Coronary artery calcification can effectively stratify risk for all-cause and cardiovascular (CV) mortality in people with obesity with no prior CV disease.
Obesity increases the likelihood of developing cardiovascular risk factors, such as diabetes and hypertension, and also independently predicts risk for cardiovascular diseases (CVD), including coronary heart disease (CHD), atrial fibrillation, heart failure, and stroke. “The emergence of new therapeutics for obesity, such as glucagon-like peptide-1 agonists (GLP-1 RAs), represents a significant advance in the management of obesity, but the high cost of these new therapies presents a substantial barrier to their widespread use among many patients with obesity,” explains Michael J. Blaha, MD, MPH. “Consequently, it’s imperative to identify patients at higher cardiovascular risk who would benefit the most from these medications.”
The SELECT clinical trial recently demonstrated significant cardiovascular benefits for patients with obesity who received a GLP-1 RA. “Results from the SELECT trial have bolstered the importance of considering personalized treatment strategies for individuals with obesity,” Dr. Blaha says. “The findings underscored the need to identify and treat these patients because of their increased risk [for] cardiovascular events and because they’re more likely to benefit from these therapies.”
Coronary artery calcification (CAC), which is measured noninvasively using cardiac-gated CT scans, is an effective and reliable risk stratification tool across different population subgroups, but it remains unclear whether CT-obtained CAC scores can effectively stratify risk in patients with obesity. For a study published in Obesity, Dr. Blaha and colleagues examined the utility of CAC for risk stratification among people with obesity by evaluating the predictive value of CAC for all-cause, cardiovascular, and CHD mortality.
Data were collected from 9,334 participants with a BMI of 30 or higher from the CAC Consortium, a retrospectively assembled cohort of patients without prior CVD. “The primary objective of our study was to demonstrate that the CAC score is a reliable test for delineating the risk spectrum of patients with obesity,” says Dr. Blaha. “Utilizing this score may facilitate more informed discussions regarding obesity management and help guide treatment decisions.”
CAC Scores Help Stratify Cardiovascular Risks in Obesity
According to the study findings, 58.5% of the participants had CAC. Compared with patients with a CAC score of 0 Agatston units (AU), patients with CAC scores of 1-99, 100-299, and 300 AU or higher had higher rates per 1000 person-years of all-cause, CVD, and CHD mortality after a mean follow-up of 10.8 years. The presence of CAC was associated with a 1.4-fold higher hazard of all-cause mortality and a 2.1-fold and 2.7-fold higher hazard of cardiovascular and CHD mortality, respectively.
In addition, patients with obesity and CAC levels of 300 AU had an even higher risk for all three outcomes of interest, particularly among patients with class 2 obesity or higher (Figure). “This is important because obesity is commonly a barrier to effective imaging use in clinical practice. Our findings show that CAC scores can function as an effective tool for cardiovascular risk stratification among individuals with obesity.”
Using CAC to Identify Candidates for Anti-Obesity Medications
According to Dr. Blaha, findings from the study suggest that CAC scores can be used to enhance approaches to obesity management. “CAC scores can serve as a guide in the shared decision-making process and help ensure that physicians offer therapies to patients who are most likely to benefit from them,” he says. “Continued risk assessments are also important because not everyone with obesity has the same risk. Of note, there is a movement to consider patients with very high CAC scores as having ‘secondary prevention level risk.’ This is important when implementing results from the SELECT trial, which enrolled secondary prevention patients. [Patients with obesity] with very high CAC scores may potentially achieve similar benefits as to what was seen in the SELECT trial.”
Dr. Blaha hopes future research will include a next-generation trial of GLP-1 RAs in patients with high CAC scores. “This would potentially extend the indication of GLP-1 RAs for cardiovascular risk lowering to primary prevention patients with so-called advanced subclinical atherosclerosis.”
