Discontinuation of Antiplatelet Therapy for Colonoscopy and the Associated Thromboembolic Risk

Izi D Obokhare, MD, Jose Cordova, MD, David E Beck, MD FACS, Charles B Whitlow, MD FACS, David , A Margolin, MD FACS. Department of Colon and Rectal Surgery Ochsner Medical Center

Introduction:
Discontinuation of antiplatelet therapy (APT) is associated with a low risk of thromboembolic events. There is a dearth of data to guide the management of antiplatelet therapy in patients undergoing colonoscopy. Current guidelines are based on small trials and expert opinion. The decision to withhold APT in the periendoscopic period is not a trivial one.

Methods and procedures:
A prospectively collected data base involving 4049 colonoscopies performed in a 10 month period between November 2010 and August 2011 was reviewed. 122 patients on APT were identified. Our current protocol involves checking with prescriber and if safe stopping the clopidogrel for 7 days prior to colonoscopy and restarting immediately after the procedure if no therapeutic maneuvers are performed. If polypectomy is performed we continue to hold the clopidogrel for 3 days. The length of time off clopidogrel prior to and after colonoscopy was recorded. Exclusion criteria included patients who continued clopidogrel use and patients on clopidogrel and coumadin. Patient demographics, and post procedural complications were recorded. The primary endpoint was thromboembolic events and the secondary endpoint was clinically significant hemorrhage within 60 days of clopidogrel interruption.

Results
Out of 4049 patients, 122 were eligible for the study, 70 % were male and 60 % < 70 yrs old. 80% of the patients were on aspirin and clopidogrel, while 20% were on clopidogrel only. Of the patient population, 40 % had stents and 14% had a history of cerebrovascular event. The mean time off APT prior to colonoscopy was 6 ± 2 days, and after colonoscopy was 2 ±1.7 days for both groups of patients with thromboembolic events (TE) and without thromboembolic complication (NTE). P = 0.39 and 0.47 respectively.
The incidence of all thromboembolic complications was 5.7%, and the incidence of bleeding requiring hospitalization and transfusion of blood products was 4.9%.
Comparing the subgroup of patients with a clinically significant hemorrhage with the rest of the cohort, the mean duration of APT was similar: 6 days prior and 1 day post colonoscopy. P = 0.36 and 0.37 respectively.

Conclusion(s)
Discontinuation of antiplatelet medication can be safely done in patients without any major thromboembolic events such as stroke or pulmonary embolism. Minor thromboembolic events were noted such as NSTEMI and thrombosis of grafts and superficial venous thrombosis. There were no strokes noted in the study population and thromboembolic events were classified as mild. The risk of bleeding in this patient population can be significant requiring hospitalization.

Key words: Post polypectomy bleeding, clopidogrel, antiplatelet therapy and colonoscopy.
 

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