Evaluation of appropriate use of transthoracic echocardiography in 1,820 consecutive patients using the 2011 revised appropriate use criteria for echocardiography.

Revised Appropriate Use Criteria (AUC) for Echocardiography were published in 2011 and classify potential procedure indications as appropriate (score of 7 to 9), uncertain (score of 4 to 6), or inappropriate (score of 1 to 3). The appropriate utilization rate of transthoracic echocardiography in clinical practice using the revised AUC is unknown. The aim of the present study was to determine the appropriate utilization rate of echocardiography in a large number of consecutive studies in clinical practice and to determine the number of "unclassifiable" studies using the revised and expanded AUC. The clinical indication for transthoracic echocardiography (TTE) was determined on the basis of a detailed review of preprocedural clinical documentation. These clinical indications were further classified (when possible) into 1 of the 98 indications described in the 2011 AUC for echocardiography. From December 2010 to January 2011, 1,825 patients (mean age 63.2 years) underwent TTE for clinical reasons. Of the final study group of 1,820 patients, TTE was appropriate in 82%, inappropriate in 12.3%, and uncertain in 5.3%, and 0.4% studies were unclassifiable. The evaluation of symptoms potentially due to a cardiac etiology was the most common appropriate indication for TTE (27.5%). The most common inappropriate indication was routine surveillance (<1 year) of heart failure without a change in clinical status (2.5%). In conclusion, most TTE studies were appropriately ordered, and only a very small number of studies were unclassifiable.

Appropriate use of transthoracic echocardiography.

The appropriateness criteria for echocardiography were published in 2007 and classified potential procedural indications as appropriate, uncertain, or inappropriate. The appropriate use rates for outpatient transthoracic echocardiography (TTE) by cardiologists have not been well defined. The objective of the present study was to prospectively determine the appropriate use rate of outpatient TTE in a large private practice group of >40 cardiologists (Cardiovascular Consultants, PA, Kansas City, Missouri). For each transthoracic echocardiographic study, we classified the stated reason for the examination into one of the 59 indications specified in the 2007 Appropriateness Criteria for Echocardiography publication. During the study period, 772 transthoracic echocardiographic studies were performed. Adequate information was available to classify 716 (92.7%) of these studies. The transthoracic echocardiographic studies were appropriately ordered for 533 patients (74%). Symptoms of potential cardiac origin (eg, dyspnea) was the most common reason for TTE (n = 156, 21.8%). The most common inappropriate use was routine repeat evaluation of patients with heart failure and no change in clinical status (n = 74, 10.3%). In conclusion, the appropriateness criteria for echocardiography were easily applied to real-world patients. Most patients in our series had undergone TTE for an appropriate indication.

Temporal obesity trends in patients undergoing transthoracic echocardiography 2002-2006.

In a recent data brief, the National Center for Health Statistics reported that obesity prevalence has plateaued in recent years, with no increase in obesity from 2003 to 2006. We have subjectively observed a marked increase in clinically severe obesity over this same period in patients presenting to our echocardiographic laboratory. The aim of this study was to determine temporal trends in obesity prevalence in patients presenting for transthoracic echocardiographic studies. A retrospective database analysis was performed using the Cardiovascular Consultants (Kansas City, Missouri) database (ProSolv Cardiovascular, Indianapolis, Indiana). The height and weight of patients who underwent transthoracic echocardiography in 2002 (n = 10,804) and 2006 (n = 17,556) were obtained. Body mass index was calculated as weight/height squared. Patients were grouped into 1 of 6 body mass index categories (underweight, normal weight, overweight, obese, morbidly obese, or super obese). Continuous variables were compared using Student's t test, and categorical variables were compared using chi-square test. In the 2 years, approximately (1/3) of patients were normal weight and (1/3) of patients were overweight. Obesity prevalence increased significantly (by nearly 8%) over the study period, with 28.1% of patients in the obese category by 2006. Clinically severe obesity (morbidly obese and super obese) increased dramatically from 2002 to 2006 (16%, p <0.008, and 41.7%, p <0.001, increases, respectively). In conclusion, clinically severe obesity has markedly increased in our midwestern echocardiographic laboratory in the period from 2002 to 2006.

Appropriate utilization of transesophageal echocardiography.

