Background
The 2007 appropriate use criteria (AUC) for echocardiography were revised in 2011 to cover a wider range of scenarios of use. The aim of this study was to compare the 2011 AUC with the 2007 AUC to determine if the 2011 AUC better classify transesophageal echocardiography (TEE) and to determine the impact of the 2011 AUC on the rates of appropriate and inappropriate TEE at an academic medical center.
Methods
A retrospective chart review was conducted to examine inpatient and outpatient TEE utilization. TEE ordering behavior was compared using both the 2007 and 2011 AUC, and studies were classified as appropriate, uncertain, inappropriate, or not classifiable.
Results
We reviewed 202 consecutive transesophageal echocardiographic studies (154 inpatient, 48 outpatient) performed in 2011. Using the 2007 AUC, 166 studies (82%) were classifiable, and using the 2011 AUC, 199 (99%) were classifiable ( P < .001). Among the classified studies, the percentage of appropriate studies using the 2007 AUC was 94% and using the 2011 AUC was 95% ( P = .68). Using 2007 and 2011 AUC, the percentages of inappropriate studies were 0% and 4% ( P = .02), and the percentages of uncertain studies were 6% and 1% ( P = .006), respectively.
Conclusions
The 2011 AUC classify a significantly greater proportion of transesophageal echocardiographic studies than the 2007 AUC. The rate of inappropriate studies using the 2011 AUC is higher than when using the 2007 AUC. These findings suggest that the expanded AUC offer an opportunity for improvement in the utilization of TEE.
Increasing utilization of cardiac imaging generally, and echocardiography in particular, has been a significant focus of attention for cardiology societies and health policy makers. To increase the appropriate use of echocardiography, the American College of Cardiology Foundation, along with the American Society of Echocardiography and other subspecialty societies, published appropriate use criteria (AUC). Revised and expanded AUC for echocardiography were published in 2011. Awareness of and adherence to the AUC have become an important focus for quality improvement in echocardiography laboratories, and tracking appropriateness is now a requirement for accreditation.
Numerous implementation studies examining the 2007 AUC for transthoracic echocardiography (TTE) have been performed, and more recently, studies have begun to evaluate performance of the 2011 AUC for TTE. However, fewer studies have evaluated the appropriateness of transesophageal echocardiography (TEE), and to our knowledge, there have been no studies examining the 2011 AUC for TEE. The available data using the 2007 AUC show that the appropriateness rate of TEE (94%–97%) is higher than for TTE, and fewer transesophageal echocardiographic studies are unclassified by the AUC (6%–9%). Despite these encouraging results derived from the original AUC, opportunity for improvement in the utilization of TEE remains. It is unknown if the 2011 AUC for TEE better classify studies and what effect that has on appropriateness rates.
To assess the performance of the 2011 AUC for TEE, we applied both the 2007 and 2011 AUC to consecutive transesophageal echocardiographic studies ordered at a large academic medical center. We hypothesized that the 2011 AUC would better classify TEE compared with the 2007 AUC and allow a more accurate determination of appropriateness ratings.
Methods
Study Population
We conducted a retrospective chart review of consecutive inpatient and outpatient transesophageal echocardiographic studies performed from March 1 to May 19, 2011. Exclusion criteria were (1) patient age < 18 years, (2) TEE ordered as part of a research study, (3) insufficient information in the electronic medical record (EMR) that prevented the determination of the clinical reason for TEE, and (4) intraoperative TEE. TEE performed in the cardiac catheterization and electrophysiology laboratories was included in the study.
The study protocol was reviewed and approved by the Partners Healthcare institutional review board. The investigators had no contact with the patients, nor did they attempt to influence the care of the patients in any way.
Data Collection
Ordering information, patient demographics, and results of TEE were determined from a review of the EMR. Signs and symptoms and the reason(s) for TEE were abstracted from the TEE order and the EMR. The EMR is a comprehensive database including physician notes, imaging results, and laboratory findings. The date of each patient’s most recent prior transesophageal echocardiographic study, if any, was also noted. The EMR contains transesophageal echocardiographic reports from all hospitals within our health care network, and typically, results of outside TEE are scanned into the system. Three study investigators (R.S.B., D.M.C., R.B.W.) reviewed the reasons for ordering TEE. Investigators classified the clinical indication for each study using both the 2007 and 2011 AUC, allowing the determination of an appropriateness rating (appropriate, uncertain, or inappropriate). If the reason for TEE did not have a corresponding indication in the 2007 or 2011 AUC, it was considered unclassifiable. At least two of the investigators independently reviewed each order for TEE blinded to the other reviewer, and agreement on the AUC classification was required. For indications for which there was not initial consensus, review of the order for TEE and the EMR was conducted by three investigators to achieve consensus.
