Background. Unrecognized myocardial infarctions (UMIs) are common in the general population but have not been well studied in patients with chronic kidney disease (CKD). The purpose of this study was to determine the prevalence and prognosis for mortality of UMI among adults with CKD. Methods. The current study included 18 864 participants in the population-based REasons for Geographic And Racial Differences in Stroke (REGARDS) study who completed a baseline examination including a 12-lead electrocardiogram (ECG). UMI was defined as the presence of myocardial infarction (MI) by Minnesota ECG classification in the absence of self-reported or recognized MI (RMI). Estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation and albuminuria using albumin-to-creatinine ratio from a spot urine sample. All-cause mortality was assessed over a median 4 years of follow-up. Results. The prevalence of UMI was 4, 6, 6 and 13% among participants with eGFR levels of <60, 4559.9, 3044.9 and <30 mL/min/1.73m2, respectively, and 4, 5, 7 and 10% among participants with albuminuria levels of <10, 1029.9, 30299.9 and <300 mg/g, respectively. Compared to those with no MI, the multivariable adjusted hazard ratio for all-cause mortality associated with UMI and RMI was 1.65 [95% confidence interval (CI): 1.092.49] and 1.65 (95% CI: 1.202.26), respectively, among individuals with an eGFR <60 mL/min/1.73m2 and 1.49 (95% CI: 1.032.16) and 1.88 (95% CI: 1.402.52) among individuals with albuminuria <30 mg/g. Conclusion. UMIs are common among individuals with an eGFR <60 mL/min/1.73m2 and albuminuria and associated with an increased mortality risk. © 2011 The Author.
