Association between Transesophageal Echocardiography and Clinical Outcomes after Coronary Artery Bypass Graft Surgery

The Society of Thoracic Surgeons Adult Cardiac Surgery Database: Intraoperative Echocardiography Reporting

OBJECTIVES

To identify trends in the reporting of intraoperative transesophageal echocardiographic (TEE) data in the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD) and the Adult Cardiac Anesthesiology (ACA) module by period, practice type, and geographic distribution, and to elucidate ongoing areas for practice improvement.

DESIGN

A retrospective study.

SETTING

STS ACSD.

PARTICIPANTS

Procedures reported in the STS ACSD between July 2017 and December 2021 in participating programs in the United States.

INTERVENTIONS

None MEASUREMENTS AND MAIN RESULTS: Intraoperative TEE is reported for 73% of all procedures in ACSD. Although the intraoperative TEE data reporting rate increased from 2017 to 2021 for isolated coronary artery bypass graft surgery, it remained low at 62.2%. The reporting of relevant echocardiographic variables across a wide range of procedures has steadily increased over the study period but also remained low. The reporting in the ACA module is high for most variables and across all anesthesia care models; however, the overall contribution of the ACA module to the ACSD remains low.

CONCLUSIONS

This progress report suggests a continued need to raise awareness regarding current practices of reporting intraoperative TEE in the ACSD and the ACA, and highlights opportunities for improving reporting and data abstraction.

Efficient algorithms for building representative matched pairs with enhanced generalizability

Many recent efforts center on assessing the ability of real-world evidence (RWE) generated from non-randomized, observational data to produce results compatible with those from randomized controlled trials (RCTs). One noticeable endeavor is the RCT DUPLICATE initiative. To better reconcile findings from an observational study and an RCT, or two observational studies based on different databases, it is desirable to eliminate differences between study populations. We outline an efficient, network-flow-based statistical matching algorithm that designs well-matched pairs from observational data that resemble the covariate distributions of a target population, for instance, the target-RCT-eligible population in the RCT DUPLICATE initiative studies or a generic population of scientific interest. We demonstrate the usefulness of the method by revisiting the inconsistency regarding a cardioprotective effect of the hormone replacement therapy (HRT) in the Women's Health Initiative (WHI) clinical trial and corresponding observational study. We found that the discrepancy between the trial and observational study persisted in a design that adjusted for the difference in study populations' cardiovascular risk profile, but seemed to disappear in a study design that further adjusted for the difference in HRT initiation age and previous estrogen-plus-progestin use. The proposed method is integrated into the R package match2C.

Echocardiography as a Tool to Assess Cardiac Function in Critical Care-A Review

In critically ill patients, hemodynamic disturbances are common and often lead to a detrimental outcome. Frequently, invasive hemodynamic monitoring is required for patients who are hemodynamically unstable. Although the pulmonary artery catheter enables a comprehensive assessment of the hemodynamic profile, this technique carries a substantial inherent risk of complications. Other less invasive techniques do not offer a full range of results to guide detailed hemodynamic therapies. An alternative with a lower risk profile is transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE). After training, intensivists can obtain similar parameters on the hemodynamic profile using echocardiography, such as stroke volume and ejection fraction of the right and left ventricles, an estimate of the pulmonary artery wedge pressure, and cardiac output. Here, we will review individual echocardiography techniques that will help the intensivist obtain a comprehensive assessment of the hemodynamic profile using echocardiography.

Predictors of Intraoperative Echocardiography: Analysis of The Society of Thoracic Surgeons Database

BACKGROUND

Intraoperative transesophageal echocardiography (TEE) is associated with improved outcomes after cardiac surgery, but unexplained practice pattern variation exists. This study aimed to identify and quantify the predictors of intraoperative TEE use among patients undergoing isolated coronary artery bypass graft surgery (CABG) or cardiac valve surgery.

METHODS

This observational cohort study used The Society of Thoracic Surgeon (STS) Adult Cardiac Surgery Database data to identify and quantify the predictors of intraoperative TEE use among adult patients aged 18 years or more undergoing either isolated CABG or open cardiac valve repair or replacement surgery between January 1, 2011, and December 31, 2019. Generalized linear mixed models were used to measure the relationship between intraoperative TEE and patient characteristics, surgical volume, and geographic location, while accounting for clustering within hospitals (primary analysis) or surgeons (secondary analysis).

