Initiation and Continuation of Preventive Therapies Post-CAC Scan

Nonzero coronary artery calcium (CAC) scores significantly increase the likelihood of patients starting or continuing pharmacological and lifestyle therapies to prevent cardiovascular disease, according to a systematic review and meta-analysis published August 7 in JACC: Cardiovascular Imaging.

Ankur Gupta, MD, PhD, et al., searched the medical literature using PubMed, EMBASE (Excerpta Medica Database), Web of Science, Cochrane CENTRAL (Central Register of Controlled Trials), ClinicalTrials.gov and the International Clinical Trials Registry Platform to evaluate the association of CAC scores with downstream interventions.

After reviewing 6,256 citations and 54 full-text papers, a total of six studies from 2006 to 2011 met the researchers' eligibility criteria. Majority of the studies included were observational. The combined population included 11,256 patients, whose mean age ranged from 43-65 years and whose mean follow-up time ranged from 1.6-6 years. "All studies examined populations that were predominantly Caucasian except for the MESA study, which was multiethnic in nature," write the authors.

Regarding pharmacological therapies, the researchers found a two- to three-fold increase in the odds of aspirin initiation (ASA), lipid-lowering medication (LLM) initiation and blood pressure-lowering medication (BPLM) initiation. A two-fold increase in LLM continuation was also found for patients with nonzero CAC scores; however, no significant difference was found for those continuing ASA or BPLM.

Similar results were noted for CAC scores and lifestyle therapies. Researchers uncovered a two-fold increase in the odds of implementing increased exercise activity or dietary changes in patients with a nonzero CAC score. Additionally, the few studies that included a weight or smoking status did not show an association between CAC detection and smoking cessation or weight loss.

While the identification of coronary atherosclerosis by CAC scans increases the likelihood of preventive therapies, the authors underline that the "association of calcified coronary plaque with the downstream use of preventative therapies … does not, in itself, imply causation."

In an editorial comment, David J. Maron, MD, FACC, noted some important limitations to the study, including whether the patient, family member, health care provider or a combination of decision makers trigger the changes, what method of presentation of CAC scan results is most effective for commencing or continuing preventive therapies, whether previously described changes result in a decrease in cardiovascular events for this population, and more.

"The next big step is to learn from a randomized controlled trial if atherosclerotic cardiovascular disease outcomes are reduced in asymptomatic individuals who are found to have CAC and subsequently undergo preventative therapy," he wrote. "Then we can determine the value of incorporating CAC testing into routine screening for CAD risk factors."


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