Standardized guidelines for the interpretation of dobutamine echocardiography reduce interinstitutional variance in interpretation

The diagnostic value of stress echocardiography with limited myocardial ischemia in high-risk patients

BACKGROUND

The diagnostic value of limited myocardial ischemia in DSE is not well known.

OBJECTIVES

We investigated whether myocardial ischemia during dobutamine stress echocardiography (DSE) in 1 apical segment of any of the ventricular walls of the left ventricle relates to the anatomical and functional stenosis of the suppling coronary artery.

METHODS

Our observational, prospective study enrolled 212 patients, symptomatic or asymptomatic, with newly diagnosed limited myocardial ischemia on DSE. Almost 25% of them had already known CAD, while the rest were divided into low-risk and high-risk groups, integrating 1-2 and ≥3 classical cardiovascular risk factors, respectively. After DSE, all patients underwent invasive coronary angiography (ICA) and were followed up for one year. In coronary arteries distributing ischemic area, the calculated stenosis ≥50% and FFR<0.8 were considered anatomically and functionally significant, respectively. In the latter cases, the patients underwent coronary revascularization.

RESULTS

Significant anatomical and functional stenosis of the supplying coronary artery was common among patients with already known CAD (62.5% and 44.5%, respectively) or those without CAD but a high-risk profile (60.2% and 25.6%, respectively). In logistic regression analysis, CAD revascularization was independently determined by an already known CAD, diabetes mellitus, and high-risk profile. During follow-up, 24 patients experienced ACS or new angina episodes, which were associated with diabetes and smoking in univariate analysis.

CONCLUSION

Limited myocardial ischemia may implicate significant anatomical and functional coronary stenosis among individuals with a history of CAD or those without known CAD but a high-risk profile. The prognostic value of our findings requires further investigation.

Additive prognostic and diagnostic value of diastolic exercise parameters in patients referred for exercise echocardiography

AIMS

Exercise echocardiography (ExE) may evaluate left ventricular (LV) systolic and diastolic function. We aimed to assess the value of diastolic parameters at exercise [early LV inflow velocity to early tissue Doppler annulus velocity (E/e')] in patients with normal or abnormal resting diastolic function (DF) referred for a clinically indicated ExE.

METHODS AND RESULTS

LV systolic and DF according to ASE/EACVI guidelines and mitral regurgitation (MR) were evaluated at rest in 772 patients (age 67 ± 12 years) with preserved LV ejection fraction (LVEF ≥ 50%). We assessed regional/global LV systolic function at peak exercise, while MR and E/e' where evaluated in the immediate post-exercise period. Abnormal ExE was defined as ischaemia or fixed wall motion abnormalities, and raised E/e' values as >15 at rest and at exercise (e' at the septal level). Patients were grouped as complaining or not of dyspnoea. Events were overall mortality, myocardial infarction, admission for unstable angina or cardiac failure, and coronary revascularization. DF was abnormal at rest in 221 patients (29%) and indeterminate in 77 (10%), with similar percentages in patients with and without dyspnoea. Exercise E/e' >15 was found in 37% of patients with abnormal DF, 21% with indeterminate DF, and 6% with normal DF (P < 0.001). Patients with abnormal ExE had more often abnormal resting DF (39% vs. 25%, P = 0.001) and exercise E/e' >15 (25% vs. 13%, P < 0.001) than those with normal ExE. During a median follow-up of 1.68 years, there were 132 events. Independent predictors included peak exercise LVEF [hazard ratio (HR) = 0.93, 95% confidence interval (CI) = 0.91-0.94, P < 0.001], and exercise E/e' (HR= 1.04, 95% CI = 1.01-1.07, P = 0.01). Neither resting E/e' values nor resting abnormal DF by ASE/EACVI guidelines, were independent predictors. Annualized event-rates were 43.2% in patients with (+) ExE plus (+) exercise E/e', 23.8% in those with (+) ExE and (-) exercise E/e', 7.9% in (-) ExE and (+) exercise E/e', and 3.6% with both variables normal.

CONCLUSIONS

The results of diastolic dysfunction at rest and at exercise were similar between patients with or without dyspnoea referred for ExE, but they were associated with abnormal ExE. Exercise E/e' reclassified 21% of patients with indeterminate DF and further predicted outcome on top of ExE results.

Comparison of two strategies in a chest pain unit: stress echocardiography and multidetector computed tomography

INTRODUCTION AND OBJECTIVES

This study aimed to compare stress echocardiography (SE) and multidetector computed tomography (MCT) in patients admitted to a chest pain unit to detect acute coronary syndrome (ACS).

METHODS

A total of 203 patients with ≥ 1 cardiovascular risk factor, no ischemic electrocardiogram changes and negative biomarkers were randomized to SE (n=103) or MTC (n=100). The primary endpoint was a combination of hard events (death and nonfatal myocardial infarction), revascularizations, and readmissions during follow-up. The secondary endpoint was the cost of the 2 strategies.

RESULTS

Invasive angiography was performed in 61 patients (34 [33%] in the SE group and in 27 [27%] in the MCT group, P=.15). A final diagnosis of ACS was made in 53 patients (88% vs 85%, P=.35). There were no significant differences between groups in the primary endpoint (42% vs 41%, P=.91), or in hard events (5% vs 7%, P=.42). There were no significant differences in overall cost, but costs were lower in patients with negative SE than in those with negative MCT (€557 vs €706, P <.02).

CONCLUSIONS

No significant differences were found in efficacy and safety for the stratification of patients with a low to moderate probability of ACS admitted to a chest pain unit. The cost of the 2 strategies was similar, but cost was significantly lower for SE on comparison of negative studies.

Global Longitudinal Strain at Rest as an Independent Predictor of Mortality in Liver Transplant Candidates: A Retrospective Clinical Study

Speckle tracking echocardiography enables the detection of subclinical left ventricular dysfunction at rest in many heart diseases and potentially in severe liver diseases. It could also possibly serve as a predictor for survival. In this study, 117 patients evaluated for liver transplantation in a single center between May 2010 and April 2016 with normal left ventricular ejection fraction were included according to clinical characteristics of their liver disease: (1) compensated (n = 29), (2) clinically significant portal hypertension (n = 49), and (3) decompensated (n = 39). Standard echocardiography and speckle tracking echocardiography were performed at rest and during dobutamine stress. Follow-up amounted to three years to evaluate survival and major cardiac events. Altogether 67% (78/117) of the patients were transplanted and 32% (31/96 patients) died during the three-year follow-up period. Global longitudinal strain (GLS) at rest was significantly increased (became more negative) with the severity of liver disease (p < 0.001), but reached comparable values in all groups during peak stress. Low (less negative) GLS values at rest (male: >−17/female: >−18%) could predict patient survival in a multivariate Cox regression analysis (p = 0.002). GLS proved valuable in identifying transplant candidates with latent systolic dysfunction.

