Appropriate use and clinical impact of transthoracic echocardiography

Electrocardiogram changes as predictors for new imaging findings in repeat transthoracic echocardiography

Aim: To determine if electrocardiogram (EKG) findings may be a useful tool to predict changes in repeat transthoracic echocardiogram (TTE). Methods: We evaluated patients who underwent TTE during hospitalization and their EKGs, and whether findings differed between studies. Results: Of 229 hospitalized patients who underwent repeat TTE, 183 (80%) were abnormal. Each minor and major EKG abnormality resulted in a 1.8 (1.2 to 2.6; p = 0.002) and 2.1 (1.3 to 3.3; p < 0.001) increased odds of abnormal imaging on TTE, respectively. The negative likelihood ratio for an unchanged EKG to predict an unchanged TTE was 0.68 (95% CI = 0.62 to 0.73). Conclusion: Among hospitalized patients with prior imaging results, an unchanged EKG predicts an unchanged TTE.

The Emerging Role of Artificial Intelligence in Valvular Heart Disease

Valvular heart disease (VHD) is a morbid condition in which timely identification and evidence-based treatments can lead to improved outcomes. Artificial intelligence broadly refers to the ability for computers to perform tasks and problem solve like the human mind. Studies applying AI to VHD have used a variety of structured (eg, sociodemographic, clinical) and unstructured (eg, electrocardiogram, phonocardiogram, and echocardiograms) and machine learning modeling approaches. Additional researches in diverse populations, including prospective clinical trials, are needed to evaluate the effectiveness and value of AI-enabled medical technologies in clinical care for patients with VHD.

Association between Wait Time for Transthoracic Echocardiography and 28-Day Mortality in Patients with Septic Shock: A Cohort Study

Background: the optimal timing of Transthoracic echocardiography (TTE) performance for patients with septic shock remains unexplored. Methods: a retrospective cohort study included patients with septic shock in the MIMIC-Ⅲ database. Risk-adjusted restricted cubic splines modeled the 28-day mortality according to time elapsed from ICU admission to receive TTE. The cut point when a smooth curve inflected was selected to define early and delayed group. We applied propensity score matching (PSM) to ensure our findings were reliable. Causal mediation analysis was used to assess the intermediate effect of fluid balance within 72 h after ICU admission. Results: 3264 participants were enrolled and the risk of 28-day mortality increased until the wait time was around 10 h (Early group) and then was relatively flat afterwards (Delayed group). A beneficial effect of early TTE in terms of the 28-day mortality was observed (HRs 0.73−0.78, all p < 0.05) in the PSM. The indirect effect brought by the fluid balance on day 2 and 3 was significant (both p = 0.006). Conclusion: early TTE performance might be associated with lower risk-adjusted 28-day mortality in patients with septic shock. Better fluid balance may have mediated this effect. A wait time within 10 h after ICU may represent a threshold defining progressively increasing risk.

Effects of transthoracic echocardiography on the prognosis of patients with acute respiratory distress syndrome: a propensity score matched analysis of the MIMIC-III database

Background

Acute respiratory distress syndrome (ARDS) has high mortality and is mainly related to the circulatory failure.Therefore, real-time monitoring of cardiac function and structural changes has important clinical significance.Transthoracic echocardiography (TTE) is a simple and noninvasive real-time cardiac examination which is widely used in intensive care unit (ICU) patients.The purpose of this study was to analyze the effect of TTE on the prognosis of ICU patients with ARDS.

Methods

The data of ARDS patients were retrieved from the MIMIC-III v1.4 database and patients were divided into the TTE group and non-TTE group. The baseline data were compared between the two groups. The effect of TTE on the prognosis of ARDS patients was analyzed through multivariate logistic analysis and the propensity score (PS). The primary outcome was the 28-d mortality rate. The secondary outcomes included pulmonary artery catheter (PAC) and Pulse index continuous cardiac output (PiCCO) administration, the ventilator-free and vasopressor-free days and total intravenous infusion volume on days 1, 2 and 3 of the mechanical ventilation. To illuminate the effect of echocardiography on the outcomes of ARDS patients,a sensitivity analysis was conducted by excluding those patients receiving either PiCCO or PAC. We also performed a subgroup analysis to assess the impact of TTE timing on the prognosis of patients with ARDS.

Results

A total of 1,346 ARDS patients were enrolled, including 519 (38.6%) cases in the TTE group and 827 (61.4%) cases in the non-TTE group. In the multivariate logistic regression, the 28-day mortality of patients in the TTE group was greatly improved (OR 0.71, 95%CI 0.55–0.92, P = 0.008). More patients in the TTE group received PAC (2% vs. 10%, P < 0.001) and the length of ICU stay in the TTE group was significantly shorter than that in the non-TTE group (17d vs.14d, P = 0.0001). The infusion volume in the TTE group was significantly less than that of the non-TTE group (6.2L vs.5.5L on day 1, P = 0.0012). Importantly, the patients in the TTE group were weaned ventilators earlier than those in the non-TTE group (ventilator-free days within 28 d: 21 d vs. 19.8 d, respectively, P = 0.071). The Kaplan–Meier survival curves showed that TTE patients had significant lower 28-day mortality than non-TTE patients (log-rank = 0.004). Subgroup analysis showed that TTE after hemodynamic disorders can not improve prognosis (OR 1.02, 95%CI 0.79–1.34, P = 0.844).

Conclusion

TTE was associated with improved 28-day outcomes in patients with ARDS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02028-5.

Do I really need this transthoracic ECHO? An over-utilized test in trauma and surgical intensive care units

INTRODUCTION

Clinical use of transthoracic echocardiogram (TTE) in intensive care units (ICU) has dramatically increased without clear guidance on validated assessment indications, appropriateness, and patient value.

METHODS

A retrospective analysis of consecutive TTEs performed among patients admitted to a tertiary trauma/surgical ICU over 2.5 years was performed. A bivariate analysis and Poisson regression was used to compare patients who received a TTE. Sensitivity analysis was performed to assess patient factors that predict change in management based on TTE. An abnormal exam was defined as having at least one of the following: ejection fraction < 55%, wall motion, pericardial effusion, pericardial effusion, or other significant abnormality including filling defect. The effect on management was derived from clinical course. We hypothesize that these studies are usually normal and rarely lead to changes in clinical management.

