Abstract 13711: Coronary Artery Calcium, Ankle-brachial Index, High Sensitivity C-reactive Protein, and a Family History of Coronary Artery Disease as Predictors of Incident Cardiovascular Events at Different Stages of Hypertension: The Multi-ethnic Study of Atherosclerosis

Abstract

Background: Coronary artery calcium (CAC), ankle-brachial index (ABI), high-sensitivity CRP (hsCRP), and family history (FHx) of coronary artery disease (CAD) are used as complementary aids in cardiac risk stratification. The 2017 ACC/AHA hypertension guideline’s new Stage I hypertension group has created uncertainty regarding intensity of blood pressure (BP) treatment in this group. We evaluated the comparative utility of CAC, ABI, hsCRP and FHx CAD as risk predictors of cardiovascular (CVD) events within different BP strata. Methods: The MESA cohort was followed for a median of 13 years with regards to incident coronary heart disease (CHD) and CVD events. BP was categorized per ACC/AHA guideline: normal- <120/<80, elevated 120-129/<80, stage I 130-139/80-89, and stage II ≥140/≥90. Participants on BP medications were assigned stage II. Cox regression was used to compare prediction of CHD and CVD events by CAC>300, CAC>75 t h %, ABI<0.9, hsCRP>2 mg/L and FHx CAD, stratifying by BP groups after adjusting for demographics, CVD risk factors and use of BP and cholesterol medications. Results: Of 6268 persons, 539 incident CHD events and 572 incident CVD events were noted. CAC>300 and CAC>75 th % predicted an increased CHD event risk throughout all BP groups. ABI<0.9 was predictive of CHD events in stage I and II, while hsCRP was not predictive in any group. CAC>300 predicted a 2-fold increased CVD risk in all BP groups after adjustment. In the Stage I group, CAC>300, CAC>75 th % and ABI<0.9 showed additive predictive value in incident CHD and CVD events. Using the adjusted model to predict CHD survival, CAC>300 had a consistently higher C-statistic throughout all BP categories compared to other risk markers. Conclusion: CAC>300 was associated with increased CHD and CVD risk in all BP groups and demonstrated superior prognostic utility compared to other risk markers. CAC>300, CAC>75 th % and ABI<0.9 showed potential as risk modifiers in the new Stage I hypertension group.