Implications of Abnormal Exercise Electrocardiography With Normal Stress Echocardiography

IMPORTANCE

Patients with abnormal (positive) exercise electrocardiography, but normal stress echocardiography (+ECG/-Echo) are commonly encountered in clinical practice; however, the prognostic significance of this discordant result is unclear.

OBJECTIVE

To determine whether patients with +ECG/-Echo have a higher rate of adverse clinical events and a poorer prognosis than patients with negative exercise ECG and normal stress Echo imaging (-ECG/-Echo).

DESIGN, SETTING, AND PARTICIPANTS

Between January 1, 2000, and February 28, 2014, a total of 47 944 consecutive patients without known coronary artery disease who underwent exercise stress Echo at Duke University Medical Center were evaluated for inclusion in this observational cohort study. Data analysis was conducted from January 1, 2000, to December 31, 2016.

INTERVENTIONS/EXPOSURES

Patients were categorized as having -ECG/-Echo, +ECG/-Echo, or +Echo (-ECG/+Echo and +ECG/+Echo).

MAIN OUTCOMES AND MEASURES

The primary outcome was a composite end point of death, myocardial infarction, hospitalization for unstable angina, and coronary revascularization. Secondary outcomes included individual adverse events and downstream testing.

RESULTS

After excluding submaximal tests and nondiagnostic ECG or stress imaging results, 15 077 patients (mean [SD] age, 52 [13] years; 6228 [41.3%] men) were classified by stress test results. Of these, 12 893 patients (85.5%) had -ECG/-Echo, 1286 patients (8.5%) had +ECG/-Echo, and 898 patients (6.0%) had +Echo. Through a median follow-up of 7.3 (interquartile range, 4.4-10.0) years, the composite end point occurred in 794 patients with -ECG/-Echo (8.5%), 142 patients with +ECG/-Echo (14.6%), and 297 patients with +Echo (37.4%). Death occurred in 425 patients with -ECG/-Echo (4.8%), 50 patients with +ECG/-Echo (5.9%), and 70 patients with +Echo (11.2%). Myocardial infarction occurred in 195 patients with -ECG/-Echo (2.2%), 31 patients with +ECG/-Echo (3.6%), and 59 patients with +Echo (8.7%). The addition of stress ECG findings to clinical and exercise data yielded incremental prognostic value. Patients with -ECG/-Echo imaging results had the least downstream testing (2.3%), followed by +ECG/-Echo (12.8%), and +Echo (33.6%) (P < .001).

CONCLUSIONS AND RELEVANCE

The presence of +ECG results with normal stress Echo imaging may identify a population of patients who are at slightly increased risk for adverse cardiac events, which was not previously recognized. Further study is needed to determine whether these patients will benefit from intensification of medical management.

Effect of comprehensive initial training on the variability of left ventricular measures using fast-SENC cardiac magnetic resonance imaging

Cardiac magnetic resonance (CMR) is becoming the imaging modality of choice in multicenter studies where highly reproducible measurements are necessary. The purpose of this study was to assess the effect of comprehensive initial training on reproducibility of quantitative left ventricular (LV) parameters estimated using strain-encoded (SENC) imaging. Thirty participants (10 patients with heart failure (HF) and preserved LV ejection fraction (HFpEF), 10 patients with HF and reduced LV ejection fraction (HFrEF) and 10 healthy volunteers) were examined using fast-SENC imaging. Four observers with different experience in non-invasive cardiac imaging completed comprehensive initial training course and were invited to perform CMR data analysis. To assess agreement between observers, LV volumes, mass, ejection fraction (LVEF), global longitudinal strain (GLS) and global circumferential strain (GCS) were estimated using dedicated software (MyoStrain, USA). To test intraobserver agreement data analysis was repeated after 4 weeks. SENC imaging and analysis were fast and were completed in less than 5 minutes. LV end-diastolic volume index (LVEDVi), LVEF and strain were significantly lower in HFpEF patients than in healthy volunteers (p = 0.019 for LVEDVi; p = 0.023 for LVEF; p = 0.004 for GLS and p < 0.001 for GCS). All LV functional parameters were further reduced in HFrEF. Excellent interobserver agreement was found for all LV parameters independently of the level of experience. The reproducibility of LV mass was lower, especially at the intraobserver level (ICC 0.91; 95% CI 0.74–0.96). LV volumetric and functional parameters derived using fast-SENC imaging, are highly reproducible. The appropriate initial training is relevant and allows to achieve highest concordance in fast-SENC measurements.

Left ventricular mass estimation by real-time 3D echocardiography favourably competes with CMR in congenital left ventricular disease

Assessment of left ventricular mass (LVM) is important in the evaluation of patients with congenital heart disease (CHD) and cardiac magnetic resonance imaging (CMR) is the gold standard. Recent software allows LVM calculation by real-time 3-dimensional echocardiography (RT3DE). We investigated the impact of different software analysis tools on LVM determination by CMR or RT3DE in a cohort of patients with heterogeneous left ventricular (LV) disease. 37 subjects (17 patients, mean age 18.7 y; 20 controls, mean age 13.2 y) underwent CMR and RT3DE. CMR LVM and RT3DE calculations were done using two different LV-analysis software packages for each modality: CMR i) customized software “CMR HDZ”, CMR ii) “CMR ISP”; RT3DE i) “Toshiba”, RT3DE ii) “Tomtec”, 4D LV-Analysis Version 3.1 (built 3.1.0.258661). Intra- and interobserver variabilities were calculated. Only RT3DE-derived LVM showed significant software-dependent differences. RT3DE-derived LVM (both softwares) was significantly higher than CMR-derived LVM (both softwares). The two different methods and four evaluation software packages for LVM assessment were well correlated with each other. Intra- and interobserver variability of LVM as assessed by each single modality or software was low. Despite software dependency and overestimation of RT3DE-assessed LVM by 5 to 10%, RT3DE still competes with the gold standard, CMR, even in patients with various forms of LV disease. The use of optimized software, especially for RT3DE, should improve the accuracy of LVM assessment, overcoming LVM overestimation.

Quality control of regional wall motion analysis in stress Echo 2020

BACKGROUND

The trial "Stress Echo (SE) 2020" evaluates novel applications of SE beyond coronary artery disease. The aim of the study was control quality and harmonize reading criteria.

METHODS

One reader from 78 centers of the SE 2020 network asked for credentials to read a set of 20 SE video-clips selected by the core lab. All aspiring centers met the pre-requisite of high-volume and the years of experience in SE ranged from 5 to 31years (mean value 18years). The diagnostic gold standard was a reading by the core lab. The a priori determined pass threshold was 18/20 (≥90%).

