長期接受抗凝的患者在植入起搏器時圍手術期的管理對醫生而言是相當困難的。尤其是對那些具有中高危動脈血栓栓塞(ATE)風險的患者(如風險>4%每年),如機械性瓣膜置換術後、CHADS2高評分的房顫患者。
無過渡抗凝措施的圍手術期ATE風險,可用發生事件的年風險指數來評估。如,機械性二尖瓣置換術後的患者,其不使用口服抗凝藥物的ATE年風險為17%,也就說7天內發生ATE的風險為0.4%。同樣的,CHADS2評分3分以上的房顫患者,不使用口服抗凝藥物的ATE年風險為5.9%,估計七天內風險為0.16%。上訴估算方法為線性估計,也就是說,沒有考慮圍手術風險上升的可能。但已有數據表明外科手術本身會導致高凝狀態,導致血栓栓塞風險一過性升高。
臨床醫生處理圍手術期血栓栓塞的對策是給中高危患者使用過渡抗凝治療。在過渡方案中,術前3~5天停用口服抗凝藥物,代之以靜脈使用的普通肝素或使用低分子肝素,後者更為常見。術後,患者繼續使用普通肝素或低分子肝素,知道口服抗凝藥達到治療水平。
多項指南都推薦了這種方案,都建議應在患者的血栓栓塞風險和因手術而升高的出血風險之間做出權衡,都提及機械性瓣膜置換術後尤其是二尖瓣置換術後患者、合併其他危險因素的房顫患者、近期(3個月內)靜脈血栓患者的血栓栓塞風險最高。臨床上最詳細且接受程度最高的指南是ACCP2008年的指南,其中推薦中高危動靜脈血栓患者應使用過渡抗凝。
加拿大渥太華大學的MARK J. PERRIN,希望通過研究,探討現實醫療工作中,此過渡抗凝治療方案在多大程度上被臨床醫生接受、執行。
MARK J. PERRIN等檢視了預先設定的14個月期間內所有接受抗凝治療且行起搏器植入的患者。這些患者根據臨床資料集ACCP2008年指南,分為中高危組和低危組。隨後將兩組患者圍手術期抗凝治療與指南推薦的方案比較,並評估兩組患者圍手術期出血率和血栓栓塞發生率。
研究小組一共回顧了129名患者的臨床資料。其中62名(48%)為中高危患者,67名(52%)為低危患者。在中高危組中有47名(76%)接受了圍手術期抗凝治療,僅有25名(40%)術前術後都應用過渡抗凝或未中斷使用華法林。在低危組中,22名(33%)接受了圍手術期抗凝治療。起搏器囊袋血中或圍手術期出血,共有10例(8%)其中4例發生在不恰當地接受了過渡抗凝治療的低危組患者中。圍手術期未發生血栓栓塞事件。
基於這個小規模的研究,MARK J. PERRIN等得出結論,過渡抗凝治療明顯地執行的不夠充分,尤其是術後階段,在中高危組患者中。與此相反,對低危組患者,卻過度適用了過渡抗凝治療並出現了出血併發症。這一結論提示,臨床醫生在植入起搏器時應更多的遵從目前的專家指南,適用過渡抗凝治療。(生物谷Bioon.com)
Anticoagulation Bridging Around Device Surgery: Compliance with Guidelines
MARK J. PERRIN M.B.B.S., Ph.D.1, BRIAN Z. VEZI M.D.1, ANDREW C. HA M.D.2, ARIEH KEREN M.D.1, PABLO B. NERY M.D.1, DAVID H. BIRNIE M.B., Ch.B., M.D.1
Background:Current guidelines recommend bridging anticoagulation in patients undergoing cardiac rhythm device surgery with a 「moderate to high risk」 of thromboembolism. Patients at 「low risk」 are advised to stop oral anticoagulation without bridging to the procedure. This study examines real world adherence to accepted guidelines and the clinical sequelae of nonadherence. Methods:We performed a review of all patients undergoing device surgery receiving chronic anticoagulation over a prespecified time period of 14 months. Patients were classified per American College of Chest Physician guidelines as 「moderate/high risk」 or 「low risk」 of thromboembolism. We then compared perioperative management of anticoagulation to guideline recommendations and assessed the rate of perioperative bleeding and thromboembolism. Results:One hundred and twenty-nine patients were included in this study. Sixty-two (48%) were classified as 「moderate/high risk」 and 67 (52%) 「low risk.」 In the 「moderate/high risk」 group 47/62 (76%) received perioperative anticoagulation but only 25/62 (40%) were bridged both pre- and postprocedure or maintained on uninterrupted warfarin. In the 「low risk」 group, 22/67 (33%) received bridging therapy. Device pocket hematoma or perioperative bleeding occurred in 10/129 (8%) with 4/10 receiving inappropriate bridging for a calculated low risk of thromboembolism. There were no perioperative thromboembolisms. Conclusions:Our study identified significant underutilization of bridging, particularly in the postoperative period, in patients at 「moderate/high risk」 of thromboembolism. Conversely, bridging was overused in 「low risk」 patients and associated with bleeding complications. Physicians should be urged to follow current expert guidelines in regard to bridging anticoagulation for cardiac rhythm device surgery.