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

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: Not yet recruiting
• Conditions: Coronary Artery Disease; Surgical Site Infection; Coronary Artery Bypass Grafting
• Intervention / Treatment: Procedure: Skeletonized LIMA Harvesting; Procedure: Non-Skeletonized LIMA Harvesting

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: Interventional
• Enrollment (Estimated): 1116
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ingrid Copland; Phone Number: 905-296-5754; Email: comfort@phri.ca

Participation Criteria

Eligibility Criteria

• 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

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
Graft Patency	Binary assessment of LIMA-LAD graft patency versus graft failure	1.5 years after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
MACE	The composite of cardiovascular mortality, myocardial infarction, or repeat revascularization	2 years after surgery
Sternal Surgical Site Infection	The composite of sternal surgical site infection	90 days after surgery
Sternal Chronic Postsurgical Pain	The composite of non-infected sternal chronic postsurgical pain	90 days after surgery
LIMA-LAD Driven Repeat Revascularization or Occlusion	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

• Sponsor: Hamilton Health Sciences Corporation
• Collaborators: Population Health Research Institute
• Investigators: Principal Investigator: Andre Lamy, MD, Population Health Research Institute

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): April 30, 2029

Study Registration Dates

• First Submitted: July 17, 2026
• First Submitted That Met QC Criteria: July 17, 2026
• First Posted (Actual): July 22, 2026

Study Record Updates

• Last Update Posted (Actual): July 22, 2026
• Last Update Submitted That Met QC Criteria: July 17, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: CABG; Left Internal Mammary Artery; Skeletonized Harvesting
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Postoperative Complications; Pathologic Processes; Heart Diseases; Infections; Arteriosclerosis; Arterial Occlusive Diseases; Coronary Disease; Myocardial Ischemia; Wound Infection; Pathological Conditions, Signs and Symptoms; Coronary Artery Disease; Surgical Wound Infection
• Other Study ID 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