Appropriateness criteria for echocardiography were recently published and classify potential procedural indications as appropriate (scores of 7 to 9), uncertain (scores of 4 to 6), or inappropriate (scores of 1 to 3). The rate of the appropriate utilization of transesophageal echocardiography (TEE) in clinical practice is unknown. The aim of this study was to determine the appropriate utilization rate of TEE in a large consecutive patient series. A retrospective review of consecutive patients referred for TEE within Saint Luke's Health System (Kansas City, Missouri) was performed. The clinical indication for TEE was determined on the basis of a detailed review of preprocedural clinical documentation. These indications were then further classified into 1 of the 59 indications specified in the appropriateness criteria publication. From January 2006 to August 2007, 1,260 patients (mean age 61 years) underwent TEE for clinically indicated reasons. Among the final study group of 1,235 patients, the procedures were appropriate in 1,156 (93.6%). Appropriateness was uncertain in 43 patients (3.5%), and the procedures were inappropriate in 36 patients (2.9%). The most common "appropriate" use of TEE was to inform clinical decision making for atrial fibrillation or flutter. All the "uncertain" cases were for the evaluation of cerebrovascular accidents in patients with normal findings on transthoracic echocardiography, no history of atrial fibrillation, and normal electrocardiographic results. The most common "inappropriate" indication for TEE was evaluation for endocarditis in patients with transient fever but no bacteremia or new murmurs. In conclusion, most transesophageal echocardiographic studies in our health system were performed for appropriate indications.

Combined assessment of myocardial perfusion and diastolic function enhances risk stratification in patients with anterior wall myocardial infarction.

OBJECTIVE: Evaluate the utility of a combined risk stratification scheme including diastolic dysfunction and "no-reflow," to identify high-risk patients following acute myocardial infarction (AMI). BACKGROUND: Recent studies have demonstrated that the "no-reflow" phenomenon (defined by myocardial contrast echocardiography) and severe diastolic dysfunction (identified by Doppler echocardiography) identify patients at high risk for mortality following AMI. METHODS: We evaluated 111 patients with recent anterior acute myocardial infarction from July 2000 to June 2004. Diastolic function and myocardial perfusion was evaluated by echocardiography. Patients were placed into 1 of 3 groups based on diastolic function and myocardial perfusion: Group 1 (normal perfusion and normal diastolic function), Group 2 (abnormal perfusion or abnormal diastolic function), and Group 3 (abnormal perfusion and abnormal diastolic function). We compared the long term all-cause mortality within these groups. RESULTS: Patients in each group were similar with respect to myocardial infarction size as defined by biomarkers, extent and severity of coronary artery disease, and medical and interventional therapy. Mortality was much higher in Group 3 (26.9%) compared to Group 1 (0%) and Group 2 (15.2%) (p = 0.048). CONCLUSION: Combined assessment of diastolic function and myocardial perfusion enhances risk stratification post myocardial infarction.

Acute mortality in hospitalized patients undergoing echocardiography with and without an ultrasound contrast agent (multicenter registry results in 4,300,966 consecutive patients).

We sought to define acute mortality in a large multicenter cohort of hospitalized patients undergoing clinically indicated echocardiography with and without use of an ultrasound contrast agent. Although the United States Food and Drug Administration recently relaxed the issued warnings for perflutren-containing ultrasound contrast agents on May 13, 2008, concerns still exist regarding the safety of these compounds, particularly in critically ill patients. A retrospective analysis was performed using the Premier Perspective Database. Patients undergoing echocardiography during hospitalization were separated into those performed without contrast enhancement and those performed with perflutren lipid microsphere (PLM) injectable suspension contrast agent (Definity, Lantheus Medical Imaging, North Billerica, Massachusetts). Vital status within 1 day of the echocardiogram was available for all patients using hospital billing data. Between January 1, 2002 and October 31, 2007, 4,300,966 patients underwent transthoracic echocardiography at rest during hospitalization (unenhanced studies n = 4,242,712 and contrast-enhanced studies n = 58,254). Multivariate logistic regression analysis was used to compare 24-hour mortality, controlling for case mix and clinical covariates; 1-day mortality rates were 1.08% (n = 45,789 deaths) for patients undergoing noncontrast studies and 1.06% (n = 616 deaths) for patients undergoing contrast-enhanced examinations (p = 0.613). Multivariate logistic regression analysis revealed that, in patients undergoing an echocardiogram, patients receiving PLM injectable suspension contrast agent were 24% less likely to die within 1-day than patients not receiving a contrast agent (adjusted odds ratio = 0.76, 95% confidence interval 0.70 to 0.82). In conclusion, acute crude mortality was not increased in patients receiving PLM injectable suspension contrast agent. Multivariate logistic regression analysis revealed that, compared with patients not receiving a contrast agent, administration of PLM injectable suspension contrast agent during echocardiography was associated with a 24% decreased risk of mortality.

Acute mortality in hospitalized patients undergoing echocardiography with and without an ultrasound contrast agent: results in 18,671 consecutive studies.

