Irwin Adriane N, McCool Kathleen H, Delate Thomas, Witt Daniel M
Pharmacy Department, Kaiser Permanente Colorado, Aurora, Colorado, USA.
Pharmacotherapy. 2013 Nov;33(11):1175-83. doi: 10.1002/phar.1307. Epub 2013 Jun 6.
To quantify the change in weekly warfarin dose after bariatric surgery in patients requiring long-term warfarin therapy.
Retrospective matched-cohort study.
Anticoagulation management service in an integrated health care delivery system.
Patients receiving long-term warfarin anticoagulation who underwent bariatric surgery between January 1, 1996, and December 31, 2010 (27 patients), were matched by date of surgery (± 2 years), age (± 5 years), and target international normalized ratio (INR) range to patients receiving long-term anticoagulation therapy who underwent other abdominal surgical procedures: cholecystectomy or endoscopic retrograde cholangiopancreatography (59 patients [control group]).
The main end point was change in postoperative warfarin dose from baseline (preoperative dose), measured at weekly postoperative intervals from weeks 1 to 8 and again at months 3 and 6. After surgery, patients in the bariatric surgery group had statistically significant decreases in weekly warfarin doses compared with preoperative dose at all postoperative time points (week 1 dose vs preoperative dose, p<0.01; doses at all other time points vs preoperative dose, p<0.001), except at 6 months (p>0.05). No statistically significant decreases in warfarin dose were detected at any postoperative time points in the control group. Twenty patients (74.1%) in the bariatric surgery group experienced a 20% or more decrease in weekly warfarin dose compared with 19 patients (32.2%) in the control group (p=0.004). No significant differences in warfarin-related adverse events were noted between groups.
Weekly warfarin doses decreased in the immediate postoperative period in anticoagulated patients after bariatric surgery but returned to their preoperative doses after approximately 6 months. A similar pattern was not observed in patients in the control group who underwent other types of abdominal surgery. Compared with preoperative anticoagulation control, this resulted in reduced anticoagulation control despite close INR monitoring. If a causal relationship between bariatric surgery and warfarin sensitivity is established in future research, developing and validating a postbariatric surgery warfarin-dosing algorithm would be valuable.
量化接受长期华法林治疗的患者在减肥手术后每周华法林剂量的变化。
回顾性配对队列研究。
综合医疗保健服务系统中的抗凝管理服务部门。
1996年1月1日至2010年12月31日期间接受减肥手术的长期接受华法林抗凝治疗的患者（27例），按手术日期（±2年）、年龄（±5岁）和目标国际标准化比值（INR）范围与接受其他腹部手术（胆囊切除术或内镜逆行胰胆管造影术）的长期抗凝治疗患者进行配对（59例[对照组]）。
主要终点为术后华法林剂量相对于基线（术前剂量）的变化，在术后第1至8周每周测量一次，术后3个月和6个月再次测量。术后，减肥手术组患者在所有术后时间点的每周华法林剂量与术前剂量相比均有统计学显著下降（第1周剂量与术前剂量相比，p<0.01；所有其他时间点的剂量与术前剂量相比，p<0.001），但6个月时除外（p>0.05）。对照组在任何术后时间点均未检测到华法林剂量有统计学显著下降。减肥手术组20例患者（74.1%）的每周华法林剂量较对照组19例患者（32.2%）下降了20%或更多（p=0.004）。两组间华法林相关不良事件无显著差异。
减肥手术后接受抗凝治疗的患者术后即刻每周华法林剂量下降，但约6个月后恢复至术前剂量。接受其他类型腹部手术的对照组患者未观察到类似模式。与术前抗凝控制相比，尽管密切监测INR，但抗凝控制仍有所降低。如果未来研究确定减肥手术与华法林敏感性之间存在因果关系，那么开发并验证减肥手术后华法林给药算法将很有价值。
