medwireNews: Results of a multiethnic cohort study suggest that coronary artery calcium (CAC) scoring can predict long-term cardiovascular risk in patients with and without metabolic abnormalities.
As reported in JAMA Cardiology, Shaista Malik (University of California, Irvine, USA) and team compared the ability of CAC scores to predict coronary heart disease (CHD) and atherosclerotic cardiovascular disease (CVD) among participants of the Multi-Ethnic Study of Atherosclerosis who had type 2 diabetes, metabolic syndrome (MetS), or neither condition.
Over an average 11.1 years of follow-up, 9.5% of the 881 patients with diabetes, 6.6% of the 1738 patients with MetS, and 3.8% of the 4132 participants with neither condition experienced CHD events.
Although patients with diabetes had the highest overall cardiovascular risk, Malik and colleagues observed “a stepwise increase” in the incidence of CHD and atherosclerotic CVD events with increasing severity of CAC.
In multivariable analyses adjusting for factors including Framingham Risk Score, ethnicity, and socioeconomic status and using a CAC score of 0 as the reference, having a CAC score of 1–99 was associated with a 2.31-fold increased risk for CHD among patients with diabetes, a 2.63-fold increased risk among patients with MetS, and a 2.33-fold increased risk for those with neither condition.
And for those in the highest CAC score category (≥400), the risk for CHD was elevated 5.60-fold, 6.42-fold, and 7.87-fold for patients with diabetes, MetS, or neither, respectively. The researchers observed a similar pattern of results for atherosclerotic CVD risk.
These findings “indicate that evaluation of subclinical atherosclerosis with CAC scoring identifies downstream CHD and [atherosclerotic] CVD events more than a decade after screening has been done regardless of the presence of diabetes or MetS,” say Malik and team.
Moreover, “the severity of CAC appears to be a more important clinical prognostic indicator than measures of disease severity, such as insulin use, glycemic control, and diabetes duration,” they add.
Indeed, when patients in the diabetes group were categorized according to disease duration, the rates of CHD and atherosclerotic CVD risk were largely comparable between patients with diabetes duration of up to versus at least 10 years. This was true for participants across all categories of calcification except the group with the highest CAC scores, in which patients with diabetes duration of at least 10 years had substantially higher rates of CHD (30.7 vs 17.9 per 1000 person–years) and atherosclerotic CVD (42.6 vs 28.4 per 1000 person–years) than those with a shorter duration of disease.
Furthermore, having a lower CAC score was associated with a lower risk for CHD and atherosclerotic CVD risk after controlling for insulin use and glycemic control.
Taken together, these results “support the clinical utility of CAC scoring in those with diabetes and MetS,” write the researchers.
And they call for further research to investigate whether mediations such as sodium–glucose co-transporter 2 inhibitors or glucagon-like peptide-1 receptor agonists “could be considered for those at increased risk based on extent of CAC or other measures of subclinical atherosclerosis.”
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