Abstract 11370: Coronary Artery Calcium Incidence Varies by ASCVD Risk: Insights From the Dallas Heart Study
Introduction: Absence of coronary artery calcium (CAC=0) is associated with favorable cardiovascular outcomes and can be useful for down-classifying risk in middle-aged asymptomatic individuals. Identifying predictors of incident CAC can inform preventive measures.
Hypothesis: We hypothesized that in a young, multi-ethnic, population-based cohort, increasing atherosclerotic cardiovascular disease (ASCVD) risk would be associated with incident CAC on repeat scanning.
Methods: Participants of the Dallas Heart Study (DHS) underwent CAC scanning at baseline (EBCT) and at follow up (MDCT), after a mean interval of 6.9 years. Participants with baseline CAC=0 were included, and those with clinical ASCVD or on statin therapy were excluded. Incident CAC was analyzed as CAC >0 as well as CAC >10 at follow up. ASCVD risk was calculated using the 2013 AHA/ACC risk estimator.
Results: Among 2,272 participants with baseline and follow up CAC measurements, 756 participants meeting exclusion criteria had absent CAC (CAC=0) at baseline, with a mean age of 42 years, 65.6% women, and 42.2% blacks. Of these individuals, incident CAC occurred in 23.8% using CAC >0 and in 8.3% using CAC >10. Risk markers associated with incident CAC >0 included baseline 10-year ASCVD risk, family history of coronary heart disease, low density lipoprotein particle concentration, diabetes and statin use at follow up. In fully adjusted analyses, only baseline 10-year ASCVD risk was associated with incident CAC >0. The prevalence of CAC >0 at follow up by baseline 10-year ASCVD risk categories of <5%, ≥5 to <7.5%, and >7.5% was 21.2%, 41.5%, and 51.4%, respectively (p-trend<0.01). The prevalence of CAC >10 was 7%, 12.2%, and 27.1% respectively.
Conclusions: In this young cohort, one in four individuals with absent CAC developed incident CAC after approximately 7 years. Reassessing risk, including consideration of repeat CAC measurement in those with higher baseline 10-year ASCVD risk, may be warranted.
Author Disclosures: A. Mehta: None. P. Joshi: None. C. Ayers: None. K. Nasir: Consultant/Advisory Board; Modest; Dr. Nasir is on the advisory board for Quest Diagnostic and a consultant for Regeneron. J. Berry: None. A. Rohatgi: None. A. Khera: None.
- © 2016 by American Heart Association, Inc.