Stress echocardiography in the detection of myocardial ischemia. Head-to-head comparison of exercise, dobutamine, and dipyridamole tests

Automated interpretation of stress echocardiography reports using natural language processing

Aims

Stress echocardiography (SE) findings and interpretations are commonly documented in free-text reports. Reusing SE results requires laborious manual reviews. This study aimed to develop and validate an automated method for abstracting SE reports in a large cohort.

Methods and results

This study included adult patients who had SE within 30 days of their emergency department visit for suspected acute coronary syndrome in a large integrated healthcare system. An automated natural language processing (NLP) algorithm was developed to abstract SE reports and classify overall SE results into normal, non-diagnostic, infarction, and ischaemia categories. Randomly selected reports (n = 140) were double-blindly reviewed by cardiologists to perform criterion validity of the NLP algorithm. Construct validity was tested on the entire cohort using abstracted SE data and additional clinical variables. The NLP algorithm abstracted 6346 consecutive SE reports. Cardiologists had good agreements on the overall SE results on the 140 reports: Kappa (0.83) and intraclass correlation coefficient (0.89). The NLP algorithm achieved 98.6% specificity and negative predictive value, 95.7% sensitivity, positive predictive value, and F-score on the overall SE results and near-perfect scores on ischaemia findings. The 30-day acute myocardial infarction or death outcomes were highest among patients with ischaemia (5.0%), followed by infarction (1.4%), non-diagnostic (0.8%), and normal (0.3%) results. We found substantial variations in the format and quality of SE reports, even within the same institution.

Conclusions

Natural language processing is an accurate and efficient method for abstracting unstructured SE reports. This approach creates new opportunities for research, public health measures, and care improvement.

Does chest shape influence exercise stress echocardiographic results in patients with suspected coronary artery disease?

Despite the good specificity of exercise stress echocardiography (ESE) for the detection of coronary artery disease (CAD), false positive (FP) results may occur. We have previously reported that chest abnormalities may affect parameters of cardiac contractility. The influence of chest shape on ESE results has never been previously investigated. We retrospectively analyzed 160 consecutive patients (64.4 ± 13.0-year old, 91 women) who had undergone coronary angiography at our Institution because of positive ESE, between June 2014 and May 2020. Modified Haller index (MHI; chest transverse diameter over the distance between sternum and spine) was assessed in all patients. Obstructive CAD was diagnosed by ≥ 70% stenosis in any epicardial coronary artery. Outcome was false-positivity at ESE. 80.6% of patients were diagnosed with obstructive CAD, while 19.4% had no CAD (FP). We separately analyzed patients with normal chest shape (MHI ≤ 2.5) and those with concave-shaped chest wall (MHI > 2.5). These latter were mostly women with small cardiac chambers, mitral valve prolapse (MVP) and exercise-induced ST-segment changes. Likelihood of false-positivity was significantly higher in subjects with MHI > 2.5 than those with MHI ≤ 2.5 (30.7% vs 9.4%, p = 0.001). By multivariate logistic regression analysis, MHI > 2.5 (OR 4.04, 95%CI 1.45-11.2, p = 0.007), MVP (OR 3.47, 95%CI 1.32-9-12, p = 0.01) and dyssynergy in the left circumflex territory (OR = 3.35, 95%CI 1.26-8.93, p = 0.01) were independently associated with false-positivity. Concave-shaped chest wall (MHI > 2.5) may be associated with false-positive stress echocardiographic result. Mechanisms underpinning this finding need to be further explored.

Coronary Flow Velocity Reserve Using Dobutamine Test for Noninvasive Functional Assessment of Myocardial Bridging

Background: It has been shown that coronary flow velocity reserve (CFVR) measurement by transthoracic Doppler echocardiography (TTDE) during dobutamine (DOB) provocation provides a more accurate functional evaluation of myocardial bridging (MB) compared to adenosine. However; the cut-off value of CFVR during DOB for identification of MB associated with myocardial ischemia has not been fully clarified. Purpose: This prospective study aimed to determine the cut-off value of TTDE-CFVR during DOB in patients with isolated-MB, as compared with stress-induced wall motion abnormalities (VMA) during exercise stress-echocardiography (SE) as reference. Methods: Eighty-one symptomatic patients (55 males [68%], mean age 56 ± 10 years; range: 27–74 years) with the existence of isolated-MB on the left anterior descending artery (LAD) and systolic MB-compression ≥50% diameter stenosis (DS) were eligible to participate in the study. Each patient underwent treadmill exercise-SE, invasive coronary angiography, and TTDE-CFVR measurements in the distal segment of LAD during DOB infusion (DOB: 10–40 μg/kg/min). Using quantitative coronary angiography, both minimal luminal diameter (MLD) and percent DS at MB-site at end-systole and end-diastole were determined. Results: Stress-induced myocardial ischemia with the occurrence of WMA was found in 23 patients (28%). CFVR during peak DOB was significantly lower in the SE-positive group compared with the SE-negative group (1.94 ± 0.16 vs. 2.78 ± 0.53; p < 0.001). ROC analyses identified the optimal CFVR cut-off value ≤ 2.1 obtained during high-dose dobutamine (>20 µg/kg/min) for the identification of MB associated with stress-induced WMA, with a sensitivity, specificity, positive and negative predictive value of 96%, 95%, 88%, and 98%, respectively (AUC 0.986; 95% CI: 0.967–1.000; p < 0.001). Multivariate logistic regression analysis revealed that MLD and percent DS, both at end-diastole, were the only independent predictors of ischemic CFVR values ≤2.1 (OR: 0.023; 95% CI: 0.001–0.534; p = 0.019; OR: 1.147; 95% CI: 1.042–1.263; p = 0.005; respectively). Conclusions: Noninvasive CFVR during dobutamine provocation appears to be an additional and important noninvasive tool to determine the functional severity of isolated-MB. A transthoracic CFVR cut-off ≤2.1 measured at a high-dobutamine dose may be adequate for detecting myocardial ischemia in patients with isolated-MB.

Myocardial function reclassification: Echocardiographic strain patterns in patients with chronic Chagas cardiomyopathy and intraventricular dyssynchrony

BACKGROUND

We aimed to identify, among Chronic Chagas Cardiomyopathy (CCC) patients with left ventricular dysfunction (LVD) and non-left bundle branch block (non-LBBB), subgroups with different functional and mechanical patterns of global longitudinal strain (GLS) and intraventricular dyssynchrony (IVD) at rest and after exercise stress test, and reclassify them using a new echocardiographic approach.

METHODOLOGY

In this single-center cross-sectional study, 40 patients with CCC, left ventricular ejection fraction (LVEF) ≤ 35% and non-LBBB underwent rest echocardiography and then treadmill exercise stress echocardiography with GLS and IVD analysis. The sample was divided into four groups, based on GLS and IVD significant variation between rest and exercise: GLS + IVD+ (9 patients); GLS + IVD- (9 patients); GLS-IVD+ (10 patients); GLS-IVD- (10 patients).