RESULTS

912 TTEs were performed in 806 patients. The median age was 68 years (IQR 57, 77) and 63.5% were male. Syncope (21.7%) or hypotension/hypovolemia (20.5%) were the most common indications for a TTE. In total, 39.4% TTEs were abnormal and only 7.6% resulted in a change in management. Predictive factors associated with an abnormal exam included: age >50, serum troponin ≥0.1 ng/ml, abnormal ECG, and clinical suspicion of heart failure or acute myocardial infarction. A troponin cutoff level <0.25 ng/mL was the most reliable factor to predict no change in management after TTE with a negative predictive value of 94.3% (95% CI 93.1, 95.3).

CONCLUSION

TTE is commonly used for patient assessment in critically ill surgical patients but the majority of exams are normal without change in clinical management. Certain patient factors, such as troponin level, may help distinguish which patients would benefit from this diagnostic test. Given the considerable cost associated with TTE and the minimal effect on management, guidelines on appropriate use would provide improved patient value.

Strategies to Reduce Low-Value Cardiovascular Care: A Scientific Statement From the American Heart Association

Low-value health care services that provide little or no benefit to patients are common, potentially harmful, and costly. Nearly half of the patients in the United States will receive at least 1 low-value test or procedure annually, creating risk of avoidable complications from subsequent cascades of care and excess costs to patients and society. Reducing low-value care is of particular importance to cardiovascular health given the high prevalence and costs of cardiovascular disease in the United States. This scientific statement describes the current scope and impact of low-value cardiovascular care; reviews existing literature on patient-, clinician-, health system-, payer-, and policy-level interventions to reduce low-value care; proposes solutions to achieve meaningful and equitable reductions in low-value care; and suggests areas for future research priorities.

Appropriateness and subsequent management of inpatient echocardiograms: An evaluation of low value care

Study objective

Transthoracic echocardiograms (TTE) are perceived to be overused and multiple TTEs are often ordered within one inpatient visit with unclear utility. This study identified inpatients who received multiple TTEs to determine the appropriateness, results, and subsequent management of repeat TTEs.

Design

Retrospective Cohort Study.

Setting

Single academic medical center.

Participants

Subjects over age 18 who underwent >1 TTE during hospitalization in 2020.

Interventions

N/A.

Main outcome measures

Appropriateness of TTE, TTE results, subsequent changes in management.

Results

Of the 875 subjects, the average age was 60 years old with a male predominance (57.8%). In comparing the first and second TTE results, the frequency of new abnormal findings decreased significantly from 44.7% to 15.1% (p < .0001). Changes in clinical management in relation to the TTEs decreased from 47.1% to 32.5% (p < .0001), of which medication changes were most common. The majority of tests were appropriate, with a slight increase of inappropriate TTEs from 0.6% to 1.8% (p < .0001) between first and second TTEs.

Conclusions

While the rate of inappropriate TTE use increased after the initial TTE, the overall rate of inappropriate use was very small indicating that stricter adherence to AUC would not appreciably reduce duplication of inpatient TTEs. The non-negligible frequency of new abnormal findings for the repeat TTEs at 15% cannot be ignored. Our data suggests that the assumption that repeat TTEs are in large part unnecessary is more complicated than originally thought.

Use of Echocardiography and Heart Failure In-Hospital Mortality from Registry Data in Japan

Background: Echocardiography requires a high degree of skill on the part of the examiner, and the skill may be more improved in larger volume centers. This study investigated trends and outcomes associated with the use and volume of echocardiographic exams from a real-world registry database of heart failure (HF) hospitalizations. Methods: This study was based on the Diagnosis Procedure Combination database in the Japanese Registry of All Cardiac and Vascular Datasets (JROAD-DPC). A first analysis was performed to assess the trend of echocardiographic examinations between 2012 and 2016. A secondary analysis was performed to assess whether echocardiographic use was associated with in-hospital mortality in 2015. Results: During this period, the use of echocardiography grew at an average annual rate of 6%. Patients with echocardiography had declining rates of hospital mortality, and these trends were associated with high hospitalization costs. In the 2015 sample, a total of 52,832 echocardiograms were examined, corresponding to 65.6% of all HF hospital admissions for that year. We found that the use and volume of echocardiography exams were associated with significantly lower odds of all-cause hospital mortality in heart failure (adjusted odds ratio (OR): 0.48 for use of echocardiography and 0.78 for the third tertile; both p < 0.001). Conclusions: The use of echocardiography was associated with decreased odds of hospital mortality in HF. The volumes of echocardiographic examinations were also associated with hospital mortality.

The Rate of Appropriate Adult Transthoracic Echocardiogram at King Abdulaziz University Hospital Based on Appropriate Use Criteria of 2011, 2017, and 2019

Background: Transthoracic echocardiography (TTE) is a basic method for cardiovascular disease diagnosis and treatment. Studies done to assess the appropriate use of TTE in the Kingdom of Saudi Arabia (KSA) are scarce.

Objectives: To assess the pattern of ordering TTE in King Abdulaziz University Hospital (KAUH) and the appropriateness of its ordering.

Methods: A retrospective study was done from October to November 2018 at KAUH, Echo lab, Jeddah City, KSA. Patients, more than 18 years who had TTE at KAUH were included.

Results: The criteria used were the 2019 criteria for most patients and the orders were appropriate for 77.9% of the 954 patients. Orders were significantly inappropriate for patients who had older age, and the number of indications were significantly higher for those whose orders were - "maybe appropriate" (M). The anesthesia department for outpatients and the surgical department for inpatients ordered a significantly high number of inappropriate requests. Inpatients had a significantly higher percentage of "appropriate" (A) orders, and a significant positive correlation was present between patients’ age and number of indications.

Conclusion: There is a need to maximize compliance with AUCs and its effect on clinical results should be evaluated.

Association between delayed transthoracic echocardiography and in-hospital mortality in type A acute aortic dissection-associated ST-segment elevated myocardial infarction

Background

This study evaluates the association between transthoracic echocardiography (TTE) timing and in-hospital mortality among individuals presenting with ST-segment elevated myocardial infarction (STEMI) complicating type A acute aortic dissection (TAAAD).

Methods

This cohort study obtained the data of previously published case reports from searches of PubMed (1990–2020), and adults with STEMI secondary to TAAAD were finally included. Delayed TTE (dTTE) exposure was defined as when the TTE test was made available after antithrombotic management for STEMI due to an initially missed diagnosis of TAAAD. The primary outcome of interest was in-hospital mortality, comparing individuals with dTTE and those with emergency TTE (eTTE). The odds ratio (OR) with 95% confidence interval (CI) were calculated to provide an estimate of association.

