Magnetically Controlled Capsule Endoscopy for Assessment of Antiplatelet Therapy–Induced Gastrointestinal Injury

Background: Gastrointestinal bleeding is the most frequent major complication of antiplatelet therapy. In patients at low bleeding risk, however, clinically overt gastrointestinal bleeding is relatively uncommon. Objectives: The authors sought to assess the effects of different antiplatelet regimens on gastrointestinal mucosal injury by means of a novel magnetically controlled capsule endoscopy system in patients at low bleeding risk. Methods: Patients (n = 505) undergoing percutaneous coronary intervention in whom capsule endoscopy demonstrated no ulcerations or bleeding (although erosions were permitted) after 6 months of dual antiplatelet therapy (DAPT) were randomly assigned to aspirin plus placebo (n = 168), clopidogrel plus placebo (n = 169), or aspirin plus clopidogrel (n = 168) for an additional 6 months. The primary endpoint was the incidence of gastrointestinal mucosal injury (erosions, ulceration, or bleeding) at 6-month or 12-month capsule endoscopy. Results: Gastrointestinal mucosal injury through 12 months was less with single antiplatelet therapy (SAPT) than with DAPT (94.3% vs 99.2%; P = 0.02). Aspirin and clopidogrel monotherapy had similar effects. Among 68 patients without any gastrointestinal injury at randomization (including no erosions), SAPT compared with DAPT caused less gastrointestinal injury (68.1% vs 95.2%; P = 0.006), including fewer new ulcers (8.5% vs 38.1%; P = 0.009). Clinical gastrointestinal bleeding from 6 to 12 months was less with SAPT than with DAPT (0.6% vs 5.4%; P = 0.001). Conclusions: Despite being at low risk of bleeding, nearly all patients receiving antiplatelet therapy developed gastrointestinal injury, although overt bleeding was infrequent. DAPT for 6 months followed by SAPT with aspirin or clopidogrel from 6 to 12 months resulted in less gastrointestinal mucosal injury and clinical bleeding compared with DAPT through 12 months.