RESULTS

At rest, median LVEF was 28% (21.3%-33%) and GLS (-7% (-5%/-9.3%), were not different among groups. The average response of GLS was an increase of 0.74% over rest values, and the average response of IVD was a decrease of 6.9 ms. Group GLS-IVD+ presented more dyssynchrony at rest (p = 0.01). Left atrial (LA) volume (higher in GLS-IVD-) (p = 0.022) and TAPSE (higher in GLS + IVD+) (p = 0.015) were also different among groups at baseline. Of the 40 patients evaluated, 27 (67.5%) had very severe LVD (GLS < -8%). In addition, among these patients, 11 patients had contractile reserve after undergoing stress echocardiography.

CONCLUSIONS

In patients with CCC, severe LVD and non-LBBB, the evaluation of GLS and IVD between rest and exercise was able to reclassify myocardial function and to identify subgroups with contractile reserve and significant dyssynchronopathy.

Should we routinely assess coronary artery Doppler in daily echocardiography practice?

A lot of people with coronary artery disease do not have specific symptoms, and myocardial infarction or death are the first manifestation of the disease. New accurate, non-invasive and safe screening methods are required that can assess the prognosis of patients during routine examinations performed on millions of people. The aim of this review was to discuss the current literature regarding the utility of non-invasive ultrasound imaging of the coronary artery in assessing a patient's prognosis in daily practice. Assessment of coronary artery flow during common stress echocardiography or echocardiography can provide additive incremental prognostic information without the burden of radiation. Exercise or pharmacologic stress echocardiography tests combined with coronary flow velocity reserve assessment has advantages over stress tests based only on regional wall motion abnormalities. Scanning of main coronary arteries as an addition to routine echocardiography can reveal patients at high risk of adverse cardiac events in the near future.

Pharmacological and simulated exercise cardiac stress tests produce different ischemic signatures in high-resolution experimental mapping studies

OBJECTIVE

Test the hypothesis that exercise and pharmacological cardiac stressors create different electrical ischemic signatures.

INTRODUCTION

Current clinical stress tests for detecting ischemia lack sensitivity and specificity. One unexplored source of the poor detection is whether pharmacological stimulation and regulated exercise produce identical cardiac stress.

METHODS

We used a porcine model of acute myocardial ischemia in which animals were instrumented with transmural plunge-needle electrodes, an epicardial sock array, and torso arrays to simultaneously measure cardiac electrical signals within the heart wall, the epicardial surface, and the torso surface, respectively. Ischemic stress via simulated exercise and pharmacological stimulation were created with rapid electrical pacing and dobutamine infusion, respectively, and mimicked clinical stress tests of five 3-minute stages. Perfusion to the myocardium was regulated by a hydraulic occluder around the left anterior descending coronary artery. Ischemia was measured as deflections to the ST-segment on ECGs and electrograms.

RESULTS

Across eight experiments with 30 (14 simulated exercise and 16 dobutamine) ischemic interventions, the spatial correlations between exercise and pharmacological stress diverged at stage three or four during interventions (p<0.05). We found more detectable ST-segment changes on the epicardial surface during simulated exercise than with dobutamine (p<0.05). The intramyocardial ischemia formed during simulated exercise had larger ST40 potential gradient magnitudes (p<0.05).

CONCLUSION

We found significant differences on the epicardium between cardiac stress types using our experimental model, which became more pronounced at the end stages of each test. A possible mechanism for these differences was the larger ST40 potential gradient magnitudes within the myocardium during exercise. The presence of microvascular dysfunction during exercise and its absence during dobutamine stress may explain these differences.

Functional Assessment of Myocardial Bridging With Conventional and Diastolic Fractional Flow Reserve: Vasodilator Versus Inotropic Provocation

Background

Functional assessment of myocardial bridging (MB) remains clinically challenging because of the dynamic nature of the extravascular coronary compression with a certain degree of intraluminal coronary reduction. The aim of our study was to assess performance and diagnostic value of diastolic‐fractional flow reserve (d‐FFR) during dobutamine provocation versus conventional‐FFR during adenosine provocation with exercise‐induced myocardial ischemia as reference.

Methods and Results

This prospective study includes 60 symptomatic patients (45 men, mean age 57±9 years) with MB on the left anterior descending artery and systolic compression ≥50% diameter stenosis. Patients were evaluated by exercise stress‐echocardiography test, and both conventional‐FFR and d‐FFR in the distal segment of left anterior descending artery during intravenous infusion of adenosine (140 μg/kg per minute) and dobutamine (10–50 μg/kg per minute), separately. Exercise–stress‐echocardiography test was positive for myocardial ischemia in 19/60 patients (32%). Conventional‐FFR during adenosine and peak dobutamine had similar values (0.84±0.04 versus 0.84±0.06, P=0.852), but d‐FFR during peak dobutamine was significantly lower than d‐FFR during adenosine (0.76±0.08 versus 0.79±0.08, P=0.018). Diastolic‐FFR during peak dobutamine was significantly lower in the exercise‐stress‐echocardiography test –positive group compared with the exercise‐ stress‐echocardiography test –negative group (0.70±0.07 versus 0.79±0.06, P<0.001), but not during adenosine (0.79±0.07 versus 0.78±0.09, P=0.613). Among physiological indices, d‐FFR during peak dobutamine was the only independent predictor of functionally significant MB (odds ratio, 0.870; 95% CI, 0.767–0.986, P=0.03). Receiver‐operating characteristics curve analysis identifies the optimal d‐FFR during peak dobutamine cut‐off ≤0.76 (area under curve, 0.927; 95% CI, 0.833–1.000; P<0.001) with a sensitivity, specificity, and positive and negative predictive value of 95%, 95%, 90%, and 98%, respectively, for identifying MB associated with stress‐induced ischemia.

Conclusions

Diastolic‐FFR, but not conventional‐FFR, during inotropic stimulation with high‐dose dobutamine, in comparison to vasodilatation with adenosine, provides more reliable functional significance of MB in relation to stress‐induced myocardial ischemia.

Accuracy and Prognostic Value of Physiologist-Led Stress Echocardiography for Coronary Disease

BACKGROUND

We demonstrated that physiologist-led stress echocardiography (PLSE) is feasible for coronary artery disease (CAD) assessment. We sought to extend our work by assessing its accuracy and prognostic value.

METHODS

Retrospective study of 898 subjects undergoing PLSE (n=393) or cardiologist-led stress echocardiography (CLSE) (n=505) for CAD assessment using exercise or dobutamine. For accuracy assessment, the primary outcome was the ability of stress echocardiography to identify significant CAD on invasive coronary angiography (ICA). Incidence of 24-month non-fatal MI, total and cardiac mortality, revascularisation and combined major adverse cardiac events (MACE) were assessed.

