BSE procedure guidelines for the clinical application of stress echocardiography, recommendations for performance and interpretation of stress echocardiography: a report of the British Society of Echocardiography Policy Committee

Silent Myocardial Ischemia Revisited, Another Silent Killer, Emphasis on the Diagnostic Value of Stress Echocardiography with Focused Update and Review

Silent myocardial ischemia (SMI) is a relatively common phenomenon in patients with coronary artery disease (CAD). The original description of SMI dates back to the 1970s. We performed an extensive search of the literature starting from 2000, using MEDLINE or PubMed, and 676 documents were analyzed, and only 45 articles found suitable for the study were selected. Data regarding the prevalence and risk factors of SMI were discussed, along with the different mechanistic processes behind it; also, methods for screening and diagnosis are exposed, namely electrocardiographic stress test, stress echocardiography, and single-photon emission computed tomography (SPECT). The silent nature of the condition presumes that patients are diagnosed at a more advanced stage, and screening high-risk patients for early management is essential. Education of patients is necessary, and medical management along with cardiac rehabilitation is valid for mild cases, whereas patients with moderate-to-severe myocardial ischemia might require a more invasive approach. SMI is relatively common, diagnostic approach offers data regarding the presence of ischemia along with its anatomic extent, providing important prognostic value. Given its silent and critical nature, future directions for better screening and management must be searched and implemented extensively.

The Utility of Low-Dose-Dobutamine Stress Echocardiography in Patients with Heart Failure with Reduced Ejection Fraction: An Update

Despite significant advancements in medical therapy, heart failure with reduced ejection fraction (HFrEF) continues to be a significant cause of death and disability. Reversible ischaemic left ventricular dysfunction due to viable myocardium is one such contributing factor. In these cases, coronary revascularization has shown promise in improving left ventricular function and prognosis. For patients with HFrEF and wide QRS, cardiac resynchronization therapy (CRT) is an effective option to address electromechanical dyssynchrony. However, approximately 30% of patients do not respond positively to CRT, highlighting the need to refine candidate selection for this treatment. In some patients with reduced HFrEF, there is a condition known as classical low-flow, low-gradient aortic stenosis (AS) that may be observed. This condition is characterized by a low transaortic flow, which leads to reductions in both the transaortic mean gradient and aortic valve area. Decision-making regarding revascularization, CRT, and pharmacological treatment play a crucial role in managing HFrEF. Cardiac imaging can be valuable in guiding decision-making processes and assessing the prognosis of patients with HFrEF. Among the imaging modalities, dobutamine stress echocardiography has come a long way in establishing itself as a feasible, safe, effective, relatively cheap non-invasive technique. The aim of this review is to explore the current literature on the utility of low-dose stress echocardiography in diagnosing and prognosticating patients with HFrEF.

The value of cardiopulmonary exercise testing and stress echocardiography in the prediction of all-cause mortality in adults with end-stage renal disease

We aimed to assess the prognostic utility of different parameters routinely assessed from cardiopulmonary exercise testing (CPET) and exercise echocardiography in adults with end-stage renal disease (ESRD). Forty-two ESRD (37 male) individuals (age: 58 ± 13 years, height: 169.30 ± 8.30 cm, weight: 81 ± 15 kg, body surface area: 1.92 ± 0.20 m²) underwent a maximal/symptom limited CPET, with a full cross-sectional echocardiogram performed at baseline and peak exercise. All participants were prospectively followed over a 10-year period, with all-cause mortality as the primary endpoint. After the follow-up period, a total of 19 participants (45%) died. Left atrial size (4.70 ± 0.70 vs. 3.65 ± 0.50 cm, P < 0.001) and anteroseptal wall thickness (1.28 ± 0.40 vs. 1.06 ± 0.02 cm, P = 0.002) were significantly greater in those that died, while peak heart rate was significantly lower (108 ± 12 vs. 128 ± 14 bpm, P < 0.001). The prevalence of myocardial ischaemia (13 vs. 8 participants, P = 0.03) was significantly greater, while peak VO₂ (9.80 ± 2.10 vs. 15.90 ± 4.30 ml·kg^-1·min^-1, P < 0.001) was significantly lower in those that died. Following multivariate cox regression, myocardial ischaemia (Hazard Ratio 3.08; 95% Confidence Interval 1.09-8.70; P = 0.03) and peak VO₂ (HR 0.73; 95% CI 0.64-0.84; P < 0.001) were significant independent predictors of 10-year all-cause mortality. This is the first study to establish peak VO₂ as powerful marker of all-cause mortality when assessed with clinical, resting and stress echocardiography parameters in people with ESRD over a 10-year follow up period. This observation indicates that, in clinical practice, CPET and exercise echocardiography may serve as valuable tools for the risk stratification of individuals with ESRD. HIGHLIGHTSWe aimed to assess the prognostic utility of cardiopulmonary exercise testing (CPET) and exercise echocardiography in end-stage renal disease (ESRD) with 10-year mortality.Peak aerobic capacity and the presence of ischaemic heart disease were independently associated with all-cause mortality.This observation indicates that, in clinical practice, CPET and exercise echocardiography may serve as valuable tools for the risk stratification of individuals with end-stage renal disease.