RESULTS

Of the initial 78 who started, 57 completed the first attempt: individual readers' score on first attempt ranged from 07/20 to 20/20 (accuracy from 35% to 100%, mean 78.7±13%) and 44 readers passed it. There was a very poor correlation between years of experience and the reader's score on first attempt (r=-0.161, p=0.231). Of the 13 readers who failed the first attempt, 12 took it again after the web-based session and their accuracy improved (74% vs. 96%, p<0.001). The kappa inter-observer agreement before and after web-based training was 0.59 on first attempt and rose to 0.91 on the last attempt.

CONCLUSIONS

In SE reading, the volume of activity or years of experience is not synonymous with diagnostic quality. Qualitative analysis and operator-dependence can become a limiting weakness in clinical practice, in the absence of strict pathways of learning, credentialing and audit.

Long-term prognostic value of peak exercise echocardiogram in patients hospitalized with acute chest pain

INTRODUCTION

Peak exercise echocardiogram (EEcho) has shown reasonable sensitivity and specificity in detecting significant coronary artery disease (CAD). The objective was to evaluate the prognostic value of EEcho in patients hospitalized for acute chest pain (CP) and its additional prognostic information regarding exercise electrocardiogram test (EECG).

METHODS

Prospective observational study performed between May 2011 and September 2013, including 250 patients consecutively admitted for acute CP with normal cardiac biomarkers and nondiagnostic electrocardiogram. All patients were prospectively followed for 1 year, and major adverse cardiovascular events (MACE) were recorded: cardiac death, nonfatal myocardial infarction (MI), or angina with coronary revascularization.

RESULTS

EEcho was positive in 16%. Patients with positive EEcho had a higher incidence of hypertension and higher TIMI risk score, showing significant CAD in 66%. We observed contradictory results (EECG-EEcho) in 20%. Patients with positive EEcho and negative EECG had significant CAD in the 66%, and patients undergoing coronary angiography with negative EEcho and positive EECG did not show significant coronary artery disease. Only positive EEcho (P<.001, HR 0.169; 95% CI, 0.088-0.250) and atrial fibrillation (P<.025, HR 0.125; 95% CI, 0.016-0.233) were independently associated with MACE during follow-up. In patients with negative EEcho, the presence of MACE was 2%.

CONCLUSIONS

EEcho in patients hospitalized for acute chest pain presents good ability to diagnose acute coronary syndrome, while providing additional information when combined with an EECG in up to 20% of cases. Moreover, a negative EEcho in this cohort seems to provide prognostic information beyond the acute event to predict long-term MACE.

Left ventricular torsion and circumferential strain responses to exercise in patients with ischemic coronary artery disease

LV torsion during exercise in patients with coronary artery disease (CAD) is not well known. Circumferential strain (CS) and left ventricular (LV) torsion (Tor) have not been evaluated during ischemia in these patients. We aimed to assess the effect of ischemia during exercise echocardiography (ExE) on CS and Tor. We studied a group of 73 patients with true positive ExE results (Ischemic group: ischemia plus an abnormal coronary angiogram) and a matched control group of 66 patients with negative ExE and either normal coronary angiography or low post-test probability of CAD. Basal rotation (Rot) and apical rotation and basal and apical CS were studied by speckle tracking at rest and exercise. Apical CS and apical and basal Rot values were similar between groups at rest, except basal CS which was already worse in the ischemic group. At exercise, all rotational and CS parameters were impaired in the ischemic in comparison with the control group (basal CS: -18 ± 5 vs. -25 ± 7 %, p < 0.001; apical CS: -31 ± 11 vs. - 43 ± 9 %, p < 0.001; time to basal CS: 52 ± 6 vs. 48 ± 7 %, p = 0.001; time to apical CS: 55 ± 7 vs. 49 ± 6 %, p < 0.001; basal rotation: -0.7 ± 6.5° vs. -6.2 ± 8.5°, p < 0.001; LV twist 13.0 ± 10.4° vs.19.7 ± 11.5°, p < 0.001; LV-Tor 1.9 ± 1.6°/cm vs. 2.8 ± 1.7˚/cm, p = 0.001) with the exception of apical rotation which was similar (12.3 ± 7.4° vs. 13.4 ± 7.7°, p = NS). Basal and apical CS and basal rotation impair during exercise-induced ischemia. LV-Tor decreases with ischemia due to worsening of basal rotation, whereas apical rotation does not impair, suggesting the existence of an apical compensatory mechanism.

Outcome by Exercise Echocardiography in Patients with Low Pretest Probability of Coronary Artery Disease

BACKGROUND

Recommendations for testing in patients with low pretest probability of coronary artery disease differ in guidelines from no testing at all to different tests. The aim of this study was to assess the value of exercise echocardiography (ExE) to define outcome in this population.

METHODS

A retrospective analysis was conducted of 1,436 patients with low pretest probability of coronary artery disease (<15%) who underwent initial ExE. Overall mortality, major adverse cardiac events (MACEs), defined as cardiac death or nonfatal myocardial infarction, and revascularization during follow-up, were assessed. Ischemia (development of new wall motion abnormalities with exercise) and fixed wall motion abnormalities were measured.

RESULTS

The mean age was 50 ± 12 years. Resting wall motion abnormalities were seen in 13 patients (0.9%) and ischemia in 108 (7.5%). During follow-up, 38 patients died, 10 of cardiac death (annualized death rate, 0.39%); 20 patients had MACEs (annualized MACE rate, 0.21%); and 48 patients (29 with ischemia) underwent revascularization (annualized revascularization rate, 0.51%). The number and percentage of MACEs in the abnormal and normal ExE groups were similar (two [1.7%] vs 18 [1.4%], P = .70), as was the annualized MACE rate (0.31% vs 0.21%, P = .50). Peak left ventricular ejection fraction exhibited a nonsignificant trend for predicting MACEs (P = .11). The number of studies needed to detect an abnormal finding was 12.6 and to detect a patient with extensive ischemia was 26.1.

CONCLUSIONS

ExE offers limited prognostic information in patients with low pretest probability of coronary artery disease. The small number of abnormal findings on ExE and low event rates and the large number of studies needed to detect an abnormal finding limit further the value of imaging in this population.

The value of core lab stress echocardiography interpretations: observations from the ISCHEMIA Trial

BACKGROUND

Stress echocardiography (SE) is dependent on subjective interpretations. As a prelude to the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) Trial, potential sites were required to submit two SE, one with moderate or severe left ventricular (LV) myocardial ischemia and one with mild ischemia. We evaluated the concordance of site and core lab interpretations.

METHODS

Eighty-one SE were submitted from 41 international sites. Ischemia was classified by the number of new or worsening segmental LV wall motion abnormalities (WMA): none, mild (1 or 2) or moderate or severe (3 or more) by the sites and the core lab.

