CT Data Challenge Diabetes as a Cardiac Risk
Major finding: On CT examination, coronary artery calcium scores appeared similar in patients with diabetes, metabolic syndrome, or neither disease.
Source of data: The findings are based on a new analysis of data from the Multi-Ethnic Study of Atherosclerosis (MESA), which enrolled more than 6,800 people aged 45–84 who were free of cardiovascular disease at baseline. The new analysis focused on coronary CT exams of people with diabetes, metabolic syndrome, or neither disease at baseline.
Disclosures: Dr. Malik had no financial disclosures. One of her coauthors is a consultant for GE, and another associate is on the speakers bureau for Takeda.
ORLANDO — Nearly 40% of adults with diabetes had absolutely no evidence of coronary artery disease in a study of 881 patients, raising questions about the appropriateness of automatically considering diabetes a risk equivalent to coronary disease.
The study findings also suggested that assessing coronary calcium may be a way to stratify the coronary disease risk of patients with diabetes, as well as those with metabolic syndrome and people without either of these conditions, Dr. Shaista Malik explained at the annual scientific sessions of the American Heart Association.
“Our results raise questions as to whether diabetes should be considered a risk equivalent. They suggest that coronary artery calcium [CAC] screening may identify both low- and high-risk subsets in patients with metabolic syndrome and in patients with diabetes,” said Dr. Malik, a cardiologist at the University of California, Irvine.
“High-risk people, such as those with diabetes, have not been recommended for coronary calcium screening since aggressive treatment guidelines [for these patients] already exist,” she noted. But her new analysis suggests that CAC scoring can play an important role in stratifying the coronary heart disease risk of patients with diabetes.
These results “add to the controversy over whether diabetes is truly a coronary heart disease risk equivalent,” commented Dr. Prakash C. Deedwania, professor of medicine and chief of cardiology at the University of California, San Francisco in Fresno.
“Perhaps some patients [with diabetes], particularly those with longer-duration diabetes, are probably close to having a coronary heart disease risk equivalent, but there probably should be an effort made to identify the low- and high-risk patients within the diabetes cohort,” Dr. Deedwania said.
Dr. Malik used data collected in the Multi-Ethnic Study of Atherosclerosis (MESA), which enrolled more than 6,800 people aged 45–84 who were free of cardiovascular disease at baseline.
The new analysis focused on 881 people in MESA diagnosed with diabetes at baseline based on a fasting glucose level of 126 mg/dL or higher; 1,686 people diagnosed with metabolic syndrome at baseline based on National Heart, Lung, and Blood Institute criteria; and 4,036 people who did not have either diagnosis. All 6,603 of these people underwent a baseline coronary CT examination to produce a CAC score. Follow-up tracked their incidence of coronary heart disease events over an average of 4.6 years.
Baseline CAC scores showed that among people with diabetes, 39% had no coronary calcium, 27% had mild coronary disease with a CAC of 1–99, 14% had moderate coronary disease with a score of 100–399, and 21% had significant disease, with a CAC of at least 400. People with metabolic syndrome and those with neither diagnosis had higher percentages with no coronary calcium and lower percentages with significant coronary disease, but in general the CAC scores in all three subgroups were similar.
During follow-up, coronary events occurred in 33 people in the diabetes group, 43 in the metabolic syndrome group, and 52 in the people without either diagnosis.
Calculation of the 10-year event rate within each of these three subgroups showed roughly similar rates within each CAC score category (see table), especially among those with a CAC score of zero.
'Coronary artery calcium screening may identify both low- and high-risk subsets.'
Source DR. MALIK
Source Elsevier Global Medical News