Results

A total of 109 individuals with a mean age of 56.7 [standard deviation (SD) 12.9] years, and of whom 75 were men (68.8%) presenting with STEMI complicating TAAAD were included. Of all patients, 68 (62.4%) had a dTTE test, which tended to be associated with increased in-hospital mortality after adjustment (OR, 2.320; 95% CI, 0.743–7.248). The association between dTTE and in-hospital death was significant only among patients presenting with a high-risk examination (HRE) (OR, 11.196; 95% CI, 1.322–94.803) and with surgical therapy (OR, 5.375; 95% CI, 1.080–26.700), and not among those presenting with negative HRE (OR, 0.150; 95% CI, 0.016–1.397) and no surgical therapy (OR, 0.177; 95% CI, 0.008–4.018).

Conclusions

This study found an association between dTTE and increased in-hospital mortality in TAAAD-associated STEMI patients with surgical management. This association warrants further investigation.

Quality Assurance and Improvement Project in Echocardiography Laboratory: The Pivotal Importance of Organizational and Managerial Processes

Echocardiography plays a vital role in the diagnosis and management of cardiovascular conditions. Echocardiography use is progressively increasing nowadays, and this is correlated to the evolving echo indications, to the relatively new available echocardiography modes (tissue Doppler imaging, speckle tracking imaging, three-dimensional mode, etc.) and modalities (transthoracic, transesophageal, and intracardiac) along with the various available clinical approaches (point of care echo, portable echo, etc.). Quality assurance in echocardiography is correlated to appropriate use criteria, adequate equipment, standardization of performance and reporting, along with timely storage and archiving. Quality improvement plan must target strategic planning, with metrics and timeline for assessment and re-assessment of results. Improvement project aims to ensure and enhance conformity with appropriate use criteria and standardization, timely completion of exams and reports, detection of discrepancies, and continuous improvement of knowledge and skills. Strategic planning is essential in this context in order to develop organizational and managerial processes, with regular auditing for a highly professional and advanced level of echocardiography, while ensuring teamwork and standards of ethical values.

Echocardiogram Utilization Patterns and Association With Mortality Following Severe Traumatic Brain Injury

BACKGROUND

Severe traumatic brain injury (TBI) can result in left ventricular dysfunction, which can lead to hypotension and secondary brain injuries. Although echocardiography is often used to examine cardiovascular function in multiple clinical settings, its use and association with outcomes following severe TBI are not known. To address this gap, we used the National Trauma Data Bank (NTDB) to describe utilization patterns of echocardiography and examine its association with mortality following severe TBI.

METHODS

A retrospective cohort study was conducted using a large administrative trauma registry maintained by the NTDB from 2007 to 2014. Patients >18 years with isolated severe TBI, and without concurrent severe polytrauma, were included in the study. We examined echocardiogram utilization patterns (including overall utilization, factors associated with utilization, and variation in utilization) and the association of echocardiography utilization with hospital mortality, using multivariable logistic regression models.

RESULTS

Among 47,808 patients, echocardiogram was utilized as part of clinical care in 2548 patients (5.3%). Clinical factors including vascular comorbidities and hemodynamic instability were associated with increased use of echocardiograms. Nearly half (46.0%, 95% confidence interval [CI], 40.3%-51.7%) of the variation in echocardiogram utilization was explained at the individual hospital level, above and beyond patient and injury factors. Exposure to an echocardiogram was associated with decreased odds of in-hospital mortality following severe TBI (adjusted odds ratio [OR] = 0.77; 95% CI, 0.69-0.87; P < .001).

CONCLUSIONS

Echocardiogram utilization following severe TBI is relatively low, with wide variation in use at the hospital level. The association with decreased in-hospital mortality suggests that the information derived from echocardiography may be relevant to improving patient outcomes but will require confirmation in further prospective studies.

Optimizing cardiovascular imaging in Staphylococcus aureus endocarditis

INTRODUCTION

The shift toward value-based health care drives physicians to examine opportunities to optimize use of healthcare resources. There is discordance between providers' use of cardiovascular imaging (CVI) in assessing patients for infective endocarditis (IE) with Staphylococcus aureus bacteremia (SAB). An evidence-based algorithm was created to minimize variation of CVI use. The primary objective was to ensure sensitivity of the algorithm to recommend CVI in patients suspected of IE.

METHODS

A retrospective review evaluated patients at Ochsner Medical Center who developed SAB between 1/1/13 and 12/31/14. Predefined patient demographics, use of CVI, outcomes, and 12-week follow-up for readmission after first positive blood culture were collected from chart review. The created algorithm was applied retrospectively to determine its sensitivity and specificity in recommending the right CVI test.

RESULTS

181 patients admitted were admitted with SAB, of which 114 (63%) were male. There were 115 TTEs and 55 TEEs performed. Out of 15 patients diagnosed with IE, 3 were found on TTE and 12 were found on TEE. The algorithm would have recommended a TEE in all 15 patients who had high-risk features for IE and a true diagnosis of IE, suggesting a sensitivity of 100% and specificity of 74.7% for the algorithm to have recommended a highly sensitive CVI modality.

CONCLUSION

This algorithm optimizes CVI for diagnosing IE in patients with SAB. As healthcare adapts to a value-based system, use of best-practice algorithms will promote consistency in practice among providers and help optimize patient outcomes and use of resources.

Reducing Unnecessary Noninvasive Testing for Inpatients With Unstable Angina: The RUNIT Protocol

Background

Routine inpatient transthoracic echocardiography (TTE) for patients with unstable angina is common, but it anecdotally adds little value to clinical care. A practice audit at our academic hospital demonstrated that 61.5% of patients with troponin-negative chest pain (TNCP) had normal left ventriculography (LVG) during coronary angiography and normal TTE on the same admission (duplicate testing).

Methods

We developed the Reducing Non-Invasive Testing (RUNIT) protocol, a clinical algorithm applied by clinical nurses to patient with TNCP. We performed a prospective assessment of rate of duplicate testing before and after intervention. If patients met certain simple clinical criteria, their TTE was cancelled (RUNIT positive). Patients then proceeded to have either coronary angiography with LVG or noninvasive risk stratification. We aimed to reduce duplicate testing by 25% over a 1-year period. Balancing measures included pathology on ordered TTEs, 30-day readmission, length of stay, and number of LVG.

