I take issue with the conclusion of the POEM entitled “Can you safely interrupt warfarin for an elective procedure?” in your May issue.1
The Fast Track excerpt says “Most patients who stop taking warfarin for 5 or fewer days are at little risk of a thromboembolic event.” But the article says the prevalence of events was 0.54%. There are 3 problems with characterizing that number as “little risk”:
- This percentage probably represents the low side of the actual risk, based on previous reports that the risk of thromboembolic events when withholding warfarin is about 1%.2
- One event is not insignificant. I have several hundred patients in my practice taking warfarin. If only 100 of them have a skin biopsy, cataract surgery, or dental procedure in a given year, then the practice of withholding warfarin for these procedures causes 1 thromboembolism a year. Hardly insignificant to the affected person!
- You failed to ask what the other side of the risk equation is. What would be the consequence of continuing warfarin during such procedures? My reading of the literature suggests the burden would be less onerous than 1 thromboembolism every year in my practice.
As a result, we do not routinely withhold warfarin for dental procedures, skin procedures, or cataract surgery.
Douglas R. Morrissey, MD
Cornerstone Family Health Associates, Lititz, PA
doug777morrissey@hotmail.com