Abstract 10804: Incidence and Prognostic Significance of Silent Versus Clinically Manifest Myocardial Infarction in the Atherosclerosis Risk in Communities (ARIC) Study
Background: Differences in the incidence and prognostic significance of silent myocardial infarction (SMI) vs. MI with clinical manifestations (CMI) are not well-established in racially diverse populations.
Methods: We compared the incidence of SMI and CMI and their associations with coronary heart disease (CHD) death and death from all causes in 9,498 participants (mean age 54 years, 56.9% women, 20.3% African-American) from the Atherosclerosis Risk in Communities (ARIC) study who were free of cardiovascular disease at baseline visit (1987-89). Incident SMI was defined as ECG evidence of MI without documented CMI occurring after the baseline visit until visit 4 (1996-98). CHD and all-cause deaths were ascertained starting from ARIC visit 4 until 2010 (median follow up 12 years).
Results: There were 386 (4.1%) incident CMIs and 317 (3.3%) SMIs. Both CMI and SMI were more common in men (6.8% and 4.3%, respectively) than in women (2.0% and 2.6%, respectively) p<0.001. Although SMI rates were comparable in blacks and whites (3.8% vs.3.2%, respectively), CMI was higher in whites (4.4% vs. 2.8%, respectively), p=0.003. In multivariable adjusted Cox Proportional models, both SMI and CMI (compared to no MI) were associated with increased risk of CHD and all-cause deaths, but the risk was higher in the CMI group (Table). A significant interaction by sex was observed; SMI and CMI were associated with higher risk of CHD and all-cause deaths in women compared to men (interaction p-value= 0.014). No significant interactions by age or race were detected.
Conclusions: SMI is as common as CMI, and both are associated with increased risk of CHD and all-cause mortality. Racial and sex differences in the distribution of SMI and CMI, as well as sex differences in the prognostic significance of SMI and CMI exist. These findings suggest that an ECG finding of MI in persons without a history of MI may warrant consideration in personalized CHD prevention risk management efforts particularly in women.
Author Disclosures: Z. Zhang: None. P.M. Rautaharju: None. R.J. Prineas: None. C.J. Rodriguez: None. L. Loehr: None. W. Rosamond: None. D. Kitzman: None. D. Couper: None. E.Z. Soliman: None.
- © 2015 by American Heart Association, Inc.