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Clinical Utility and Prognostic Value of Appropriateness Criteria in Stress Echocardiography for the Evaluation of Valvular Heart Disease
Abstract
Objectives: Identify the clinical and prognostic value of stress echocardiography (SE) appropriateness criteria for evaluation of valvular heart disease (VHD).
Background: Appropriateness criteria for patients undergoing SE have recently been published. There are no data which establish the clinical utility of these criteria for evaluation of VHD.
Methods: 100 consecutive patients undergoing SE for evaluation of VHD were identified. Patients were classified into appropriate, uncertain and inappropriate categories according to appropriateness criteria guidelines. A positive SE was defined according to VHD guidelines. The end-point was the composite of heart failure admission or death.
Results: Of the 100 patients undergoing SE 49%,36% and 15% of studies were classified as appropriate, uncertain and inappropriate, respectively. A positive test was identified in 32 (32%) patients. Of which a significantly greater proportion of positive tests occurred in patients classified as appropriate 19 (38.8%) or uncertain 13 (36.1%) compared to patients classified as inappropriate 0 (0%), p<0.0001. Over a median follow-up of 12.6 months, 24 events (16 deaths and 8 heart failure admissions) occurred. Of the 32 patients with a positive SE, events occurred in 18 (56.3%) patients compared to only 6 events (8.8%) in the 68 patients with a negative SE, p<0.0001. 12 month event free survival was significantly reduced in patients with appropriate or uncertain studies compared to patients with inappropriate studies (p=0.04, p=0.005 respectively). Of the important clinical and echocardiographic parameters, the only independent predictor of events was a positive SE (hazard ratio 15.5, p<0.0001).
Conclusion: Stress echocardiography for VHD has prognostic value when incorporated into clinical practice. The appropriateness criteria for evaluation of VHD provide the ability to differentiate between patients at high (appropriate group) and low risk (inappropriate group) of subsequent cardiac events. Patients with an uncertain indication for SE have reduced event free survival compared to patients classified as inappropriate. Re-classification of the uncertain group may improve their applicability to current clinical practice.
... 20 Finally, appropriateness criteria have been developed in stress echocardiography and the clinical and prognostic value of these in patients with valvular heart disease assessed by stress echocardiography have recently been demonstrated. 21 ...
Stress echocardiography is a widely utilised test in patients with known or suspected coronary artery disease (CAD), valvular heart disease and cardiomyopathies. Its advantages include the ubiquitous availability of echocardiography, lack of ionising radiation, choice of physiological or pharmacological stressors, good diagnostic accuracy and robust supporting evidence base. SE has evolved significantly as a technique over the past three decades and has benefitted considerably from improvements in overall image quality (superior resolution), machine technology (e.g. digital cine-loop acquisition and side-by-side image display) and development of second generation ultrasound contrast agents that have improved reader confidence and diagnostic accuracy. The purpose of this article is to review the breadth of SE in contemporary clinical cardiology and discuss the recently launched British Society of Echocardiography (BSE) Stress Echocardiography accreditation scheme.
... Therefore, we advocate SE for evaluation of both these patient groups. 36 ...
Both organic and functional mitral regurgitation are dynamic. Alterations in left ventricular and annular geometry, together with changing loading conditions on exertion, may lead to changes in the severity of mitral regurgitation. Exercise echocardiography is able to identify exercise-induced increases in the severity of mitral regurgitation and pulmonary artery systolic pressure which are responsible for symptoms in patients with mild or moderate dysfunction at rest. Prognostic parameters (exercise induced changes in effective orifice area, ejection fraction and global longitudinal strain) may help risk-stratify patients with moderate or severe mitral regurgitation who are asymptomatic. This review examines the evidence base for dynamic mitral regurgitation, methods of assessment, clinical implications as well as possible therapies.
... Lehnert et al demonstrated in a single-center study that 14% of knee and 37% of shoulder MRIs did not follow the AC, and inappropriate examinations had significantly higher odds of having negative results [21]. In small single-center studies, 87%-100% of inappropriately ordered imaging studies demonstrate negative/insignificant imaging findings [21][22][23]. This finding, in the context of the current study, suggests a potential for significant cost savings, although the cohorts in the current study did not allow for assessment of individual study indications and findings. ...
Purpose:
Available data are limited on the level of adherence to established guidelines for appropriate utilization of MR in musculoskeletal imaging. This study estimates the percentage of MRI examinations for knee and shoulder pain or tendonitis performed without prior radiography, which thus may fall outside the ACR Appropriateness Criteria for the Medicare and commercially insured populations.
Methods:
The percentage of MRI examinations for knee and shoulder pain or tendonitis performed without prior radiography was estimated among patients in the Medicare 5% carrier claims limited data set and among commercially insured patients in the Truven Marketscan Treatment Pathways database in 2010.
Results:
Approximately 28% of all knee MRIs, and 35%-37% of all shoulder MRIs were performed without recent prior radiographs. The extrapolated expense of these potentially unwarranted MRIs in the entire fee-for-service Medicare population was between 35 million. Between 20% and 23% of patients undergoing knee MRI, and 27%-32% undergoing shoulder MRI, did not have radiographic examination at any point before the MRI in the same calendar year.
Conclusions:
MRI performed without prior radiography represents a potential gap in care and should be considered as an area for establishment of performance measures.