RESULTS

Demographics, comorbidities, CAD predictors, CAD pre-test probability and cardiac medications were matched between the PLSE and CLSE groups. PLSE had high sensitivity, specificity, positive and negative predictive value and accuracy (85%, 74%, 69%, 88%, 78% respectively). PLSE accuracy measures were similar and non-inferior to CLSE. There was a similar incidence of individual and combined outcomes in PLSE and CLSE subjects. Negative stress echocardiography conferred a comparably low incidence of non-fatal MI (PLSE 1.4% vs. CLSE 0.9%, p=0.464), cardiac mortality (0.6% vs. 0.0%, p=0.277) and MACE (6.8% vs. 3.1%, p=0.404).

CONCLUSION

This is the first study of the accuracy compared with gold standard of ICA, and prognostic value of PLSE CAD assessment. PLSE demonstrates high and non-inferior accuracy compared with CLSE for CAD assessment. Negative PLSE and CLSE confer a similarly very low incidence of cardiac outcomes, confirming for the first time the important prognostic value of PLSE.

Impairment of coronary flow velocity reserve and global longitudinal strain in women with cardiac syndrome X and slow coronary flow

BACKGROUND

Microvascular dysfunction (MVD) is associated with adverse prognosis and may account for abnormal stress tests and angina symptoms in women with cardiac syndrome X (CSX). The aim of our study was to assess MVD by coronary flow velocity reserve (CFVR) and left ventricular (LV) contractile function by LV global longitudinal strain (LVGLS) in CSX patients with respect to presence of slow coronary flow (SCF). It was of additional importance to evaluate clinical status of CSX patients using Seattle Angina Questionnaire.

METHODS AND RESULTS

Study population included 70 women with CSX (mean age 61 ± 7 years) and 34 age-matched controls. CSX group was stratified into two subgroups depending on SCF presence: CSX-Thrombolysis In Myocardial Infarction (TIMI) 3- normal flow subgroup (n = 38) and CSX-TIMI 2- SCF subgroup (n = 32) as defined by coronary angiography. LVGLS measurements and CFVR of left anterior descending (LAD) and posterior descending (PD) artery were performed. CFVR-LAD and PD were markedly impaired in CSX group compared to controls (2.34 ± 0.25 vs 3.05 ± 0.21, p < 0.001; 2.32 ± 0.24 vs 3.01 ± 0.13, p < 0.001), and furthermore decreased in CSX-TIMI 2 patients. Resting, peak, and ΔLVGLS were all significantly impaired in CSX group compared to controls (for all p < 0.001), and furthermore reduced in CSX-TIMI 2 subgroup. Strongest correlation was found between peak LVGLS and CFVR LAD (r = -0.784, p < 0.001) and PD (r = -0.772, p < 0.001). CSX-TIMI 2 subgroup had more frequent angina symptoms and more impaired quality of life.

CONCLUSIONS

MVD in CSX patients is demonstrated by reduction in CFVR and LVGLS values. SCF implies more profound impairment of microvascular and LV systolic function along with worse clinical presentation.

The additive prognostic value of coronary flow velocity reserve during exercise echocardiography

Aims

The aim of the study was to assess the additive prognostic value of coronary flow velocity reserve (CFVR) alongside wall motion analysis during exercise echocardiography in patients with known or suspected coronary artery disease (CAD).

Methods and results

In a prospective, single-centre, observational study, we evaluated 689 patients (449 males; 56 + 9 years) who underwent supine bicycle stress echo (ESE) with CFVR evaluation of the left anterior descending artery (LAD) by Doppler. ESE was positive for regional wall motion abnormalities in 359 (52%) patients. Mean CFVR was 1.9 ± 0.8. During a median follow-up of 36.6 months, there were 200 patients with major adverse cardiac events (MACE): 15 deaths, 17 non-fatal myocardial infarctions [11 of them also had percutaneous coronary intervention with stenting (PCI) or/and coronary artery bypass graft surgery (CABG)] and 179 patients underwent revascularization. The 37 months' event-free survival showed the best outcome for those patients with negative ESE by wall motion criteria and normal CFVR, and the worst outcome for patients with positive ESE by wall motion and abnormal CVFR (99 vs. 42%, P < 0.0001). At multivariable analysis, CFVR in LAD (OR 0.53, 95% CI 0.35-0.79, P < 0.0001), positivity for regional wall motion abnormalities during testing (OR 0.10, 95% CI 0.04-0.25, P < 0.000), previous PCI (OR 0.38, 95% CI 0.16-0.90, P < 0.003), male sex (OR 0.44, 95% CI 0.27-0.71, P < 0.0009), and heart rate reached during exercise (OR 0.98, 95% CI 0.96-0.99, P < 0.02) were independent prognostic predictors of MACE.

Conclusion

In patients with known or suspected CAD, exercise stress tests measuring wall motion criteria and CFVR are additive and complementary for the identification of patients at risk of experiencing major adverse events.

Type-2 diabetic aldehyde dehydrogenase 2 mutant mice (ALDH 2*2) exhibiting heart failure with preserved ejection fraction phenotype can be determined by exercise stress echocardiography

E487K point mutation of aldehyde dehydrogenase (ALDH) 2 (ALDH2*2) in East Asians intrinsically lowers ALDH2 activity. ALDH2*2 is associated with diabetic cardiomyopathy. Diabetic patients exhibit heart failure of preserved ejection fraction (HFpEF) i.e. while the systolic heart function is preserved in them, they may exhibit diastolic dysfunction, implying a jeopardized myocardial health. Currently, it is challenging to detect cardiac functional deterioration in diabetic mice. Stress echocardiography (echo) in the clinical set-up is a procedure used to measure cardiac reserve and impaired cardiac function in coronary artery diseases. Therefore, we hypothesized that high-fat diet fed type-2 diabetic ALDH2*2 mutant mice exhibit HFpEF which can be measured by cardiac echo stress test methodology. We induced type-2 diabetes in 12-week-old male C57BL/6 and ALDH2*2 mice through a high-fat diet. At the end of 4 months of DM induction, we measured the cardiac function in diabetic and control mice of C57BL/6 and ALDH2*2 genotypes by conscious echo. Subsequently, we imposed exercise stress by allowing the mice to run on the treadmill until exhaustion. Post-stress, we measured their cardiac function again. Only after treadmill running, but not at rest, we found a significant decrease in % fractional shortening and % ejection fraction in ALDH2*2 mice with diabetes compared to C57BL/6 diabetic mice as well as non-diabetic (control) ALDH2*2 mice. The diabetic ALDH2*2 mice also exhibited poor maximal running speed and distance. Our data suggest that high-fat fed diabetic ALDH2*2 mice exhibit HFpEF and treadmill exercise stress echo test is able to determine this HFpEF in the diabetic ALDH2*2 mice.

