The importance of nonobstructive plaque characteristics in symptomatic and asymptomatic coronary artery disease

CGPS, the CATCH, and the VERDICT Investigators , The Copenhagen General Population Study investigators (CGPS), The Cardiac CT in the Treatment of Acute Chest Pain investigators (CATCH), The Very Early versus Deferred Invasive Evaluation using Computerized Tomography in Patients with Acute Coronary Syndromes investigators (VERDICT)

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Background: We examined obstructive and nonobstructive plaque volumes in populations with subclinical and clinically manifested coronary artery disease (CAD) using quantitative computed tomography (QCT). Methods: 855 participants with CAD (274 asymptomatic individuals, 254 acute chest pain patients without acute coronary syndrome (ACS), and 327 patients with ACS) underwent QCT of proximal coronary segments to assess participant-level plaque volumes of dense calcium, fibrous, fibrofatty, and necrotic core tissue. Results: Nonobstructive (<50% stenosis) plaque volumes were greater than obstructive plaque volumes, irrespective of population (all p<0.0001): Asymptomatic individuals (mean (95% CI)): 218 [190-250] vs. 16 [12-22] mm3; acute chest pain patients without ACS: 300 [263-341] vs. 51 [41-62] mm3; patients with ACS: 370 [332-412] vs. 159 [139-182] mm3. After multivariable adjustment, nonobstructive fibrous and fibrofatty tissue volumes were greater in acute chest pain patients without ACS compared to asymptomatic individuals (fibrous tissue: 122 [107-139] vs. 175 [155-197] mm3, p<0.01; fibrofatty tissue: 44 [38-50] vs. 71 [63-80] mm3, p<0.01. Necrotic core tissue was greater in ACS patients (29 [26-33] mm3) compared to both asymptomatic individuals (15 [13-18] mm3, p<0.0001) and acute chest pain patients without ACS (21 [18-24] mm3, p<0.05). Nonobstructive dense calcium volumes did not differ between the three populations: 29 [24-36], 29 [23-35], and 41 [34-48] mm3, p>0.3 respectively. Conclusion: Nonobstructive CAD was the predominant contributor to total atherosclerotic plaque volume in both subclinical and clinically manifested CAD. Nonobstructive fibrous, fibrofatty and necrotic core tissue volumes increased with worsening clinical presentation, while nonobstructive dense calcium tissue volumes did not.

Original languageEnglish
JournalJournal of Cardiovascular Computed Tomography
Volume18
Issue number2
Pages (from-to)203-210
Number of pages8
ISSN1934-5925
DOIs
Publication statusPublished - 2024

Bibliographical note

Funding Information:
Conventional assessments of CAD focus on the identification of hemodynamically obstructive lesions. Multivessel obstructive disease has been shown to be associated with increased risk of adverse cardiac events compared to single-vessel disease.7,8 It is now being questioned, however, whether obstructive lesions hold independent prognostic information or if their presence merely reflects a large underlying plaque burden which subsequently drives adverse cardiac events. Chang et al.9 investigated the prognostic significance of lesion stenosis, independent of plaque burden, and found diameter stenosis to predict future ACS. Sensitivity using a ≥50 ​% stenosis threshold, however, was low and the authors recommend a combined assessment of plaque tissue volumes and high-risk plaque features at patient-level to guide risk assessment. These findings are supported by the work of Stone et al.26 who investigated the natural history of coronary atherosclerosis in 697 ACS patients using intravascular ultrasound imaging. These investigators found that stenosis (minimal luminal diameter ≤4 ​mm2) was associated with a 3-fold increased risk of ACS and plaque burden ≥70 ​% was associated with a 5-fold increased risk of ACS. The authors conclude that non-culprit lesions giving rise to a new ACS event were most often angiographically mild, were thin-cap fibroatheromas or were characterized by a large plaque burden, a small luminal area, or some combination of these characteristics. Overall, the volumetric assessment of CAD tissue type, and not just the identification of obstructive lesions, appears central for prognostic evaluation.MCK is supported by The Danish Heart Foundation (grant number 16-R107-A6719-22959) and Eva og Henry Frænkels Mindefond.

Funding Information:
MCK is supported by The Danish Heart Foundation (grant number 16-R107-A6719-22959) and Eva og Henry Frænkels Mindefond.

Publisher Copyright:
© 2024 The Authors

Keywords

  • Computed tomography
  • Coronary artery disease
  • Nonobstructive plaque
  • Plaque composition
  • Quantitative computed tomography

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