Detection of coronary artery disease (CAD) through coronary computed tomography angiography (CCTA) may affect treatment, particularly the use of statins and aspirin, lowering cholesterol in a sustainable way and possibly improving long-term cardiovascular health.

Following three cohorts of patients who underwent CCTA from 2004 through 2011 at Massachusetts General Hospital or Brigham and Women’s Hospital in Boston, researchers wanted to determine how much effect the imaging process had on treatment and outcomes. These three groups, diagnosed by use of CCTA, in which patients either had no CAD, non-obstructive CAD or obstructive CAD, were followed for an average of 3.6 years.

Edward Hulten, MD, MPH, of Brigham and Women’s Hospital, and colleagues found that prescribing choices changed following imaging and the odds of lipid-lowering therapy being increased by the physician were increased for obstructive (63 percent, odds ratio 5.6) and non-obstructive (47 percent, odds ratio 3.6) cardiovascular disease.

Overall, patients saw a significant decrease in their low-density lipoprotein (LDL) cholesterol levels following a decision to intensify lipid prescriptions after a scan, contributing to reductions in risk of MI or death in the follow-up period. Most patients, whether diagnosed with CAD or not, saw a three- to four-fold increase in the prescription of aspirin as part of their therapy.

Comparing their results with other studies, Hulten et al noted that their findings were consistent but they were unsure as to why prescription rates were not higher following CT scans. “While patient factors (adverse effects, non-adherence, patient preference) may partially explain this finding, a breakdown in communication of results from imagers to clinicians or the failure of the treating clinician to alter medical therapy when indicated may play a role.”

They suggested that the care process be improved to keep at-risk patients from failing to receive preventative care.

While the tests themselves don’t directly affect medical outcomes, clinicians prescribing behaviors based on the results do. “Therefore, in order for a diagnostic test such as CCTA to improve patient outcomes, it is essential that the test leads to meaningful changes in therapies and, consequently, risk factors,” Hulten et al wrote.

This study was published online June 6 in Circulation: Cardiovascular Imaging.