... Several investigators have identified the clinical utility and prognostic value of implementation of these criteria. 4,5,6 There is much less clarity over what represents a robust QA system, although the American Society of Echocardiography and European Association of Cardiovascular Imaging have recently published recommendations 3,7 Reduction of physician/sonographer inter-observer variability is important both for accuracy, and for long-term follow-up of chronic disease in particular valvular heart disease to determine timing of surgery 8 and patients require serial cardiac monitoring of left ventricular function (such as those undergoing trastuzumab therapy). Inter-observer variability of 14% for determination of left ventricular (LV) ejection fraction and concordance of between 58 and 92% for determination of diastolic class have been reported. ...
There are minimal data on methods to measure and improve quality in image interpretation when reporting cardiovascular imaging studies. We sought to identify the feasibility and clinical utility of a nationally implemented quality assurance (QA) process.
A web-based platform was developed to administer a national QA module to 27 echocardiography departments within the UK. Three QA modules were delivered from 2011. The proportion of units using the QA module increased from 14 (52.2%) in the first module to 22 (81.5%) in the third module. There was no significant change in the proportion of correct answers between the first module (88.9%) and the third module (82.8%), P = 0.3. The number of echocardiographers with at least one incorrect answer increased from 16 (21.6%) in the first module to 54 (34%) in the third module, P = 0.03. Overall, in valvular heart disease cases there were 36 (10.6%) incorrect responses where qualitative assessment of the severity of valve dysfunction was tested compared with 4 (3.6%) incorrect responses where quantitative assessment of valve dysfunction was tested, P = 0.04. In chamber quantification cases, there were 36 (6.8%) incorrect responses where qualitative assessment of chamber function was tested compared with 3 (2.1%) incorrect responses where quantitative assessment of chamber function was tested, P = 0.04.
The incorporation of national QA programme is feasible with rapid uptake. The platform allows comparison of an individual's interpretation skills against a reference standard which can be used as a method to identify inter-observer variability and as a training tool.
... The same group has also demonstrated the clinical value of exercise SE in patients with degenerative MR [16]. A recent analysis clearly indicated the value of SE in valve disease in daily clinical practice and also suggested expansion of SE in valve disease beyond that indicated by current guidelines [17]. ...
Echocardiography remains the most frequently performed cardiac imaging investigation and is an invaluable tool for detailed and accurate evaluation of cardiac structure and function. Echocardiography, nuclear cardiology, cardiac magnetic resonance imaging, and cardiovascular-computed tomography comprise the subspeciality of cardiovascular imaging, and these techniques are often used together for a multimodality, comprehensive assessment of a number of cardiac diseases. This paper provides the general cardiologist and physician with an overview of state-of-the-art modern echocardiography, summarising established indications as well as highlighting advances in stress echocardiography, three-dimensional echocardiography, deformation imaging, and contrast echocardiography. Strengths and limitations of echocardiography are discussed as well as the growing role of real-time three-dimensional echocardiography in the guidance of structural heart interventions in the cardiac catheter laboratory.
This document addresses the evaluation of the Appropriate Use Criteria (AUC) of multimodality imaging in the diagnosis and management of aortic valve disease. The goal of this AUC document is to provide a comprehensive resource for multimodality imaging in the context of aortic valve disease, encompassing multiple imaging modalities. Clinical scenarios are developed in a simple way to illustrate patient presentations encountered in everyday practice.
Echocardiography is an important tool in the diagnosis and management of cardiovascular disease. However, there has been concern in recent years regarding the rapid growth of echocardiography utilization. The American College of Cardiology Foundation (ACCF), along with other subspecialty societies, developed Appropriate Use Criteria (AUC) in an effort to promote more effective utilization of diagnostic testing and procedures in cardiovascular medicine, and echocardiography has been a focus of the AUC. AUC are distinct from clinical practice guidelines, as AUC delineate clinical scenarios in which ordering a test or procedure may be considered appropriate or less appropriate. Revised and updated AUC for adult echocardiography were published in 2011. One of the first uses of the AUC for echocardiography was to characterize practice patterns and determine appropriateness rates in clinical practice. Moving beyond a description of ordering patterns in clinical practice, educational intervention studies have been designed which incorporate AUC into the process of educating ordering clinicians. Several studies indicate that it is feasible to teach clinicians about appropriate use and that providing feedback about ordering behavior may improve utilization. The importance and role of feedback in AUC-based educational efforts is supported by the results of these studies. The optimal approach to incorporate AUC into patient selection remains to be determined, and it should be emphasized that clinical judgment remains important and is not to be replaced by criteria. Adherence to AUC and the subsequent impact on clinical outcomes, although difficult to study, is a critical area in need of further investigation.
Purpose:
Cardiac imaging expenditures have come under scrutiny, and a focus on appropriate use criteria (AUC) has arisen to ensure cost-effective resource utilization. Although AUC has been developed by clinical experts, it has not undergone rigorous quality assurance testing to ensure that inappropriate indications for testing yield little clinical benefit. The objective of the study was to evaluate the potential incremental prognostic value of coronary computed tomographic angiography (CCTA) in the different AUC categories.
Materials and methods:
Consecutive patients enrolled into a cardiac CT Registry were collated. Patient indications were reviewed and based on the 2010 AUC (appropriate, uncertain, and inappropriate). Patients were followed-up for death, myocardial infarction (MI), and late revascularization, with the primary composite endpoint being cardiac death, nonfatal MI, and late revascularization. The prognostic value of CCTA over clinical variables in each of the AUC categories was assessed.
