ACC: Calcium scoring protocol adds no benefit to CT in predicting CAD events

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In patients with suspected coronary artery disease (CAD), combined coronary artery calcium (CAC) scoring and coronary CT angiography (CCTA) are no more beneficial than the CCTA protocol alone in the prediction of major adverse cardiac events (MACE), based on the results of a poster presentation at the American College of Cardiology (ACC) annual conference in Atlanta earlier this month.

Sung Woo Kwon, MD, of Yale University Health Services in New Haven, Conn., and colleagues said that their study explored differential prognostic values of CCTA scanning protocols in contemporary multislice CT (MSCT) technology, and in consideration of radiation exposure, CAC scoring is not a necessary protocol for the detection of CAD.

“Prior to the multislice CT technology era, previous studies have shown that the coronary artery calcium scoring protocol has additional benefit [when added] to CCTA, but this study has shown that there is no significant difference to CCTA alone and combining [the two protocols],” said Kwon.

Kwon and colleagues recruited 4,338 patients between the ages of 50-70 years (53 percent male) who had undergone 64-slice CT for the evaluation of suspected CAD. Exclusion criteria included early revascularization within 60 days after CT, wrote the authors.

Data were analyzed by way of CCTA and CAC scoring, which was classified as 0, 1-10, 11-100, 101-400 and greater than 400. The extent of CAD was grouped according to occurrences of no CAD, one-vessel disease, two-vessel disease and three-vessel disease, and severity of the disease was considered as 0 percent, 1-39 percent (mild) 40-69 percent (moderate) and greater than 70 percent (severe). In addition, the researchers said that that by merging extent and severity of CAD diagnosed by CCTA, nine subgroups of data emerged.

The study endpoints were any occurrences of cardiac death, non-fatal MI, unstable angina requiring hospitalization, and revascularization.

CCTA was found to be better than CAC scoring for the prediction of MACE in patients with suspected CAD and the authors concluded that the combination of CAC scoring to the 64-slice CCTA protocol is not necessary any longer for this patient population.

“We do not need to perform the coronary artery calcium scoring protocol anymore,” said Kwon. “With the concern of radiation, we do not need the added exposure if it is of no benefit to the patient.”