The relative risk of death or myocardial infarction (MI) went down with statin therapy in a cohort study of patients with either nonobstructive coronary artery disease (CAD) or no CAD at computed tomographic angiography (CTA). The absolute benefit of statins was directly proportional to CAD burden at imaging.

The findings speak to the effectiveness of statin therapy in patients without obstructive CAD at CTA and the evaluation of coronary artery calcium (CAC) for suspected CAD, and support a greater role for CTA and CAC scoring in deciding whether to initiate statins for primary prevention, proposes a report published online July 14 in JACC: Cardiovascular Imaging.

“Previously, there was a lack of evidence about how statins could possibly influence the outcomes of these patients,” said first author Kristian A. Øvrehus, MD, PhD, Odense University Hospital, Odense, Denmark, in an interview with theheart.org | Medscape Cardiology.

“The higher the cardiovascular risk, the more absolute benefits there are. That could possibly give us a tool in the future to help physicians and patients to decide whether to start preventive therapy not only based on risk factors but also visualized coronary artery disease,” Øvrehus said.

The researchers identified 33,552 adult patients with suspected CAD in the Western Denmark Cardiac Computed Tomography registry from 2008 to 2017 who were found not to have obstructive CAD at CTA.

Of the total, 19,669 patients had no CAD at imaging and 13,883 had nonobstructive CAD, defined as an absence of coronary stenoses ≥50% severity.

Their CAC scores were compared with the cohort’s use of statins 90 days before and after the imaging procedure and compared with cardiovascular events over a median follow-up of 3.5 years, with statin use and outcomes based on data from other registries.

Their CAD burden by CAC score was directly proportional to their rate of MI or death, expressed as events per 1000 patient-years:

• 4.13 in patients with no CAD
• 7.74 in those with mild CAD (score 0-99),
• 13.72 in patients with moderate CAD (score 100-399)
• 32.47 in those with severe CAD (score 400 and higher)