Race and Sex Differences in the Incidence and Prognostic Significance of Silent Myocardial Infarction in the Atherosclerosis Risk in Communities (ARIC) Study.

BACKGROUND: Race and sex differences in silent myocardial infarction (SMI) are not well established.

METHODS AND RESULTS: The analysis included 9498 participants from the Atherosclerosis Risk in Communities (ARIC) study who were free of cardiovascular disease at baseline (visit 1, 1987-1989). Incident SMI was defined as ECG evidence of MI without clinically documented MI (CMI) after the baseline until ARIC visit 4 (1996-1998). Coronary heart disease and all-cause deaths were ascertained starting from ARIC visit 4 until 2010. During a median follow-up of 8.9 years, 317 participants (3.3%) developed SMI and 386 (4.1%) developed CMI. The incidence rates of both SMI and CMI were higher in men (5.08 and 7.96 per 1000-person years, respectively) than in women (2.93 and 2.25 per 1000-person years, respectively; P

CONCLUSIONS: SMI represents >45% of incident MIs and is associated with poor prognosis. Race and sex differences in the incidence and prognostic significance of SMI exist that may warrant considering SMI in personalized assessments of coronary heart disease risk.