Comparative Outcomes of Mammary Artery Harvesting: Infection, Occlusion Rates and Thoracic Pain Assessment (COMFORT)

July 24, 2026 updated by: Hamilton Health Sciences Corporation

COMFORT: Comparative Outcomes of Mammary Artery Harvesting: Infection, Occlusion Rates and Thoracic Pain Assessment

The COMFORT Trial is a randomized controlled superiority trial comparing skeletonized (SK) versus non-skeletonized (non-SK) harvesting of the left internal mammary artery (LIMA) to left anterior descending artery (LAD) graft in patients undergoing isolated coronary artery bypass grafting (CABG).

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Withdrawn

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The COMFORT trial is an international, multicentre, blinded, expertise-based randomized controlled trial evaluating two commonly used techniques for harvesting the left internal mammary artery (LIMA) during coronary artery bypass grafting (CABG): skeletonized and non-skeletonized (pedicled) harvesting.

Although skeletonized harvesting has been associated with reduced sternal wound complications and postoperative pain, concerns have emerged regarding its potential impact on graft patency and long-term cardiovascular outcomes. Existing evidence is largely derived from observational studies and post hoc analyses, and no adequately powered randomized trial has prospectively compared these techniques using systematic imaging-based graft assessment.

The COMFORT trial will enroll approximately 1,116 patients undergoing isolated CABG with a planned LIMA-to-LAD graft. Participants will be randomly assigned to undergo either skeletonized or non-skeletonized LIMA harvesting performed by surgeons experienced in both techniques. Participants and outcome assessors will remain blinded to treatment allocation.

Participants will undergo protocol-mandated coronary computed tomography angiography (CTA) at 1.5 years after surgery, with follow-up extending to 2 years. Independent blinded committees and a central CTA core laboratory will adjudicate imaging and clinical outcomes. In addition to graft assessment, the study will evaluate the effects of harvesting technique on cardiovascular outcomes, sternal wound complications, chronic postoperative pain, quality of life, and healthcare resource utilization.

The findings of COMFORT are expected to provide definitive evidence to guide surgical practice and inform future guidelines regarding the optimal method of internal mammary artery harvesting during CABG surgery.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Age 18 years or older
  2. Undergoing isolated CABG surgery with median sternotomy and a planned LIMA-LAD graft
  3. Provision of written informed consent

Exclusion Criteria:

  1. Non-sternotomy surgical approach (e.g., minimally invasive, thoracotomy)
  2. Emergency surgery (defined as surgery required within 24 hours of presentation)
  3. History of prior sternotomy
  4. Currently receiving systemic antibiotics or with an active bacterial infection at the time of surgery
  5. History of chronic sternal pain prior to the index surgery
  6. Known left subclavian artery stenosis (>50%)
  7. Previous radiation therapy to the chest
  8. Known allergy or contraindication to iodinated contrast media that cannot be managed with premedication
  9. Estimated glomerular filtration rate (eGFR) <30 mL/min/1.73m² at baseline (relative contraindication to CTA contrast) as determined based on each centre's laboratory standard.
  10. Known pregnancy or plans for pregnancy during the study period
  11. Life expectancy less than 1.5 years due to non-cardiac conditions
  12. Inability or unwillingness to comply with follow-up procedures including CTA at 1.5 years

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Skeletonized LIMA Harvesting
Harvesting of the left internal mammary artery as a skeletonized conduit during CABG surgery, with removal of surrounding tissues while preserving the artery as an isolated graft conduit.
Procedure: Skeletonized LIMA Harvesting
Skeletonized (SK) harvesting of the left internal mammary artery (LIMA) to left anterior descending artery (LAD) graft: the LIMA is isolated without surrounding satellite veins, endothoracic fascia, and intercostal nerves
Active Comparator: Non-Skeletonized LIMA Harvesting
Conventional pedicled harvesting of the left internal mammary artery during CABG surgery, with preservation of the surrounding veins, fascia, and supporting tissues around the graft conduit.
Procedure: Non-Skeletonized LIMA Harvesting
Non-skeletonized (non-SK) harvesting of the LIMA-LAD graft: the LIMA is harvested with surrounding satellite veins, endothoracic fascia, and intercostal nerves (standard pedicled technique)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Number of Participants with Graft Patency
Time Frame: 1.5 years after surgery
Binary assessment of LIMA-LAD graft patency versus graft failure
1.5 years after surgery

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
MACE
Time Frame: 2 years after surgery
The composite of cardiovascular mortality, myocardial infarction, or repeat revascularization
2 years after surgery
Number of Participants with a Sternal Surgical Site Infection
Time Frame: 90 days after surgery
The composite of sternal surgical site infection
90 days after surgery
Number of Participants with LIMA-LAD Driven Repeat Revascularization or Occlusion
Time Frame: 2 years after surgery
Any coronary revascularization procedure (PCI or CABG) targeting the LIMA-LAD graft territory, or occlusion of the LIMA-LAD graft revealed by clinically indicated coronary angiography or CTA
2 years after surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Hamilton Health Sciences Corporation

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Population Health Research Institute

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Andre Lamy, MD, Population Health Research Institute

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2028

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 30, 2029

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 17, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 17, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 22, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 28, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 24, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • COMFORT

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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