108 Risk Factors for Acute GI Bleeding Following Myocardial Infarction in Patients Who are Prescribed Clopidogrel

Abstract

G A A b st ra ct s was defined as the composite of myocardial infarction, unstable angina pectoris, stroke and/ or all-cause mortality. Peptic ulcer disease was also used as primary gastrointestinal outcome. The presence of risk factors for cardiovascular and gastrointestinal complications was identified for each subject during a 1-year history period prior to index date. These included all diagnoses, procedures and treatments reimbursed by the health insurance. Cox proportional hazard regression analysis was used to calculate the risk of cardiovascular and gastrointestinal outcomes in clopidogrel patients with or without PPI use. Results: A total of 18,139 new clopidogrel users were identified, of whom 5,734 (32%) used PPIs concurrently. Patients on PPIs were significantly older, used more co-medications and suffered from more comorbidities. Use of clopidogrel and PPIs was associated with an increased risk of myocardial infarction (HR 1.93, 95% CI 1.40-2.65), unstable angina pectoris (HR 1.79, 95% CI 1.602.03) and the composite cardiovascular endpoint (HR 1.75, 95% CI 1.58-1.94) compared to clopidogrel users without PPIs. PPI users also had an increased risk of gastrointestinal events compared those not using PPIs (HR 4.76, 95%CI 1.18-19.17). No significant differences were found between different types of PPIs and associated risks of adverse outcomes. Conclusion: New clopidogrel users on PPIs are at an increased risk of cardiovascular and gastrointestinal complications compared to those not using PPIs. Although a metabolic effect of PPIs on clopidogrel cannot be excluded, we suggest that the inferior cardiovascular profile of clopidogrel users on PPIs and the occurrence of channelling bias are important factors underlying this observation.