OBJECTIVES: We sought to define acute mortality in hospitalized patients undergoing clinically indicated echocardiography with and without use of an ultrasound contrast agent. BACKGROUND: The U.S. Food and Drug Administration recently issued a boxed warning and new contraindications for the perflutren-containing ultrasound contrast agents following post-marketing reports of 4 patient deaths that were temporally related to Definity (Bristol-Myers Squibb Medical Imaging, Billerica, Massachusetts) administration. To appreciate the incremental risk of any medical procedure, the ambient risk of untoward outcome in the population in question must first be defined. There are no published data on short-term major adverse cardiac events in hospitalized patients undergoing echocardiography, either with or without administration of an ultrasound contrast agent. METHODS: A retrospective analysis of hospitalized patients undergoing clinically indicated echocardiography between January 2005 and October 2007, within Saint Luke's Health System, Kansas City, Missouri, was performed. Studies were separated into 2 groups, those performed without contrast enhancement (n = 12,475) and those performed with Definity (n = 6,196). Vital status within 24 h of the echocardiographic study was available for all patients using a combination of the Social Security Death Master File and Saint Luke's Health System medical records. Incidence of death within 24 h was compared by chi-square test between Definity and unenhanced procedures. RESULTS: Of the 18,671 patient events, 72 patients died within 24 h. Of those that underwent unenhanced echocardiography, 46 died within 24 h (0.37%). Of patients receiving Definity during the echocardiogram, 26 died within 24 h (0.42%). There was no statistical difference between these 2 groups (p = 0.60). No patient died within 1 h of the echocardiographic study. In a random sampling from the unenhanced (n = 201) and Definity groups (n = 202), patients who underwent Definity-enhanced echocardiography exhibited higher clinical acuity, and more significant comorbidities. CONCLUSIONS: Approximately 0.4% of hospitalized patients die within 24 h of echocardiography. There is no increased mortality risk associated with Definity-enhanced examinations, despite evidence for higher clinical acuity and more comorbid conditions in patients undergoing contrast studies.

Contrast administration reduces interobserver variability in determination of left ventricular ejection fraction in patients with left ventricular dysfunction and good baseline endocardial border delineation.

Echocardiographic contrast agents improve endocardial border delineation in patients with technically difficult baseline studies. With medical and device therapy for heart failure increasingly based on left ventricular (LV) ejection fraction (EF) partition values, the accurate and reproducible assessment of LV function is necessary. It was hypothesized that routine contrast enhancement would significantly reduce interobserver variability in the determination of LVEFs in a cohort of patients with LV dysfunction and good baseline endocardial delineation. All patients underwent baseline noncontrast studies followed by contrast-enhanced imaging using Definity. Two experienced echocardiographers, blinded to the clinical data, determined LVEFs using 4 different techniques: noncontrast estimated (NCE), noncontrast calculated (NCC), contrast estimated (CE), and contrast calculated (CC). Using a mixed-model procedure that allows for fixed and random events, the variance due to error and that due to the patient was obtained (interclass correlation). The proportion of variation due to the reader was calculated as 1--interclass correlation. Mean standardized percentage differences ([reader 1 EF--reader 2 EF]/mean EF) were also calculated for each method. The proportion of variation due to the reader was smallest in the CC group and largest in the NCC group (NCE = 0.21, NCC = 0.33, CE = 0.25, CC = 0.11). The results were similar when only patients with NCE EFs >or=20% and or=20% and or=20% and

Usefulness of myocardial contrast echocardiography in predicting late mortality in patients with anterior wall acute myocardial infarction.

We investigated whether myocardial contrast echocardiography (MCE) performed soon after acute myocardial infarction (AMI) improves risk stratification for late mortality. MCE after AMI identifies microvascular "no-reflow" and predicts early outcomes; however, the predictive value of MCE for late mortality is unknown. One hundred sixty-seven patients with anterior AMI and left ventricular dysfunction underwent MCE 2 days after admission, and a perfusion score index (PSI) was calculated. Long-term follow-up (mean 39 months) was available for all patients. Patients with normal and abnormal perfusion had similar baseline characteristics. Myocardial contrast echocardiographic PSI was a predictor of mortality as a continuous variable (odds ratio 3.2 for each 1.0 increase in PSI, 95% confidence interval 1.1 to 9.7, p = 0.04). In a logistic regression model, age (odds ratio 2.6 per decade, 95% confidence interval 1.6 to 4.4, p = 0.0002) and PSI (odds ratio 4.5 for each 1.0 increase in PSI, 95% confidence interval 1.3 to 15.4, p = 0.02) were the only significant predictors of mortality. In a subanalysis comparing patients >70 years old with abnormal PSI with all other patients, Kaplan-Meier estimates showed a marked difference in survival over a mean follow-up of 39 months (24% vs 4% mortality, p = 0.0002). In conclusion, MCE refines risk stratification soon after anterior AMI in patients with left ventricular dysfunction. Patients at very high and very low risk of mortality can be identified, and myocardial contrast echocardiographic data are incrementally useful compared with existing clinical and angiographic variables.