RESULTS

Core lab classified 6 SE as no ischemia, 35 mild and 40 moderate or greater. There was agreement between the site and core in 66 of 81 total cases (81%, weighted kappa coefficient [K] =0.635). Agreement was similar for SE type - 24 of 30 exercise (80%, K = 0.571) vs. 41 of 49 pharmacologic (84%, K = 0.685). The agreement between poor or fair image quality (27 of 36 cases, 75%, K = 0.492) was not as good as for the good or excellent image quality cases (39 of 45 cases, 87%, K = 0.755). Differences in concordance were noted for degree of ischemia with the majority of discordant interpretations (87%) occurring in patients with no or mild LV myocardial ischemia.

CONCLUSIONS

While site SE interpretations are largely concordant with core lab interpretations, this appears dependent on image quality and the extent of WMA. Thus core lab interpretations remain important in clinical trials where consistency of interpretation across a range of cases is critical.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01471522.

Exercise left ventricular ejection fraction predicts events in right bundle branch block

OBJECTIVE

Interpretation of the electrocardiogram (ECG) during exercise is not easy in patients with right bundle branch block (RBBB). Also, the value of exercise echocardiography (ExE) for predicting outcome in them has not been addressed. We sought to assess its prognostic value in patients with RBBB and known/suspected coronary disease.

DESIGN

Retrospective analysis of data on 703 patients with RBBB who were submitted to a clinically-indicated ExE. The end points were overall mortality and combined myocardial infarction and cardiovascular mortality.

RESULTS

During follow-up (4.1 ± 4.5 years) there were 130 deaths and 108 combined events. Independent predictors of combined events were history of coronary artery disease (hazard ratio [HR] = 2.37, 95% Confidence Interval [CI] = 1.24-4.52, p = 0.009) resting wall motion score index (HR = 2.14, 95% CI = 1.12-4.10, p = 0.02), metabolic equivalents (HR = 0.89, 95% CI = 0.93-0.97, p = 0.007), Δ in double product with exercise (HR = 0.96, 95% CI = 0.92-1.00, p = 0.036) and Δ in left ventricular ejection fraction (LVEF) with exercise (HR = 0.97, 95% CI = 0.94-0.99, p = 0.01). Neither positive clinical nor ECG exercise testing was predictive. Combined event rates were 3.3% in patients with ΔLVEF > 5%, 4.7% in those with ΔLVEF between 1-5% and 8.2% in those with no increase (Δ < 1%).

CONCLUSIONS

A decrease in LVEF during exercise is predictive of serious events in patients with RBBB.

Two-dimensional speckle tracking for the assessment of coronary artery disease during dobutamine stress echo: clinical tool or merely research method

BACKGROUND

Two-dimensional speckle tracking provides valuable information for regional wall motion abnormalities. The purpose of this study was to determine the diagnostic value of left ventricular longitudinal strain and torsion to diagnose coronary artery disease during dobutamine stress echocardiography.

METHODS

We studied 100 patients (mean age 60.8 ± 10.7 years, 72 male) with known or suspected coronary artery disease, excluding those with prior history of transmural infraction. All of them underwent dobutamine stress echo and coronary angiography within one month. Wall-motion score index, left ventricular global longitudinal strain and torsion were measured at rest and peak stress. Additionally, the respective differences between rest and stress were also calculated. Optimal cut-offs were derived from receiver operating characteristic curves for strain and torsion values.

RESULTS

Mean left ventricular ejection fraction was 55 ± 5.4 %. Coronary angiography revealed significant lesions in 67 patients. Values regarding sensitivity, and specificity for wall motion score index difference were 78 % and 88 % respectively (area under curve 0.84). Global longitudinal strain difference (median 0.5 %) illustrated 81 % sensitivity and 72 % specificity for disease detection (area under curve 0.80, cut-off value ≤0 %). The respective values for torsion difference (median 4.7°) were 81 % and 82 % (area under curve 0.76, cut-off value ≤6.5°). Combination of wall motion score index difference and torsion difference for disease detection showed 91 % sensitivity and 79 % specificity (area under curve 0.85).

CONCLUSIONS

The implementation of speckle tracking during dobutamine stress echo could serve as an adjunct method for coronary artery disease assessment, providing quantitative diagnostic information.

Prognostic value of exercise-induced left ventricular systolic dysfunction in hypertensive patients without coronary artery disease

INTRODUCTION AND OBJECTIVES

We sought to assess the prognostic value of exercise-induced left ventricular systolic dysfunction in hypertensive patients with normal resting echocardiography and absence of coronary artery disease.

METHODS

From our database of patients referred for treadmill exercise echocardiography, we identified 93 hypertensive patients with preserved resting left ventricular ejection fraction (≥ 50%), no evidence of structural heart disease, and absence of coronary artery disease on angiography. Overall, 39 patients developed exercise-induced left ventricular systolic dysfunction (defined as a decrease in left ventricular ejection fraction below 50% at peak exercise) and 54 exhibited a normal left ventricular ejection fraction response to exercise. The mean follow-up was 6.1 (3.7) years. End points were all-cause mortality, cardiac death, heart failure, and the composite event of cardiac death or heart failure.

RESULTS

Patients who developed exercise-induced left ventricular systolic dysfunction were at higher risk of death from any cause (hazard ratio=3.4; 95% confidence interval, 1.1-10.3), cardiac death (hazard ratio=5.6; 95%CI, 1.1-29.4), heart failure (hazard ratio=8.9; 95% confidence interval, 1.8-44.2), and the composite end point (hazard ratio=5.7; 95% confidence interval, 1.7-19.0). In the multivariate analysis, exercise-induced left ventricular systolic dysfunction remained an independent predictor of both heart failure (hazard ratio=6.9; 95% CI, 1.3-37.4) and the composite event of cardiac death or heart failure (hazard ratio=4.5; 95% confidence interval, 1.2-16.0).

CONCLUSIONS

In hypertensive patients with preserved resting left ventricular ejection fraction and absence of coronary artery disease, exercise-induced left ventricular systolic dysfunction is a strong predictor of cardiac events and may represent early hypertensive heart disease.

Left ventricular torsion during exercise in patients with and without ischemic response to exercise echocardiography

INTRODUCTION AND OBJECTIVES

Left ventricular torsion decreases during transmural myocardial ischemia, but the effect of exercise on left ventricular torsion has not been widely studied. We hypothesized that exercise-induced ischemia may impair left ventricular torsion. Therefore, our aim was to study the effects of exercise on left ventricular torsion in patients with an ischemic response to exercise echocardiography and in patients with a normal response.

