Characteristics of provoked deep venous thrombosis in a tertiary care center.

OBJECTIVE: Provoked deep venous thrombosis (DVT) is precipitated by a specific event. This paper compares the characteristics of provoked DVT in patients with transient risk (TR) factors and patients with continuous risk (CR) factors.

METHODS: A retrospective review of records of all consecutive patients diagnosed with DVT between January 2013 and August 2014 was performed. Patients with provoked DVT were included in the TR group if the provoking event resolved in 2 weeks and they did not have ongoing risk of thrombosis. Patients in the CR group had a provoked DVT with ongoing risk of thrombosis due to individual factors deemed to be ongoing risks of thrombosis, such as cancer, hypercoagulable disorder, and prolonged immobilization. Demographics, risk factors, association with pulmonary embolism (PE) and its severity, risk of recurrent venous thromboembolism (VTE), and mortality were compared between the two groups.

RESULTS: A total of 838 patients were diagnosed with DVT, and 50.7% (425) were provoked. There were 127 (29.9%) patients with TR and 298 (70.1%) with CR. TR patients were younger (60.4 ± 16.3 vs 65.9 ± 16.0; P = .001). TR was more likely to be provoked by surgery (70.9% vs 55.4%; P = .003), whereas CR was more likely to be provoked by immobilization (21.5% vs 12.6%; P = .032). CR patients were affected by cancer (48.7%) and hypercoagulable disorders (4.4%). TR patients were more likely to have calf DVTs (36.2% vs 26.2%; P = .047). There was a trend toward lower association with PE on presentation in TR (17.3% vs 21.1%; P = .072), but that did not reach statistical significance. However, TR factors were more likely to be associated with low-risk PE compared with CR factors (30.2% vs 54.6%; P = .040). After mean follow-up of 7.2 months, CR had higher risk of recurrent VTE (14.0% vs 6.8%; P = .045) and mortality (23.5% vs 7.1%; P < .0001).

CONCLUSIONS: Provoked DVT with CR factors affects older patients and is associated with high recurrence of VTE and mortality compared with provoked DVT with TR factors.