Patient demographics recorded were age, sex, cardiac risk factors (diabetes mellitus, smoking history, hypertension, and hyperlipidemia), previous cardiac procedures (coronary artery bypass grafting, valve surgery, and percutaneous coronary intervention), comorbidities (angina, heart failure, prior myocardial infarction, atrial fibrillation, peripheral arterial disease, chronic obstructive pulmonary disease, chronic kidney disease, connective tissue disease, dementia, and cancer), and hospitalization within the past 6 months.
Performance of TEE
All transesophageal echocardiographic studies were performed and reported according to previously published guidelines by level III and/or board-certified echocardiographers. All studies were performed using either a Phillips iE33 or 5500 ultrasound machine (Philips Medical Systems, Andover, MA). For the purpose of this study, findings on TEE were determined by review of the final clinical transesophageal echocardiographic report in the EMR. Left ventricular systolic function was determined via visual estimation or quantitative calculation (i.e., biplane method) at the discretion of the echocardiographer performing and interpreting the study. The presence and severity of valvular lesions were determined using an integration of semiquantitative and quantitative methods. For example, mitral regurgitation severity may be determined by measuring the vena contracta or by the proximal isovelocity surface area method and integrating that information with the expert visual interpretation. The presence of pulmonary hypertension was defined as an estimated right ventricular systolic pressure ≥ 50 mm Hg, which was determined from the maximum tricuspid regurgitation velocity and a standard right atrial pressure of 10 mm Hg.
Classification of Findings on TEE
An abnormality on TEE was defined as the presence of any one of the following: left ventricular ejection fraction < 45%, LV regional wall motion abnormality, right ventricular dysfunction, pulmonary hypertension (right ventricular systolic pressure ≥ 50 mm Hg), moderate or greater valvular regurgitation, significant valve stenosis (aortic stenosis [aortic valve area < 1.5 cm 2 ], mitral stenosis [mitral valve area < 1.5 cm 2 ]), moderate or greater pericardial effusion, or any other significant abnormality (i.e., thrombus, vegetation, tumor, or tamponade).
In situations in which prior TEE had been performed, the current study was compared to the prior study. A “new significant transesophageal echocardiographic abnormality” was defined as a new abnormality from the list above that was not previously noted. A change in findings on TEE was defined as a change of at least one grade in severity from the finding reported in the previous study. If the findings directly influenced the management of the patient, on the basis of review of the EMR, this was noted.
Statistical Analysis
Categorical variables for ordering characteristics using the 2007 and 2011 AUC were compared using χ 2 or Fisher’s exact tests as required. Continuous variables are reported as mean ± SD. Statistical significance was indicated by a two-tailed P value < .05.
Results
Study Population
Two hundred two transesophageal echocardiographic studies (154 inpatient, 48 outpatient) reviewed during the study period met the inclusion criteria. Ordering provider characteristics for the studies are detailed in Table 1 . Cardiologists were the most common ordering providers, followed by general internal medicine physicians and cardiac surgeons. Other providers, including other medical subspecialists (e.g., oncologists, pulmonologists), other surgical specialists, and anesthesiologists ordered the remainder of the studies. Patients were seen by cardiologists, as either the primary physicians of record or as consultant physicians, in 88% of cases.
| Variable | n (%) |
|---|---|
| Total number of studies | 202 |
| Specialty | |
| Cardiology | 146 (73) |
| General internal medicine | 29 (14) |
| Cardiac surgery | 15 (7) |
| Other | 12 (6) |
Patient Characteristics
Characteristics of the patients who underwent TEE in our cohort are summarized in Table 2 . The majority of studies were performed on inpatients (76%). The patients were more commonly male and had cardiac risk factors such as hypertension and hyperlipidemia. The majority of patients had histories of atrial fibrillation (66%).