METHODS

A retrospective analysis was performed in 172 patients with ejection fraction ≥ 50% who were referred for exercise-echocardiography and studied by speckle imaging at rest, peak and postexercise. Torsion was defined as apical rotation - basal rotation (in degrees) / left ventricular length (in centimeters). A total of 114 patients had a normal exercise echocardiography and 58 patients had an ischemic response to exercise echocardiography.

RESULTS

Patients with ischemic response to the test exhibited less basal rotation at peak exercise (+0.30° [2.39°] vs -0.65° [2.61°] in the normal group; P = .03), whereas peak apical rotation was similar (ischemic response to the test, 7.80° [3.51°]; normal response, 7.27° [3.28°]; P =.36). Torsion at peak exercise was also similar (1.07° [0.60°] in the ischemic response to the test group vs 1.16° [0.57°] in normal group; P =.37). A more impaired peak basal rotation was found in patients with anterior or anterior+posterior involvement (anterior ischemic response, +1.22° [2.45°]; anterior + posterior ischemic response, -0.20° [2.25°]; posterior ischemic response, -0.71° [1.96°]; normal response, -0.65° [2.60°]; P =.02).

CONCLUSIONS

Basal rotation at peak exercise is impaired in patients with an ischemic response to exercise echocardiography, particularly in those with anterior involvement. Apical rotation and torsion are similar to those in patients with normal exercise echocardiography.

Value of an exercise workload ≥10 metabolic equivalents for predicting inducible myocardial ischemia

BACKGROUND

We sought to identify extensive ischemia on exercise echocardiography (ExE) relative to workload in patients without known coronary artery disease and to investigate whether ExE is useful in predicting outcomes in those with high exercise capacity (≥10 metabolic equivalents [METs]) plus a maximal test (≥85% of their maximal age-predicted heart rate [MAPHR]).

METHODS AND RESULTS

The analysis was performed on 4269 patients who underwent ExE, of whom 3995 achieved ≥85% of their MAPHR. These patients were divided according to the reached workload (<7, 7-9, or ≥10 METs) and compared for ExE results. Outcomes in the group achieving ≥10 METs plus ≥85% of their MAPHR (n=2221) were specifically assessed. Ischemia was defined as new/worsening wall motion abnormalities with exercise. ExE results were different between groups because the METs were lower. Still, among patients achieving ≥10 METs plus ≥85% of their MAPHR, 9.3% had extensive ischemia and 6% multiterritory disease. During follow-up in this subgroup, 108 patients died and 42 had a major cardiac event. Annualized mortality and major cardiac event rates were 0.84% and 0.32% in patients without ischemia versus 2.26% and 0.84% in those with ischemia, respectively (P<0.001 and P=0.002, respectively). Ischemia was an independent predictor of mortality (hazard ratio, 1.88; 95% confidence interval, 1.23-2.89; P=0.004) and major cardiac event (hazard ratio, 2.39; 95% confidence interval, 1.22-4.71; P=0.01).

CONCLUSIONS

Patients without known coronary artery disease achieving ≥10 METs plus ≥85% of their MAPHR may still have ischemia. However, the low event rates even in those with ischemia limit the usefulness of imaging for assessing outcomes in this group.

The impact of confounders on the test performance of natriuretic peptides for cardiac dysfunction in subjects aged 80 and older

The hypothesis that natriuretic peptides could be used to identify 'pancardiac' damage has been proposed. However, multiple factors are known to influence circulating levels of natriuretic peptides, especially in the very old. Therefore, the impact of confounders on the association between natriuretic peptide levels and cardiac dysfunction was further explored in subjects aged 80 and older. A diagnostic cross-sectional study embedded within the BELFRAIL study (n=567) was performed. Baseline BNP and NT-proBNP levels were measured and echocardiograms were performed at the subject's home. Cardiac dysfunction was defined as systolic dysfunction, valvular heart disease or isolated severe diastolic dysfunction. Several functional and structural echocardiographic parameters were independently related to circulating levels of natriuretic peptides. Cystatin C, BMI, β blockers, diabetes, heart frequency, usCRP, age and sex were identified as confounders. The prevalence of cardiac dysfunction was 17.1% in the subjects without and 30.8% in the subjects with chronic atrial fibrillation (CAF) or pacemaker (PM). Only in subjects with CAF or PM the C statistic for cardiac dysfunction improved after correcting for confounders. The post-test probability for a negative test (PTP-) ranged from 3.7% to 12.2% and the PTP+ ranged from 21.9% to 62.2% in different strata of confounders. According to these data adjusting for identified confounders does not improve the diagnostic accuracy of the natriuretic peptides for cardiac dysfunction, except in subjects with CAF or PM. Stratifying for individual confounders showed that different cut-off values could be used to optimize the diagnostic characteristics of natriuretic peptides.

Improving stress echocardiography accuracy for detecting left circumflex artery stenosis: a new echocardiographic sign?

BACKGROUND

The accuracy and reproducibility of stress echocardiography (SE) for the detection of coronary artery lesions requires improvement, particularly in the left circumflex artery (LCx).

AIMS

To evaluate the feasibility and diagnostic value of a new sign: Rise of the Apical lateral wall and/or Horizontal displacement of the Apex toward the septum ("RA-HA") in apical echocardiographic views.

METHODS

Consecutive patients with normal left ventricular function at rest, positive SE and an indication for coronary angiography were included. SEs were analysed blindly by three independent cardiologists: two seniors (S1 and S2) and one junior (J).

RESULTS

Of 81 patients, 58 had an exercise SE and 23 had a dobutamine SE. Significant coronary stenosis was found in 59 of 77 patients who underwent coronary angiography (76.6%). Interobserver reproducibility for the presence of RA-HA was very good between S1 and S2 (κ = 0.86), and good between S1 and J (0.67) and S2 and J (0.70). The sensitivity, specificity and positive and negative predictive values of RA-HA for the detection of significant coronary artery stenosis were, respectively, 39-41%, 83-89%, 88-92% and 29-31% for S1/S2; and 29%, 83%, 85% and 26% for J. To predict LCx stenosis (single or multivessel): 67-70%, 89%, 80-81% and 80-82% for S1/S2, respectively, and 50%, 89%, 75% and 74% for J.

CONCLUSION

With a short learning curve, RA-HA is easily diagnosed with a very good interobserver reproducibility. It has high specificity and PPV for the detection of a coronary artery stenosis, particularly in the LCx artery, during exercise or dobutamine SE.

Impact of electrocardiographic interpretability on outcome in patients referred for stress testing

BACKGROUND

There is limited insight into the association of electrocardiographic interpretability with outcome in patients referred for stress testing.

METHODS

Exercise echocardiography was performed in 8226 patients with known or suspected coronary artery disease. Electrocardiograms were considered uninterpretable in the presence of left bundle-branch block (LBBB), left ventricular hypertrophy (LVH) with strain, repolarization abnormalities because of digitalis therapy, ventricular paced rhythm, preexcitation or ST depression ≥ 0.1 mV because of other causes. End points were all-cause mortality, cardiac death and hard cardiac events (i.e. cardiac death or nonfatal myocardial infarction).