Results

Among 254 patients admitted with TNCP over 12 months, we reduced duplicate testing from 61.5% (before intervention) to 34% (P = 0.001). There was no clinical difference in 30-day readmission (0.9% vs 0.7%), and length of stay was significantly shorter in RUNIT positive (3.48 vs 4.16 days, P = 0.02). The majority of duplicate TTEs did not reveal any management-informing pathology. RUNIT-positive patients underwent more LVG than RUNIT-negative patients (78.3% vs 62.8%, P = 0.008).

Conclusion

We achieved a sustained reduction in reflexive TTE ordering in patients with TNCP, and we discuss the potential of nursing-led interventions to address other areas of low value care in cardiology.

Impact of Appropriate Use Criteria for Transthoracic Echocardiography in Valvular Heart Disease on Clinical Outcomes

BACKGROUND

The association between appropriate use criteria for transthoracic echocardiography (TTE) and clinical outcomes is unknown for patients with valvular heart disease (VHD). The aim of this study was to identify the association of TTE appropriateness with downstream cardiac tests and clinical outcomes in patients with VHD over 365 days.

METHODS

A subset of 2,297 patients with VHD across six Ontario academic hospitals was selected from the Echo WISELY (Will Inappropriate Scenarios for Echocardiography Lessen Significantly) trial and linked to administrative databases. Each patient's index TTE was classified as "rarely appropriate" (rA) versus "appropriate" (comprising "appropriate" and "may be appropriate" TTE according to the 2011 appropriate use criteria). Overall, 431 of 452 patients with rA TTE were matched 1:1 with patients with appropriate TTE using propensity scores to account for measured confounding.

RESULTS

Matched patients with rA TTE were less likely to undergo repeat TTE (relative risk, 0.46; 95% CI, 0.33-0.66) or cardiac catheterization (relative risk, 0.27; 95% CI, 0.16-0.47) at 90 days compared with patients with appropriate TTE. rA TTE was significantly associated with a decreased hazard of aortic valve intervention (hazard ratio, 0.40; 95% CI, 0.14-0.42), all-cause hospitalization (hazard ratio, 0.44; 95% CI, 0.34-0.57), and death (hazard ratio, 0.31; 95% CI, 0.15-0.66) over 365 days of follow-up.

CONCLUSIONS

Patients with appropriate TTE for VHD were more likely to undergo subsequent cardiac testing within 90 days and valve intervention within 1 year than those with a rA TTE. The 2011 appropriate use criteria for TTE have important clinical implications for outcomes in patient with VHD.

Focus-assessed transthoracic echocardiography: Implications in perioperative and intensive care

Transthoracic echocardiography is a potent and appealing diagnostic tool by virtue of rapidity, noninvasiveness, and repeatability. Focus-assessed transthoracic echocardiography (FATE) forms quick guidance to interpret the echocardiographic information and relates it to the clinical context. It can be applied in the perioperative period, intensive care units (ICUs), and emergency situations, in trauma and as resuscitation aids. FATE intents to assess cardiac function including contractility, chamber size and hypertrophy, valvular dysfunction, cardiac tamponade, and pericardial and pleural effusions. Thence, FATE has become a quintessential scanning tool perioperatively and in ICUs.

Diagnostic and treatment utility of echocardiography in the management of the cardiac patient

BACKGROUND

Echocardiograms are an incredibly useful diagnostic tool due to their lack of harmful radiation, the relative ease and speed with which they can be performed, and their almost ubiquitous availability. Unfortunately, the advantages that support the use of echocardiography can also lead to the overuse of this technology. We sought to evaluate the physician perceived impact echocardiography has on patient management.

AIM

To evaluate the physician perceived impact echocardiography has on patient management.

METHODS

Surveys were distributed to the ordering physician for echocardiograms performed at our institution over a 10-wk period. Only transthoracic echocardiograms performed on the inpatient service were included. Surveys were distributed to either the attending physician or the resident physician listed on the echocardiogram order. The information requested in the survey focused on the indication for the study and the perceived importance and effect of the study. Observational statistical analysis was performed on all of the answers from the collected surveys.

RESULTS

A total of 103 surveys were obtained and analyzed. The internal medicine (57%) and cardiology (37%) specialties ordered the most echocardiograms. The most common reason for ordering an echocardiogram was to rule out a diagnosis (38.2%). Only 27.5% of physicians reported that the echocardiogram significantly affected patient care, with 18.6% reporting a moderate effect, and 30.4% reporting a mild effect. A total of 19.6% of physicians stated that there was no effect on patient management. Additionally, 43.1% of physicians reported that they made changes in patient management due to no change having occurred in the disease, 11.8% reported that changes in management were based on the recommendation of a specialist, and only 9.8% reported that further imaging was ordered due to the results of the echocardiogram. The majority of physicians (67.6%) considered an echocardiogram to be “somewhat essential” in the management of adult inpatients, with only 15.7% considering it “essential”.

CONCLUSION

The majority of physicians surveyed report the echocardiogram had only a mild effect on management with only 27.5% reporting a significant effect. However, the majority of physicians (83.3%) perceived an echocardiogram to be somewhat or entirely essential for management. Only 9.8% reported the echo led to further imaging. These insights into ordering physician reasoning should help guide better definition of the optimal and ideal use of echocardiography.

The application of appropriate use criteria for transthoracic echocardiography in a cardiac intensive care unit

BACKGROUND

Appropriate use criteria (AUC) represent an important mechanism by which to promote the rational utilization of healthcare resources. No study to date has been conducted assessing the applicability of current AUC to transthoracic echocardiograms (TTEs) performed in a cardiac intensive care unit (CICU). We analyzed 2 years of consecutive TTEs performed in a CICU at a quaternary-care academic medical center, hypothesizing that current AUC may not adequately describe the role of TTE in a modern CICU.

METHODS

Indications for TTEs were independently classified by two investigators in accordance with 2011 AUC. If investigators were unable to assign an AUC classification to a given study, it was deemed to be unclassifiable. Disagreements between investigators were resolved by consensus. Cases in which consensus could not be reached underwent definitive adjudication by a third investigator.

RESULTS

Of the 826 TTEs, 619 TTEs were classified as appropriate (74.9%, CI 71.8%-77.9%), 12 as uncertain (1.5%, CI 0.75%-2.5%), 21 as rarely appropriate (2.5%, CI 1.6%-3.9%), and 174 were unable to be classified (21.1%, CI 18.3%-24.0%). The most common unclassifiable indication was "initial evaluation of cardiac structure or function after cardiac arrest of unknown etiology" (n = 101).

CONCLUSION

Current AUC for TTEs may not adequately address the complexity of clinical cases encountered in the CICU. In our study of 826 consecutive TTEs, 21.1% were unable to be classified, reflecting the difficulty in applying AUC to this unique clinical environment. Further studies are therefore needed to better delineate the appropriateness of TTEs performed in the CICU.

Association Between Inpatient Echocardiography Use and Outcomes in Adult Patients With Acute Myocardial Infarction

IMPORTANCE

Guidelines recommend that patients with acute myocardial infarction (AMI) undergo echocardiography for assessment of cardiac structure and ejection fraction, but little is known about the association between echocardiography as used in routine clinical management of AMI and patient outcomes.

OBJECTIVE

To examine the association between risk-standardized hospital rates of transthoracic echocardiography and outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study of data from 397 US hospitals that contributed to the Premier Healthcare Informatics inpatient database from January 1, 2014, to December 31, 2014, used International Classification of Diseases, Ninth Revision (ICD-9) codes to identify 98 999 hospital admissions for patients with AMI. Data were analyzed between October 2017 and January 2019.

EXPOSURES

Rates of transthoracic echocardiography.

MAIN OUTCOMES AND MEASURES

Inpatient mortality, length of stay, total inpatient costs, and 3-month readmission rate.

RESULTS

Among the 397 hospitals with more than 25 admissions for AMI in 2014, a total of 98 999 hospital admissions for AMI were identified for analysis (38.2% women; mean [SD] age, 66.5 [13.6] years), of which 69 652 (70.4%) had at least 1 transthoracic echocardiogram performed. The median (IQR) hospital risk-standardized rate of echocardiography was 72.5% (62.6%-79.1%). In models that adjusted for hospital and patient characteristics, no difference was found in inpatient mortality (odds ratio [OR], 1.02; 95% CI, 0.88-1.19) or 3-month readmission (OR, 1.01; 95% CI, 0.93-1.10) between the highest and lowest quartiles of echocardiography use (median risk-standardized echocardiography use rates of 83% vs 54%, respectively). However, hospitals with the highest rates of echocardiography had modestly longer mean lengths of stay (0.23 days; 95% CI, 0.04-0.41; P = .01) and higher mean costs ($3164; 95% CI, $1843-$4485; P < .001) per admission compared with hospitals in the lowest quartile of use. Multiple sensitivity analyses yielded similar results.

CONCLUSIONS AND RELEVANCE

In patients with AMI, hospitals in the quartile with the highest rates of echocardiography showed greater hospital costs and length of stay but few differences in clinical outcomes compared with hospitals in the quartile with the lowest rates of echocardiography. These findings suggest that more selective use of echocardiography might be used without adversely affecting clinical outcomes, particularly in hospitals with high rates of echocardiography use.

Trends in the use of echocardiography in patients with Staphylococcus aureus bacteremia: an analysis using the Nationwide Inpatient Sample data

BACKGROUND

Infective endocarditis occurs in approximately 10%-30% of patients with Staphylococcus aureus bacteremia (SaB). Guidelines recommend echocardiography in patients with SaB and risk factors for infective endocarditis in the absence of any obvious source of infection. Herein, we explored the trends in the use of echocardiography in patients with SaB and its relationship to outcomes using a large national database.

METHOD

All patients with a principal discharge diagnosis of SaB were identified using the National Inpatient Sample database from 2001 to 2014. Procedure code 88.72 was used to identify echocardiography. Logistic regression models were estimated to identify the year-over-year trends in echocardiogram, predictors of use, and association with mortality.

RESULTS

From 2001 to 2014, there were 668 423 hospitalizations with SaB diagnosis and 86 387 (12.9%) had echocardiogram. The rate of echocardiography increased from 10.7% in 2001 to 15.2% in 2014 (p_trend  < 0.001). Major predictors of echocardiogram usage were younger age, male gender, presence of sepsis, valvular or congenital heart disease, prosthetic heart valve (PHV), cardiac implantable electronic device (CIED), hemodialysis, and drug abuse. The adjusted rates of echocardiography increased from approximately 10% to 15% in hospitalizations without risk factors for IE while for high-risk groups like PHV and CIED it remained constant at 30% and 19%, respectively. Echocardiography was associated with 31% lower odds of in-hospital mortality.

CONCLUSION

The increase in echocardiography rate was largely attributable to increased use in those without risk factors while usage in those with PHV and CIED remained much lower than expected. Echocardiography use was associated with lower risk-adjusted mortality. These findings require further study and confirmation.

Handheld ultrasound to reduce requests for inappropriate echocardiogram (HURRIE)

Background

Handheld ultrasound could provide sufficient information to satisfy the clinical questions underlying 'rarely appropriate' echo requests, but there are limited data about its use as a gatekeeper to standard echocardiography. We sought to determine whether the use of handheld ultrasound could improve the appropriate use of echocardiography.

Method

A prospective study comparing handheld ultrasound strategy to standard echocardiography for studies deemed rarely appropriate, using a questionnaire based on appropriate use criteria was conducted across two hospitals, from October 2017 to April 2018.

Results

Groups undergoing Handheld ultrasound (n = 76, 58 (46.5-72.5) years, 53 males, 78% outpatients) and standard echocardiography (n = 72, 61 (49.0-71.5) years, 42 males, 76% outpatients) were comparable. There was a significant decrease in the time to scan from just over 1 month in standard group to a median of 12 days in handheld ultrasound group (P < 0.001). This difference was small for inpatients (from 1 day to a median of 10 min in handheld ultrasound, P = 0.014), but prominent in outpatients (from 1.5 months in the standard group to median of 2 weeks in the handheld ultrasound group, P < 0.001). There was no increase in the need for follow-up scan within 6 months and no significant differences in length of hospital stay for inpatients.

Conclusion

Handheld ultrasound can be an effective gatekeeper to standard echocardiography for requests deemed rarely appropriate, reducing time to echocardiography significantly and potentially decreasing the need for standard echocardiography by up to 20%.

Association Between Transthoracic Echocardiography Appropriateness and Echocardiographic Findings

BACKGROUND

The association between appropriate use criteria and echocardiographic findings in patients with chronic cardiovascular diseases is unknown.

