The Archives of Internal Medicine has published the results of a prospective observational study that aimed to assess the impact of discontinuing warfarin therapy before an invasive procedure on thromboembolic risk.
The study included 1,204 patients and 1,293 separate interruptions of warfarin therapy. The average age of the patients was 71.9 years and 42.8% were female. The main indications for warfarin therapy were atrial fibrillation (46%), venous thromboembolism (12%) and mechanical heart valves (11%). Patients were followed up for thromboembolism or clinically significant bleeds occurring within 30 days of stopping warfarin therapy.
The results of the study are as follows:
- Perioperative heparin was used in a total of 8.3% of cases
- 7 patients developed thromboembolism within 30 days, none had received perioperative heparin
- 23 patients had clinically significant bleeds, 14 had received perioperative heparin
- More than 80% of patients had therapy withheld for 5 days or less
The authors conclude that, "interruption of warfarin therapy is associated with a low risk of thromboembolism". They also recommend that, "the risk of clinically significant bleeding should be weighed against the thromboembolic risk of an individual patient before the administration of bridging anticoagulant therapy".
Action: This observational data indicates that short-term interruptions to anticoagulant therapy are associated with a low risk of thromboembolism and that bridging therapy increases the risk of significant bleeding events. Clinicians should consider how this information affects the advice they currently give to patients on anticoagulant therapy who are referred for invasive procedures.