Noninvasive assessment of myocardial bridging by coronary flow velocity reserve with transthoracic Doppler echocardiography: vasodilator vs. inotropic stimulation

BACKGROUND

To consider hemodynamic assessment of myocardial bridging (MB) adequate, it is believed that inotropic stimulation with dobutamine should be estimated because its dynamic nature depends on the degree of extravascular coronary compression. This study evaluated comparative assessment of hemodynamic relevance of MB using coronary flow velocity reserve (CFVR) measurements by transthoracic Doppler echocardiography (TTDE) with vasodilatative and inotropic challenges.

METHODS

This prospective study included forty-four patients with angiographic evidence of isolated MB of the left anterior descending coronary artery (LAD) and systolic compression of ≥50% diameter stenosis. All patients were evaluated by exercise stress-echocardiography (ExSE) test for signs of myocardial ischemia, and CFVR of the distal segment of LAD during iv.infusion of adenosine (ADO:140μg/kg/min) and iv.infusion of dobutamine (DOB:10-40μg/kg/min), separately.

RESULTS

Exercise-SE was positive for myocardial ischemia in 8/44 (18%) of patients. CFVR during ADO was significantly higher than CFVR during peak DOB (2.85±0.68 vs. 2.44±0.48, p=0.002). CFVR during peak DOB was significantly lower in SE-positive group in comparison to SE-negative group (2.01±0.16 vs. 2.54±0.47, p<0.001), but not for ADO (2.47±0.51 vs. 2.89±0.70, p=0.168), respectively. Multivariable logistic analysis showed that CFVR peak DOB was the most significant predictor of functional significant MB (OR 0.011, 95%CI: 0.001-0.507, p=0.021). Receiver-operating characteristic curves have shown that TTDE-CFVR obtained by high-dose of dobutamine infusion is better than those by adenosine regarding to functional status of MB (AUC 0.861, p=0.004; AUC 0.674, p=0.179, respectively).

CONCLUSIONS

Non-invasive CFVR measurement by TTDE during inotropic stimulation, in comparison to vasodilation, provides more reliable functional evaluation of MB.

The prognostic value of cardiac dysfunction assessed by bedside echocardiography in critically ill patients with COPD requiring mechanical ventilation: a study protocol

INTRODUCTION

Chronic obstructive lung disease is not only a major cause of morbidity and mortality, but is also the major reason for intensive care unit (ICU) admission. Cardiac function is often impaired in this disease, but its association with clinical outcome has not been fully established.

METHODS AND ANALYSIS

This is a prospective observational study conducted in a 47-bed mixed ICU of a tertiary academic teaching hospital. The study will be performed from January 2014 to December 2015. All patients meeting the diagnostic criteria of acute exacerbation of chronic obstructive pulmonary disease and admitted to the ICU are potentially eligible for the present study. The relevant demographics and laboratory measurements have been obtained. Transthoracic echocardiography was performed immediately after ICU admission by experienced intensivists. The Cox proportional hazard regression model has been fitted by using a stepwise forward selection and backward elimination technique. If linear assumption is not satisfied, the linear spline function will be used.

ETHICS AND DISSEMINATION

The study protocol was approved by the ethics committee of Jinhua municipal central hospital. The results will be published in a peer-reviewed journal and shared with the worldwide medical community.

TRIAL REGISTRATION NUMBER

The study protocol is registered at ClinicalTrials.gov (NCT02099279).

Glycogen phosphorylase isoenzyme BB plasma kinetics is not related to myocardial ischemia induced by exercise stress echo test

BACKGROUND

Glycogen phosphorylase BB (GPBB) is released from cardiac cells during myocyte damage. Previous studies have shown contradictory results regarding the relation of enzyme release and reversible myocardial ischemia. The aim of this study was to determine the plasma kinetics of GPBB as a response to the exercise stress echocardiographic test (ESET), and to define the relationship between myocardial ischemia and enzyme plasma concentrations.

METHODS

We studied 46 consecutive patients undergoing ESET, with recent coronary angiography. In all patients, a submaximal stress echo test according to Bruce protocol was performed. Concentration of GPBB was measured in peripheral blood that was sampled 5 min before and 10, 30 and 60 min after ESET.

RESULTS

There was significant increase of GPBB concentration after the test (p=0.021). Significant increase was detected 30 min (34.9% increase, p=0.021) and 60 min (34.5% increase, p=0.016) after ESET. There was no significant effect of myocardial ischemia on GPBB concentrations (p=0.126), and no significant interaction between sampling intervals and myocardial ischemia, suggesting a similar release profile of GPBB in ischemic and non-ischemic conditions (p=0.558). Patients in whom ESET was terminated later (stages 4 or 5 of standard Bruce protocol; n=13) had higher GPBB concentrations than patients who terminated ESET earlier (stages 1, 2 or 3; n=33) (p=0.049). Baseline GPBB concentration was not correlated to any of the patients' demographic, clinical and hemodynamic characteristics.

CONCLUSIONS

GPBB plasma concentration increases after ESET, and it is not related to inducible myocardial ischemia. However, it seems that GPBB release during ESET might be related to exercise load/duration.

Mental stress-induced ischemia in patients with coronary artery disease: echocardiographic characteristics and relation to exercise-induced ischemia

OBJECTIVE

The aims of this study were to investigate the incidence and parameters associated with myocardial ischemia during mental stress (MS) as measured by echocardiography and to evaluate the relation between MS-induced and exercise-induced myocardial ischemia.

METHODS

Study participants were 79 patients (63 men; mean [M] [standard deviation {SD}] age = 52 [8] years) with angiographically confirmed coronary artery disease and previous positive exercise test result. The MS protocol consisted of mental arithmetic and anger recall task. The patients performed a treadmill exercise test 15 to 20 minutes after the MS task. Data of post-MS exercise were compared with previous exercise stress test results.

RESULTS

The frequency of echocardiographic abnormalities was 35% in response to the mental arithmetic task, compared with 61% with anger recall and 96% with exercise (p < .001, exercise versus MS). Electrocardiogram abnormalities and chest pain were substantially less common during MS than were echocardiographic abnormalities. Independent predictors of MS-induced myocardial ischemia were: wall motion score index at rest (p = .02), peak systolic blood pressure (p = .005), and increase in rate-pressure product (p = .004) during MS. The duration of exercise stress test was significantly shorter (p < .001) when MS preceded the exercise and in the case of earlier exercise (M [SD] = 4.4 [1.9] versus 6.7 [2.2] minutes for patients positive on MS and 5.7 [1.9] versus 8.0 [2.3] minutes for patients negative on MS).

