Study of Feasibility for Surgical Patients Undergoing Heart Surgery With the Mammary Arteries: Reviewing Infection, Occlusion Rates and Pain Assessments. (COMFORT pilot)

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

The Pilot study for the COMFORT Trial is a single centre trial to determine the feasibility of the full COMFORT Trial.

The main COMFORT Trial will be a multi-centre trial to investigate the coronary artery bypass grafting outcomes when harvesting the Left Internal Mammary Artery (LIMA) using a skeletonized approach (artery is isolated without the surrounding veins, fascia and nerves) compared to harvesting the LIMA using a non-skeletonized approach (artery is isolated with the surrounding veins, fascia and nerves). Harvesting the LIMA with the non-skeletonized approach is the standard technique. Participants will complete a Coronary Artery Tomography scan at 1 year to determine if the LIMA graft remains open. Follow up of the participants will continue until 2 years post surgery.

Study Overview

• Status: Not yet recruiting
• Conditions: Graft Patency
• Intervention / Treatment: Procedure: Skeletonized vs non-skeletonized harvesting of the left internal mammary artery

Detailed Description

Prior to expansion of the COMFORT Trial to multiple centres, a pilot phase will be conducted at UOHI to evaluate the feasibility of implementing the study protocol within the local clinical and research environment.

Conducting an initial pilot phase allows the study team to assess the practical aspects of trial implementation, including patient screening and recruitment, informed consent procedures, randomization workflow, intraoperative documentation of the harvesting technique, and completion of study data collection.

The pilot phase will also allow evaluation of study logistics related to follow-up procedures, including postoperative data collection and coordination of protocol-mandated computed tomography angiography (CTA). This process will help identify and address any operational challenges prior to broader trial implementation across participating centres.

Participants enrolled during the pilot phase will undergo the same randomized study procedures described in the main COMFORT Trial protocol. Data collected during this phase may contribute to the overall COMFORT Trial dataset, subject to confirmation that the pilot procedures align with the finalized trial protocol and statistical analysis plan.

• Study Type: Interventional
• Enrollment (Estimated): 35
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Nahya Awada, BSN, MCR, Ph.D.; Phone Number: 613-696-7000; Email: naawada@ottawaheart.ca

Study Locations

• Canada
  • Ontario
    • Ottawa, Ontario, Canada, K1Y 4W7
      • University of Ottawa Heart Institute
      • Contact: Nahya Awada, BSN, MCR, Ph.D.; Phone Number: 613-696-7000; Email: naawada@ottawaheart.ca

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

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

Exclusion Criteria:

• Non-sternotomy surgical approach (e.g., minimally invasive, thoracotomy)
• Emergency surgery (defined as surgery required within 24 hours or presentation
• History of prior ternotomy
• Currently receiving systemic antibiotics or with an active bacterial infection at the time of surgery
• History of chronic sternal pain prior to the index surgery.
• Known left subclavian artery stenosis (>50%)
• Previous radiation therapy to the chest
• Known allergy or contraindication to iodinated contrast media that cannot be managed with premedication.
• Estimated glomerular filtration rate (eGFR) <30 ml/min/1.73m2 at baseline (relative contraindications to CTA contrast). The eGFR will be determined by each participating institution according to their standard practice.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Skeletonized Harvesting of LIMA; LIMA is harvested using the skeletonized harvesting technique. This technique isolates the artery without the surrounding satellite veins, endothoracic fascia, and intercoastal nerves.	Procedure: Skeletonized vs non-skeletonized harvesting of the left internal mammary artery; This intervention is the surgical technique used to harvest the artery that will be used to perform the bypass surgery.
Active Comparator: Non-Skeletonized Harvesting of LIMA; LIMA is harvested using the non-skeletonized harvesting technique. This technique isolates the artery with the surrounding satellite veins, endothoracic fascia, and intercoastal nerves.	Procedure: Skeletonized vs non-skeletonized harvesting of the left internal mammary artery; This intervention is the surgical technique used to harvest the artery that will be used to perform the bypass surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Feasibility of Implementation	Combined assessment of screening, recruitment, randomization, surgical protocol adherence, and completion of study data collection and follow up procedures.	2 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Recruitment Rate	Measurement of rate of participant enrollment to determine ability to efficiently recruit into the main trial.	Activation of study to 6 months.
Protocol Adherence	Ability to complete all protocol required tests and assessments.	activation to 2 years per participant.
Completeness of Study Data Collection	Measurement of ability to collect all protocol-required data.	activation to 2 years per participant.
Completion of CTA at 1 year.	Feasibility of completing the CTA at 1 year for all participants.	enrollment to 1 year.

Collaborators and Investigators

• Sponsor: Ottawa Heart Institute Research Corporation
• Collaborators: Population Health Research Institute
• Investigators: Principal Investigator: Fraser Rubens, MD, MSc., Ottawa Heart Institute Research Corporation

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): September 1, 2027
• Study Completion (Estimated): June 1, 2028

Study Registration Dates

• First Submitted: May 14, 2026
• First Submitted That Met QC Criteria: May 14, 2026
• First Posted (Actual): May 20, 2026

Study Record Updates

• Last Update Posted (Actual): May 20, 2026
• Last Update Submitted That Met QC Criteria: May 14, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: CABG surgery; LIMA; bypass graft harvesting; skeletonized harvesting; non-skeletonized harvesting; Left Internal Mammary Artery
• Other Study ID Numbers: 20260183-01H

Drug and device information, study documents

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