CAC Score Improves Coronary and CV Risk Assessment Above Statin Indication by ESC and AHA/ACC Primary Prevention Guidelines.

OBJECTIVES: The aim of this study was to assess the difference in indication for statin therapy by European Society of Cardiology (ESC) versus American Heart Association/American College of Cardiology (AHA/ACC) guidelines and to quantify the potential additional role of coronary artery calcification (CAC) score over updated guidelines in a primary prevention cohort.

BACKGROUND: Recently, ESC and AHA/ACC updated the guidelines regarding statin therapy in primary prevention.

METHODS: In 3,745 subjects (59 ± 8 years of age, 47% men) from the population based longitudinal Heinz Nixdorf Recall cohort study without cardiovascular disease or lipid-lowering therapy at baseline CAC score was assessed between 2000 and 2003. Subjects remained unaware of their initial CAC score. Statin indication was determined according to 2012 ESC and 2013 AHA/ACC guidelines based on subjects individual baseline characteristics.

RESULTS: The frequency of statin recommendation was lower according to ESC compared to AHA/ACC guidelines (34% vs. 56%; p < 0.0001), whereas low CAC score (<100) was common in subjects with statin indication by both guidelines (59% for ESC, 62% for AHA/ACC). During 10.4 ± 2.0 years of follow-up, 131 myocardial infarctions occurred. For ESC recommendations, CAC score differentiated risk for subjects without (1.0 [95% confidence interval (CI): 0.4 to 1.5] vs. 6.5 [95% CI: 4.1 to 8.9] coronary events per 1,000 person-years for CAC 0 vs. ≥100) and with statin indication (2.6 [95% CI: 0.6 to 4.7] vs. 9.9 [95% CI: 7.3 to 12.5] per 1,000 person-years for CAC 0 vs. ≥100). Likewise, CAC score stratified proportions experiencing events subjects with statin indication according to AHA/ACC (2.7 [95% CI: 1.1 to 4.2] vs. 9.1 [95% CI: 7.0 to 11.0] per 1,000 person-years for CAC 0 vs. ≥100), whereas event rate in subjects without statin indication was low (1.1 [95% CI: 0.65 to 1.68] per 1,000 person-years).

CONCLUSIONS: Current ESC and AHA/ACC guidelines lead to markedly different recommendation regarding statin therapy in a German primary prevention cohort. Quantification of CAC score in addition to the guidelines improves stratification between subjects at high versus low risk for coronary events, indicating that CAC scoring may help to match intensified risk factor modification to atherosclerotic plaque burden as well as actual risk while avoiding therapy in subjects with low coronary atherosclerosis that have low 10-year event rate.