CONCLUSIONS

Echocardiography can be successfully used to document myocardial ischemia induced by MS. MS-induced ischemia was associated with an increase in hemodynamic parameters during MS and worse function of the left ventricle. MS may shorten the duration of subsequent exercise stress testing and can potentiate exercise-induced ischemia in susceptible patients with coronary artery disease.

Diagnostic accuracy of exercise stress testing for coronary artery disease: a systematic review and meta-analysis of prospective studies

BACKGROUND

Exercise stress testing offers a non-invasive, less expensive way of risk stratification prior to coronary angiography, and a negative stress test may actually avoid angiography. However, previous meta-analyses have not included all exercise test modalities, or patients without known Coronary artery disease (CAD).

METHODS AND RESULTS

We systematically reviewed the literature to determine the diagnostic accuracy of exercise stress testing for CAD on angiography. MEDLINE (January 1966 to November 2009), MEDION (1966 to July 2009), CENTRAL (1966 to July 2009) and EMBASE (1980-2009) databases were searched for English language articles on diagnostic accuracy of exercise stress testing. We included prospective studies comparing exercise stress testing with a reference standard of coronary angiography in patients without known CAD. From 6,055 records, we included 34 studies with 3,352 participants. Overall, we found published studies regarding five different exercise testing modalities: treadmill ECG, treadmill echo, bicycle ECG, bicycle echo and myocardial perfusion imaging. The prevalence of CAD ranged from 12% to 83%. Positive and negative likelihood ratios of stress testing increased in low prevalence settings. Treadmill echo testing (LR+ = 7.94) performed better than treadmill ECG testing (LR+ = 3.57) for ruling in CAD and ruling out CAD (echo LR- = 0.19 vs. ECG LR- = 0.38). Bicycle echo testing (LR+ = 11.34) performed better than treadmill echo testing (LR+ = 7.94), which outperformed both treadmill ECG and bicycle ECG. A positive exercise test is more helpful in younger patients (LR+ = 4.74) than in older patients (LR+ = 2.8).

CONCLUSIONS

The diagnostic accuracy of exercise testing varies, depending upon the age, gender and clinical characteristics of the patient, prevalence of CAD and modality of test used. Exercise testing, whether by echocardiography or ECG, is more useful at excluding CAD than confirming it. Clinicians have concentrated on individualising the treatment of CAD, but there is great scope for individualising the diagnosis of CAD using exercise testing.

Atropine as an adjunct to supine bicycle stress echocardiography: an alternative strategy to achieve target heart rate or rate pressure product

AIMS

To investigate the use of atropine to achieve target heart rate (THR) and rate pressure product (RPP) during supine bicycle exercise stress echocardiography (SBESE) to increase the number of diagnostic stress tests.

METHODS AND RESULTS

Forty-four patients that were unable to achieve THR or RPP during SBESE performed to evaluate ischaemia were given 0.4-1.2 mg of atropine to augment THR and RPP. After atropine (0.7 ± 0.3 mg) the maximum heart rate (HR) achieved was 133 (± 16) bpm, mean THR was 82% (± 8%), and average RPP was 22 716 (± 4915) b/min × mmHg. Of the patients with a non-diagnostic SBESE, with the use of atropine 80% of those patients achieved a diagnostic test. There were no major adverse affects from the administration of atropine.

CONCLUSION

The use of atropine to augment the HR or RPP during SBESE (i) is safe; (ii) enables the assessment of ischaemia at peak effort; and (iii) allows assessment of exercise haemodynamics in patients with sub-maximal exercise capacity and chronotropic incompetence.

Detection of prolonged regional myocardial systolic dysfunction after exercise-induced myocardial ischemia by strain echocardiography with high frame rate tissue Doppler echocardiography

BACKGROUND

Strain echocardiography has enabled quantification of regional myocardial systolic function objectively and is less influenced by tethering effects and cardiac translational artifact than Doppler tissue imaging. Although strain echocardiography has been applied for the detection of inducible ischemia during dobutamine stress, it has not been fully applied to exercise stress echocardiography (ESE) because of technical difficulties. Prolonged myocardial systolic dysfunction after exercise-induced ischemia has been shown previously. Thus, we designed this study to evaluate whether the myocardial strain analysis can detect myocardial ischemia by the assessment of prolonged regional left ventricular (LV) dysfunction in ESE.

METHODS

We performed ESE with myocardial strain imaging system in 20 consecutive patients who had exercise Tl-201 single photon emission computed tomography (SPECT). Myocardial strain curves were obtained at six segments in mid LV walls from the apical approach before and 5 min after ESE. We measured the duration from the R wave in the electrocardiogram to the timing of peak systolic strain corrected by the square root of the RR interval (TPSc). We finally calculated the differences of TPSc (ΔTPSc) before ESE and 5 min after ESE. The results were compared with SPECT as a reference standard.

RESULTS

A receiver operating characteristic curve demonstrated that a ΔTPSc cutoff value of 70 ms had a sensitivity of 80% and a specificity of 84% for the detection of myocardial ischemia.

CONCLUSIONS

Prolonged regional LV systolic dysfunction assessed by ESE with strain analysis was useful for the detection of myocardial ischemia.

Favorable short-term outcome of transplanted hearts selected from marginal donors by pharmacological stress echocardiography

BACKGROUND

Because of the shortage of donor hearts, the criteria for acceptance have been considerably expanded. Abnormal results on pharmacologic stress echocardiography are associated with significant coronary artery disease and/or occult cardiomyopathy on verification by cardiac autopsy. The aim of this study was to establish the feasibility of an approach based on pharmacologic stress echocardiography as a gatekeeper for extended heart donor criteria.

METHODS

From April 2005 to April 2010, 39 "marginal" candidate donors (mean age, 56 ± 6 years; 21 men) were initially enrolled. After legal declaration of brain death, marginal donors underwent rest echocardiography, and if the results were normal, dipyridamole (0.84 mg/kg over 6 min, n = 25) or dobutamine (up to 40 μg/kg/min, n = 3) stress echocardiography.

RESULTS

A total of 19 eligible hearts were found with normal findings. Of these, three were not transplanted because of the lack of a matching recipient, and verification by cardiac autopsy showed absence of significant coronary artery disease or cardiomyopathy abnormalities. The remaining 16 eligible hearts were uneventfully transplanted in marginal emergency recipients. All showed normal (n = 14) or nearly normal (minor single-vessel disease in two) angiographic, intravascular ultrasound, hemodynamic and ventriculographic findings at 1 month. At follow-up (median, 14 months; interquartile range, 4-31 months), 14 patients survived and two had died, one at 2 months from general sepsis and one at 32 months from allograft vasculopathy in recurrent multiple myeloma.

CONCLUSIONS

Pharmacologic stress echocardiography can safely be performed in candidate heart donors with brain death and shows potential for extending donor criteria in heart transplantation.

