Results from the BioImage study showed that limiting statins in elderly patients without coronary artery calcium (CAC) resulted in less overtreatment with little or no loss in sensitivity, according to new data published in the Journal of the American College of Cardiology.
BioImage was a prospective observational cohort of men aged 55 to 80 years and women aged 60 to 80 years (n=5805) who did not have atherosclerotic cardiovascular disease (ASCVD). Estimated 10-year ASCVD risk was ≥7.5% in 86% patients, making them statin-eligible. Risk was ≥15% in 55% of patients.
Among patients with a ≥7.5% 10-year risk for ASCVD, 28% had no CAC and 20% had no carotid plaque. The prevalence of significant atherosclerosis, defined as CAC ≥100 or carotid plaque burden ≥300, was similar in both the coronary and carotid arteries (39%).
Martin Bødtker Mortensen, MD of Aarhus University Hospital in Denmark, and colleagues assessed the consequences of down-classifying individuals with a 10-year ASCVD risk of 7.5% to <15% from statin-eligible to ineligible if CAC was 0, and up-classifying those with an “intermediate” ASCVD risk of 5% to <7.5% if CAC was ≥100 from optional to clear statin-eligible.
Researchers found that specificity, or less overtreatment, increased from 15% to 25% for both coronary heart disease (CHD) and CVD without any significant loss in sensitivity. Binary net reclassification index was 0.11 for CHD and 0.08 for CVD.
When the research team expanded the population eligible for down-classification to all individuals with a 10-year ASCVD risk ≥7.5% and CAC of 0, they found that specificity doubled, resulting in a binary net reclassification index of 0.20 for CHD and 0.14 for CVD.
Limiting statins to patients to those with 7.5% to <15% 10-year ASCVD risk decreased sensitivity nearly as much as specificity increased, resulting in no net effect on reclassification index. However, limiting statins for all individuals with a 10-year ASCVD risk ≥7.5% who also had carotid plaque burden of 0 resulted in specificity increasing (net reclassification index: .09 for CHD) more than sensitivity decreased (net reclassification index: .06 for CVD).
Mortensen MB, Fuster V, Muntendam, et al. A simple disease-guided approach to personalize ACC/AHA-recommended statin allocation in elderly people. The BioImage Study. J Am Coll Cardiol. 2016.68(9):881-891. doi:10.1016/j.jacc.2016.05.084.