CTA-Derived Plaque Characteristics and Risk of Acute Coronary Syndrome in Patients With Coronary Artery Calcium Score of Zero: Insights From the ICONIC Trial.
Authors
Affiliations (39)
Affiliations (39)
- Department of Cardiovascular Disease, Rush University Medical Center, 1725 W Harrison St, Chicago, IL 60612.
- Department of Cardiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
- Department of Vascular Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.
- Cleerly, Inc., Denver, CO.
- Division of Cardiology, The George Washington University School of Medicine, Washington, DC.
- Icahn School of Medicine at Mount Sinai, New York, NY.
- Department of Internal Medicine, Division of Cardiology, College of Medicine, Ewha Womans University, Seoul, South Korea.
- Centro Cardiologico Monzino, IRCCS, Milan, Italy.
- Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy.
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
- Fondazione Monasterio/CNR, Pisa, Italy.
- Beaumont Hospital, Royal Oak, MI.
- Departments of Medicine (Cardiology) and Radiology, University of Ottawa Heart Institute, University of Ottawa, Ottawa, ON, Canada.
- Department of Biomedical, Surgical, and Dental Sciences, Centro Cardiologico Monzino, IRCCS, Milan, Italy.
- Division of University Cardiology, IRCCS Ospedale Galeazzi-Sant'Ambrogio, Milan, Italy.
- Department of Radiology, Miami Cardiac and Vascular Institute, Miami, FL.
- Department of Radiology, Medical University of Innsbruck, Innsbruck, Austria.
- Department of Radiology and Nuclear Medicine, German Heart Center Munich, Munich, Germany.
- Department of Internal Medicine, Seoul National University College of Medicine, Cardiovascular Center, Seoul National University Hospital, Seoul, South Korea.
- IRCCS SYNLAB SDN, Naples, Italy.
- Faculdade de Medicina da Universidade Católica Portuguesa, Lisboa, Portugal.
- Departments of Internal Medicine III and Cardiology, Innsbruck Medical University, Innsbruck, Austria.
- Department of Perioperative Cardiology and Cardiovascular Imaging, Centro Cardiologico Monzino IRCCS, Milan, Italy.
- Department of Biomedical, Surgical, and Dental Sciences, University of Milan, Milan, Italy.
- University of Virginia Health System, Charlottesville, VA.
- Department of Medicine, Division of Cardiology, University of Arkansas for Medical Sciences, Little Rock, AR.
- Department of Cardiology, National Heart Centre Singapore, Singapore.
- Cardiovascular Division, Severance Cardiovascular Hospital, Yonsei University College of Medicine, Seoul, South Korea.
- Yonsei University College of Medicine, Yonsei University Health System, Seoul, South Korea.
- Department of Cardiology, Hanyang University Seoul Hospital, Hanyang University College of Medicine, Seoul, South Korea.
- Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX.
- CONNECT-AI Research Center, Yonsei University College of Medicine, Seoul, South Korea.
- Department of Cardiology, Catholic Kwandong University International St. Mary's Hospital, Incheon, South Korea.
- Department of Medicine, Lundquist Institute at Harbor-UCLA, Torrance, CA.
- Georgia Heart Institute, Northeast Georgia Health System, Gainesville, GA.
- Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, MA.
- Department of Pathology, CVPath Institute, Gaithersburg, MD.
- University of Texas Health Houston, Houston, TX.
- Division of Cardiology, Severance Cardiovascular Hospital and Severance Biomedical Science Institute, Yonsei University College of Medicine, Yonsei University Health System, Seoul, South Korea.
Abstract
<b>BACKGROUND</b>. Coronary artery calcium (CAC) scoring is used to stratify acute coronary syndrome (ACS) risk. Nonetheless, patients with a CAC score of zero (CAC<sub>0</sub>) remain at risk from noncalcified plaque components. <b>OBJECTIVE</b>. The purpose of this study was to explore CTA-derived coronary artery plaque characteristics in symptomatic patients with CAC<sub>0</sub> who subsequently have ACS through comparisons with patients with a CAC score greater than 0 (CAC<sub>> 0</sub>) who subsequently have ACS as well as with patients with CAC<sub>0</sub> who do not subsequently have ACS. <b>METHODS</b>. This study entailed a secondary retrospective analysis of prior prospective registry data. The international multicenter CONFIRM (Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter) registry collected longitudinal observational data on symptomatic patients who underwent clinically indicated coronary CTA from January 2004 to May 2010. ICONIC (Incident Coronary Syndromes Identified by CT) was a nested cohort study conducted within CONFIRM that identified patients without known coronary artery disease (CAD) at the time of CTA who did and did not subsequently have ACS (i.e., the ACS and control groups, respectively) and who were propensity matched in a 1:1 ratio on the basis of CAD risk factors and CAD severity on CTA. The present ICONIC substudy selected matched patients in the ACS and control groups who both had documented CAC scores. CTA examinations were analyzed using artificial intelligence software for automated quantitative plaque assessment. In the ACS group, invasive angiography findings were used to identify culprit lesions. <b>RESULTS</b>. The present study included 216 patients (mean age, 55.6 years; 91 women and 125 men), with 108 patients in each of the ACS and control groups. In the ACS group, 23% (<i>n</i> = 25) of patients had CAC<sub>0</sub>. In the ACS group, culprit lesions in the subsets of patients with CAC<sub>0</sub> and CAC<sub>> 0</sub> showed no significant differences in fibrous, fibrofatty, or necrotic-core plaque volumes (<i>p</i> > .05). In the CAC<sub>0</sub> subset, patients with ACS, compared with control patients, had greater mean (± SD) fibrous plaque volume (29.4 ± 42.0 vs 5.5 ± 15.2 mm<sup>3</sup>, <i>p</i> < .001), fibrofatty plaque volume (27.3 ± 52.2 vs 1.3 ± 3.7 mm<sup>3</sup>, <i>p</i> < .001), and necrotic-core plaque volume (2.8 ± 6.4 vs 0.0 ± 0.1 mm<sup>3</sup>, <i>p</i> < .001). <b>CONCLUSION</b>. After propensity-score matching, 23% of patients with ACS had CAC<sub>0</sub>. Patients with CAC<sub>0</sub> in the ACS and control groups showed significant differences in volumes of noncalcified plaque components. <b>CLINICAL IMPACT</b>. Methods that identify and quantify noncalcified plaque forms may help characterize ACS risk in symptomatic patients with CAC<sub>0</sub>.