No abstract

Background The improvement in discrimination gained by adding nontraditional cardiovascular risk markers cited in the 2013 American College of Cardiology/American Heart Association cholesterol guidelines to the atherosclerotic cardiovascular disease (ASCVD) risk estimator (pooled cohort equation [PCE]) is untested. Objectives We assessed the predictive accuracy and improvement in reclassification gained by the addition of coronary artery calcium (CAC) score, ankle-brachial index (ABI), high-sensitivity C-reactive protein (hsCRP), and family history (FH) of ASCVD to the PCE in participants of the MESA (Multi Ethnic Study of Atherosclerosis). Methods The PCE was calibrated (cPCE) and used for this analysis. Cox proportional hazard model, Harrell's C-statistics, and net reclassification improvement analyses were used. ASCVD was defined as myocardial infarction, coronary heart disease death, or fatal or nonfatal stroke. Results Of 6,814 MESA participants not on statins at baseline, 5,185 had complete data and were included in this analysis. Mean age was 61years; 53.1% were women, 9.8% diabetic, and 13.6% current smokers. After 10 years of follow-up, 320 (6.2%) ASCVD events occurred. CAC, ABI, and FH were independent predictors of ASCVD events in the multivariable Cox models. CAC modestly improved the Harrell's C-statistic (0.74 vs. 0.76; p = 0.04) while ABI, hsCRP, and FH showed no improvement in Harrell's C-statistic when added to the cPCE. Conclusions CAC, ABI, and FH are independent predictors of ASCVD events. CAC modestly improved the discriminative ability of the cPCE best compared with other nontraditional risk markers.

IMPORTANCE-Myocardial infarction (MI) is an established risk factor for atrial fibrillation (AF). However, the extent to which AF is a risk factor for MI has not been investigated. OBJECTIVE-To Conflict of Interest Disclosures: None reported.Previous Presentation: An abstract of this article (No. 1151-49) was presented at the American College of Cardiology Annual 2013 Meeting; March 9, 2013; San Francisco, California. Additional Contributions:The authors thank the investigators, staff, and participants of the REGARDS study for their valuable contributions. A full list of participating REGARDS investigators and institutions can be found at http://www.regardsstudy.org. CONCLUSIONS AND RELEVANCE-AF is independently associated with an increased risk of incident MI, especially in women and blacks. These findings add to the growing concerns of the seriousness of AF as a public health burden: in addition to being a well-known risk factor for stroke, AF is also associated with increased risk of MI. NIH Public AccessAtrial fibrillation (AF) is a major public health problem owing to its increasing prevalence and strong association with morbidity and mortality. 1,2 Patients with AF have 4 to 5 times the risk of stroke and about double the risk of mortality compared with those without AF. [3][4][5][6] Myocardial infarction (MI) is an established risk factor for AF, 7 with AF occurring in 6% to 21% of patients with MI. 8 Conversely, sporadic cases of thromboembolic acute MI also have been reported in patients with AF, 9-16 and presence of AF during acute MI has been associated with increased risk of developing in-hospital reinfarction. 8 These findings suggest that AF could also be a risk factor for MI. However, evidence from population studies to support this assertion is lacking. Therefore, we examined the association between AF and risk of incident MI in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, 17 a large biracial population-based cohort study. MethodsThe study protocol was reviewed and approved by the participating institutions' institutional review boards. Informed consent was obtained initially on the telephone and subsequently in writing during an in-person evaluation.The goals and design of the REGARDS study have been published elsewhere. 17 Briefly, the study was designed to investigate causes of regional and racial disparities in stroke mortality, oversampling blacks and residents of the southeastern stroke belt region (North Carolina, South Carolina, Georgia, Alabama, Mississippi, Tennessee, Arkansas, and Louisiana). During the period from January 2003 to October 2007, participants (n = 30 239) were recruited from a commercially available list of residents using a combination of postal For this report, individuals with prevalent coronary heart disease (CHD) (self-reported history of MI or coronary revascularization procedure at baseline or evidence of prior MI on the baseline electrocardiogram [ECG]) were excluded. We also excluded participants with missing informatio...