Results:
Indications for CCTA were appropriate, uncertain, and inappropriate in 1284 (66.5%), 312 (16.2%), and 334 (17.3%) patients, respectively. Rates of all-cause of death, cardiac death, nonfatal MI, and late revascularization were similar across patients with appropriate, uncertain, and inappropriate indications for CCTA. Moreover, in each AUC category, CCTA had incremental prognostic value over a routine clinical risk score (National Cholesterol Education Program) with hazard ratios of 9.98, 7.39, and 5.61.
Conclusions:
CCTA has incremental prognostic value in all AUC categories, even when the reason for the study was deemed "inappropriate." This suggests that CCTA may still have clinical value in "inappropriate" indications and that further quality assurance AUC studies are needed.
Major advances in diagnosis and risk stratification, combined with enormous progress in surgical valve replacement and repair, have led to improved outcomes of patients with valvular heart disease over the past 30 years. The most important indication for surgical intervention in patients with hemodynamically significant aortic or mitral valve disease is the development of symptoms, as emphasized in recent guidelines [1–3]. As symptoms may develop slowly and indolently in these chronic conditions, many patients are unaware of subtle changes in effort tolerance, even when questioned directly by their physicians. Hence, recent guidelines of both the American College of Cardiology/American Heart Association (ACC/AHA) and the European Society of Cardiology (ESC) [2, 3] have placed renewed emphasis on the role of exercise testing to provide objective evidence of exercise capacity and symptom status. In addition, while Doppler echocardiography is the method of choice for assessing severity of valvular disease, there is a growing utilization of stress two-dimensional and Doppler echocardiography to assess dynamic changes in hemodynamics in concert with the clinical findings of exercise testing.
Background:
Despite previous studies demonstrating suboptimal appropriate use of stress echocardiography (SE), few interventions have been demonstrated to improve its appropriate use. The aim of this study was to develop a novel mechanism to improve the appropriateness of SE by implementing a point-of-care decision support tool and ordering requisition coupled with an educational strategy.
Methods:
A prospective pre- and postintervention analysis was conducted. The intervention included education and the development and implementation of novel ordering requisition coupled with a decision support tool that integrated appropriate use criteria (AUC) for SE.
Results:
In the baseline period, 256 consecutive stress echocardiographic studies were evaluated, and 97% were classifiable by the 2011 AUC. During the intervention period, 159 studies were evaluated (98% classifiable). The intervention resulted in an increase in the appropriate proportion from 65% to 76% and a reduction in the rarely appropriate proportion from 31% to 19% (P = .017). After adjustment for physician specialty, the postintervention period had lower odds of rarely appropriate testing (0.54; 95% CI, 0.3-0.95; P = .04). Cardiology had significant lower odds of rarely appropriate testing (0.23; 95% CI, 0.11-0.50; P < .001) compared with family practice (the reference standard). Vascular surgery had the highest odds (5.76; 95% CI, 2.18-21.52; P = .002) of rarely appropriate testing.
Conclusion:
AUC have not previously been applied to SE in a single-payer, publicly funded health system. The development of an educational intervention involving a new requisition and decision support tool that integrated AUC resulted in a significantly reduced proportion of rarely appropriate SE. Cardiologists ordered the highest proportion of appropriate SE. Further study is needed to determine the generalizability of the results.
Background Appropriate use criteria (AUC) for cardiac imaging have been available for almost 10 years. The extent to which there has been a reported improvement in appropriate use is undefined.
Objectives This study systematically reviewed published evidence to identify whether the promulgation of AUC has led to an improvement in the proportion of appropriate cardiac imaging requests.
Methods Electronic databases were systematically searched for English-language papers related to AUC and cardiovascular imaging. We found 59 reports involving 103,567 tests that were published from 2000 to 2012. The rate of appropriate testing over time was analyzed in a meta-regression.
Results New AUC were associated with apparent improvements in appropriateness for transthoracic echocardiography (TTE) (80% [95% confidence interval (CI): 0.75 to 0.84] vs. 85% [95% CI: 0.81 to 0.89]), transesophageal echocardiography (TEE) (89% [95% CI: 0.81 to 0.94] vs. 95% [95% CI: 0.93 to 0.96]) and computed tomography angiography (CTA) (37% [95% CI: 0.21 to 0.55] vs. 55% [95% CI: 0.44 to 0.65]) but not stress echocardiography (53% [95% CI: 0.45 to 0.61] vs. 52% [95% CI: 0.42 to 0.61]) or single-photon emission computed tomography (72% [95% CI: 0.66 to 0.77] vs. 68% [95% CI: 0.60 to 0.74]). Although there were no correlations between the proportion of appropriate TTEs and published year (p = 0.36) for 2007 AUC, there was a positive correlation between proportion of appropriateness and the year of publication (p = 0.01) for 2011 AUC. There was a significant decrease in the proportion of appropriateness over time using the 2007 TEE AUC (p = 0.03) and 2006 CT AUC (p = 0.02). There were no meaningful associations between appropriateness and publication year for stress echocardiography, CTA, or single-photon emission computed tomography.
Conclusions Rates of reported appropriate use in imaging show improvements for TTE and CTA but not for stress imaging and TEE. The observed reductions in imaging studies are not matched by reported rates of appropriate use.