RESULTS

A total of 2450 patients had uninterpretable electrocardiograms. During a follow-up period of 4.1 ± 3.5 years, there were 1011 deaths (of which 478 were cardiac deaths) and 1069 patients experienced a hard cardiac event. The 5-year rates of death, cardiac death and hard cardiac events were, respectively, 18.7%, 10.9% and 18.8% in patients with uninterpretable ECGs, compared with 9.5%, 4.1% and 10.9% in those with interpretable ECGs (P < 0.001). After covariate adjustment, lack of ECG interpretability remained an independent predictor of all-cause mortality (hazard ratio [HR] 1.25, 95% confidence interval [CI] 1.08-1.44, P = 0.002), cardiac death (HR 1.63, 95% CI 1.32-2.01, P < 0.001) and hard cardiac events (HR 1.28, 95% CI 1.11-1.47, P < 0.001). When the specific ECG abnormalities were included as covariates, LBBB, LVH and digitalis therapy remained predictors of cardiac death; LBBB and LVH were predictors of hard cardiac events, and LVH remained predictive of all-cause mortality.

CONCLUSION

Uninterpretable ECGs portend a worse prognosis in patients referred for stress testing.

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.

Prognostic value of exercise echocardiography in patients with left ventricular systolic dysfunction and known or suspected coronary artery disease

BACKGROUND

The prognostic value of exercise echocardiography (ExE) in patients with left ventricular systolic dysfunction (LVSD) has not been characterized. We sought to assess the value of ExE for predicting outcome in patients with LVSD and known/suspected coronary artery disease.

METHODS

This study is a retrospective analysis of a prospectively collected database of 1,107 patients who underwent treadmill ExE and had resting LVSD (left ventricular ejection fraction <50%). Ischemia was defined as an increase in wall motion score index from rest to exercise. The end points were all-cause mortality and major cardiac events (MACE).

RESULTS

Overall, 494 patients (44.6%) developed new or worsening wall motion abnormalities. During a mean follow-up of 4.1 +/- 3.4 years, 301 patients died and 166 had a MACE. In patients with mild LVSD, the 5-year mortality rate was 8.8% in those without ischemia and 21% in those with ischemia (P < .001). For patients with moderate LVSD without ischemia, the 5-year mortality rate was 18.3%, whereas it was 29.2% when ischemia was present (P = .009). In those with severe LVSD, the 5-year mortality rate was 23.9% without ischemia and 35.7% with ischemia (P = .03). In the multivariate analysis, increase in wall motion score index was an independent predictor of mortality (hazard ratio 2.25, 95% CI 1.26-2.06, P = .001) and MACE (hazard ratio 2.60, 98% CI 1.34-5.04, P = .005). The addition of the ExE results to clinical, resting echocardiography and exercise variables provided significant incremental prognostic information for predicting mortality (P = .001) and MACE (P = .005).

CONCLUSIONS

The ExE provides significant information for predicting outcome in patients with LVSD and known/suspected coronary artery disease.

Treadmill exercise echocardiography as a predictor of events in patients with left ventricular hypertrophy

BACKGROUND

Exercise echocardiography (EE) is recommended for patients with known/suspected coronary artery disease (CAD) and electrocardiogram (ECG) abnormalities. Left ventricular hypertrophy (LVH) is associated with worse outcome and patients with LVH have frequently resting ECG abnormalities. We sought to assess the value of EE for predicting outcome in patients with known/suspected CAD and LVH.

METHODS

Retrospective analysis over 1,058 patients, classified according to the presence (n = 557) or absence (n = 501) of LVH (LV mass > or =163 g for women, > or =225 g for men) who underwent EE. Wall motion score index (WMSI) was evaluated at rest and with exercise. Ischemia was defined as the development of new or worsening wall motion abnormalities (WMA) with exercise. The endpoints were all-cause mortality and major cardiac events (MACE). Overall, 352 patients (33%) developed new/worsening WMA.

RESULTS

During a follow-up of 4.6 +/- 4.0 years, 178 patients died and 129 had a MACE. The 5-year mortality and MACE rates were 6.4 and 7.1% in patients without ischemia vs. 15.3 and 13.6% in those with ischemia, respectively (P < 0.001). In the multivariable analysis, LV mass (hazard ratio (HR) 1.03, 95% confidence interval (CI) 1.02-1.04, P = 0.008) and DeltaWMSI (HR 1.94, 95% CI 1.12-3.35, P = 0.02) were independent predictors of mortality. DeltaWMSI was also an independent predictor of MACE in the overall population (P = 0.002) and in patients with LVH (P = 0.04).

CONCLUSION

LV mass independently predicts mortality, even when EE data are considered. EE provides significant information for predicting events in patients with LVH and known/suspected CAD.

Prognostic value of an exaggerated exercise blood pressure response in patients with diabetes mellitus and known or suspected coronary artery disease

The prognostic value of an exaggerated exercise systolic blood pressure response (EESBPR) remains controversial. Our aim was to assess whether an EESBPR is associated with the long-term outcome in patients with diabetes mellitus and known or suspected coronary artery disease (CAD). From an initial population of 22,262 patients with known or suspected CAD who underwent treadmill exercise electrocardiography or exercise echocardiography at our institution, 2,591 patients with a history of diabetes mellitus were selected for the present study. EESBPR was defined as systolic blood pressure >220 mm Hg during exercise. The end points were all-cause mortality and hard events (ie, death or myocardial infarction). A total of 236 patients (9.1%) developed an EESBPR during the tests. During a mean follow-up of 6.5 +/- 3.9 years, 484 patients died and 646 experienced hard events. The 10-year mortality rate was 16.6% in patients with an EESBPR compared to 30.9% in those without an EESBPR (p <0.001). The 10-year hard event rate was also lower in patients with an EESBPR (23.2% vs 38.9% in patients without an EESBPR; p <0.001). On multivariate analysis, an EESBPR remained independently associated with a lower risk of all-cause mortality (hazard ratio 0.53, 95% confidence interval 0.36 to 0.78, p = 0.001) and hard events (hazard ratio 0.57, 95% confidence interval 0.41 to 0.79; p <0.001). These results remained consistent in the subgroup of patients without a known history of CAD. In conclusion, an EESBPR was associated with improved survival and a lower rate of death or myocardial infarction in patients with diabetes mellitus and known or suspected CAD.

Prognostic value of exercise echocardiography in patients with atrial fibrillation

AIMS

Non-invasive imaging techniques for the detection of coronary artery disease (CAD) may have technical problems in patients with atrial fibrillation (AF). Although the prognostic value of exercise echocardiography (ExEcho) has been well established in several subgroups of patients, it has not yet been specifically evaluated in these patients.

