Coronary Artery Calcium in Relation to Initiation and Continuation of Cardiovascular Preventive Medications

BACKGROUND: Whether measuring and reporting of coronary artery calcium scores (CACS) might lead to changes in cardiovascular risk management is not established. In this observational study, we examined whether high baseline CACS were associated with the initiation as well continuation of new lipid-lowering medication (LLM), blood pressure-lowering medication (BPLM), and regular aspirin (ASA) use in a multi-ethnic population-based cohort. METHODS AND RESULTS: The Multi-Ethnic Study of Atherosclerosis (MESA) is a prospective cohort study of 6814 participants free of clinical cardiovascular disease at entry who underwent CAC testing at baseline examination (examination 1). Information on LLM, BPLM, and regular ASA usage was also obtained at baseline and at exams 2 and 3 (average of 1.6 and 3.2 years after baseline, respectively). In this study, we examined (1) initiation of these medications at examination 2 among participants not taking these medications at baseline; and (2) continuation of medication use to examination 3 among participants already on medication at baseline. Among MESA participants, initiation of LLM, BPLM, and ASA was greater in those with higher CACS. After taking into account age, sex, race, MESA site, LDL cholesterol, diabetes mellitus, body mass index, smoking status, hypertension, systolic blood pressure, and socioeconomic status (income, education, and health insurance), the risk ratios for medication initiation comparing those with CACS >400 versus CACS=0 were 1.53 (95% confidence interval CI, 1.08, 2.15) for LLM, 1.55 (95% CI, 1.10 to 2.17) for BPLM, and 1.32 (95% CI, 1.03 to 1.69) for ASA initiation, respectively. The risk ratios for medication continuation among those with CAC >400 versus CACS=0 were 1.10 (95% CI, 1.01 to 1.20) for LLM, 1.05 (95% CI, 1.02 to 1.08) for BPLM, and 1.14 (95% CI, 1.04 to 1.25) for ASA initiation, respectively. CONCLUSIONS: CACS >400 was associated with a higher likelihood of initiation and continuation of LLM, BPLM, and ASA. The association was weaker for continuation than for initiation of these preventive therapies.