Higher Mortality in Patients with Coronary Artery Disease and Gastrointestinal Bleeding While on Dual Antiplatelet Therapy with Oral Anticoagulants

Abstract

Introduction: For patients with coronary artery disease (CAD) on aspirin (ASA), risk of gastrointestinal bleeding (GIB) increases significantly in those requiring dual antiplatelet therapy (DAPT) and a vitamin K antagonist (known as triple therapy). Outcomes of patients with CAD and GIB while on triple therapy compared to ASA alone are unknown. Our objective was to compare the post-discharge mortality for patients on triple therapy compared to ASA alone in a subset of patients with CAD hospitalized with lower GIB.Table 1: Patient Characteristics Associated with Triple Therapy UseTable 2: Multivariate Logistic Regression of Risk Factors Associated with 6 Month MortalityMethods: Using a validated ICD-9 classification tree with a priori sensitivity and specificity of 92.3% for identifying patients with lower GIB, 716 patients were identified with CAD and use of aspirin admitted to an academic tertiary medical center from 2008-2015 with a lower GIB. ICD-9 codes were utilized to identify co-morbidities, while demographics, labs and medications were extracted from the medical record. Patients dying during index hospitalization were excluded from the analysis. Mortality data was linked to social security death indices. Univariate and multivariate logistic regression was used to evaluate the association between triple therapy use in CAD patients and 6 month mortality. Results: 716 patients with CAD were admitted with a lower GIB while on ASA. 9% (n=65) were on triple therapy at index admission. Patients on triple therapy had a higher prevalence of congestive heart failure (72.3% vs 53.0%, p=0.004), atrial fibrillation (43.1% vs 28.4%, p= 0.01, and were more likely to require blood transfusion (57.0% vs. 35.8%, p < 0.001). 9.7 % (n=70) died within 6 months of discharge after lower GIB. Use of triple therapy at index GIB was associated with an increased 6 month odds of mortality on univariate analysis (OR 2.61, 95%CI 1.29-4.94), as was malignancy (OR 2.98 95%CI 1.72-5.08) and higher Charlson index (OR 1.22, 95%CI 1.12-1.32). On multivariate analysis adjusted for age, comorbidity, admission hemoglobin, ICU needs, congestive heart failure, and malignancy, use of triple therapy remained associated with increased 6 month mortality risk (OR 2.55, 95% CI 1.29-4.95). Conclusion: Use of triple therapy with dual antiplatelet and oral anticoagulation is associated with higher 6 month mortality in patients with CAD and GIB.