Impaired left ventricular stroke volume reserve during clinical dobutamine stress predicts future episodes of pulmonary edema

OBJECTIVES

The purpose of this study was to determine whether dobutamine-induced abnormal stress changes in left ventricular stroke volume (LVSV) and aortic stiffness predict future pulmonary edema.

BACKGROUND

Increased aortic stiffness that decreases LVSV during adrenergic stress may serve as a marker for future pulmonary edema (PE).

METHODS

We measured LVSV, ventriculovascular stiffness (pulse pressure/LVSV(index)), and aortic distensibility at rest and during intravenous dobutamine administration using cardiovascular magnetic resonance. Personnel blinded to dobutamine cardiovascular magnetic resonance followed participants longitudinally over time to identify those admitted to the hospital with PE. Data for 44 participants who had a hospital admission for PE were compared with data for 72 participants of similar age, sex, and resting left ventricular ejection fraction who remained PE free.

RESULTS

Expressed as median and interquartile range, participants with and without PE exhibited a decreased stress/rest LVSV ratio (0.9 [range 0.7 to 1.1] vs. 1.0 [range 0.9 to 1.2], respectively; p = 0.002), an increased ventriculovascular stiffness stress/rest ratio (1.4 [range 1.0 to 1.6] vs. 1.0 [range 0.8 to 1.3], respectively; p ≤ 0.001); and a decreased stress-induced measure of aortic distensibility (0.8 mm Hg(-3) [range 0.3 to 1.3 mm Hg(-3)] vs. 1.6 mm Hg(-3) [range 1.2 to 3.2 mm Hg(-3)], respectively; p = 0.002). After accounting for age, sex, left ventricular ejection fraction, risk factors for PE, and the presence of dobutamine-induced ischemia, LVSV reserve and the stress/rest ventriculovascular stiffness ratio still differed (p < 0.008 for both) in those with and without PE.

CONCLUSIONS

In patients without inducible ischemia during dobutamine stress testing in whom one might otherwise assume a favorable prognosis, the failure to increase LVSV or an increase in ventriculovascular stiffness indicates patients at risk of subsequent PE.

Value of exercise echocardiography for predicting mortality in elderly patients

BACKGROUND

Elderly patients with suspected or known coronary artery disease are often referred for pharmacological stress testing. Data on the value of exercise echocardiography (ExEcho) for predicting outcome (particularly all-cause mortality) in these patients are scarce.

METHODS

Peak treadmill ExEcho was performed in 2159 patients ≥ 70 years of age with known or suspected coronary artery disease. Left ventricular wall motion was evaluated at baseline and with exercise, and the increase in wall motion score index from rest to peak exercise (ΔWMSI) was calculated. Ischaemia was diagnosed when new or worsening wall motion abnormalities developed with exercise. The end points were all-cause mortality and major cardiac events (cardiac death or myocardial infarction).

RESULTS

Ischaemia developed in 844 patients (38·6%) during exercise. Over a mean follow-up of 3·5 ± 3·1 years, 439 deaths occurred. The cumulative 5-year mortality rate was 29·3% in patients with ischaemia versus 16·8% in those without ischaemia (P < 0·001). After covariate adjustment, ΔWMSI remained an independent predictor of mortality [hazard ratio (HR) 2·37, 95% confidence interval (CI) 1·66-3·39, P < 0·001] and major cardiac events (HR 3·48, 95% CI 2·11-5·74, P < 0·001). These results remained significant even in patients with chronotropic incompetence. When added to a model with clinical, resting echocardiographic and exercise electrocardiogram variables, ExEcho results provided incremental value for the prediction of both end points (P < 0·001).

CONCLUSIONS

ExEcho is feasible in elderly patients with suspected or known coronary artery disease and provides useful information for risk stratification in these patients.

Resource utilization after introduction of a standardized clinical assessment and management plan

INTRODUCTION

A Standardized Clinical Assessment and Management Plan (SCAMP) is a novel quality improvement initiative that standardizes the assessment and management of all patients who carry a predefined diagnosis. Based on periodic review of systemically collected data the SCAMP is designed to be modified to improve its own algorithm. One of the objectives of a SCAMP is to identify and reduce resource utilization and patient care costs.

METHODS

We retrospectively reviewed resource utilization in the first 93 arterial switch operation (ASO) SCAMP patients and 186 age-matched control ASO patients. We compared diagnostic and laboratory testing obtained at the initial SCAMP clinic visit and control patient visits. To evaluate the effect of the SCAMP over time, the number of clinic visits per patient year and echocardiograms per patient year in historical control ASO patients were compared to the projected rates for ASO SCAMP participants.

RESULTS

Cardiac magnetic resonance imaging (MRI), stress echocardiogram, and lipid profile utilization were higher in the initial SCAMP clinic visit group than in age-matched control patients. Total echocardiogram and lung scan usage were similar. Chest X-ray and exercise stress testing were obtained less in SCAMP patients. ASO SCAMP patients are projected to have 0.5 clinic visits and 0.5 echocardiograms per year. Historical control patients had more clinic visits (1.2 vs. 0.5 visits/patient year, P<.01) and a higher echocardiogram rate (0.92 vs. 0.5 echocardiograms/patient year, P<.01)

CONCLUSION

Implementation of a SCAMP may initially lead to increased resource utilization, but over time resource utilization is projected to decrease.

Exercise echocardiography

Exercise echocardiography has been used for 30 years. It is now considered a consolidated technique for the diagnosis and risk stratification of patients with known or suspected coronary artery disease (CAD). Of the stress echocardiography techniques, it represents the first choice for patients who are able to exercise. Given that the cost-effectiveness and safety of stress echocardiography are higher than those of other imaging techniques, its use is likely to be expanded further. Recent research has also proposed this technique for the evaluation of cardiac pathology beyond CAD. Although the role of new technology is promising, the assessment of cardiac function relies on good quality black and white harmonic images.

Right ventricular pressure dynamics and stress echocardiography in pharmacological and exercise stress testing

REASONS FOR PERFORMING STUDY

There is interest in using pharmacological stress testing (PST) as a substitute for exercise stress testing (EST) to evaluate cardiac function in horses.

OBJECTIVES

To compare the effect of PST and EST on right ventricular pressure dynamics and stress echocardiography.

METHODS

Five horses completed a PST and EST in a randomised crossover design. High fidelity pressure transducers were placed in the right ventricle. Continuous pressure signals were digitally collected and stored, and dP/dtmax, dP/dtmin and tau calculated from these measurements. ECGs were recorded continuously for 20 h. Echocardiography was performed prior to EST and PST, during and after PST, and immediately post EST. Plasma cardiac troponin I concentrations were measured pre- and 3-4 h post stress testing. For PST, 5 microg/kg bwt glycopyrrolate i.v. followed after 10 min by 5 microg/kg bwt/min dobutamine infusion over 10 min was given. EST consisted of a 2 min gallop at 110% speed required to elicit VO2max.

