Intraoperative Echocardiography in Low-Risk CABG Surgery

Default vs As-Needed Intraoperative Transesophageal Echocardiography (TEE) in Low-Risk Isolated Coronary Artery Bypass Graft (CABG) Surgery: A Randomized Controlled Trial

This goal of this study is to better understand when and where intraoperative transesophageal echocardiography (TEE) should (or should not) be used during coronary artery bypass graft (CABG) surgeries.

Study Overview

• Status: Completed
• Conditions: Heart Diseases; Coronary Artery Disease; Chest Pain; STEMI; Stenosis Coronary
• Intervention / Treatment: Device: TEE probe

Detailed Description

This trial will look at benefits and harms to two different treatments strategies in order to improve clinical outcomes. Intraoperative TEE is an ultrasound-based, imaging device that uses sound waves to look at the heart continuously during a heart surgery.

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19104
      • Hospital of the University of Pennsylvania

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Scheduled to undergo isolated CABG surgery at a hospital within the UPenn Health System
2. Age ≥18 years
3. Ejection fraction ≥50%
4. Transthoracic echocardiography within one year of scheduled surgery date
5. Left heart catheterization within one year of scheduled surgery date
6. English language fluency or facilitated via language interpreter
7. Able to provide informed consent either in English or via a language interpreter
8. Willing to comply with all study procedures

Exclusion Criteria:

1. Documented valve (aortic, mitral, tricuspid, or pulmonic) disease (stenosis or regurgitation) moderate or greater.
2. Any CABG surgery with either "possible" or "definite" aortic intervention listed as a planned part of the procedure. plan for either definite or possible surgical intervention.
3. Any CABG surgery with either "possible" or "definite" valve repair/replacement listed as a planned part of the procedure.
4. Having undergone any previous cardiac surgeries (i.e. scheduled with a "REDO" modifier).
5. Proximal/critical left main coronary disease (e.g. greater than or equal to 90% stenosis).
6. Preexisting anomalous coronary arteries
7. Preexisting end-stage renal disease on hemodialysis
8. Preexisting chronic kidney disease (CKD) stage 3, 4, or 5
9. Stroke with residual focal neurological deficit(s) within 90 days of surgery

10. Any of the following presurgical, mechanical circulatory support devices:

    1. Intraaortic balloon pump
    2. Percutaneous right ventricular assist device (RVAD)
    3. Impella
    4. Extracorporeal membrane oxygenation (ECMO)

11. Absolute contraindication to echocardiography defined as one or more of the following documented conditions:

    1. Esophagectomy
    2. Esophagogastrectomy
    3. Esophageal trauma

12. Any of these three relative contraindication to TEE:

    1. Esophageal varies
    2. Gastric bypass surgery
    3. Descending thoracic aortic aneurysm

13. Severe pulmonary hypertension defined as:

    1. Pulmonary arterial pressure ≥60 mmHg
    2. Pulmonary vascular resistance (PVR) ≥3 Woods Units

14. Hemodynamic instability after induction and following placement of an endotracheal tube will be defined as one or more of the following events or scenarios:

    1. Placement of an intraaortic balloon pump (IABP)
    2. Initiation of venoarterial extracorporeal membrane oxygenation (VAECMO)
    3. Placement of a right or left percutaneous mechanical circulatory support device
    4. Initiation of epinephrine infusion at a dose ≥ 6 mcg/min for a duration ≥5 minutes
    5. Initiation of norepinephrine at a dose ≥8 mcg/min for a duration ≥ minutes
    6. Initiation of phenylephrine infusion at a dose ≥100 mcg/min for a duration ≥ minutes
    7. Initiation of vasopressin infusion at a dose ≥0.04 units/min for a duration ≥ minutes

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Health Services Research
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Default TEE; The TEE probe is placed after going under general anesthesia and a breathing tube is placed. TEE issued to take pictures of the heart before and after a CABG surgery. If randomized to this group, the TEE probe will remain in place throughout the surgery.	Device: TEE probe; Transesophageal echocardiography, ultrasound probe; Other Names: Philips transesophageal echocardiography (TEE), ultrasound probe
Other: As-needed TEE; The TEE probe is placed only in situations where a surgeon requires information that can only be obtained by ultrasound imaging of the heart.	Device: TEE probe; Transesophageal echocardiography, ultrasound probe; Other Names: Philips transesophageal echocardiography (TEE), ultrasound probe

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Enrollment and Randomization Feasibility	Enrollment and randomization feasibility defined as the proportion of patients approached for enrollment who consented and were successfully randomized. Of 72 patients approached for enrollment, 40 were randomized.	At time of enrollment and randomization (baseline)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Protocol Adherence	Protocol adherence defined as receipt of the intraoperative transesophageal echocardiography strategy corresponding to randomized assignment.	During index surgical procedure (from induction of anesthesia to completion of surgery; typical duration approximately 5-8 hours)
Rescue Echocardiography Use in the Backup TEE Arm	Use of rescue transesophageal echocardiography among participants randomized to the Backup TEE strategy, defined as intraoperative TEE performed in response to a clinical indication per protocol. Of 20 participants randomized to Backup TEE, 3 (15%) received rescue TEE.	During index surgical procedure (from induction of anesthesia to completion of surgery; typical duration approximately 5-8 hours)

Collaborators and Investigators

• Sponsor: University of Pennsylvania
• Collaborators: National Institutes of Health (NIH)
• Investigators: Principal Investigator: Emily MacKay, DO, MS, University of Pennsylvania, Penn Medicine

Study record dates

Study Major Dates

• Study Start (Actual): January 22, 2024
• Primary Completion (Actual): March 15, 2025
• Study Completion (Actual): March 15, 2026

Study Registration Dates

• First Submitted: November 13, 2023
• First Submitted That Met QC Criteria: November 30, 2023
• First Posted (Actual): December 4, 2023

Study Record Updates

• Last Update Posted (Actual): May 12, 2026
• Last Update Submitted That Met QC Criteria: April 20, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: CABG; Stenosis; Heart; TEE; Artery; Chest Pain; Bypass
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Pathological Conditions, Anatomical; Infarction; Necrosis; Arteriosclerosis; Arterial Occlusive Diseases; Coronary Disease; Myocardial Ischemia; Myocardial Infarction; Ischemia; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; ST Elevation Myocardial Infarction; Constriction, Pathologic; Heart Diseases; Coronary Artery Disease; Coronary Stenosis; Chest Pain; Diagnostic Techniques and Procedures; Diagnosis; Diagnostic Imaging; Diagnostic Techniques, Cardiovascular; Heart Function Tests; Echocardiography; Cardiac Imaging Techniques; Ultrasonography; Echocardiography, Transesophageal
• Other Study ID Numbers: 853364

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes