Factors associated with atherosclerosis burden and ischemia may be more strongly associated with patient outcomes than pericoronary adipose tissue (PCAT) computed tomography attenuation (PCATa) scans of the right coronary artery, according to a study published May 3 in JACC: Cardiovascular Imaging and being presented at ACC.21.

Pepijn A. van Diemen, MD, et al., looked at the prognostic value of PCATa beyond determining plaque measurements and ischemia in patients with suspected coronary artery disease (CAD). The researchers conducted imaging to assess coronary artery calcium (CAC) score; presence of obstructive CAD, defined as ≥50% stenosis, and high-risk plaques; total plaque volume; calcified and noncalcified plaque volume; PCATa; and myocardial ischemia. The primary endpoint was a composite of death and nonfatal myocardial infarction (MI).

A total of 539 patients received imaging and were followed for a median of five years. During the follow-up period, 17 patients (3%) had an MI, including 16 who died. Of the 17 patients who had an MI, 11 (65%) had NSTEMI and five (29%) had STEMI. The right coronary artery and left anterior descending arteries were the culprits for MI in four patients each, while the circumflex artery was the culprit in three patients. Overall, 109 patients (20%) underwent early revascularization and 31 patients (6%) underwent late revascularization.

Obstructive CAD, high-risk plaques and ischemia were more common in patients who met the primary endpoint. In addition, CAC score, total plaque volume, and both calcified and noncalcified plaque volume were higher in patients who experienced an event. Right coronary artery PCATa above scanner-specific thresholds was associated with a worse prognosis, but there was no association between left anterior descending artery and circumflex artery PCATa and outcomes. The prognostic value of right coronary artery PCATa above scanner-specific thresholds was consistent when adjusted for imaging variables and clinical characteristics associated with the endpoint, such as age, diabetes, hyperlipidemia and early revascularization.

According to the researchers, there was a stronger association between outcomes and factors linked to atherosclerotic burden and ischemia than to right coronary artery PCATa. They conclude right coronary PCATa above scanner-specific thresholds, "as a marker of global coronary inflammation, provides incremental prognostic value beyond clinical characteristics, [CAC score], obstructive CAD, [high-risk plaques], quantitative plaque volume, and myocardial ischemia."

The study's findings are "intriguing," Markus Goeller, MD, and Mohamed Marwan, MD, write in an accompanying editorial comment, adding that the "potential of PCAT attenuation measurement for assessing patients' cardiovascular risk beyond clinical and quantitative parameters is promising." Going forward, large prospective trials are "warranted to deliver conclusive data that might pave the way toward a 'game changer' in the search of the 'vulnerable patient,'" they conclude.

Clinical Topics: Cardiovascular Care Team, Dyslipidemia, Noninvasive Imaging, Stable Ischemic Heart Disease, Vascular Medicine, Atherosclerotic Disease (CAD/PAD), Computed Tomography, Nuclear Imaging, Chronic Angina

Keywords: ACC Annual Scientific Session, ACC21, Calcium, Coronary Artery Disease, ST Elevation Myocardial Infarction, Constriction, Pathologic, Hyperlipidemias, Plaque, Atherosclerotic, Myocardial Ischemia, Myocardial Infarction, Tomography, X-Ray Computed, Atherosclerosis, Diabetes Mellitus, Adipose Tissue, Inflammation, Diagnostic Imaging

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