METHODS AND RESULTS

From a population of 8095 patients with known or suspected CAD referred for ExEcho, 419 had AF at the time of the tests. Ischaemia was defined as the development of new or worsening wall motion abnormalities with exercise. Endpoints were hard cardiac events (i.e. cardiac death or non-fatal myocardial infarction). Mean age was 68.4 +/- 8.5 years, and 256 patients (61.1%) were men. Ischaemia was detected in 92 patients (22%). Over a mean follow-up of 3.10 +/- 2.98 years, 59 hard cardiac events occurred. The 5-year hard cardiac event rate was 37.3% in patients with ischaemia, when compared with 14.5% in patients without ischaemia (P < 0.001). In multivariate analysis, ischaemia on ExEcho remained an independent predictor of hard cardiac events (hazard ratio 1.99, 95% confidence interval 1.06-3.74, P = 0.03), and also provided incremental value over clinical, resting echocardiographic and treadmill exercise data for the prediction of hard cardiac events (P = 0.04).

CONCLUSION

ExEcho provides significant prognostic information for predicting hard cardiac events in patients with AF.

Prognostic value of peak and post-exercise treadmill exercise echocardiography in patients with known or suspected coronary artery disease

AIMS

Although peak may have higher sensitivity than post-treadmill exercise echocardiography (EE) for the detection of coronary artery disease (CAD), its prognostic value remains unknown. We sought to assess the relative values of peak and post-EE for predicting outcome in patients with known/suspected CAD.

METHODS AND RESULTS

We studied 2947 patients who underwent EE. Wall motion score index (WMSI) was evaluated at rest, peak, and post-exercise. Ischaemia was defined as the development of new or worsening wall motion abnormalities with exercise. Separate analyses for all-cause mortality and major cardiac events (MACE) were performed. Ischaemia developed in 544 patients (18.5%). Among them, ischaemia was detected only at peak exercise in 124 patients (23%), whereas 414 (76%) had ischaemia at peak plus post-exercise imaging and six patients (1%) had ischaemia only at post-exercise. During follow-up, 164 patients died. The 5-year mortality rate was 3.5% in patients without ischaemia, 15.3% in patients with peak ischaemia alone, and 14% in patients with post-exercise ischaemia (P < 0.001 normal vs. ischaemic groups). In the multivariate analysis, post-exercise WMSI was an independent predictor of MACE [hazard ratio (HR) 1.87, 95% confidence interval (CI) 1.09-2.19, P = 0.02]. Peak exercise WMSI was an independent predictor of MACE (HR 2.19, 95% CI 1.30-3.69, P = 0.003) and mortality (HR 1.58, 95% CI 1.07-2.35, P = 0.02). The addition of peak EE results to clinical, resting echocardiography, exercise variables, and post-EE provided incremental prognostic information for MACE (P = 0.04) and mortality (P = 0.04).

CONCLUSION

Peak treadmill EE provides significant incremental information over post-EE for predicting outcome in patients with known or suspected CAD.

Prediction of mortality and major cardiac events by exercise echocardiography in patients with normal exercise electrocardiographic testing

OBJECTIVES

We sought to assess the value of exercise echocardiography (EE) for predicting outcome in patients with known or suspected coronary artery disease and normal exercise electrocardiogram (ECG) testing.

BACKGROUND

The prognostic value of EE in patients with normal exercise ECG testing has not been characterized.

METHODS

We studied 4,004 consecutive patients (2,358 men, mean age [+/- SD] 59.6 +/- 12.5 years) with interpretable ECG who underwent treadmill EE and did not develop chest pain or ischemic ECG abnormalities during the tests. Wall motion score index (WMSI) was evaluated at rest and with exercise, and the difference (DeltaWMSI) was calculated. Ischemia was defined as the development of new or worsening wall motion abnormalities with exercise. End points were all-cause mortality and major cardiac events (MACE).

RESULTS

Overall, 669 patients (16.7%) developed ischemia with exercise. During a mean follow-up of 4.5 +/- 3.4 years, 313 patients died, and 183 patients had a MACE before any revascularization procedure. The 5-year mortality and MACE rates were 6.4% and 4.2% in patients without ischemia versus 12.1% and 10.1% in those with ischemia, respectively (p < 0.001). In the multivariate analysis, DeltaWMSI remained an independent predictor of mortality (hazard ratio [HR]: 2.73, 95% confidence interval [CI]: 1.40 to 5.32, p = 0.003) and MACE (HR: 3.59, 95% CI: 1.42 to 9.07, p = 0.007). The addition of the EE results to the clinical, resting echocardiographic and exercise hemodynamic data significantly increased the global chi-square of the models for the prediction of mortality (p = 0.005) and MACE (p = 0.009).

CONCLUSIONS

The use of EE provides significant prognostic information for predicting mortality and MACE in patients with interpretable ECG and normal exercise ECG testing.

Contrast biases the autocorrelation phase shift estimation in Doppler tissue imaging

Quantitative assessment of regional myocardial function at rest and during stress with Doppler tissue imaging (DTI) plays an important role in daily routine echocardiography. However, reliable visual analysis is largely dependent on image quality and adequate border delineation, which still remains a challenge in a significant number of patients. In this respect, an ultrasound contrast agent (UCA) is often used to improve visualization in patients with suboptimal image quality. The knowledge of how DTI measurements will be affected by UCA present in the tissue is therefore of significant importance for an accurate interpretation of local myocardial motion. The aim of this paper was to investigate how signal contribution from UCA and nonlinear wave propagation influence the performance of the autocorrelation phase shift estimator used for DTI applications. Our results are based on model experiments with a clinical 2-D grayscale scanner and computational simulations of the DTI velocity estimator for synthetically-derived pulses, simulated bubble echoes and experimentally-sampled RF data of transmitted pulses and backscattered contrast echoes. The results show that destruction of UCA present in the tissue will give rise to an apparent bidirectional velocity bias of individual velocity estimates, but that spatial averaging of individual velocity measurements within a region-of-interest will result in a negative bias (away from the transducer) of the estimated mean or mean peak velocity. The UCA destruction will also have a significant impact on the measured integrated mean velocity over time, i.e., displacement. To achieve improved visualization with UCA during DTI-examinations, we either recommend that it is performed at low acoustic powers, mechanical index <or=0.3, thereby minimizing the effects from bubble rupture, or that each Doppler pulse package is preceded by a destruction burst similar to "Flash imaging" to clear the target area of contrast microbubbles.

