EndoTODAY 이준행

[20120316. Complications of EMR/ESD (71): Bleeding (35) - warfarin (3) experience at Cedars-Sinai Medical Center]

Los Angeles에 위치한 Cedars-Sinai Medical Center에서 Withdrawal of warfarin prior to a surgical procedure: time to follow the guidelines?라는 흥미로운 발표를 하였습니다. 초록을 옮깁니다.

"Over a 12-month period, 14 cases of cardioembolic cerebral infarction occurring during the period of warfarin withdrawal for a medical procedure were observed... Cerebral infarctions developed an average of 5.4 days after the last dose of warfarin (range 3-8)... Each had been on chronic anticoagulation with warfarin for more than 1 year." 와파린을 끊고 약 5일째 뇌경색이 발생하였다는 점이 중요할 것 같습니다. 일주일 동안 끊는 관행은 무척 위험할 수 있다고 생각합니다.

"Retrospective analysis suggested that all these cerebral infarctions had been potentially preventable. In each case, either the planned procedure did not require discontinuation of warfarin or, when withdrawal was required, no bridging, parenteral anticoagulation was provided to lessen the risk during the warfarin-free period." 합병증 사례를 잘 검토해 보았더니 각기 어딘가 문제가 있었다는 지적입니다. 가이드라인을 잘 지켰더라면 막을 수 있었다는 결론입니다. 그래서 논문의 부제가 'time to follow the guidelines?'인 모양입니다.

구체적으로 warfarin adjustment 후 내시경을 하였을 때 stroke risk를 평가한 논문도 있었습니다 (Blacker 2003). Atrial fibrillation 환자가 내시경을 했을 때 stroke의 빈도를 후향적으로 조사한 것입니다. 1.06%에서 stroke가 왔다고 합니다. 저는 매우 높은 수치라고 생각하는데 저자는 한가하게도 stroke의 위함이 낮다("The risk of stroke is low")고 말하고 있습니다. 이런...

RESULTS: Twelve strokes occurred in 987 patients undergoing 1,137 procedures (1.06%/procedure). The risk ranged from 0.31% for patients with nonvalvular AF undergoing routine procedures to 2.93% for complex patients undergoing endoscopies combined with other procedures or with comorbid illnesses. Patients with stroke were more likely to be complex (7/12 vs 219/975, p = 0.04); to be older than 80 years (6/12 vs 187/975, p = 0.017); to have a history of stroke (7/12 vs 194/975, p = 0.004), hypertension (10/12 vs 508/975, p = 0.04), or hyperlipidemia (9/12 vs 334/975, p = 0.005); or to have a family history of vascular disease (10/12 vs 502/975, p = 0.039).

CONCLUSIONS: The risk of stroke in patients with AF whose anticoagulation is adjusted for endoscopies is low, but almost tenfold higher in patients with complex clinical situations. Age, history of stroke, hypertension, hyperlipidemia, and family history of vascular disease may increase the risk of stroke.

이와는 반대로 와파린을 짧게 끊으면 ("more than 80% of patients had warfarin therapy withheld for 5 days or fewer") thromboembolic risk가 그리 높지 않다는 New Mexice 대학의 연구도 있습니다. 여하튼 무척 헷갈리는 분야입니다. 가이드라인을 얼마나 잘 지켰느냐에 달린 것 같습니다.

[참고 자료]

1) EndoTODAY 와파린

2) 항혈소판제 Antiplatelets - 내시경 혹은 조직검사 전 아스피린, 항혈소판제를 끊을 것인가?

3) 새로운 항응고제 New oral anticoagulant (NOAC)

4) 항혈소판제, 항응고제 중단 지침 (삼성서울병원 2011)