Temporarily stopping antithrombotic agents was linked with a higher risk of thromboembolic events after colonoscopy, according to a retrospective cohort study in China.
Among over 6,000 patients, interruption of at least two such agents was associated with a higher risk of thromboembolic events within 30 days of colonoscopy (adjusted OR 22.5, 95% CI 1.09-158.0), as was interruption of monotherapy with:
- Clopidogrel (Plavix): aOR 15.5 (95% CI 2.86-69.6)
- Warfarin: aOR 6.96 (95% CI 1.14-33.5)
- Direct acting oral anticoagulants (DOACs): aOR 6.23 (95% CI 1.22-26.8)
This risk was especially high for those who presented with an underlying high risk of thromboembolic events (aOR 16.8, 95% CI 6.33-46.6), reported Wai K. Leung, MD, of Queen Mary Hospital and the University of Hong Kong in China, and colleagues in Clinical Gastroenterology and Hepatology.
“While our findings are in general supportive of the recommendations to continue these agents as long as clinically allowed, our study demonstrated that the risk of post-colonoscopy thromboembolic events are very low if antithrombotic agents are continued throughout the procedure,” they wrote.
The highest rates of thromboembolic events were seen in those taking dual antiplatelet therapy (4.65%; aOR 28.0, 95% CI 3.77-142.1) and clopidogrel monotherapy (2.78%; aOR 12.2, 95% CI 2.10-57.0) compared with those not taking an antithrombotic (0.11%).
The thromboembolic event rate was 0.85% in patients on any anti-thrombotic (OR 5.86, 95% CI 2.15-18.6).
Overall, 0.4% of patients developed post-polypectomy bleeding (PPB), with the highest risk among those on aspirin (aOR 5.41) or DOACs (aOR 5.75) at baseline.
“Apart from thromboembolic events, we found that stopping aspirin (aOR 6.23) and DOACs (aOR 6.12) may not reduce the risk of post-polypectomy bleeding,” Leung. “Hence, the risk-benefit of stopping these agents during the pericolonoscopy period needs to be evaluated.”
David Greenwald, MD, of Mount Sinai Hospital in New York City, noted that “each patient and their circumstances are unique; performing this risk-benefit analysis cannot be guided by a rigid protocol and is part of the ‘art of medicine,’ although [it] needs to be informed by data such as that presented in this study.”
“These important issues should always be discussed with patients and often with their families prior to a colonoscopy,” Greenwald told MedPage Today. “The implications are clear: discontinuation of antithrombotic agents prior to colonoscopy is a decision that must be made carefully, since the consequences of a thromboembolic event, although rare, may be devastating.”
While colonoscopy is commonly used to detect and remove colonic polyps, patients undergoing the procedure may present with concomitant comorbidities, such as prior cerebrovascular or thromboembolic events that require the use of antithrombotic agents, Leung’s group explained.
A previous study found that the use of antithrombotic agents was linked to a higher risk of bleeding and PPB among those on oral DOACs versus clopidogrel, which led some physicians to temporarily halt the use of these agents to minimize this risk.
Guidelines released earlier this year from the American College of Gastroenterology and Canadian Association of Gastroenterology on the use of antithrombotics for managing patients with acute gastrointestinal bleeding or those undergoing elective endoscopy suggested continuing warfarin, but temporarily stopping DOACs.
For this real-world study, Leung and colleagues retrospectively examined data on 6,220 patients who underwent colonoscopy from January 2016 to March 2021 at Queen Mary Hospital. Of these patients, 28.2% received antithrombotic therapy; 7.8% were taking anticoagulants, 19.6% were taking antiplatelets, and 0.76% received various combinations of antiplatelets and anticoagulants.
Median age was 64, and 52% were men. Common comorbidities included hypertension (25%), ischemic heart disease (10%), and atrial fibrillation (6%).
The researchers adjusted for demographics, colonoscopy indications, antithrombotic agents, anticipated risk for PPB, and high risk for thromboembolic events.
Within 30 days of colonoscopy, 0.32% of patients experienced thromboembolic events. Nearly half underwent polypectomy, including 0.80% who experienced major bleeding episodes. Common colonoscopy indications included screening/polyp surveillance (24%), anemia (21%), and rectal bleeding (13%).
Six patients died with thromboembolic events after colonoscopy (0.1% mortality), including three from myocardial infarction, two from strokes, and one from pulmonary embolism. Of those deaths, all patients had received antithrombotic agents — three on warfarin, two on aspirin, and one on a DOAC.
Leung and colleagues noted that residual confounding may have contributed to lower thromboembolic event rates among those undergoing elective procedures. Furthermore, lab results and total days of medication interruption/resumption were unknown.
Disclosures
Leung and co-authors disclosed no relationships with industry.
Source: MedicalNewsToday.com
