I am an advanced trainee in General & Acute Care Medicine in the Auckland region, currently working as ICU Registrar at North Shore Hospital. I had been a Surgical Registrar and Anaesthetic Registrar prior to Internal Medicine training. I started my medical training in Palmerston North Hospital and was there was four years.
After First Unprovoked Venous Thromboembolism, Decision Regarding Ongoing Anti-Coagulation Therapy With The Use Of Vienna Prediction Model
The recurrence risk for unprovoked lower limb deep vein thrombosis (DVT) or pulmonary embolism (PE) approaches 30% at 5 years after cessation of anticoagulation1. Anticoagulant treatment is associated with a 2.6-fold increase in major bleeding2. The aim of this observational study was to report the experience of using Vienna prediction model3 in determining the recurrence risk of unprovoked venous thromboembolism (VTE) in a New Zealand hospital.
Patients seen in Palmerston North Hospital Haematology Clinic from 2013 to 2018 for follow up after first episode of unprovoked VTE were identified from a prospective database. Two weeks before proposed stop date of anticoagulation, D-dimer was tested. If D-dimer >500 ug/L, anticoagulation was continued long-term. If D-dimer <500 ug/L, anticoagulation was stopped and D-dimer re-tested 3 weeks later. This D-dimer was used to calculate Vienna prediction score. If the cumulative recurrence rate was predicted to be more than 5% at 12 months, anticoagulation was re-started. Clinical records were used to determine VTE recurrence and anticoagulation complications.
There were 174 patients (55.2% male) with age at diagnosis of 20 to 89 (average 63.7) years. The sites of thrombosis were PE (n=76), proximal DVT (n=71), distal DVT (n=26) and superficial thrombophlebitis (n=1). Duration of active treatment for proximal DVT and PE were mostly 6 months, distal DVT usually 3 months. After active treatment, 68 patients stayed off anticoagulation, 53 patients were re-commenced anticoagulation, 41 patients with negative D-dimers chose to start aspirin when offered, and 12 had incomplete information. Of those who stopped anticoagulation, 14 (20.6%) developed recurrence, of which 7/68 (10.3%) were unprovoked. No recurrence in patients on ongoing anticoagulation or aspirin. Bleeding occurred in one patient on Rivaroxaban.
Vienna prediction model can be used to identify patients with reduced VTE recurrence risk to support decision regarding ongoing anticoagulation.
1. Ensor J, Riley RD, Moore D, Snell KIE. Systematic review of prognostic models for recurrent venous thromboembolism (VTE) post-treatment of first unprovoked VTE. BMJ Open 2016;6:e011190. doi:10.1135/bmjopen-2016-011190.
2. Kearon C, Aki EA. Duration of anticoagulant therapy for deep vein thrombosis and pulmonary embolism. Blood 2014;123:1794-1801.
3. Eichinger S, Heinze G, Kyrle PA. D-dimer levels over time and the risk of recurrent venous thromboembolism: an update of the Vienna prediction model. J Am Heart Assoc 2014;3:e000467. doi: 10.1161/JAHA.113.000467.