Risk of Myocardial Infarction in Patients Without Angiographic Coronary Artery Disease Compared With the General Population

We examined the 10-year risk of myocardial infarction (MI) and death in patients without obstructive coronary artery disease (CAD) compared with the general population. We conducted a cohort study of every patient without obstructive CAD by coronary angiography (CAG) between 2003 and 2016 in Western Denmark. Patients were matched by gender and age with individuals from the general population of Western Denmark with no history of CAD. End points were MI and death. Ten-year risk differences in cumulative incidence proportions were computed, accounting for the competing risk of death in the case of MI. Unadjusted and adjusted incidence rate ratios (aIRRs) were estimated using conditional Poisson regression. We included 46,467 patients and 234,654 individuals from the general population. Median follow-up was 7.7 years. The 10-year cumulative incidence of MI was 2.40% (95% confidence interval [CI] 2.24 to 2.57) in patients without obstructive CAD in the CAG and 2.70% (95% CI 2.62 to 2.78) in the general population, with a reduced absolute 10-year risk (risk difference –0.30%, 95% CI –0.49 to -0.12) and a reduced aIRR (aIRR 0.70, 95% CI 0.63 to 0.77). Ten-year mortality was higher in patients without obstructive CAD in the CAG (21.44%, 95% CI 20.99 to 21.89) compared with the general population (17.25%, 95% CI 17.06 to 17.44). However, mortality rates were similar after adjustment (aIRR 1.00, 95% CI 0.96 to 1.02). In conclusion, the absence of obstructive CAD according to CAG is associated with a lower risk of MI than in the general population, and similar 10-year mortality.