METHODS

As a substudy of the Echo WISELY (Will Inappropriate Scenarios for Echocardiography Lessen Significantly) trial, 9,230 transthoracic echocardiographic (TTE) examinations from six Ontario academic hospitals were linked to a registry of echocardiographic findings. The TTE studies were rated appropriate), rarely appropriate, or may be appropriate according to the 2011 appropriate use criteria. TTE findings of appropriately ordered examinations were compared with those of rarely appropriate examinations for specific disease subsets, including heart failure and valvular heart disease.

RESULTS

There were 7,574, 1,087, and 569 TTE examinations ordered for appropriate, rarely appropriate, and may be appropriate indications, and of the 7,574 appropriate studies, 6,399 were ordered for specific indications and 1,175 for general indications. TTE examinations ordered for general indications had lower rates of left ventricular dysfunction (19.6% vs 9.1%, P < .001) and moderate to severe aortic stenosis (15.5% vs 2.6%, P < .001). Of the 2,395 TTE examinations ordered for patients with heart failure, appropriately ordered studies were more likely to result in left ventricular segmental abnormality (37.0% vs 24.9%, P = .012) but similar rates of right ventricular dilatation (15.4% vs 14.7%, P = .79), right ventricular dysfunction (14.8% vs 11.3%, P = .22), and moderate to severe mitral regurgitation (12.1% vs 9.2%, P = .35). Of the 2,859 studies ordered to assess valvular heart disease, appropriately ordered studies were significantly more likely to find moderate to severe valvular pathology, including aortic stenosis (30.4% vs 24.6%, P = .008), aortic regurgitation (8.9% vs 1.6%, P < .001), mitral stenosis (6.7% vs 3.1%, P = .002), and mitral regurgitation (16.1% vs 6.1%, P < .001), but similar rates of tricuspid regurgitation (11.2% vs 13.0%, P = .60).

CONCLUSIONS

Overall, appropriately ordered TTE examinations for heart failure and valvular heart disease were significantly more likely to have abnormal findings than rarely appropriate examinations. TTE studies ordered for general indications had fewer, although still a significant proportion, of abnormalities compared with studies ordered for specific indications.

Evidence Basis for a Point-of-Care Ultrasound Examination to Refine Referral for Outpatient Echocardiography

BACKGROUND

Few data exist on the potential utility of a cardiac point-of-care ultrasound (POCUS) examination in the outpatient setting to assist diagnosis of significant cardiac disease. Using a retrospective sequential cohort design, we sought to derive and then validate a POCUS examination for cardiac application and model its potential use for prognostication and cost-effective echo referral.

METHODS

For POCUS examination derivation, we reviewed 233 consecutive outpatient echo studies for 4 specific POCUS "signs" contained therein representing left ventricular systolic dysfunction, left atrial enlargement, inferior vena cava plethora, and lung apical B-lines. The corresponding formal echo reports were then queried for any significant abnormality. The optimal POCUS examination for identifying an abnormal echo was determined. We then reviewed 244 consecutive outpatient echo studies from another institution for associations between the optimal POCUS examination, clinical variables, and referral source with major adverse cardiac events and all-cause mortality in univariate and multivariate models. Assuming a referral model where the absence of POCUS signs or variables would negate initial echo referral, theoretical cost savings were expressed as a percentage in reduction of echo studies.

RESULTS

In the derivation cohort, the combination of two signs, denoting left atrial enlargement and inferior vena cava plethora resulted in the highest accuracy of 72% [95% CI: 65%, 78%] in detecting an abnormal echocardiogram. In the validation cohort, mortality at 5.5 years was 14.6% overall, 23% in patients with the left atrial enlargement sign (OR 3.5 [1.6, 7.6]), 25% with inferior vena cava plethora sign (OR 2.2 [0.8, 6.0]), and 8.0% (OR 0.3 [0.2, 0.7]) in those lacking both signs. After adjusting for age, both diabetes (OR 4.8 [2.0, 11.6]), and the left atrial enlargement sign (OR 2.4 [1.1, 5.4]) remained independently associated with mortality (p<0.05). In the referral model, patients younger than 65 years of age without diabetes and without the left atrial enlargement sign would not have received echo referral, resulting in a 33% reduction in total echo cost and would have constituted a low-risk group with a 1.2% 5.5-year mortality.

CONCLUSIONS

A quick-look sign for left atrial enlargement is associated with 5-year mortality and could function as an easily obtained outpatient POCUS examination to help in identifying patients in need of echo referral.

A systematic review of Appropriate Use Criteria for transthoracic echocardiography: are they relevant outside the United States?

INTRODUCTION

The 2011 Appropriate Use Criteria (AUC) were developed by the American Society of Echocardiography (ASE) to provide guidance for referring physicians in response to growing concerns about unnecessary transthoracic echocardiogram (TTE) requests. Very few studies have assessed how medical centers overseas perform against AUC. Evidence is now emerging that inappropriate referral rates in Europe are similar to those reported in the US.

OBJECTIVE

This study systematically reviewed published evidence to identify (1) whether the 2011 AUC are applicable to medical centers outside the US (2) the level of adherence to the AUC across multiple centers, (3) the main factors which cause deviation from AUC, (4) any changes in referral rates since the publication of AUC, and (5) any factors and/or intervention strategies which promote adherence to AUC.

METHODS AND RESULTS

Electronic databases were systematically searched for papers related to AUC and cardiac imaging. Following screening and application of eligibility criteria, data was extracted from ten reports involving 8561 TTE studies. Classification rates were 99.5 and 98% for US studies and studies outside the US respectively. Overall, 7119 TTE studies were classified as appropriate (83.1%) of which 3724 were US referrals (84.7%) and 3395 originated outside the US (81.5%). Six of the included studies independently observed significantly more appropriate referrals among inpatients compared to outpatients (p < 0.001). US centers observed no significant difference in appropriate referral rates between physician specialties while one UK study showed cardiac surgeons ordered inappropriate TTEs more frequently than other specialties (p < 0.05). This review found no obvious trend in appropriate referral rates between 2012 and 2015 indicating no temporal change in physician ordering patterns. Only one educational interventional study met the author's criteria which showed that while intervention was effective during its implantation (26% reduction in TTEs ordered per day), TTE referral rates regressed to pre-intervention levels overtime.

CONCLUSIONS

In conclusion, the American guideline AUC are applicable to centers outside the US and their implementation across five international centers suggest almost 1 in 5 scans could be avoided.