RESULTS

Both EST and PST resulted in a significant increase in right-ventricular dP/dtmax and dP/dtmin over baseline (P<0.05) and a significant decrease in tau compared with baseline (P<0.05). EST dP/dtmax and dP/dtmin were significantly greater than PST dP/dtmax and dP/dtmin (P<0.05) and EST tau was significantly less than PST tau (P<0.05). Two minutes post EST and 5 min post PST dP/dtmax were not significantly different, but were significantly less than end-EST and during PST. Tau was also not significantly different between post EST and post PST, but was significantly decreased end-EST compared with during PST. FS were not significantly different between PST and post EST, but during PST and post EST all FS were significantly higher than baseline. Cardiac troponin I concentrations were significantly elevated post PST and were greater than post EST. The clinical relevance of this is unknown.

CONCLUSIONS

PST had a similar, although less marked effect on the cardiac parameters related to right-ventricular pressure dynamics and a similar effect on echocardiography as exercise stress testing.

POTENTIAL RELEVANCE

PST deserves further evaluation in normal horses and those with cardiac disease, and may be complementary to EST to better identify exercise-induced cardiac dysfunction.

Feasibility of real-time three-dimensional stress echocardiography: pharmacological and semi-supine exercise

Background

Real time three dimensional (RT3D) echocardiography is an accurate and reproducible method for assessing left ventricular shape and function.

Aim

assess the feasibility and reproducibility of RT3D stress echocardiography (SE) (exercise and pharmacological) in the evaluation of left ventricular function compared to 2D.

Methods and results

One hundred eleven patients with known or suspected coronary artery disease underwent 2D and RT3DSE. The agreement in WMSI, EDV, ESV measurements was made off-line.

The feasibility of RT-3DSE was 67%. The inter-observer variability for WMSI by RT3D echo was higher during exercise and with suboptimal quality images (good: k = 0.88; bad: k = 0.69); and with high heart rate both for pharmacological (HR < 100 bpm, k = 0.83; HR ≥ 100 bpm, k = 0.49) and exercise SE (HR < 120 bpm, k = 0.88; HR ≥ 120 bpm, k = 0.78). The RT3D reproducibility was high for ESV volumes (0.3 ± 14 ml; CI 95%: -27 to 27 ml; p = n.s.).

Conclusions

RT3DSE is more vulnerable than 2D due to tachycardia, signal quality, patient decubitus and suboptimal resting image quality, making exercise RT3DSE less attractive than pharmacological stress.

Methodological Analysis of Diagnostic Dobutamine Stress Echocardiography Studies

BACKGROUND

Dobutamine stress echocardiography (DSE) is an accepted test for the diagnosis of coronary artery disease (CAD), despite its wide diagnostic accuracy.

AIM

Which factors cause test variability of DSE for the diagnosis of CAD.

METHODS

In a retrospective analysis of 46 studies in 5,353 patients, the potential causes of diagnostic variability were systematically analyzed, including patient selection, definition of CAD, chest pain characteristics, confounding factors for DSE (left ventricular hypertrophy, left bundle branch block, female gender), work-up bias (present when patient's chance to undergo coronary angiography is influenced by the result of DSE), review bias (present when DSE is interpreted in relation to CAG), DSE protocol and definition of a positive DSE.

RESULTS

Diagnostic variability was related to definition of a positive test, but not related to the definition of CAD or DSE protocol. However, only three of eight methodological standards for research design found general compliance. Differences in the selection of the study population (quality of echocardiographic window, angina pectoris), handling of confounding factors and analysis of disease in individual coronary arteries were observed. Lack of data on analysis of relevant chest pain syndromes and handling of nondiagnostic test results hampered further evaluation of these standards.

CONCLUSION

Methodological problems may explain the wide range in diagnostic variability of DSE. An improvement of clinical relevance of DSE testing is possible by stronger adherence to common and new methodological standards.

Factors affecting sensitivity and specificity of diagnostic testing: dobutamine stress echocardiography

BACKGROUND

Clinical characteristics of patients, angiographic referral bias, and several technical factors may all affect the reported diagnostic accuracy of tests. The aim of this study was to assess their influence on the diagnostic accuracy of dobutamine stress echocardiography (DSE).

METHODS

The medical literature from 1991 to 2006 was searched for diagnostic studies using DSE and meta-analysis was applied to the 62 studies thus retrieved, including 6881 patients. These studies were analyzed for patient characteristics, angiographic referral bias, and several technical factors.

RESULTS

The sensitivity of DSE was significantly related to the inclusion of patients with prior myocardial infarctions (0.834 vs 0.740, P < .01) and defining the results of DSE as already positive in case of resting wall motion abnormalities rather than obligatory myocardial ischemia (0.786 vs 0.864, P < .01). Specificity tended to be lower when patients with resting wall motion abnormalities were included in a study (0.812 vs 0.877, P < .10). The presence of referral bias adversely affected the specificity of DSE (0.771 vs 0.842, P < .01).

CONCLUSION

This analysis suggests that the reported sensitivity of DSE is likely higher and the specificity lower than expected in routine clinical practice because of the inappropriate inclusion of patients with prior myocardial infarctions, the definition of positive results on DSE, and the negative influence of referral bias. However, in the patient subset that will be sent to coronary angiography, the opposite results can be expected.

Observer bias in the interpretation of dobutamine stress echocardiography

BACKGROUND AND HYPOTHESIS

Blinded image analysis is typically utilized in published studies evaluating the accuracy of dobutamine stress echocardiography (DSE). However, in clinical settings, practical considerations may limit the use of blinded interpretations and thus the potential for observer bias arises. This study evaluated the relationships between clinical and blinded interpretations of DSE.

METHODS

Wall motion analysis from clinical and blinded DSE interpretations were compared and factors associated with their concordance were investigated in 115 consecutive patients with known or suspected coronary artery disease.

RESULTS

Clinical and blinded interpretations agreed on the presence or absence of inducible ischemia in 102 of 115 cases (88.7%: k = 0.76, p < 0.00001). In studies in which the clinical and blinded interpretations were in agreement, there was greater ST-segment depression (STD) in echocardiographically positive compared with negative studies (mean STD 0.73 +/- 0.65 vs. 0.42 +/- 0.67 mm; p = 0.008). In contrast, studies in which there was disagreement had significantly less ST-segment changes (mean STD 0.19 +/- 0.56 mm; p = 0.012) despite comparable results on blinded wall motion analysis. Multiple logistic regression for factors related to the results of clinical and blinded wall motion analysis disclosed that angina pectoris and ST-segment changes were related to clinical interpretations, whereas only angina pectoris was related to the findings on blinded analysis.

CONCLUSIONS

Clinical interpretations of echocardiographic images during DSE overall demonstrate good agreement with the results of blinded analysis. Ancillary testing data may influence the analysis of wall motion abnormalities, and thus the potential for observer bias exists unless these interpretations are performed blinded to other clinical data.