Recent advances in dobutamine stress echocardiography

Dobutamine stress echocardiography (DSE) is a reliable cardiac risk stratifier that has widespread applicability because of its clinical accuracy and cost effectiveness. Dobutamine has positive inotropic and chronotropic effects and is commonly used in patients who cannot exercise or achieve an adequate heart rate response with exercise. Recently available long-term results from several independent clinical trials, combined with enhancements in image quality, have improved the ability to detect significant coronary artery disease and determine myocardial viability. Dobutamine stress echocardiography has an excellent safety profile with clinical results superior to regular exercise electrocardiography and comparable with exercise echocardiography and radionucleotide perfusion stress imaging. Low-dose dobutamine response can accurately predict dysfunctional yet viable myocardial regions that may improve with revascularization. Clinical studies are now available refining the common use of DSE preoperatively in female patients with valvular disease, as well as in the emergency department. Dobutamine stress echocardiography does have some limitations in discriminating particular regions of ischemia when multiple ventricular segments are involved and when the imaging is suboptimal. It can be applied using minimal additional resources in an otherwise functioning echocardiography laboratory and, with appropriate training, can result in clinical results comparable with those of large-scale multicenter trials. Ongoing improvements in technology and the development of new reagents such as myocardial contrast agents hold promise for further advancement in the near future.

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.

Assessment of Diastolic Function During Exercise Echocardiography: Annulus Mitral Velocity or Transmitral Flow Pattern?

OBJECTIVES

We hypothesize that the change in the left ventricular (LV) diastolic pattern (DP) may be measured with high reproducibility and correlates with exercise echocardiography (EE) better than the ratio of early LV inflow velocity to early diastolic annulus velocity (E/e' index).

BACKGROUND

The E/e' index has been related to LV filling pressures but has not been compared with DP.

METHODS

We selected 179 consecutive patients who were referred for EE. Early (E) and late (A) LV inflow velocities by conventional pulsed Doppler, and septal annulus e' velocity by pulsed Doppler myocardial imaging were measured at rest (R) and post-exercise (PE).

RESULTS

Four LV-DPs were found: abnormal relaxation (AR) at R and PE (E < A) in 110 patients; AR at PE (E > A at R; E < A at PE) in 22 patients; restrictive pattern (RP) at R and PE (E > A) in 18 patients; and RP at PE (E < A at R; E > A at PE) in 29 patients. The more accurate PE cutoff E/e' values to predict abnormal EE, ischemic response, poor functional capacity (< 8 Mets in men; < 6 Mets in women), and lack of increase in left ventricular ejection fraction (LVEF) were 12, 12, 11, and 11 (areas under the curve were 0.53, 0.53, 0.63, and 0.57, respectively). Corresponding areas under the curve for an RP at R + PE or only at PE were 0.57, 0.55, 0.54, and 0.56 (P = not significant). The sensitivity of an RP at R + PE or only at PE was lower and the specificity was higher than those of the different E/e' cutoff values for predicting abnormal EE, functional capacity, ischemic response, and lack of increase in LVEF. Achieved Mets were lower in patients with an RP at R + PE or only at PE irrespectively of the E/e' values, whereas achieved Mets in patients with AR at R + PE or only at PE were lower if the E/e' was > or = 11 (8.2 +/- 2.9 vs. 9.8 +/- 3.1, P = .01). Interobserver and intraobserver concordance were 95% (kappa = 0.86) and 100% (kappa = 1.0) for an RP, and 86% (kappa = 0.73) and 92% (kappa = 0.78) for a PE-E/e' value of > or = 11.

CONCLUSIONS

E/e' does not allow further stratification in patients with exercise RP. We propose both measurement of E/e' and determination of the LV-DP (a quickly assessable variable) for the assessment of diastolic function during EE. However, when an RP persists or develops with exercise, further assessment may not be more informative.

Left ventricular opacification for the diagnosis of coronary artery disease with stress echocardiography: an angiographic study of incremental benefit and cost-effectiveness

BACKGROUND

Left ventricular opacification (LVO) improves image quality at stress echocardiography (SE). We examined whether routine use of LVO adds incremental benefit and is cost-effective for diagnosis of coronary artery disease (CAD).

METHODS

Contrast pharmacologic and/or exercise SE was performed in 135 patients (81 men; 56 +/- 10 years) undergoing coronary angiography. Observers sequentially interpreted first standard, then LVO images; a positive SE was defined by resting or inducible wall motion abnormality in > or = 2 segments. Coronary artery disease (75 patients, 119 territories) was defined as > 50% stenosis. Three cost-effectiveness models were studied, and a sensitivity analysis was performed.

RESULTS

Left ventricular opacification increased the sensitivity of SE (80%-91%; P = .03), including single-vessel CAD (65%-87%; P = .04), with no significant change in specificity (72%-77%; P = NS). Left ventricular opacification was of benefit to 14% of patients, unrelated to resting image quality. Use of LVO in all patients added 59% to the cost of the procedure (P < .001), at a cost of $1069 per additional correct diagnosis. In a cost-effectiveness model based on cardiac outcomes after SE, LVO resulted in an increase in total cost of $1069. A 3.7% improvement in sensitivity resulted in a negative cost to identify CAD, but even 15% to 20% improvements in specificity failed to balance the cost of contrast for exclusion of CAD.

CONCLUSIONS

Left ventricular opacification adds significant incremental diagnostic benefit to standard SE, especially single-vessel CAD. Despite improved sensitivity, the use of contrast in all patients was not cost-effective when analyzed with a model based on previously published patient outcomes.

Prognostic significance of exercise stress echocardiography in 3329 outpatients (5-year longitudinal study)

BACKGROUND

Appraisal of the risk to which outpatients with chest pain are exposed is a major clinical problem. Up to now, there have been no reports on the prognostic significance of exercise stress echocardiography in this patient cohort.

PATIENTS AND METHODS

In order to investigate the prognostic significance of exercise stress echocardiography (SE) in outpatients only, 3329 patients were monitored during a long-term follow-up regarding the occurrence of hard events (cardiac death, myocardial infarction, revascularization). The patients came to the cardiology practice complaining of chest pain.

RESULTS

The sensitivity/specificity of SE for hard events was 81.1/92.8 in the first year, that of exercise ECG, 27.4/87.0. During the observation period (5.1+/-1.1 years (median 5.2, 3-7 years)), a total of 446 (13.4%) hard events occurred. In patients with positive SE findings, 262 (61.9%) hard events occurred, in patients with negative SE findings, hard events were rarer (184, 6.3%, p<0.001). In the multivariate analysis, the positive SE finding was the most unambiguous, significant independent predictor of hard events (HR 6.6, CI 5.21-8.25, p<0.001).

CONCLUSIONS

In outpatients with chest pains, exercise stress echocardiography is of major prognostic significance (independent of other parameters) and its prognostic reliability is clearly superior to that of the exercise ECG. SE should always be performed in cases with symptoms requiring clarification.