Myocardial contrast echocardiographic estimates of infarct size predict likelihood of left ventricular remodeling after acute anterior wall myocardial infarction.

OBJECTIVES: We sought to determine the utility of myocardial contrast echocardiography (MCE) in predicting left ventricular (LV) remodeling (LVR) in patients with a recent anterior wall myocardial infarction and residual regional LV akinesis. BACKGROUND: Although recent studies have shown that MCE predicts recovery of regional and global LV systolic function after myocardial infarction, the relationship between myocardial perfusion patterns and likelihood of subsequent LVR has not been extensively studied. METHODS: In all, 50 patients (mean age 62 years) underwent contrast-enhanced echocardiography for determination of LV volumes and ejection fraction, and MCE, 2 days after admission, with follow-up contrast-enhanced echocardiography 6 months later. LVR was defined as greater than 15% increase in LV end-diastolic volume index at follow-up. RESULTS: LVR occurred in 19 patients (38%) (group 1), with stable LV volumes in 31 patients (62%) (group 2). Routine clinical and angiographic variables did not differ between groups 1 and 2. Both transmural extent of infarction and number of abnormally perfused myocardial segments (assessed by MCE) predicted LVR. LVR occurred in 55% of patients with transmural perfusion defects, and was less common in those with subendocardial perfusion defects or normal perfusion (31% and 21%, respectively). The mean percent increase in LV size was significantly greater for transmural infarcts (15 +/- 7%) versus subendocardial infarcts or normal perfusion (-1 +/- 8 and 8 +/- 8, respectively). When more than 5 myocardial segments were abnormally perfused, remodeling always occurred and was extensive. CONCLUSIONS: MCE markers of infarct size are useful in predicting subsequent risk of LVR after myocardial infarction. Routine performance of MCE studies in select patients early after infarction may be helpful in further refining risk stratification.

Usefulness of myocardial contrast echocardiography in predicting global left ventricular functional recovery after anterior wall acute myocardial infarction.

Although multiple recent studies have shown that myocardial contrast echocardiography (MCE) reliably differentiates between regional stunning and necrosis after acute myocardial infarction (AMI), prognosis is more closely related to measures of global left ventricular systolic function. One hundred fifteen patients underwent baseline wall motion assessment and MCE 2 days after admission and follow-up echocardiography a mean of 69 days later. Good agreement was found between perfusion score index and follow-up wall motion score index, indicating that MCE performed early after anterior wall AMI may be clinically useful in routine post-AMI risk stratification.

Reperfusion assessment using myocardial contrast echocardiography in patients with ST-segment elevation acute myocardial infarction.

In this study, 29 patients underwent myocardial contrast echocardiography after presentation with ST-segment elevation acute myocardial infarction but before coronary angiography using a continuous infusion of microbubbles and real-time imaging with a low mechanical index. Patients with transmural perfusion defects at presentation subsequently had much larger infarctions (as measured by peak creatine phosphokinase-MB fraction) than did those with normal perfusion, indicating that myocardial contrast echocardiography may be a useful means to determine adequacy of reperfusion after thrombolytic therapy and in the selection of patients for adjunctive treatment, such as "rescue angioplasty."

Real-time assessment of myocardial perfusion during balloon angioplasty of the left anterior descending coronary artery.

Balloon occlusion and release during elective percutaneous coronary intervention (PCI) provides a unique opportunity to study dynamic temporal alterations in myocardial perfusion in a controlled setting. These changes in flow and volume mimic those that occur during presentation with, and successful therapy of, ST-segment elevation acute myocardial infarction (AMI). Eleven patients underwent myocardial contrast echocardiography (MCE) using a continuous infusion of Definity at baseline, during coronary occlusion, and during reactive hyperemia immediately after balloon deflation. Fifty separate flow state sequences were acquired, and off-line analysis was performed to determine myocardial contrast intensity within a region of interest in the distribution of the left anterior descending artery (LAD). A reader blinded to flow state also performed qualitative evaluation (perfusion or lack of perfusion). Quantitative analysis demonstrated significant differences in myocardial contrast intensity by flow state (p = 0.0001 for occlusion vs reperfusion). Qualitative assessment demonstrated a high rate of correct classification (92%). Real-time myocardial perfusion assessment using MCE accurately differentiates coronary occlusion and reactive hyperemia in humans by qualitative and quantitative assessment. This technique may be clinically useful in assessing the efficacy of thrombolytic therapy in ST-segment elevation AMI and in clinical trial assessment of new drugs and devices aimed at limitation of infarct size.