Training, competence, and quality improvement in echocardiography: the European Association of Cardiovascular Imaging Recommendations: update 2020

The primary mission of the European Association of Cardiovascular Imaging (EACVI) is ‘to promote excellence in clinical diagnosis, research, technical development, and education in cardiovascular imaging’. Echocardiography is a key component in the evaluation of patients with known or suspected cardiovascular disease and is essential for the high quality and effective practice of clinical cardiology. The EACVI aims to update the previously published recommendations for training, competence, and quality improvement in echocardiography since these activities are increasingly recognized by patients, physicians, and payers. The purpose of this document is to provide the general requirements for training and competence in echocardiography, to outline the principles of quality evaluation, and to recommend a set of measures for improvement, with the ultimate goal of raising the standards of echocardiographic practice. Moreover, the document aims to provide specific guidance for advanced echo techniques, which have dramatically evolved since the previous publication in 2009.

Stress Echocardiography: Concept and Criteria, Structure and Steps, Obstacles and Outcomes, Focused Update and Review

Stress echocardiography (SEC) is a technique established more than 35 years ago; however, it is still poorly implemented in many countries and institutions, and this reluctance may be related to many obstacles such as operator skills, lack of awareness or institutional policy. Stress echo was initially used for assessing coronary artery disease (CAD), with respect to myocardial viability, using wall motion response; however, current use of stress echo extends beyond CAD, such as valvular heart disease and diastolic stress test. Dobutamine is a commonly used agent when pharmaceutical approach is implemented. With regard to CAD, there are four stress responses: normal, ischemic, viable and necrotic. A low dose dobutamine protocol is recommended in patients with baseline wall motion abnormalities, and a very low dose dobutamine is used in low flow low gradient aortic stenosis in order to check the flow and contractility reserve. Of note, respecting protocols, indications and contraindications are important to avoid or minimize risks of complications during the procedure. This article presents a focused update and review regarding SEC, along with an overview of the different indications, structures and steps, and obstacles and outcomes; also the article aims to highlight more awareness and sensitization on this useful technique.

Comparison of Heart Rate Blood Pressure Product Versus Age-Predicted Maximum Heart Rate as Predictors of Cardiovascular Events During Exercise Stress Echocardiography

Exercise stress echocardiograms (ESEs) are a functional cardiovascular (CV) test typically used for the investigation of coronary artery disease. ESEs are often terminated at a predetermined age-predicted maximum heart rate (APMHR) to facilitate timely acquisition of ultrasound images at peak exercise. Although an APMHR of 85% is often used, this has not been validated as a suitable termination end point. Heart rate blood pressure product (HRBPP) as an established measure of myocardial work may provide a more reliable assessment of cardiac workload. The aim of this study was to assess maximal HRBPP (MHRBPP) and APMHR as markers of cardiac workload during ESE, using CV events at mean follow-up as the outcome variable. After exclusions, 712 patients being investigated for ischemic heart disease, performed an ESE to volitional fatigue using the standard Bruce protocol. Patient demographics and test data were collected and patients followed for 4.4 ± 2.1 years. Cut-points for MHRBPP (25,060; area under curve 0.77) and APMHR (93.8% and 97.9%; area under curve 0.71; p = 0.12 for difference) were established from receiver operating characteristic analysis. Those achieving an APMHR >85% but MHRBPP <25,060 had significantly more CV events than achieving an MHRBPP >25,060 regardless of APMHR (p <0.05). In conclusion, the current study demonstrates the superior prognostic power of MHRBPP over APMHR alone for the prediction of future CV events in patients performing an otherwise negative ESE for the detection of myocardial ischemia.

Does stress echocardiography still have a role in the rapid access chest pain clinic post NICE CG95?

