P1095 Impact of inflammatory bowel disease on the risk of acute coronary syndrome: A Swedish Nationwide cohort study 2003-2021

There are conflicting data on the risk of acute coronary syndrome (ACS) in patients with inflammatory bowel disease (IBD) and only a few previous reports include patients diagnosed in the last decade. The aim of this study was to assess the risk of ACS in a modern population of IBD patients vs general population comparators. In this cohort study, we used nationwide registers to identify patients diagnosed with IBD in Sweden 2003-2021. Every patient was matched by birth year, sex, calendar year of diagnosis, and area of residence with up to ten general population comparators. The primary outcome was incident ACS (i.e. ST-segment elevation myocardial infarction [MI], non–ST-segment elevation MI, unspecific MI and unstable angina). Cox proportional hazard models were used to estimate hazard ratios (HRs). Overall, 76,517 patients with IBD (Crohn's disease (CD), N=22,732; ulcerative colitis (UC), N=42,194 and IBD-unclassified, N=11,591) and 757,141 comparators were identified (Table 1). During a median follow-up of 8 years, 2546 patients with IBD (37.5/10,000 person-years) were diagnosed with ACS as compared with 19,598 (28.0/10,000 person-years) in the general population comparators. This corresponded to an HR of 1.30 (95% confidence interval [CI]: 1.24-1.35) after adjustings for potential confounders, and approximately 1 extra case of ACS in 100 IBD patients followed for 10 years. HRs for ACS were higher during the first year of follow-up but remained increased even after 5 years of follow-up (Figure 1). The highest HRs for ACS were observed in patients with elderly onset IBD (≥60 years; HR: 1.35; 95% CI: 1.28-1.43) and in patients with CD and UC with extra-intestinal manifestations (HR in CD: 1.58; 95% CI: 1.20-2.09; HR in UC: 1.98; 95% CI: 1.63-2.40). When restricting analyes to patients with elderly onset IBD, the absolute risk increase corresponded to 1 additional case of ACS for every 30 IBD-patient followed for 10 years. In contrast, no increased HRs were observed in patients diagnosed with IBD before the age of 40. But of note, just a few of the patients diagnosed with IBD before 40 years of age were followed-up beyond 50 years of age. HRs for ACS were stable during the whole study period 2003-2021 with no signs of leveling off during recent years. In this contemporary cohort of patients with IBD, exposed to modern IBD-care, an increased risk for ACS was observed as compared with individuals of the general population. The highest HRs were observed in patients with elderly onset IBD and in patients with CD and UC with extra-intestinal manifestations.