Clinical relevance of chest pain during dobutamine stress echocardiography in women

BACKGROUND

Dobutamine stress echocardiography (DSE) is commonly used for diagnosis and management of patients with known or suspected coronary artery disease. Chest pain occurring during DSE potentially provides additional diagnostic accuracy. Our experience suggests that chest pain occurs frequently in women undergoing DSE.

HYPOTHESIS

It was the purpose of this study to determine the frequency with which chest pain occurs in women undergoing DSE and the relation to inducible ischemia or coronary artery stenosis.

METHODS

To determine the prevalence and clinical significance or chest pain during DSE, we reviewed the records of 154 consecutive women undergoing DSE in our laboratory. Of these, 59 patients (37.5%) also underwent coronary angiography. The presence or absence of chest pain was correlated with ECG changes, left ventricular wall motion abnormalities during DSE, and coronary stenosis by angiography.

RESULTS

Forty-one women (26%) developed chest pain during DSE. Patients experiencing chest pain were older (58.5 +/- 9.3 vs. 54.9 +/- 12.6; p = 0.05), and had lower resting heart rates (71 +/- 12.2 vs. 77.9 +/- 14.9; p = 0.008), but received similar maximum doses of dobutamine and reached comparable peak heart rates (131.1 +/- 17.4 vs. 133.5 +/- 21.7; p = NS). Patients with chest pain more commonly exhibited ST-segment depression > or = 1 mm during dobutamine infusion (13/41, 32%, vs. 17/113, 15%; p = 0.02), but chest pain showed no statistically significant correlation with abnormal DSE or with coronary stenosis.

CONCLUSIONS

In women undergoing DSE, chest pain occurs in 26% and does not appear to be related to inducible myocardial ischemia. Electrocardiographic changes occur more frequently in patients who experience chest pain, but are also often unrelated to inducible myocardial ischemia.

Current status of stress echocardiography

Stress echocardiography is a widely applied technique for the evaluation of individuals with known or suspected coronary artery disease. The technique combines echocardiographic imaging with exercise testing or pharmacologic stress. Advances in digital image acquisition and harmonic imaging have substantially improved the quality of echocardiographic images, and have therefore increased general applicability of stress echocardiography.

Head to head comparison of transesophageal and transthoracic contrast-enhanced echocardiography during dobutamine administration for the detection of coronary artery disease

Dobutamine stress echocardiography (DSE) has been shown to be a very useful non-invasive technique for the detection of coronary artery disease. However, inadequate transthoracic images preclude the use of DSE in a significant proportion of patients. Transesophageal (TEE) or transthoracic contrast echocardiography (CE) can however overcome this limitation. The comparison between the two techniques has never been investigated during a stress test. Therefore, we designed a prospective study to compare DSE-CE and DSE-TEE for the detection of coronary artery disease in patients with poor echo image quality. We studied 42 patients scheduled for quantitative coronary angiography. Prospective DSE-CE and DSE-TEE with maximum one day interval were performed in a random order. Significant coronary artery disease was detected in 30 patients, nine with single vessel disease and 21 with multivessel disease. Sensitivity of DSE was higher with CE than with TEE (90% vs 87%, p=NS). There was no significant difference with respect to specificity in both groups (100% vs 92%, p=NS). The diagnostic accuracy was similar in both groups (93% vs 88%, NS). The kappa value for identical interpretation of a stress echocardiography study was nearly identical with both modalities 0.75 to 0.78. In poorly echogenic patients, DSE-CE is a valuable alternative for the detection of myocardial ischemia in comparison with DSE-TEE. Because DSE-CE is more comfortable than TEE, it should be used in patients with suboptimal transthoracic echocardiograms for the evaluation of coronary artery disease during DSE.

Stress echocardiography expert consensus statement: European Association of Echocardiography (EAE) (a registered branch of the ESC)

Stress echocardiography is the combination of 2D echocardiography with a physical, pharmacological or electrical stress. The diagnostic end point for the detection of myocardial ischemia is the induction of a transient worsening in regional function during stress. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician. Among different stresses of comparable diagnostic and prognostic accuracy, semisupine exercise is the most used, dobutamine the best test for viability, and dipyridamole the safest and simplest pharmacological stress and the most suitable for combined wall motion coronary flow reserve assessment. The additional clinical benefit of myocardial perfusion contrast echocardiography and myocardial velocity imaging has been inconsistent to date, whereas the potential of adding - coronary flow reserve evaluation of left anterior descending coronary artery by transthoracic Doppler echocardiography adds another potentially important dimension to stress echocardiography. New emerging fields of application taking advantage from the versatility of the technique are Doppler stress echo in valvular heart disease and in dilated cardiomyopathy. In spite of its dependence upon operator's training, stress echocardiography is today the best (most cost-effective and risk-effective) possible imaging choice to achieve the still elusive target of sustainable cardiac imaging in the field of noninvasive diagnosis of coronary artery disease.

The diagnostic accuracy of pharmacological stress echocardiography for the assessment of coronary artery disease: a meta-analysis

BACKGROUND

Recent American Heart Association/American College of Cardiology guidelines state that "dobutamine stress echo has substantially higher sensitivity than vasodilator stress echo for detection of coronary artery stenosis" while the European Society of Cardiology guidelines and the European Association of Echocardiography recommendations conclude that "the two tests have very similar applications". Who is right?

AIM

To evaluate the diagnostic accuracy of dobutamine versus dipyridamole stress echocardiography through an evidence-based approach.

METHODS

From PubMed search, we identified all papers with coronary angiographic verification and head-to-head comparison of dobutamine stress echo (40 mcg/kg/min +/- atropine) versus dipyridamole stress echo performed with state-of-the art protocols (either 0.84 mg/kg in 10' plus atropine, or 0.84 mg/kg in 6' without atropine). A total of 5 papers have been found. Pooled weight meta-analysis was performed.

RESULTS

the 5 analyzed papers recruited 435 patients, 299 with and 136 without angiographically assessed coronary artery disease (quantitatively assessed stenosis > 50%). Dipyridamole and dobutamine showed similar accuracy (87%, 95% confidence intervals, CI, 83-90, vs. 84%, CI, 80-88, p = 0.48), sensitivity (85%, CI 80-89, vs. 86%, CI 78-91, p = 0.81) and specificity (89%, CI 82-94 vs. 86%, CI 75-89, p = 0.15).

CONCLUSION

When state-of-the art protocols are considered, dipyridamole and dobutamine stress echo have similar accuracy, specificity and - most importantly - sensitivity for detection of CAD. European recommendations concluding that "dobutamine and vasodilators (at appropriately high doses) are equally potent ischemic stressors for inducing wall motion abnormalities in presence of a critical coronary artery stenosis" are evidence-based.