The increasing cost of healthcare is a widespread international problem to which the cost of imaging has been an important contributor. Some imaging tests are ordered inappropriately and contribute to wasted use of resources. Appropriate use criteria have been developed in the USA in order to guide test selection, but there are a number of problems, including the evidence base for these criteria and the steps that can be taken to change physician practice. A restrictive approach to test ordering is difficult to fit to the nuances of clinical presentation and may compromise patient care. We propose an alternative approach to physician guidance based on the most common markers of inappropriate testing.
Health jurisdictions across the world are troubled by the same topic—how the imaging component of the health budget can be spent wisely. Contributors to this problem are the ageing population, apparently limitless demand for imaging, and increasing sophistication and expense of imaging and treatment. Perhaps in no space is this more challenging than cardiovascular imaging, the growth of which has exceeded the overall growth of medical costs over the last decades.1 Part of the response to the disconnect between the growth in imaging and its value in North America has been the development of appropriate use criteria (AUC). Although the initial application of AUC were not directed towards cardiovascular imaging,2 the initial AUC for transthoracic and transoesophageal echocardiography were launched in 2007 and redefined in 2011,3 and similar situations have occurred for Single Photon Emission Computed Tomography (SPECT) and cardiac CT. The concept of appropriate use has had an extraordinary influence on the relationship between patients, physicians, administrators and insurance companies over the last decade.
AUC differ importantly from guidelines in that they are developed by consensus.4 A potential question, therefore, is whether they are necessarily correct. The study reported by Bhattacharyya et al ,5 appears somewhat encouraging in this respect. Inappropriate stress echocardiograms had a low risk of cardiac events, similar to results found in Italy by Cortigiani et al ,6 and in …
Aims:
Stress echocardiography (SE) is one of the leading modalities for the assessment of coronary artery disease and dynamic valvular heart disease. A wide range of different techniques have been established. There are no data which identify how current techniques have been integrated into clinical practice.
Methods and results:
An electronic questionnaire was devised to identify SE practice in five core areas: service demographics, indications, methods, reporting, and adverse events. The questionnaire was sent to 198 National Health Service hospitals. Eighty-five (71%) out of the 120 departments who perform SE responded. Each unit performed a median of 400 SE (inter-quartile range 175-600). Thirty-two (37.6%) operators performed <100 SE per year. Exercise, dobutamine, dipyridamole, adenosine, and pacing SE were available in 57 (67.1%), 85 (100%), 6 (7.1%), 11 (12.9%), and 34 (40%) units, respectively. Eighty-one (95.3%) units performed SE for the evaluation of low-flow, low-gradient aortic stenosis. Thirty-four (40%) and 32 (37.6%) performed SE for the evaluation of asymptomatic severe aortic stenosis and symptomatic moderate mitral regurgitation, respectively. Eighty-three (97.6%) administered contrast agents during SE. Additional analysis of perfusion and strain was performed in 9 (10.5%) and 13 (15.3%) units, respectively.
Conclusion:
SE has been incorporated into the majority of UK hospitals. A substantial proportion of operators perform less than the recommended number of procedures per year. The use of exercise SE, vasodilator SE, and SE for the evaluation of VHD are under-utilized. Penetration of new techniques is variable, contrast for left ventricular opacification has been almost universally adopted, while myocardial perfusion and mechanics are used much less.
Mitral stenosis (MS) may exhibit a dynamic valvular reserve. When resting gradients and systolic pulmonary pressure (sPAP) do not reflect the real severity of the disease, a dynamic evaluation becomes necessary. The aim of the study was to assess the clinical utility of exercise echocardiography in symptomatic patients with apparently subcritical MS.
One hundred and thirty consecutive patients were referred for symptomatic MS. Patients with unimpressive resting MVA (>1-1.5 cm(2)) and mean PG (≥5-9 mmHg) underwent exercise echocardiography. Cardiac performance and mitral indices (MVA, peak/mean PG, sPAP) were measured. Exhaustion of valvular reserve capacity under exercise was defined as appearance of symptoms and sPAP > 60 mmHg. Forty-six patients (35%) (age: 53 ± 10 years; 74%, female) with resting MVA (1.2 ± 0.36 cm(2)), mean PG (6.8 ± 2.7 mmHg), and sPAP (38 ± 7 mmHg) inconsistent with symptoms underwent stress echocardiography. Exercise was stopped for dyspnoea (76%) or fatigue (24%). At peak workloads (57.2 ± 21.8 Watts), increased mean PG (17.2 ± 4.8 mmHg, P< 0.001) and sPAP (67.4 ± 11.4 mmHg; P< 0.0001) were observed, without change in MVA (1.25 ± 0.4 cm(2); P= n.s.). At univariate analysis, predictors of adaptation to exercise were age (-0.345; P = 0.024), mean PG (0.339; P= 0.023), and sPAP (0.354; P= 0.024); at multivariate analysis, best predictor was resting mean PG, although correlation was poor (-0.339; P= 0.015).
In MS with limiting symptoms despite unimpressive findings at rest, valvular capacity exhaustion should be tested on a dynamic background, as no single resting index can predict potential haemodynamic adaptation to exercise. In such context, the contribution of exercise echocardiography remains extremely valuable.
