Abstract 18513: Escalating Risk of All Cause Mortality in Asymptomatic Individuals with Very High Coronary Artery Calcium Scores: Is a Severely Elevated Coronary Artery Calcium Threshold of 1000 Severe Enough?
Background: In clinical practice, coronary artery calcium (CAC) score are generally categorized into ranges that include 0, 1–10, 11–100, 101–400, 401–1000, and >1000. A CAC>1000_the most severe of these categories_portends a very high risk of adverse cardiac events for asymptomatic patients. At present, whether there is increased mortality risk with further increases in CAC score above 1000 is unknown.
Methods: The study cohort was derived from 44,052 (54±11 years, 54% males) individuals undergoing CAC scoring for atherosclerosis risk assessment. Overall 4% (n=1595) of the individuals had CAC>1000, and were further classified according to increasing CAC scores (1001–1500, 1501–2000, 2001–2500 & >2500). Follow-up was performed for a median of 4.5 years (range 1–13 years) for occurrence of mortality from any cause.
Results: 1595 asymptomatic individuals without known coronary artery disease (CAD) comprised the study population (mean age: 66±10 years, 56% men). Individuals with increasing CAC scores >1,000 were more likely to be older (p=0.0003) and diabetic (p=0.001), whereas no differences in other CAD risk factors were noted (all p=NS). During follow-up, 195 deaths (12.2%) occurred, with survival rates ranging from 90.4%-81.1% across increasing CAC categories. After risk adjustment, log increase in CAC scores was associated with a 32% increase in mortality (HR 1.32, 95% CI 1.26–1.39, p<0.0001). As compared to those with CAC scores 1001–1500, no increased risk of mortality was noted for those with CAC between 1501–2000. However, CAC>2000 and CAC>2500 were significantly associated with a 64% and 89% increase in mortality (Table 1).
Conclusions: Amongst individuals with a CAC>1000, a CAC>2000 represents an additional discrete threshold that is associated with escalating risk. Future studies examining this threshold for risk reclassification and patient management should be performed.
- © 2010 by American Heart Association, Inc.