Coronary Artery Calcium Scanning Improves Risk Stratification

In the JUPITER study, patients with low cholesterol levels but raised high-sensitivity C-reactive protein (hsCRP) levels were seen to benefit from treatment with rosuvastatin, although overall cardiovascular events were low.  In this study, the authors investigated whether the use of coronary artery calcium (CAC) scoring could further stratify risk in a population of patients from the Multi-Ethnic Study of Atherosclerosis (MESA) who all met criteria for entry into the JUPITER study.

950 participants were selected, and the burden of coronary artery calcium was scored as either 0, 1-100, or >100.  Coronary heart disease and cardiovascular disease event rates and multivariable-adjusted hazard ratios were compared after stratifying amongst the three CAC groups.  The 5-year number needed to treat was calculated by applying the benefit recorded in JUPITER to the event rates within each CAC strata.

The median follow-up was 5.8 years.  444 (47%) in the MESA JUPITER population had CAC scores of 0 and in this group very low rates of coronary heart disease events were seen: 0.8 per 1000 person-years.  74% of all coronary events were in the 239 (25%) of participants with CAC scores of more than 100: 20.2 per 100 person-years.  For cardiovascular disease, therefore, the number needed to treat was 124 for patients with a CAC of 0, 54 for those with a score of 0-100, and 19 for those with a score of over 100.  Of note, hsCRP was not associated with either coronary heart or cardiovascular disease after multivariable adjustment.

Conclusions:

CAC can be used to further risk stratify patients who meet the criteria for entry into the JUPITER trial, and could be used to target those patients who are likely to benefit the most (and the least) from statin therapy.

  • Blaha MJ, Budoff MJ, DeFilippis AP et al.  Associations between C-reactive protein, coronary artery calcium, and cardiovascular events: implications for the JUPITER population from MESA, a population-based cohort study.  Lancet 2011; 378:684-692.