Aims
Abnormal exercise test defined as the occurrence of exercise limiting symptoms, fall in blood pressure below baseline, or complex ventricular arrhythmias is useful to predict clinical events in asymptomatic patients with aortic stenosis (AS). The purpose of this study was to determine whether exercise-stress echocardiography (ESE) adds any incremental prognostic value to resting echocardiography in patients with AS having a normal exercise response.
Methods and results
One hundred and eighty-six asymptomatic patients with at least moderate AS and preserved LV ejection fraction (≥50%) were assessed by Doppler-echocardiography at rest and during a maximum ramp semi-supine bicycle exercise test. Fifty-one (27%) patients had an abnormal exercise test and were excluded from the present analysis. Among the 135 patients with normal exercise test, 67 had an event (aortic valve replacement motivated by symptoms or cardiovascular death) at a mean follow-up of 20 ± 14 months. The variables independently associated with events were: age ≥65 years [hazard ratio (HR) = 1.96; 95% confidence interval (CI): 1.15–3.47; P = 0.01], diabetes, (HR = 3.20; 95% CI: 1.33–6.87; P = 0.01), LV hypertrophy (HR = 1.96; 95% CI: 1.17–3.27; P = 0.01), resting mean gradient >35 mmHg (HR = 3.60; 95% CI: 2.11–6.37; P < 0.0001), and exercise-induced increase in mean gradient >20 mmHg (HR = 3.83; 95% CI: 2.16–6.67; P < 0.0001).
Conclusion
The exercise-induced increase in transvalvular gradient may be helpful to improve risk stratification in asymptomatic AS patients with normal exercise response. These results thus suggest that ESE may provide additional prognostic information over that obtained from standard exercise testing and resting echocardiography.
Doppler echocardiography was used to determine changes in transmitral gradient and pulmonary artery pressure after exercise in 12 patients with mitral stenosis and 11 patients with a prosthetic mitral valve. The mean transmitral gradient in the mitral stenosis group was 9 +/- 7 mm Hg at rest and increased to 17 +/- 8 mm Hg after exercise. In patients with a prosthetic mitral valve, exercise resulted in an increase in mean transmitral gradient from 5 +/- 2 to 8 +/- 3 mm Hg. Calculated pulmonary artery systolic pressure increased with exercise from 41 +/- 19 to 70 +/- 32 mm Hg in the mitral stenosis group and from 28 +/- 8 to 39 +/- 15 mm Hg in patients with a prosthetic valve. Exercise Doppler echocardiographic evaluation of changes in transmitral gradient and pulmonary artery systolic pressure was found to be technically simple and an important addition to the noninvasive evaluation of patients with mitral valve disease.
The prognostic value of dobutamine stress hemodynamic data in the setting of low-gradient aortic stenosis has been addressed in small, single-center studies. Larger studies are needed to define the criteria for selecting the patients who will benefit from valve replacement.
Six centers prospectively enrolled 136 patients with aortic stenosis (96 men; median age, 72 years [range, 65 to 77 years]; median aortic valve area, 0.7 cm2 [range, 0.6 to 0.8]; mean transaortic gradient, 29 mm Hg [range, 23 to 34 mm Hg]; cardiac index, 2.11 L x min(-1) x m(-2) [range, 1.75 to 2.55 L x min(-1) x m(-2)]). Left ventricular contractile reserve on the dobutamine stress Doppler study was present in 92 patients (group I) and absent in 44 patients (group II). Operative mortality was 5% (3 of 64 patients) in group I compared with 32% (10 of 31 patients) in group II (P=0.0002). Predictors for operative mortality were the lack of contractile reserve (odds ratio, 10.9; 95% confidence interval [CI], 2.6 to 43.4; P=0.001) and a mean transaortic gradient < or =20 mm Hg (odds ratio, 4.7; 95% CI, 1.1 to 21.0; P=0.04). Predictors for long-term survival were valve replacement (hazard ratio, 0.30; 95% CI, 0.17 to 0.53; P=0.001) and left ventricular contractile reserve (hazard ratio, 0.40; 95% CI, 0.23 to 0.69; P=0.001).
In the setting of low-gradient aortic stenosis, surgery seems beneficial for most of the patients with left ventricular contractile reserve. In contrast, the postoperative outcome of patients without reserve is compromised by a high operative mortality. Thus, dobutamine stress Doppler hemodynamics may be factored into the risk-benefit analysis for each patient.
Valvular heart diseases are not usually regarded as a major public-health problem. Our aim was to assess their prevalence and effect on overall survival in the general population.
We pooled population-based studies to obtain data for 11 911 randomly selected adults from the general population who had been assessed prospectively with echocardiography. We also analysed data from a community study of 16 501 adults who had been assessed by clinically indicated echocardiography.
In the general population group, moderate or severe valve disease was identified in 615 adults. There was no difference in the frequency of such diseases between men and women (p=0.90). Prevalence increased with age, from 0.7% (95% CI 0.5-1.0) in 18-44 year olds to 13.3% (11.7-15.0) in the 75 years and older group (p<0.0001). The national prevalence of valve disease, corrected for age and sex distribution from the US 2000 population, is 2.5% (2.2-2.7). In the community group, valve disease was diagnosed in 1505 (1.8% adjusted) adults and frequency increased considerably with age, from 0.3% (0.2-0.3) of the 18-44 year olds to 11.7% (11.0-12.5) of those aged 75 years and older, but was diagnosed less often in women than in men (odds ratio 0.90, 0.81-1.01; p=0.07). The adjusted mortality risk ratio associated with valve disease was 1.36 (1.15-1.62; p=0.0005) in the population and 1.75 (1.61-1.90; p<0.0001) in the community.