Appropriate Use Criteria for paediatric echocardiography in an outpatient practice: a validation study

BACKGROUND

Although transthoracic echocardiography is the dominant imaging modality in CHD, optimal utilisation is unclear. We assessed whether adherence to the paediatric Appropriate Use Criteria for outpatient transthoracic echocardiography could reduce inappropriate use without missing significant cardiac disease.

METHODS

Using the Appropriate Use Criteria, we determined the indication and appropriateness rating for each initial echocardiogram performed at our institution during calendar year 2014 (N=1383). Chart review documented ordering provider training, patient demographics, and study result, classified as normal, abnormal, or abnormal motivating treatment within a 2-year follow-up period. We tested whether provider training level or patient age correlated with echocardiographic findings or appropriateness rating.

RESULTS

We found that 83.9% of echocardiograms were normal and that 66.7% had an appropriate indication. Nearly all abnormal results and all results motivating treatment were in appropriate studies, giving an odds ratio of 2.73 for an abnormal result if an appropriate indication was present (95% confidence interval 1.92-3.89, p<0.001). None of the remaining initial abnormal results with less than appropriate indications became significant, resulting in treatment over 2 years. Results suggest a potential reduction in imaging volume of as much as 33% with application of the criteria. Cardiologists ordered nearly all studies resulting in treatment but also more echocardiograms with less appropriate indications. Most examinations were in older patients; however, most abnormal results were in patients younger than 1 year.

CONCLUSIONS

The Appropriate Use Criteria can be used to safely reduce echocardiography volume while still detecting significant heart disease.

Low prevalence of relevant findings in inappropriate echocardiograms and discordant perceptions between cardiologists and patients

Complementary examinations are "inadequate" whenever the likelihood of benefits from their indication is lower than the negative results. The low benefit is a result of poor performance in detecting relevant changes that lead to improved behavior. However, inadequate examinations are prevalent and little is known about patients' notions of the usefulness of such indications. The aim of this study was to describe relevant findings in inappropriate echocardiograms and to assess the level of agreement between patients and cardiologists regarding their usefulness. Adults without known cardiovascular disease who were referred for echocardiogram by inappropriate criteria according to the American College of Cardiology were selected. Relevant findings were defined by any change in the degree of moderate to severe, according to the American Society of Echocardiography. We tested the level of agreement between the patients who underwent echocardiographic examination and the physicians who requested the exam through a standard questionnaire. Five hundred patients were included, with average age of 52±17 years (47% males). Only 17 patients had any relevant changes (3.4%, 95%CI=2 to 5.4%). The most frequent alterations included valve changes in 8 and diastolic dysfunction grade II in 6 patients. Eighty-seven examinations were performed to determine the level of agreement between patients and cardiologists. For the question "Is this test really necessary?", 92% of patients responded positively, compared with 5% of cardiologists (Kappa negative 0.04; P=0.01). The frequency of relevant findings was low in inadequate echocardiograms and patients and cardiologists had a different perception regarding its usefulness.

Appropriate utilization of cardiac magnetic resonance for the assessment of heart failure and potential associated cost savings

BACKGROUND

The rapid growth in cardiac imaging utilization has led to the development of appropriate use criteria (AUC) in an effort to control costs. Recently, cardiac MRI has developed into a valuable modality in the evaluation of cardiac disease. However, there are no studies examining the appropriate use of cardiac MRI in clinical practice.

PURPOSE

To determine the appropriate utilization of cardiac MRI in a large quaternary care institution and to compare percentages of appropriate utilization pre- and postpublication of the AUC document. We hypothesized that percentages of appropriate cardiac MRI utilization will be similar to those of other comparable cardiac imaging modalities and that there would be a significant change in appropriate use pre- and post-AUC publication.

STUDY TYPE

Retrospective cohort study.

POPULATION

In all, 2032 consecutive patients undergoing cardiac MRI for the assessment of heart failure between 2012-2016.

FIELD STRENGTH

1.5T.

ASSESSMENT

Data were collected and an appropriateness category was assigned for each cardiac MRI.

STATISTICAL TESTS

Rates of major cardiac risk factors were compared between those undergoing cardiac MRIs pre- and post-AUC using the chi-square and the Mann-Whitney tests for categorical and continuous variables, respectively. Appropriateness classification was compared pre- and post-AUC publication using the chi-square test.

RESULTS

There were no significant differences in the prevalence of major cardiovascular risk factors before and after publication of the AUC. 95.5% of all cardiac MRIs were appropriate based on the AUC. Further, there was a significant difference when comparing the appropriateness classification before and after publication of the AUC (P = 0.0003), potentially associated with annual cost savings of ∼$14.8 million.

DATA CONCLUSION

We report a very high percentage of appropriate use of cardiac MRI and a significant increase in the proportion of tests classified as appropriate after AUC publication.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2019;49:e132-e138.

Derivation of a Clinical Model to Predict Unchanged Inpatient Echocardiograms

BACKGROUND

Transthoracic echocardiography (TTE) is one of the most commonly ordered tests in healthcare. Repeat TTE, defined as a TTE done within 1 year of a prior TTE, represents 24% to 42% of all studies. The purpose of this study was to derive a clinical prediction model to predict unchanged repeat TTE, with the goal of defining a subset of studies that are unnecessary.

METHODS

Single-center retrospective cohort study of all hospitalized patients who had a repeat TTE between October 1, 2013, and September 30, 2014.

RESULTS

Two hundred eleven of 601 TTEs were repeat studies, of which 78 (37%) had major changes. Five variables were independent predictors of major new TTE changes, including history of intervening acute myocardial infarction, cardiothoracic surgery, major new electrocardiogram (ECG) changes, prior valve disease, and chronic kidney disease. Using the β-coefficient for each of these variables, we defined a clinical prediction model that we named the CAVES score. The acronym CAVES stands for chronic kidney disease, acute myocardial infarction, valvular disease, ECG changes, and surgery (cardiac). The prevalence of major TTE change for the full cohort was 35%. For the group with a CAVES score of -1, that probability was only 5.6%; for the group with a score of 0, the probability was 17.7%; and for the group with a score ≥1, the probability was 55.3%. The bootstrap corrected C statistic for the model was 0.78 (95% confidence interval, 0.72-0.85), indicating good discrimination.

CONCLUSIONS

Overall, the CAVES score had good discrimination and calibration. If further validated, it may be useful to predict repeat TTEs that are unlikely to have major changes.

