Also, both approaches would produce net savings. “However, these would be greater with the broad statin prevention strategy than with the coronary calcium reclassification strategy,” the authors report.
Dr. Allan D. Sniderman, with Royal Victoria Hospital and McGill University Health Centre in Montreal, Quebec, Canada, and colleagues explain that a consensus panel of the American College of Cardiology and American Heart Association has recommended coronary artery calcium screening as a way to characterize cardiovascular risk more accurately and to target medical therapy, thereby improving clinical outcomes.
To evaluate that proposition, the team looked at two intervention strategies using data on 1,847 participants in the Multiethnic Study of Atherosclerosis who were conventionally classified as at intermediate risk (3%-10%) of having a cardiovascular event within 5 years.
Under one scenario, if all these patients were treated with 20 mg/d atorvastatin or equivalent, it would reduce clinical events by 23.1% — based on the known efficacy of statins, the authors calculated.
In the second scenario, patients were reclassified for cardiovascular risk based on their coronary artery calcium score. Those at low risk would not be treated; the remaining 1135 patients — those at intermediate risk and high risk — would receive 20 mg/d or 80 mg/d atorvastatin, respectively. This approach would produce a 22.8% decrease in clinical events, according to the report.
The net savings associated with the two strategies, however, would differ substantially because of the cost of coronary artery calcium screening. Specifically, the net savings would be US$732,152 with broad statin therapy versus $288,326 with the targeted approach.
Moreover, the authors suggest, coronary artery calcium (CAC) testing may only defer treatment of patients reclassified as low risk until some time in the future, possibly when their condition is more advanced and preventive therapy less effective.
Based on their findings, Dr. Sniderman and colleagues conclude, “A comparative effectiveness trial comparing targeted statin use based on CAC scoring to broadened use of statins to all those at IR (intermediate risk) could be considered to provide the required evidence to drive public health policy.”