Moderate or severe valvular diseases are notably common in this population and increase with age. In the community, women are less often diagnosed than are men, which could indicate an important imbalance in view of the associated lower survival. Valve diseases thus represent an important public-health problem.
Although appropriateness criteria for stress echocardiography have been developed to deliver high-quality care, the prognostic impact of these criteria remains undefined. Therefore, we sought to assess the prognostic implication of the American College of Cardiology/American Society of Echocardiography appropriateness criteria for pharmacological stress echo in a cohort of ambulatory patients.
The study population consisted of 1552 ambulatory patients who underwent pharmacological (752 dobutamine, 800 dipyridamole) stress echo for the evaluation of known (n=549) or suspected (n=1003) coronary artery disease at a single cardiology center. Patients were followed up for a median of 36 months. Indications were determined for consecutive studies by 2 reviewers and categorized as follows: 984 (63%) patients had appropriate, 145 (9%) uncertain, and 423 (27%) inappropriate indication for stress echo. Ischemia was present in 15% of patients with appropriate, 8% of those with uncertain, and 5% of those with inappropriate indication (P<0.0001). During follow-up, 146 events (89 deaths, 57 nonfatal infarctions) occurred. Annual event rate associated with appropriate, uncertain, and inappropriate study was 3.1%, 3.8%, and 1.3%, respectively. The abnormal test result in patients with appropriate, uncertain, and inappropriate study was associated with 5.0%, 5.6%, and 1.8% annual event rate, respectively, exerting an independent value only in the appropriate and uncertain subset.
Inappropriate indication for pharmacological stress echo is common, being documented in about 1 of 4 patients evaluated in an ambulatory setting, and is associated with lower rate of positive results and better survival as compared with appropriate and uncertain indication.
Steven R. Bailey, MD, FACC, FSCAI, FAHA, Moderator
Rory B. Weiner, MD, Writing Group Liaison
Peter Alagona, Jr, MD, FACC[⁎][1]
Jeffrey L. Anderson, MD, FACC, FAHA, MACP[⁎][1][∥][2]
Jeanne M. DeCara, MD, FACC, FASE[§][3]
Rowena J. Dolor, MD, MHS
Reza Fazel, MD, FACC[⁎⁎][4]
John A
The aim of this study was to evaluate the clinical application of the American College of Cardiology Foundation and American Society of Echocardiography appropriateness criteria for stress echocardiography (SE) in a single-center university hospital.
Indications were determined for consecutive studies by two reviewers and categorized as appropriate, uncertain, or inappropriate.
Of 477 studies for which primary indications could be determined, 188 specifically related to university transplantation programs were excluded. Of the remaining 289 studies, 88% were addressed in the appropriateness criteria for SE. Of these, 71% were appropriate, 9% were uncertain, and 20% were inappropriate. Inappropriate studies were more likely to be ordered on younger patients and women and were less likely to be ordered by cardiologists. Abnormal results on SE were more frequent among appropriate than inappropriate studies.
The appropriateness criteria for SE encompass and effectively characterize the majority of studies ordered in a single-center university hospital and appear to reasonably stratify the likelihood of abnormal results on SE. However, revisions will be required to fully capture and stratify appropriate clinical practice of SE.
We sought to quantify exercise-induced changes in patients with degenerative mitral regurgitation (MR), to examine the relationship between exercise-induced changes in MR and in systolic pulmonary artery pressure (PAP), and to identify their potential impact on symptom-free survival.
MR severity can change during exercise in patients with functional MR. Quantified changes in MR severity during exercise remain undetermined in patients with degenerative MR.
Resting and bicycle exercise Doppler-echocardiography were performed in 61 asymptomatic patients (age 62+/-14 years) with moderate to severe degenerative MR (i.e., mitral valve prolapse or flail). Mitral regurgitation was quantified at rest and exercise with effective regurgitant orifice (ERO) area and regurgitant volume calculated with the proximal isovelocity surface area (EROP) and the quantitative Doppler (EROD) methods.
At rest, EROP and EROD were well-correlated (r=0.87, p<0.0001), but EROD was larger than EROP (54+/-21 mm2 vs. 42+/-24 mm2, p<0.0001). During exercise, mean ERO and regurgitant volume markedly increased in 32% of patients by >or=10 mm2 and >or=15 ml, respectively. There was good correlation between exercise EROP and EROD (r=0.84, p<0.0001). Changes in systolic PAP were correlated with changes in ERO and regurgitant volume (r=0.59, p=0.02 and r=0.60, p=0.02). Patients with a marked increase in regurgitant volume during exercise had lower symptom-free survival than those in whom MR decreased or remained unchanged (p=0.0015).
Degenerative MR might be dynamic and increases during exercise in one-third of patients. Marked changes in MR severity are associated with exercise-induced changes in systolic PAP and reduced symptom-free survival.
Current guidelines recommend mitral valve surgery for asymptomatic patients with severe degenerative mitral regurgitation and preserved left ventricular systolic function when exercise pulmonary hypertension (PHT) is present. However, the determinants of exercise PHT have not been evaluated. The aim of this study was to identify the echocardiographic predictors of exercise PHT and the impact on symptoms.
