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Noninvasive Determination of Vortex Formation Time Using Transesophageal Echocardiography During Cardiac Surgery
Published on: November 28, 2018
Surgical Volume and Outcomes of Intraoperative Transesophageal Echocardiography in Coronary Artery Bypass Graft
Emily J MacKay1,2,3, Charlotte J Talham4, Wilson Y Szeto5
1Department of Anaesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia.
Insights
Intraoperative transesophageal echocardiography (TEE) during coronary artery bypass graft (CABG) surgery shows survival benefits in low- and medium-volume hospitals, especially for complex cases. However, no benefit was observed in high-volume centers, suggesting further research is needed.
Area of Science:
- Cardiology
- Surgical Innovation
- Medical Device Efficacy
Background:
- The routine use of intraoperative transesophageal echocardiography (TEE) during coronary artery bypass graft (CABG) surgery is debated.
- The benefit of TEE across diverse patient populations undergoing CABG remains unclear, necessitating subgroup analysis.
Purpose of the Study:
- To identify patient subgroups most likely to benefit from intraoperative TEE during CABG.
- To stratify the impact of TEE by hospital surgical volume.
Main Methods:
- A 2-stage, matched retrospective cohort study using the STS Adult Cardiac Surgery Database (ACSD).
- Target trial emulation methodology was applied to quantify the conditional treatment effect of intraoperative TEE.
- Analysis included patients aged 18+ undergoing isolated CABG between July 2014 and June 2022.
Main Results:
- Intraoperative TEE use was associated with a significant survival benefit in low-volume (2.47% vs 2.94%) and medium-volume (2.09% vs 2.34%) hospitals.
- No survival benefit was observed in high-volume hospitals (1.72% vs 1.77%).
- The greatest survival benefit in low- and medium-volume settings was seen in patients with >50% left-main coronary stenosis, 3+ diseased coronaries, or preoperative inotropic requirement.
Conclusions:
- Intraoperative TEE provides a survival benefit in isolated CABG at low- and medium-volume hospitals, particularly for patients with complex coronary disease or hemodynamic instability.
- The lack of benefit at high-volume hospitals suggests volume-dependent efficacy.
- These findings indicate persistent equipoise and underscore the need for randomized trials to definitively establish TEE's role in CABG.
Importance:
The routine use of intraoperative transesophageal echocardiography (TEE) during coronary artery bypass graft (CABG) surgery remains controversial. Its benefit across different patient populations is unclear.
Objectives:
To identify patient subgroups with the greatest or least likelihood to benefit from intraoperative TEE during CABG, stratified by hospital surgical volume.
Design, Setting, And Participants:
This 2-stage, matched retrospective cohort study applied target trial emulation methodologies to the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD) to quantify the conditional treatment effect of intraoperative TEE among subpopulations undergoing isolated CABG at low, medium, and high surgical volume hospitals. The study cohort consisted of patients aged 18 years or older who underwent isolated CABG surgery between July 1, 2014, and June 30, 2022. Data analysis was conducted from August 8, 2023, to December 15, 2024.
Exposure:
Receipt of an intraoperative TEE during CABG surgery.
Main Outcomes And Measures:
The primary outcome was mortality within 30 days of surgery. Statistical analyses included multivariable logistic regression and multiple TEE vs without TEE matched comparisons stratified by surgical volume and patient subpopulations.
Results:
Of 1 266 055 patients who underwent isolated CABG, 963 976 (76.1%) were male, and the mean (SD) age was 65.7 (10.0) years. Among these patients, 61.8% received TEE and 39.0% did not receive TEE. Intraoperative TEE use (vs without TEE) was associated with a significant survival benefit among patients treated at hospitals with low surgical volume (2.47% vs 2.94%; odds ratio [OR], 0.83 [95% CI, 0.78-0.89], P < .001) and medium surgical volume (2.09% vs 2.34%; OR, 0.89 [95% CI, 0.85-0.93], P < .001) but not high surgical volume (1.72% vs 1.77%; OR, 0.97 [95% CI, 0.91-1.03], P = .48). Among patients who underwent isolated CABG at low and medium surgical volume hospitals, TEE provided the greatest survival benefit to subpopulations with greater than 50% (vs ≤50%) left-main coronary stenosis, 3 or more (vs <3) diseased coronaries, and (3) a preoperative inotropic requirement.
Conclusions And Relevance:
In isolated CABG, intraoperative TEE was associated with survival benefit at low- and medium-volume hospitals, particularly in patients with complex coronary disease or hemodynamic instability, but not at high-volume hospitals. These results highlight persistent equipoise and the need for randomized evaluation.
