Coronary and Myocardial Evaluation by Cardiac CT for Acute Myocardial Infarction (COMET-AMI)

Multimodal Cardiac CT-Derived High-Risk Coronary and Myocardial Features for Predicting Adverse Outcomes After PCI in Patients With Acute Myocardial Infarction: A Multicenter Prospective Cohort Study

Acute myocardial infarction (AMI) remains a major cause of mortality and morbidity worldwide. Although percutaneous coronary intervention (PCI) combined with guideline-directed medical therapy has substantially improved survival, many patients continue to experience adverse cardiovascular events after revascularization, including recurrent ischemic events, heart failure, and malignant arrhythmias. Therefore, accurate risk stratification after PCI is essential for optimizing clinical management and improving long-term outcomes. However, currently available risk prediction tools are limited by suboptimal predictive performance or restricted clinical accessibility.

Cardiac imaging plays a central role in post-AMI evaluation. Echocardiography is routinely recommended after PCI to assess cardiac structure and function and to exclude early mechanical complications. Nevertheless, its ability to predict subsequent ventricular remodeling and long-term clinical outcomes is limited. Cardiac magnetic resonance imaging (CMR) is considered the reference standard for myocardial tissue characterization and provides important prognostic markers such as infarct size, microvascular obstruction, and intramyocardial hemorrhage. However, the routine use of CMR in patients with AMI is constrained by limited availability, high cost, and relatively long examination time. In addition, CMR does not directly evaluate coronary artery anatomy or plaque characteristics, which are important determinants of recurrent ischemic events.

Recent advances in cardiac computed tomography (CT) have enabled comprehensive assessment of coronary artery disease. Beyond evaluating coronary stenosis, coronary CT angiography can identify high-risk plaque features associated with plaque vulnerability. Furthermore, emerging CT-based techniques allow simultaneous assessment of coronary physiology, perivascular inflammation, myocardial structure and function, and myocardial tissue characteristics. CT-derived fractional flow reserve (CT-FFR) enables noninvasive functional assessment of coronary lesions, while the fat attenuation index (FAI) reflects pericoronary inflammatory activity. In addition, delayed iodine enhancement and dual-energy CT techniques allow evaluation of myocardial injury and fibrosis, and CT-derived extracellular volume fraction (ECV) provides quantitative assessment of myocardial fibrosis. These advances suggest that multimodal cardiac CT may provide an integrated imaging approach for comprehensive risk assessment after AMI.

The COMET-AMI study (Coronary and Myocardial Evaluation by Multimodal Cardiac CT in Acute Myocardial Infarction) is a prospective, multicenter cohort study designed to evaluate the prognostic value of multimodal cardiac CT in patients with AMI after PCI. A total of 1,000 patients with AMI undergoing successful PCI will be prospectively enrolled. All participants will undergo multimodal cardiac CT within 7 days after PCI to assess coronary plaque characteristics, coronary physiology, pericoronary adipose tissue inflammation, cardiac structure and function, and myocardial tissue features. A subset of participants will also undergo cardiac magnetic resonance imaging for validation of CT-derived myocardial tissue parameters.

Comprehensive clinical information, including demographic characteristics, cardiovascular risk factors, medication history, laboratory biomarkers, and procedural data, will be collected. Quantitative and qualitative analyses of coronary plaques will be performed using dedicated software to assess plaque burden, plaque composition, remodeling characteristics, and high-risk plaque features. Additional CT-derived parameters such as CT-FFR, myocardial strain, pericoronary fat attenuation index, and extracellular volume fraction will also be analyzed.

Participants will be followed longitudinally through outpatient visits, telephone interviews, and electronic medical record review for up to five years after PCI. The primary outcomes include composite thrombotic events (cardiac death, recurrent myocardial infarction, and urgent or clinically driven revascularization). Secondary outcomes include heart failure and major arrhythmic events such as new-onset heart failure, sustained ventricular arrhythmia, implantable cardioverter-defibrillator implantation, sudden cardiac death, or resuscitated cardiac arrest. All clinical events will be independently adjudicated by a blinded clinical events committee.

Using multimodal cardiac CT-derived imaging biomarkers in combination with clinical and laboratory data, machine learning-based predictive models will be developed to identify key determinants of adverse outcomes after PCI in patients with AMI. The results of this study may provide a novel imaging-based risk stratification strategy and facilitate personalized management for patients with AMI after PCI.

Study Overview

• Status: Recruiting
• Conditions: Acute Myocardial Infarction (AMI)
• Intervention / Treatment: Diagnostic test: Cardiac CT Follow-up and Echocardiographic Follow-up

• Study Type: Observational
• Enrollment (Estimated): 1000

Contacts and Locations

Study Locations

• China
  • Jiangsu
    • Nanjing, Jiangsu, China, 210006
      • Recruiting
      • Nanjing First Hospital, Nanjing Medical University, 68 Changle road, Qinhuai District
      • Contact: Nailiang Tian; Phone Number: +86-13584056788; Email: tiannailiang@163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

The study population was recruited from three large tertiary hospitals and included patients with acute myocardial infarction who underwent PCI.

Description

Inclusion Criteria:

• Age ≥18 years
• AMI within the previous 4 weeks, including STEMI or NSTEMI
• PCI performed for ACS culprit lesion according to current guidelines
• Hemodynamically stable
• Willingness to undergo multimodal cardiac CT within 7 days after PCI
• Willingness to participate in telephone follow-up

Exclusion Criteria:

• Contraindications to cardiac CT (eGFR <30 mL/min/1.73 m² or iodine contrast allergy)
• Previous coronary artery bypass graft surgery (CABG)
• History of heart failure or previous myocardial infarction
• Severe arrhythmia or structural heart disease
• Poor image quality or missing CT data
• Expected survival <6 months

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
the MACE group; patients who experienced study endpoint events during follow-up	Diagnostic test: Cardiac CT Follow-up and Echocardiographic Follow-up; All patients with AMI routinely undergo follow-up cardiac CT and echocardiography after PCI. Participants who remain free of thrombotic events, heart failure, or severe arrhythmias will be recommended to undergo repeat cardiac CT within 1 year after the baseline CT examination. Participants will undergo echocardiographic examinations at 6 months, 12 months, 2 years, 3 years, 4 years, and 5 years.
the non-MACE group; patients who did not experience study endpoint events during follow-up	Diagnostic test: Cardiac CT Follow-up and Echocardiographic Follow-up; All patients with AMI routinely undergo follow-up cardiac CT and echocardiography after PCI. Participants who remain free of thrombotic events, heart failure, or severe arrhythmias will be recommended to undergo repeat cardiac CT within 1 year after the baseline CT examination. Participants will undergo echocardiographic examinations at 6 months, 12 months, 2 years, 3 years, 4 years, and 5 years.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Thrombotic events	cardiac death; recurrent myocardial infarction; urgent or clinically driven revascularization	Up to five years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Heart failure and arrhythmic events	new-onset heart failure; sustained ventricular arrhythmia; ICD implantation; sudden cardiac death; resuscitated cardiac arrest	Up to five years

Collaborators and Investigators

• Sponsor: Nanjing First Hospital, Nanjing Medical University

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2026
• Primary Completion (Estimated): December 31, 2030
• Study Completion (Estimated): December 31, 2030

Study Registration Dates

• First Submitted: April 6, 2026
• First Submitted That Met QC Criteria: April 12, 2026
• First Posted (Actual): April 17, 2026

Study Record Updates

• Last Update Posted (Actual): April 17, 2026
• Last Update Submitted That Met QC Criteria: April 12, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: KY20260205-06

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No