RESULTS

Of 1,973,655 patients, 1,365,708 underwent isolated CABG and 607,947 underwent cardiac valve surgery. Overall, intraoperative TEE was used in 62% of surgeries. The primary hospital-level generalized linear mixed models analysis demonstrated that the strongest predictor of intraoperative TEE use was the hospital where the surgery occurred-with a median odds ratio for TEE of 10.13 in isolated CABG and 5.30 in cardiac valve surgery. The secondary surgeon-level generalized linear mixed models analysis demonstrated similar findings.

CONCLUSIONS

Intraoperative TEE use (vs lack of use) during surgery was more strongly associated with hospital and surgeon practice patterns than with any patient-level factor, surgical volume, or geographic location.

Impact of Hospital Practice and Staffing Differences on Transesophageal Echocardiography Use in Cardiac Valve or Coronary Artery Bypass Graft Surgery

OBJECTIVES

To identify and quantify the predictors of intraoperative transesophageal echocardiography (TEE) use among the patients undergoing cardiac valve or isolated coronary artery bypass graft (CABG) surgery.

DESIGN

An observational cohort study.

SETTING

This study used the Centers for Medicare and Medicaid Services administrative claims dataset of the beneficiaries undergoing valve or isolated CABG surgery between 2013 to 2015.

PARTICIPANTS

Adults aged ≥65 years of age undergoing cardiac valve or isolated CABG surgery.

INTERVENTIONS

Generalized linear mixed-model (GLMM) analyses were used to examine the relationship between the TEE and patient characteristics, hospital factors, and staffing differences, while accounting for clustering within hospitals. The proportion of variation in TEE use attributable to patient-level characteristics was quantified using odds ratios. Hospital-level factors and staffing differences were quantified using the median odds ratios (MOR) and interval odds ratios (IOR).

MEASUREMENTS AND MAIN RESULTS

Among 261,860 patients (123,702 valve procedures and 138,158 isolated CABG), the GLMM analysis demonstrated that the strongest predictor for intraoperative TEE use was the hospital where the surgery occurred (MOR for TEE of 2.57 in valve and 4.16 in isolated CABG). The TEE staffing variable reduced the previously unexplained across-hospital variability by 9% in valve and 21% in isolated CABG, and hospitals with anesthesiologist TEE staffing (versus mixed) were more likely to use TEE in both valve and CABG (MOR for TEE of 1.21 in valve and 1.84 in isolated CABG).

CONCLUSION

Hospital practice was the strongest predictor for TEE use overall. In isolated CABG surgery, hospitals with anesthesiologist TEE staffing were a primary predictor for TEE use.

[Echocardiographic Assessment of Perioperative Right and Left Ventricular Function]

The perioperative quantification of left and right ventricular function is cornerstone to provide optimal patient care. Echocardiography has emerged as the most important cardiac imaging modality in this setting, mainly due to its rapid availability, non-invasiveness and cost-efficiency. Both the transthoracic and the transesophageal acoustic windows offer manifold modes, e.g., doppler-based measurements or M-mode display, to assess systolic and diastolic ventricular function. An association with patient outcome and corresponding prognostic implications could be demonstrated for the majority of those parameters. Hence, a profound understanding of these measurements is key to delineate sufficient from failing left or right ventricular function and guide treatment decisions. This article gives the reader an overview over the most important measurements, reference values and pitfalls.

Regional Right Ventricular Function Assessed by Intraoperative Three-Dimensional Echocardiography Is Associated With Short-Term Outcomes of Patients Undergoing Cardiac Surgery

Background

The assessment of right ventricular (RV) function in patients undergoing elective cardiac surgery is paramount for providing optimal perioperative care. The role of regional RV function assessment employing sophisticated state-of-the-art cardiac imaging modalities has not been investigated in this cohort. Hence, this study investigated the association of 3D echocardiography-based regional RV volumetry with short-term outcomes.

Materials and Methods

In a retrospective single-center study, patients undergoing elective cardiac surgery were included if they underwent 3D transesophageal echocardiography prior to thoracotomy. A dedicated software quantified regional RV volumes of the inflow tract, apical body and RV outflow tract employing meshes derived from 3D speckle-tracking. Echocardiographic, clinical and laboratory data were entered into univariable and multivariable logistic regression analyses to determine association with the endpoint (in-hospital mortality or the need for extracorporeal circulatory support).

