Culprit and nonculprit recurrent ischemic events in patients with myocardial infarction: Data from SWEDEHEART (Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies)

Background--Long-term disease progression after myocardial infarction (MI) is inadequately understood. We evaluated the pattern and angiographic properties (culprit lesion [CL]/non-CL [NCL]) of recurrent MI (re-MI) in a large real-world patient population. Methods and Results--Our observational study used prospectively collected data in 108 615 patients with first-occurrence MI enrolled in the SWEDEHEART (Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) between July 1, 2006 and November 29, 2014. During follow-up (median, 3.2 years), recurrent hospitalization for MI occurred in 11 117 patients (10.2%). Of the patients who underwent coronary angiography for the index MI, a CL was identified in 44 332 patients. Of those patients, 3464 experienced an re-MI; the infarct originated from the NCL in 1243 patients and from the CL in 655 patients. In total, 1566 re-MIs were indeterminate events and could not be classified as NCL or CL re-MIs. The risk of re-MI within 8 years related to the NCL was 0.06 (95% confidence interval [CI], 0.05-0.06), compared with 0.03 (95% CI, 0.02-0.03) for the CL. There were no large differences in baseline characteristics of patients with subsequent NCL versus CL re-MIs. Independent predictors of NCL versus CL re- MI were multivessel disease (odds ratio, 2.29; 95% CI, 1.87-2.82), male sex (odds ratio, 1.36; 95% CI, 1.09-1.71), and a prolonged time between the index and re-MI (odds ratio, 1.16; 95% CI, 1.10- 1.22). Conclusions--In a large cohort of patients with first-occurrence MI undergoing percutaneous coronary intervention, the risk of re-MI originating from a previously untreated lesion was twice higher than the risk of lesions originating from a previously stented lesion.