Introduction

The 2016 NICE clinical guideline 95 (CG95) demoted functional imaging to a second-line test following computed tomography coronary angiography (CTCA). Many cardiac CT services in the UK require substantial investment and growth to implement this. Chest pain services like ours are likely to continue to use stress testing for the foreseeable future. We share service evaluation data from our department to show that a negative stress echocardiogram can continue to be used for chest pain assessment.

Methods

1815 patients were referred to rapid access chest pain clinic (RACPC) between June 2013 and March 2015. 802 patients had stress echocardiography as the initial investigation. 446 patients had normal resting left ventricular (LV) systolic function and a negative stress echocardiogram. At least 24 months after discharge, a survey was carried out to detect major adverse cardiovascular events (MACE) (cardiac death, myocardial infarction, admission to hospital for heart failure or angina, coronary artery disease at angiography, revascularisation by angioplasty or coronary artery bypass grafting) within 2 years.

Results

Overall, 351 patients were successfully followed up. The mean Diamond-Forrester (D-F) score and QRISK2 suggested a high pre-test probability (PTP) of coronary artery disease (CAD). There were nine deaths (eight non-cardiac deaths and one cardiac death). MACE occurred in four patients with a mean time of 17.5 months (11.6–23.7 months). The annual event rate was 0.6%.

Conclusion

A negative stress echocardiogram can reliably reassure patients and clinicians even in high PTP populations with suspected stable angina. It can continue to be used to assess stable chest pain post CG95.

Localized rest and stress human cardiac creatine kinase reaction kinetics at 3 T

Changes in the kinetics of the creatine kinase (CK) shuttle are sensitive markers of cardiac energetics but are typically measured at rest and in the prone position. This study aims to measure CK kinetics during pharmacological stress at 3 T, with measurement in the supine position. A shorter "stressed saturation transfer" (StreST) extension to the triple repetition time saturation transfer (TRiST) method is proposed. We assess scanning in a supine position and validate the MR measurement against biopsy assay of CK activity. We report normal ranges of stress CK forward rate (kfCK ) for healthy volunteers and obese patients. TRiST measures kfCK in 40 min at 3 T. StreST extends the previously developed TRiST to also make a further kfCK measurement during <20 min of dobutamine stress. We test our TRiST implementation in skeletal muscle and myocardium in both prone and supine positions. We evaluate StreST in the myocardium of six healthy volunteers and 34 obese subjects. We validated MR-measured kfCK against biopsy assays of CK activity. TRiST kfCK values matched literature values in skeletal muscle (kfCK  = 0.25 ± 0.03 s-1 vs 0.27 ± 0.03 s-1 ) and myocardium when measured in the prone position (0.32 ± 0.15 s-1 ), but a significant difference was found for TRiST kfCK measured supine (0.24 ± 0.12 s-1 ). This difference was because of different respiratory- and cardiac-motion-induced B0 changes in the two positions. Using supine TRiST, cardiac kfCK values for normal-weight subjects were 0.15 ± 0.09 s-1 at rest and 0.17 ± 0.15 s-1 during stress. For obese subjects, kfCK was 0.16 ± 0.07 s-1 at rest and 0.17 ± 0.10 s-1 during stress. Rest myocardial kfCK and CK activity from LV biopsies of the same subjects correlated (R = 0.43, p = 0.03). We present an independent implementation of TRiST on the Siemens platform using a commercially available coil. Our extended StreST protocol enables cardiac kfCK to be measured during dobutamine-induced stress in the supine position.

Reproducibility of human cardiac phosphorus MRS (31 P-MRS) at 7 T

PURPOSE

We test the reproducibility of human cardiac phosphorus MRS (³¹ P-MRS) at ultra-high field strength (7 T) for the first time. The primary motivation of this work was to assess the reproducibility of a 'rapid' 6½ min ³¹ P three-dimensional chemical shift imaging (3D-CSI) sequence, which if sufficiently reproducible would allow the study of stress-response processes. We compare this with an established 28 min protocol, designed to record high-quality spectra in a clinically feasible scan time. Finally, we use this opportunity to compare the effect of per-subject B₀ shimming on data quality and reproducibility in the 6½ min protocol.

METHODS

10 healthy subjects were scanned on two occasions: one to test the 28 min 3D-CSI protocol, and one to test the 6½ min protocol. Spectra were fitted using the OXSA MATLAB toolbox. The phosphocreatine to adenosine triphosphate concentration ratio (PCr/ATP) from each scan was analysed for intra- and intersubject variability. The impact of different strategies for voxel selection was assessed.

