Temporary cessation of antithrombotic therapy before colonoscopy may do more harm than good

Interrupting antithrombotic therapy among patients undergoing colonoscopy appears to contribute to higher thromboembolism (TE) events and even mortality, especially in high-risk patients, according to a study.

Researchers reviewed the medical records of 6,220 consecutive patients undergoing colonoscopy. They looked at the rates of postcolonoscopy TE events in patients taking various antithrombotic agents (with or without interruption) and in different patient groups defined by indications for colonoscopy, underlying TE, and bleeding risks.

Of the patients, 1,755 (28.2 percent) were on antithrombotic therapy. Twenty patients (0.32 percent) developed TE events, and 25 (0.80 percent) of 3,134 patients with polypectomy had major bleeding episodes. Six (0.1 percent) patients died due to TE events, all of whom were on antithrombotic therapy.

TE events occurred with the greatest frequency among patients on dual antiplatelet therapy (4.65 percent; adjusted odds ratio [aOR], 28.0, 95 percent confidence interval [CI], 3.77–142.1) and clopidogrel (2.78 percent; aOR, 12.2, 95 percent CI, 2.10–57.0), as compared with only 0.11 percent among patients not receiving antithrombotic therapy.

The risk of TE events was positively associated with cessation of ≥2 antithrombotic agents (4.55 percent; aOR, 22.5, 95 percent CI, 1.09–158.0), or discontinuation of monotherapy with clopidogrel (3.06 percent; aOR, 15.5, 95 percent CI, 2.86–69.6), warfarin (1.33 percent; aOR, 6.96, 95 percent CI, 1.14–33.5), or direct acting oral anticoagulants (0.87 percent; aOR, 6.23, 95 percent CI, 1.22–26.8).

Finally, patients with underlying high TE risk were at increased risk of postcolonoscopy TE events (aOR, 16.8, 95 percent CI, 6.33–46.6).