82.7%) of the index events, and the other 71 (17.2%) were idiopathic. Recurrence developed in 76 (18.4%) of the patients. The duration of the treatment in the first event was significantly longer in recurrent cases (p=0.007). The recurrence rate in patients diagnosed with only deep vein thrombosis or patients diagnosed with pulmonary thromboembolism + deep vein thrombosis was significantly higher than the patients diagnosed with only pulmonary thromboembolism (24% vs. 14.2%, respectively; p=0.007). The rate of idiopathic venous thromboembolism was higher in recurrent cases than in non-recurrent cases (26.3% vs. 15.2%, respectively; p=0.028). At the end of the first year, the mean D-dimer levels were higher in recurrent cases (p=0.034). Hereditary risk factors were also higher in recurrent cases (39.5% vs. 19.3%, respectively; p=0.031). There was no significant correlation between recurrence and mortality.

Conclusion: The presence of deep vein thrombosis, idiopathic events, high D-dimer levels at the end of the first year and hereditary risk factors seem to be associated with recurrence.