P6391Major acute cardiovascular events in patients with inflammatory bowel disease

Abstract

Abstract Introduction Traditional risk factors for coronary heart disease have been reported in around 85% patients who present with myocardial infarction. More recently, inflammation and immune mediated diseases have been associated with ischemic heart disease. Inflammatory Bowel Disease (IBD) is an immune mediated disorder which comprises of ulcerative colitis and Crohn's disease. Estimated prevalence of IBD in the United States in 2004 was 1.4 million people. These patients have an overall increased risk of thrombotic complications with microvascular thrombosis hypothesized to contribute in disease pathogenesis. Results from a recent meta-analysis were consistent with increased risk of ischemic heart disease among IBD patients, with risk greater in females and younger patients, although heterogeneity was considerable in overall data. Also, in a recent study, IBD was found to be associated with an increased risk of acute myocardial infarction and heart failure despite lower prevalence of coronary risk factors in IBD patients. IBD pathogenesis involves sustained activation of immune responses with upregulation of cytokines including but not limited to IL-1 beta, IL-6 and TNF-alpha. Upregulation of these cytokines has also been reported in coronary atherosclerosis. Based on above information, we explored incidence of MACE (Major Adverse Cardiac Event) in this patient population from our health system data-base. Methods Propensity scores were estimated for all 15,292 (0.4%) patients with inflammatory bowel disease from a total patient pool of 3,917,894 patients in our health system to assemble a 1:1 matched cohort balanced for age, gender, race and known cardiovascular risk factors including hypertension, hyperlipidemia, diabetes mellitus and smoking (current and former). ICD-9 and ICD-10 codes were used to identify cardiovascular risk factors and outcomes. Results Matched patients (n=30,584) had a mean age of 51 years, with 58% of all being women, and 63% Caucasian. During the median follow up of 4.4 years all-cause mortality was observed in 1.7% and 1.2% of patients from IBD and non-IBD groups respectively (hazard ratio {HR}, 1.31; 95% confidence interval {CI}, 1.08–1.58; p=0.005). Combined outcome for myocardial infarction or all-cause mortality was noted in 4.1% and 3.4% from IBD and non-IBD groups respectively (HR, 1.16; 95% CI, 1.03–1.30; p=0.014) while HRs for cardiovascular mortality, myocardial infarction and unstable angina independently were 1.04 (0.74–1.47; p=0.833), 1.05 (0.89–1.23; p=0.591) and 1.10 (0.83–1.46; p=0.524) respectively. Conclusion Inflammatory bowel disease did not show association with myocardial infarction, cardiovascular mortality or unstable angina when matched for known cardiovascular risk factors, but was associated with increased all-cause mortality and combined end-point of all-cause mortality or myocardial infarction.