Results
Populations characteristics: During the study period, 300 patients were referred to the hematology department from the internal medicine department for IT screening. after exclusion of patients with missing clinical data, 190 patients were included (Figure 1). Demographic and clinical characteristics of patients are summarized in table 1.
Index venous thrombotic event: Thrombosis sites were proximal deep venous thrombosis of lower limbs (52.5%), pulmonary embolism (12.6%), both proximal deep venous thrombosis of lower limbs and pulmonary embolism (7.9%), distal deep venous thrombosis of lower limbs (19%), superficial venous of lower limbs (7.4%), unusual sites (14.9%). the thrombotic event was secondary to a persistent risk factor (6%), transient major risk factor (5%), transient minor risk factor (28%) and mostly idiopathic (61%). Indefinite treatment duration was decided in 34 (23.4%) patients for the following reasons: thrombophilic abnormalities (n=21), previous thrombosis (n=10), Behçet disease (n=1), myeloproliferative disorder (1), immobilization (n=1). In patients who stopped treatment, the mean duration of anticoagulation was 13.9±15.5 [1-96] months. The treatment duration was statistically more prolonged in patients with pulmonary embolism or proximal deep veins than distal localizations (29.9, 13.9 vs 8.1 moonths; p=0.02 and p=0.005 respectively). However, the durations of treatment in patients with thrombosis of unusual site and in those with thrombosis of other localizations were comparable (p=0.36). Curiously, duration of anticoagulation was not significantly associated to neither a history of thrombosis (22 vs 12 months; p=0.08) nor circumstances of thrombosis: provoked by a transient factor (15.1 months), persistent factor (10.1 months) and idiopathic (13.4 months); p=0.6.
Inherited Thrombophilia screening: Laboratory investigations were indicated in the following situations: age inferior to 50 years old (57%), previous thrombosis (15%), family history of thrombosis (14%), unusual localization (10.4%), idiopathic episode (3.1%). Among the 190 included patients, 131 were screened for the four parameters. The prevalence of IT was 27.5% (n=36). As expected, the most frequent abnormality was aPCR (27.5%). Deficiencies in AT, PC, and PS were found in 2, 5 and 3 patients respectively. IT was not statistically associated to the following factors: personal previous venous thrombotic/cardiovascular events, family history of thrombosis, adverse pregnancy outcome, idiopathic thrombosis.
Follow up: Among 190 included patients, 66 were lost to follow up (Fig 1). For the other 124 patients, the mean duration of follow up was 34±37.2 months since the Index VTE and 22.3 ±24.7 months since anticoagulation withdrawal.