Long-term Risk of Acute Coronary Syndrome in Patients with Inflammatory Bowel Disease: A 13-year Nationwide Cohort Study in an Asian Population

Background: Whether patients with inflammatory bowel disease (IBD) exhibit a higher risk of developing acute coronary syndrome (ACS) remains debatable. Methods: From the inpatient claims of Taiwan's National Health Insurance Research Database, we identified 11,822 patients with IBD symptoms in the 1998-2010 period and 47,288 control patients without the disorder, frequency matched by age, sex, and admission year. Both cohorts were followed-up until the end of 2010 to estimate the risk of ACS. Results: The incidence of ACS was 87% higher in the patients with IBD than in the control patients (5.76 versus 3.08 per 1000 person-years). The multivariable Cox proportional hazards regression model measured adjusted hazard ratios of ACS at 1.72 (95% confidence interval, 1.53-1.94) for the patients with IBD. The age-specific data showed that the adjusted hazard ratio for patients with IBD, compared with control patients, was the highest for the 20- to 39-year age group, at 3.28 (95% confidence interval, 1.73-6.22), which decreased to 1.70 (95% confidence interval, 1.45-1.99). Patients with IBD who, on average, required 2 or more hospitalization per year were nearly 20-fold more likely to have ACS than those who required 1 hospitalization per year (80.7 versus 4.10 per 1000 person-years). Conclusions: The absolute risk of ACS increases sharply with age for patients with IBD, but young patients are at greater relative risk for the consequence. The risk of ACS was proportional to the severity of IBD. Careful follow-up observation and effective therapy should be sought for patients with IBD to reduce the risk of ACS.