Comprehensive resting and exercise transthoracic echocardiography was performed in 78 consecutive patients (age, 61+/-13 years; 56% men) with at least moderate degenerative mitral regurgitation (effective regurgitant orifice area =43+/-20 mm(2); regurgitant volume =71+/-27 mL). Exercise PHT was defined as a systolic pulmonary arterial pressure (SPAP) >60 mm Hg. Exercise PHT was present in 46% patients. In multivariable analysis, exercise effective regurgitant orifice was an independent determinant of exercise SPAP (P<0.0001) and exercise PHT (P=0.002). Resting PHT and exercise PHT were associated with markedly reduced 2-year symptom-free survival (36+/-14% versus 59+/-7%, P=0.04; 35+/-8% versus 75+/-7%, P<0.0001). After adjustment, although the impact of resting PHT was no longer significant, exercise PHT was identified as an independent predictor of the occurrence of symptoms (hazard ratio=3.4; P=0.002). Receiver-operating characteristics curves revealed that exercise PHT (SPAP >56 mm Hg) was more accurate than resting PHT (SPAP >36 mm Hg) in predicting the occurrence of symptoms during follow-up (P=0.032).
Exercise PHT is frequent in patients with asymptomatic degenerative mitral regurgitation. Exercise mitral regurgitation severity is a strong independent predictor of both exercise SPAP and exercise PHT. Exercise PHT is associated with markedly low 2-year symptom-free survival, emphasizing the use of exercise echocardiography. An exercise SPAP >56 mm Hg accurately predicts the occurrence of symptoms.
Exercise testing has an established role in the evaluation of patients with valvular heart disease and can aid clinical decision making. Because symptoms may develop slowly and indolently in chronic valve diseases and are often not recognized by patients and their physicians, the symptomatic, blood pressure, and electrocardiographic responses to exercise can help identify patients who would benefit from early valve repair or replacement. In addition, stress echocardiography has emerged as an important component of stress testing in patients with valvular heart disease, with relevant established and potential applications. Stress echocardiography has the advantages of its wide availability, low cost, and versatility for the assessment of disease severity. The versatile applications of stress echocardiography can be tailored to the individual patient with aortic or mitral valve disease, both before and after valve replacement or repair. Hence, exercise-induced changes in valve hemodynamics, ventricular function, and pulmonary artery pressure, together with exercise capacity and symptomatic responses to exercise, provide the clinician with diagnostic and prognostic information that can contribute to subsequent clinical decisions. Nevertheless, there is a lack of convincing evidence that the results of stress echocardiography lead to clinical decisions that result in better outcomes, and therefore large-scale prospective randomized studies focusing on patient outcomes are needed in the future.
Appropriateness criteria for stress imaging have been published to promote the effective use of stress nuclear scintigraphy and stress echocardiography. We sought to evaluate the application of the stress echocardiography appropriateness criteria to patients undergoing stress echocardiography in an academic medical center.
The stress echocardiography criteria were applied to 298 consecutive patients who underwent stress echocardiography. Patients were rated as appropriate, uncertain, inappropriate, or not classifiable. Results were compared with those of a previous analysis in the same patients using the single-photon computed tomography myocardial perfusion imaging (SPECT MPI) criteria. The level of agreement between 2 cardiac nurse abstractors for categorizing appropriateness by the stress echocardiography criteria was good (kappa=0.72). Overall, 54% of patients were classified as appropriate, 8% as uncertain, and 19% as inappropriate; 19% were not classifiable. By the SPECT MPI criteria, 64% of patients were classified as appropriate, 9% as uncertain, and 18% as inappropriate; 9% were not classifiable (P<0.001 compared with stress echocardiography criteria). By the stress echocardiography criteria, 6 clinical situations or indications accounted for more than 90% of the inappropriate tests; most of these involved asymptomatic patients.
Applying stress echocardiography appropriateness criteria to a patient population is feasible, although 1 in 5 of our patients was not classifiable. Overall, the stress echocardiography criteria classified patients differently compared with the SPECT MPI criteria. Future refinements of the appropriateness criteria for stress imaging should address gaps in the criteria and disparities between the stress echocardiography and SPECT MPI criteria.
The aim of this study was to determine the hemodynamic effects of upright bicycle ergometry in symptomatic patients with mild, mixed mitral stenosis and regurgitation.
Patients with seemingly mild rheumatic mitral valve disease often complain of exertional dyspnea or fatigue. These symptoms are usually ascribed to flow-dependent increases in the gradient across the stenotic mitral valve. Although catheterization studies in these patients may demonstrate an increase in mitral valve gradient proportional to an increase in cardiac output, this approach does not specifically address the underlying mechanism of any observed increases in mitral gradient or left atrial (i.e., pulmonary capillary wedge) pressure. Exercise echocardiography is uniquely suited to the dynamic assessment of exercise-induced hemodynamic changes.
Fourteen symptomatic patients with exertional dyspnea and mild mitral stenosis and regurgitation at rest performed symptom-limited upright bicycle ergometry with quantitative two-dimensional, Doppler and color Doppler echocardiographic analysis.
