Replacing clopidogrel with a placebo for a week before colonoscopy did not significantly reduce postpolypectomy bleeding, according to a randomized trial of 387 patients with cardiovascular disease (CVD) from Hong Kong. Those who continued taking clopidogrel, 75 mg/d, had statistically similar rates of immediate bleeding, bleeding within 30 days, and cardiothrombotic events as patients who received placebo. All patients resumed clopidogrel after colonoscopy.
The study was published in the March Gastroenterology. The following commentary by David Lichtenstein, MD, and Abhinav Vemula, MD, appeared in the ACP Journal Club section of the July 16 Annals of Internal Medicine.
The trial by Chan and colleagues found no difference in immediate or delayed bleeding in patients who continued clopidogrel before colonoscopy and polypectomy vs patients who stopped clopidogrel for 7 days before the procedure.
These results do not support current guidelines, which recommend withholding thienopyridine agents to reduce risk for postpolypectomy bleeding, a recommendation based on retrospective studies with mixed results. The study by Chan and colleagues is the first randomized trial to address this issue. The delayed postpolypectomy bleeding rate of 3.6% in patients interrupting clopidogrel was several-fold higher than expected compared with historical rates. This suggests that resuming clopidogrel immediately after polypectomy may increase rates of delayed hemorrhage and raises the question of whether risk for bleeding can be further reduced by withholding the thienopyridine antiplatelet agent before and after the procedure.
Mean polyp size was 4.7 mm, with only 7.8% of polyps ≥10 mm and none >20 mm, which indicates that the results cannot be extrapolated to larger polyps or those requiring advanced polypectomy techniques, such as endoscopic mucosal resection or endoscopic submucosal dissection.
There was a trend toward a higher rate of immediate postpolypectomy bleeding in patients continuing vs interrupting clopidogrel (8.5% vs 5.5%, P=0.38). The clinical relevance of immediate bleeding is uncertain, because it was defined as bleeding for >5 minutes after polypectomy and such bleeding is often controlled expeditiously with endoscopic hemostasis. Thus, its clinical importance is limited unless blood transfusion or hospitalization is required.
The apparent safety of uninterrupted clopidogrel before colonoscopy and polypectomy in patients with a low CV risk profile must be assessed in light of a potential reduction in postpolypectomy bleeding with extended discontinuation of the drug. Further studies are needed to determine the optimal management of thienopyridines in patients undergoing resection of larger polyps.