| Variable | Value |
|---|---|
| Age (y), mean ± SD | 63 ± 14 |
| Inpatients | 154 (76%) |
| Men | 129 (64%) |
| Medicare | 86 (43%) |
| Previous myocardial infarction | 39 (19%) |
| Previous percutaneous coronary intervention | 21 (10%) |
| History of valve surgery | 18 (9%) |
| History of coronary artery bypass grafting | 19 (9%) |
| Angina | 32 (16%) |
| Heart failure | 69 (34%) |
| Diabetes | 55 (27%) |
| Hypertension | 115 (57%) |
| Hyperlipidemia | 103 (51%) |
| History of smoking | 91 (45%) |
| Atrial fibrillation | 133 (66%) |
| Chronic kidney disease | 34 (17%) |
| Cancer | 39 (19%) |
| Chronic obstructive pulmonary disease | 22 (11%) |
| Peripheral vascular disease | 55 (27%) |
| Congenital heart disease | 17 (8%) |
Classification of Transesophageal Echocardiographic Studies
The results of the classification of studies by the 2007 and 2011 AUC are detailed in Table 3 . The classification rate of studies was significantly higher using the 2011 AUC than the 2007 AUC (99% vs 82%, P < .001). Of the classified studies, the appropriate rate of studies ordered was similar between the 2007 and 2011 AUC. The inappropriate rate was higher using the 2011 AUC than the 2007 AUC. The rate of uncertain studies was lower using the 2011 AUC compared with the 2007 AUC.
| 2007 | 2011 | P | |
|---|---|---|---|
| Classifiable | 166 (82%) | 199 (99%) | <.001 |
| Inappropriate studies of those classified | 0 (0%) | 8 (4%) | .02 |
| Appropriate studies of those classified | 156 (94%) | 190 (95%) | .68 |
| Uncertain studies of those classified | 10 (6%) | 1 (1%) | .006 |
Details of the transesophageal echocardiographic studies that were reclassified using the 2011 AUC are provided in Table 4 . Compared with the 2007 AUC, application of the 2011 AUC resulted in the reclassification of 43 of all studies (21%). Of these 43 reclassified studies, 77% were changed from unclassifiable to classifiable. Specifically, 58% of reclassified studies were changed from unclassifiable to appropriate, 16% from unclassifiable to inappropriate, and 2% from unclassifiable to uncertain. Furthermore, another 21% of reclassified studies were changed from uncertain to appropriate using the 2011 AUC. Finally, one study was reclassified from appropriate to inappropriate. The most common reasons for appropriate and inappropriate studies using the 2011 AUC are provided in Table 5 .
| n (%) | |
|---|---|
| Total reclassified studies | 43 (21) |
| Reclassified from unclassifiable to classifiable | 33 (16) |
| Reclassified from unclassifiable to appropriate | 25 (12) |
| Reclassified from unclassifiable to inappropriate | 7 (3) |
| Reclassified from unclassifiable to uncertain | 1 (1) |
| Reclassified from appropriate to inappropriate | 1 (1) |
| Reclassified from inappropriate to appropriate | 0 (0) |
| Reclassified from inappropriate or appropriate to uncertain | 0 (0) |
| Reclassified from uncertain to appropriate | 9 (4) |
| Reclassified from uncertain to inappropriate | 0 (0) |
| Indication | N (%) |
|---|---|
| Appropriate indications | |
| Evaluation to facilitate clinical decision making with regard to anticoagulation, cardioversion and/or radiofrequency ablation (indication 112) | 98 (49) |
| To diagnose infective endocarditis with a moderate or high pretest probability (e.g. staph bacteremia, fungemia, prosthetic heart valve or intracardiac device) (indication 108) | 27 (13) |
| Guidance during percutaneous noncoronary cardiac interventions (indication 103) | 20 (9) |
| Use of TEE when there is a high likelihood of a nondiagnostic TTE due to patient characteristics or inadequate visualization of relevant structures (indication 99) | 19 (9) |
| Evaluation for cardiovascular source of embolus with no identified noncardiac source (indication 109) | 11 (5) |
| Inappropriate indications | |
| To diagnose infective endocarditis with a low pretest probability (e.g., transient fever, known alternative source of infection, or negative blood cultures/atypical pathogen for endocarditis) (indication 107) | 4 (2) |
| Routine use of TEE when a diagnostic TTE is reasonably anticipated to resolve all diagnostic and management concerns (indication 100) | 2 (1) |
| Evaluation for cardiovascular source of embolus with a known cardiac source in which a TEE would not change management (indication 111) | 1 (1) |
| Surveillance of prior TEE finding for interval change (e.g., resolution of thrombus after anticoagulation, resolution of vegetation after antibiotic therapy) when no change in therapy is anticipated (indication 102) | 1 (1) |
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