Results

Out of 357 included patients, 25 (7%) reached the endpoint. Inflow RV ejection fraction (RVEF, 32 ± 8% vs. 37 ± 11%, p = 0.01) and relative stroke volume (rel. SV) were significantly lower in patients who reached the endpoint (44 ± 8 vs. 48 ± 9%, p = 0.02), while the rel. SV of the apex was higher (38 ± 10% vs. 33 ± 8%, p = 0.01). Global left and right ventricular function including RVEF and left ventricular global longitudinal strain did not differ. In univariable logistic regression, tricuspid regurgitation grade ≥ 2 [odds ratio (OR) 4.24 (1.66–10.84), p < 0.01], inflow RVEF [OR 0.95 (0.92–0.99), p = 0.01], inflow rel. SV [OR 0.94 (0.90–0.99), p = 0.02], apex rel. SV [OR 1.07 (1.02–1.13), p < 0.01] and apex to inflow rel. SV ratio [OR 5.81 (1.90–17.77), p < 0.01] were significantly associated with the endpoint. In a multivariable model, only the presence of tricuspid regurgitation [OR 4.24 (1.66–10.84), p < 0.01] and apex to inflow rel. SV ratio [OR 6.55 (2.09–20.60), p < 0.001] were independently associated with the endpoint.

Conclusions

Regional RV function is associated with short-term outcomes in patients undergoing elective cardiac surgery and might be helpful for optimizing risk stratification.

Association of Intraoperative Transesophageal Echocardiography and Clinical Outcomes After Open Cardiac Valve or Proximal Aortic Surgery

IMPORTANCE

Intraoperative transesophageal echocardiography (TEE) is used frequently in cardiac valve and proximal aortic surgical procedures, but there is a lack of evidence associating TEE use with improved clinical outcomes.

OBJECTIVE

To test the association between intraoperative TEE use and clinical outcomes following cardiac valve or proximal aortic surgery.

DESIGN, SETTING, AND PARTICIPANTS

This matched, retrospective cohort study used national registry data from the Society of Thoracic Surgeon (STS) Adult Cardiac Surgery Database (ACSD) to compare clinical outcomes among patients undergoing cardiac valve or proximal aortic surgery with vs without intraoperative TEE. Statistical analyses used optimal matching within propensity score calipers to conduct multiple matched comparisons including within-hospital and within-surgeon matches, a negative control outcome analysis, and sensitivity analyses. STS ACSD data encompasses more than 90% of all hospitals that perform cardiac surgery in the US. The study cohort consisted of all patients aged at least 18 years undergoing open cardiac valve repair or replacement surgery and/or proximal aortic surgery between 2011 and 2019. Statistical analysis was performed from October 2020 to April 2021.

EXPOSURES

The exposure was receipt of intraoperative TEE during the cardiac valve or proximal aortic surgery.

MAIN OUTCOMES AND MEASURES

The primary outcome was death within 30 days of surgery. The secondary outcomes were (1) a composite outcome of stroke or 30-day mortality and (2) a composite outcome of reoperation or 30-day mortality.

RESULTS

Of the 872 936 patients undergoing valve or aortic surgery, 540 229 (61.89%) were male; 63 565 (7.28%) were Black and 742 384 (85.04%) were White; 711 326 (81.5%) received TEE and 161 610 (18.5%) did not receive TEE; the mean (SD) age was 65.61 years (13.17) years. After matching, intraoperative TEE was significantly associated with a lower 30-day mortality rate compared with no TEE: 3.81% vs 5.27% (odds ratio [OR], 0.69 [95% CI, 0.67-0.72]; P < .001), a lower incidence of stroke or 30-day mortality: 5.56% vs 7.01% (OR, 0.77 [95% CI, 0.74-0.79]; P < .001), and a lower incidence of reoperation or 30-day mortality: 7.18% vs 8.87% (OR, 0.78 [95% CI, 0.76-0.80]; P < .001). Results were similar across all matched comparisons (including within-hospital, within-surgeon matched analyses) and were robust to a negative control and sensitivity analyses.

CONCLUSIONS AND RELEVANCE

Among adults undergoing cardiac valve or proximal aortic surgery, intraoperative TEE use was associated with improved clinical outcomes in this cohort study. These findings support routine use of TEE in these procedures.