Average pulmonary artery systolic pressure in the 13 patients with adequate spectral signals of tricuspid regurgitation increased from 36 +/- 5 mm Hg (mean +/- SD) at rest to 63 +/- 14 mm Hg at peak exercise (p < 0.001). The mean transmitral pressure gradient in all patients increased from 4.5 +/- 1.4 mm Hg at rest to 12.7 +/- 2.7 mm Hg at peak exercise (p < 0.001). Five patients developed severe mitral regurgitation during exercise.
Patients with exertional dyspnea and mild mitral stenosis and regurgitation at rest demonstrate a marked increase in pulmonary artery systolic pressure and mean transmitral pressure gradient during dynamic exercise. In a subset of these patients, marked worsening of mitral regurgitation appears to be the underlying mechanism of this hemodynamic deterioration. Because of the small sample size, this novel observation must be considered preliminary with respect to the true prevalence of exercise-related development of severe mitral regurgitation. If additional studies confirm the importance of this phenomenon, it has important implications for the management of patients with rheumatic mitral valve disease.
The safety of dobutamine echocardiography in coronary artery disease is well established.27 This study shows that dobutamine can be given safely to patients with AS during noninvasive hemodynamic monitoring. The small number of patients in this study preclude assessment of the effect of dobutamine echocardiography on outcome. A large prospective study is indicated. Although the continuity equation does not contain a flow-dependent constant, its limitations include underestimation of LV outflow diameter and failure to properly align the Doppler beam.18 However, even if errors in velocity measurement occurred, directional changes should be valid since the transducer locations were identical at baseline and dobutamine infusion.
In patients with asymptomatic valvular aortic stenosis, exercise testing may help to stratify the clinical risk. However, data are limited, and the role of quantitative exercise Doppler echocardiography has never been investigated.
Sixty-nine consecutive patients with severe asymptomatic aortic stenosis (aortic valve area <1 cm2) who prospectively underwent quantitative Doppler echocardiographic measurements at rest and during semisupine exercise test were followed up for 15+/-7 months. Of these, 26 had an abnormal response to exercise [occurrence of > or =1 of the following findings: angina, dyspnea, > or =2 mm ST segment depression, or fall or small (<20 mm Hg) rise in systolic blood pressure during the test] and 18 presented cardiac events during follow-up (symptoms in 2 patients, acute pulmonary edema in 2, aortic valve replacement in 12, and cardiac death in 2). In univariate analysis, patients who had cardiac events exhibited a higher increase in both peak (29+/-16 versus 22+/-14 mm Hg; P=0.019) and mean (23+/-8 versus 12+/-7 mm Hg; P=0.000003) transvalvular pressure gradients, whereas the left ventricular ejection fraction reached at peak stress was lower. These patients experienced more frequently symptoms during exercise (14 of 18 versus 12 of 51; P=0.0008). By multivariate Cox regression analysis, independent predictors of cardiac events were as follows: an increase in mean transaortic pressure gradient by > or =18 mm Hg during exercise (P=0.0015), an abnormal exercise test (P=0.0026), and an aortic valve area <0.75 cm2 (P=0.0031). Exercise Doppler echocardiographic findings provided incremental prognostic value over resting echocardiographic and exercise electrocardiographic parameters.
Quantitative Doppler exercise echocardiography could be useful to identify a high-risk subset of patients with asymptomatic valvular aortic stenosis and help for clinical decision making.
Rates of invasive testing and treatment for coronary artery disease have increased over time. Less is known about trends in the utilization of noninvasive cardiac testing for coronary artery disease. The objective of this study was 2-fold: to explore temporal trends in the utilization of noninvasive and invasive cardiac services in relation to changes in the prevalence of cardiac disease, and to examine whether temporal increases have been targeted to potentially underserved populations.
We performed an annual cross-sectional population-based study of Medicare patients from 1993 to 2001. We identified stress testing, cardiac catheterization, and revascularization procedures, as well as hospitalizations for acute myocardial infarction, during each year and calculated population-based rates for each using the total fee-for-service Medicare population as the denominator and adjusting for age, gender, and race. We observed marked growth in the utilization rates of cardiac services over time, with relative rates nearly doubling for most services. Acute myocardial infarction hospitalization rates have remained stable over the study period. Although rates of all procedures except coronary artery bypass increased in all subgroups, differences in rates of cardiac testing and treatment between nonblack men and other subgroups persisted over time.
Temporal increases in the use of noninvasive and invasive cardiac services are not explained by changes in disease prevalence and have not succeeded in narrowing preexisting treatment differences by gender and race. Such increases, although conferring benefit for some, may expose others to risk and cost without benefit.
Recommendations for evaluation of the severity of native valvular regurgitation with two dimensional and Doppler echocardiography Circulation (EACTS)Eur Key Words: dobutamine - exercise - stress echocardiography - valvular heart disease
- W Zoghbi
- Enriquez
- M Sarano
- E Foster
Zoghbi W, Enriquez-Sarano M, Foster E, et al. Recommendations for evaluation of the severity of native valvular regurgitation with two dimensional and Doppler echocardiography. J Am Soc Echocardiogr 2003;1:777–802. Circulation (EACTS).Eur Key Words: dobutamine - exercise - stress echocardiography - valvular heart disease. Bhattacharyya et al. Stress Echocardiography in Valvular Heart Disease J A C C : C A R D I O V A S C U L A R I M A G I N G , V O L . 6 , N O . 9 , 2 0 1 3 S E P T E M B E R 2 0 1 3 : 9 8 7 – 9 2 992