Defining Quality in Cardiovascular Imaging: A Scientific Statement From the American Heart Association

The aims of the current statement are to refine the definition of quality in cardiovascular imaging and to propose novel methodological approaches to inform the demonstration of quality in imaging in future clinical trials and registries. We propose defining quality in cardiovascular imaging using an analytical framework put forth by the Institute of Medicine whereby quality was defined as testing being safe, effective, patient-centered, timely, equitable, and efficient. The implications of each of these components of quality health care are as essential for cardiovascular imaging as they are for other areas within health care. Our proposed statement may serve as the foundation for integrating these quality indicators into establishing designations of quality laboratory practices and developing standards for value-based payment reform for imaging services. We also include recommendations for future clinical research to fulfill quality aims within cardiovascular imaging, including clinical hypotheses of improving patient outcomes, the importance of health status as an end point, and deferred testing options. Future research should evolve to define novel methods optimized for the role of cardiovascular imaging for detecting disease and guiding treatment and to demonstrate the role of cardiovascular imaging in facilitating healthcare quality.

Appropriate use of echocardiography and relation to clinical decision making in both inpatients and outpatients in a developing country

BACKGROUND

Use of echocardiography (echo) has exponentially increased in recent decades. Concerned about this scientific society developed appropriate use criteria (AUC). Clinical management still suffers geographical variations, and no objective data are available about echo AUC in developing countries. We aimed to evaluate (1) the appropriateness of referrals and (2) their relation to changes in clinical decision management.

METHODS

Prospective analysis of referrals from January to December 2014. Appropriateness and endpoints analyzed in different time points from medical archives.

ENDPOINTS

(1) change in the diagnosis, (2) indication for another method to complete the diagnosis, (3) change in clinical treatment, (4) indication for a treatment intervention, or (5) no change in management. Descriptive statistical analysis, Fisher's or chi-square tests, and Cox regression used as appropriate (significance if P < .05).

RESULTS

One thousand one hundred referrals were analyzed (55.5 ± 16.1 years, 44.6% male). 80.5% of referrals were appropriate (A), 11.2% "Rarely Appropriate" (RA), and 8.3% "May Be Appropriate" (MBA). Proportion of (A) did not differ between modalities (TTE-80.5% vs TEE-87.7% vs STR-81.2%, P = .67). (A) referrals were more related to clinical decision than (RA)+(MBA) (38.9% [A] vs 15% [RA]+[MBA], P < .001). The most frequent clinical indications of (RA) and (MBA) TTE were reevaluation of ventricular function without clinical change (AUC 10 and 11) and search of infectious endocarditis when low clinical probability (53).

CONCLUSIONS

In a developing country, appropriateness of echo was similar to the United States and Europe. However, a significant proportion of referrals were still (RA) or (MBA), with no effect in clinical management. Controlling referrals 10, 11, and 53 can optimize echo use in developing countries.

Appropriateness, diagnostic value, and outcomes of repeat testing following index echocardiography

AIMS

Emergency admission to hospital is associated with an economic burden and mortality. Echocardiography is often the first-line cardiovascular imaging investigation. Repeat testing is common; however, there are sparse data on the prevalence, appropriateness, or outcome of repeat testing.

METHODS

We performed an electronic database search for patients with emergency admissions to our institution in February 2015. An electronic patient record review of inpatient echocardiograms was undertaken. Indications for echocardiography were classified as appropriate, may be appropriate, or rarely appropriate. One-year follow-up for repeat testing and mortality was investigated.

RESULTS

A total of 409 of 2306 (17.7%) unplanned/emergency admissions underwent inpatient echocardiography. Abnormalities were identified in 165/409 (40.3%) of these patients; 154 of 409 (37.7%) had a repeat echocardiogram within the next year. Rarely appropriate indications for echocardiography occurred in 51 (33%) of repeat vs 53 (16%) of index echocardiograms, P < .0001. Repeat testing was associated with a change in findings in 17/154 (11%) patients overall. All of whom had an abnormal index echocardiogram and had an appropriate indication. There was no difference in mean survival time between patients who underwent repeat and those who only underwent a single index echocardiogram (310 days vs 327 days), P = .34.

CONCLUSION

Inpatient echocardiography in emergency hospital admissions identifies clinically important pathology. Repeated testing is common within 1 year of hospital admission. New diagnostic findings occurred in 11% of patients and only in patients with appropriate studies and an abnormal index echocardiogram. Identification of methods to reduce repeat testing and implement appropriateness criteria is warranted.

Appropriate Use Criteria for Echocardiography: Evolving Applications in the Era of Value-Based Healthcare

The current climate in healthcare is increasingly emphasizing a value-based approach to diagnostic testing. Cardiac imaging, including echocardiography, has been a primary target of ongoing reforms in healthcare delivery and reimbursement. The Appropriate Use Criteria (AUC) for echocardiography is a physician-derived tool intended to guide utilization in optimal patient care. To date, the AUC have primarily been employed solely as justification for reimbursement, though evolving broader applications to guide clinical decision-making suggest a far more valuable role in the delivery of high-quality and high-value healthcare.

Variation in the Echocardiographic Surveillance of Primary Mitral Regurgitation

BACKGROUND

Clinical outcomes after surgical treatment of mitral regurgitation are worse if intervention occurs after deterioration of left ventricular size and function. Transthoracic echocardiographic (TTE) surveillance of patients with mitral regurgitation is indicated to avoid adverse ventricular remodeling. Overly frequent TTEs can impair patient access and reduce value in care delivery. This balance between timely surveillance and overutilization of TTE in valvular disease provides a model to study variation in the delivery of healthcare services. We investigated patient and provider factors contributing to variation in TTE utilization and hypothesized that variation was attributable to provider practice even after adjustment for patient characteristics.

METHODS AND RESULTS

We obtained records of all TTEs from 2001 to 2016 completed at a large echocardiography laboratory. The outcome variable was time interval between TTEs. We constructed a mixed-effects linear regression model with the individual physician as the random effect in the model and used intraclass correlation coefficient to assess the proportion of outcome variation because of provider practice. Our study cohort was 55 773 TTEs corresponding to 37 843 intervals ordered by 635 providers. The mean interval between TTEs was 12.4 months, 17.0 months, 18.3 months, and 17.4 months for severe, moderate, mild, and trace mitral regurgitation, respectively, with 20% of providers deemed overutilizers of TTEs and 25% underutilizers.

CONCLUSIONS

We conclude that there is substantial variation in follow-up intervals for TTE assessment of mitral regurgitation, despite risk-adjustment for patient variables, likely because of provider factors.