The Society of Thoracic Surgeons Adult Cardiac Surgery Database: 2021 Update on Echocardiography

The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD) is the world's premier clinical outcomes registry for adult cardiac surgery and a driving force for quality improvement in cardiac surgery. Echocardiographic data provide a wealth of hemodynamic, structural, and functional data and have been part of STS ACSD data collection since its inception. An increasing body of evidence suggests that the use of echocardiography in patients undergoing cardiac surgery has a positive impact on postoperative outcomes. In this report, we describe and summarize the type and rate of reporting of echocardiography-related variables in the STS ACSD, including the Adult Cardiac Anesthesiology Module, from July 2017 to December 2019 for the most frequently performed cardiac surgical procedures. With this review, we aim to increase awareness of the importance of collecting accurate and consistent echocardiography data in the STS ACSD and to highlight opportunities for growth and improvement.

Transesophageal Echocardiography in Patients Undergoing Coronary Artery Bypass Graft Surgery

BACKGROUND

The impact of utilization of intraoperative transesophageal echocardiography (TEE) at the time of isolated coronary artery bypass grafting (CABG) on clinical decision making and associated outcomes is not well understood.

OBJECTIVES

The purpose of this study was to determine the association of TEE with post-CABG mortality and changes to the operative plan.

METHODS

A retrospective cohort study of planned isolated CABG patients from the Society of Thoracic Surgeons Adult Cardiac Surgery Database between January 1, 2011, and June 30, 2019, was performed. The exposure variable of interest was use of intraoperative TEE during CABG compared with no TEE. The primary outcome was operative mortality. The association of TEE with unplanned valve surgery was also assessed.

RESULTS

Of 1,255,860 planned isolated CABG procedures across 1218 centers, 676,803 (53.9%) had intraoperative TEE. The percentage of patients receiving intraoperative TEE increased over time from 39.9% in 2011 to 62.1% in 2019 (p trend <0.0001). CABG patients undergoing intraoperative TEE had lower odds of mortality (adjusted odds ratio: 0.95; 95% confidence interval: 0.91 to 0.99; p = 0.025), with heterogeneity across STS risk groups (p interaction = 0.015). TEE was associated with increased odds of unplanned valve procedure in lieu of planned isolated CABG (adjusted odds ratio: 4.98; 95% confidence interval: 3.98 to 6.22; p < 0.0001).

CONCLUSIONS

Intraoperative TEE usage during planned isolated CABG is associated with lower operative mortality, particularly in higher-risk patients, as well as greater odds of unplanned valve procedure. These findings support usage of TEE to improve outcomes for isolated CABG for high-risk patients.

Validation of Claims Data for the Identification of Intraoperative Transesophageal Echocardiography During Cardiac Surgery

OBJECTIVE

The goal of this study was to assess the validity of Current Procedural Terminology (CPT) claims data for the identification of intraoperative transesophageal echocardiography (TEE) during cardiac surgery.

DESIGN

This study was a retrospective, cohort analysis.

SETTING

This study used data from electronic medical records (EMRs), in combination with CPT billing claims data, from two hospitals within the Penn Medicine Health System-Penn Presbyterian Medical Center and the Hospital of the University of Pennsylvania.

PARTICIPANTS

The cohort consisted of adult patients, aged ≥18 years, undergoing open cardiac valve surgery (repair or replacement), coronary artery bypass graft surgery, or aortic surgery between April 1 and October 31, 2019.

INTERVENTIONS

Agreement between TEE identified using CPT billing code(s) (93312-8 with or without 93320-1 or 93325) and TEE identified by manual EMR review.

MEASUREMENTS AND MAIN RESULTS

As identified by a reference standard (ie, EMR review) of the 873 cases that met inclusion criteria, 867 (99.31%) cases were performed with TEE and six cases were performed without TEE (<1%). Of the 867 cases performed with TEE, CPT code(s) correctly identified 866 cases, as indicated by having at least one of the CPT codes (93312-8 with or without 93320-1 or 93325). These CPT codes identified intraoperative TEE with a 99.88% sensitivity, 100.00% specificity, 100.00% positive predictive value, and 85.71% negative predictive value. When billing claims for TEE were restricted to the CPT code 93312 alone, the results were identical.

CONCLUSIONS

Billing claims using CPT code(s) identified true intraoperative TEE with a high sensitivity, specificity, excellent positive predictive value, and moderate negative predictive value. These results demonstrated that claims data are a valuable data source from which to study the effect of TEE in cardiac surgical patients.