RESULTS

There were no significant differences between repeated measurements in the same subject. For the 28 min protocol, PCr/ATP in the midseptal voxel across all scans was 1.91 ± 0.36 (mean ± intersubject SD). For the 6½ min protocol, PCr/ATP in the midseptal voxel was 1.76 ± 0.40. The coefficients of reproducibility (CRs) were 0.49 (28 min) and 0.67 (6½ min). Per-subject B₀ shimming improved the fitted PCr/ATP precision (for 6½ min scans), but had negligible effect on the CR (0.67 versus 0.66).

CONCLUSIONS

Both 7 T protocols show improved reproducibility compared with a previous 3 T study by Tyler et al. Our results will enable informed power calculations and protocol selection for future clinical research studies.

Comparison of Contrast Enhanced Low-Dose Dobutamine Stress Echocardiography with 99mTc-Sestamibi Single-Photon Emission Computed Tomography in Assessment of Myocardial Viability

INTRODUCTION

Dobutamine stress echocardiography (DSE) and myocardial perfusion scan are the commonly used modalities to detect viable myocardium. DSE is comparatively cheaper and widely available but has a lower sensitivity.

AIM

We aimed to compare contrast-enhanced low-dose dobutamine echocardiography (LDDE) and gated 99mTc-sestamibi myocardial perfusion scan (MPS) for the degree of agreement in the detection of myocardial viability.

METHODS

We studied 850 left ventricular segments from 50 patients (42 men, mean age 55.5 years), with coronary artery disease and left ventricular systolic dysfunction (ejection fraction < 40%), using contrast-enhanced LDDE and 99mTc-Sestamibi gated SPECT. Segments were assessed for the presence of viability by both techniques and head to head comparisons were made.

RESULTS

Adequate visualisation increased from 80% in unenhanced segments to 96% in contrast-enhanced segments. Of the total 850 segments studied, 290 segments (34.1%) had abnormal contraction (dysfunctional). Among these, 138 were hypokinetic (16.2% of total), 144 were severely hypokinetic or akinetic (16.9% of total), and 8 segments were dyskinetic or aneurismal (0.9% of total). Among 151 segments considered viable by technetium, 137 (90.7%) showed contractile improvement with dobutamine; in contrast, only 8 of the 139 segments (5.7%) considered nonviable by technetium had a positive dobutamine response. The per cent of agreement between technetium uptake and a positive response to dobutamine was 78.6% with kappa = 0.63, suggestive of a substantial degree of agreement between the two modalities.

CONCLUSION

Use of contrast-enhanced LDDE significantly increased the adequate endocardial border visualisation. Furthermore, this study showed a strong degree of agreement between the modalities in the detection of viable segments. So, contrast-enhanced LDDE appears to be a safe and comparable alternative to MPS in myocardial viability assessment.

Stress echocardiography. Part I: Stress echocardiography in coronary heart disease

Stress echocardiography (stress echo) is a method in which various stimuli are used to elicit myocardial contractility or provoke cardiac ischemia with simultaneous echocardiographic image acquisition of left ventricular function and valvular flow, if needed. The technique is a well-recognized, safe and widely available stress test used for the diagnosis and assessment of prognosis in coronary heart disease, but may also prove valuable in valvular heart disease. The stressors used include physical exercise, pharmacological agents (dobutamine, vasodilators) and pacing stress, most often with the use of a permanent pacemaker. Two operators should perform the test: a physician experienced in stress echocardiography (at least 100 tests completed under supervision of an expert) and a trained nurse or another doctor. The laboratory should feature a defibrillator and a resuscitation kit with a set of pharmaceuticals, an intubation kit and an AMBU bag. Pacing stress echo requires an external programmer for the implanted permanent pacemaker. Exercise should be the preferred stressor for the diagnosis of ischemic heart disease with alternative of high-dose dobutamine test in cases of contraindications to physical stress. Pacing stress echo is recommended for patients with pacemakers, and dipyridamole test for the assessment of coronary flow reserve. Chest pain in patients with intermediate probability of coronary artery disease, inability to perform physical exercise and non-diagnostic resting or exercise electrocardiography are indications for stress echo. The test is also used in symptomatic patients after revascularization or patients qualified for revascularization for functional assessment of coronary artery stenosis. Low-dose dobutamine test is usually performed in patients after myocardial infarction or with moderate-to-severe left ventricular dysfunction to assess myocardial viability before potential revascularization.

Stress echocardiography (stress echo) is a method in which various stimuli are used to elicit myocardial contractility or provoke cardiac ischemia with simultaneous echocardiographic image acquisition of left ventricular function and valvular flow, if needed. The technique is a well-recognized, safe and widely available stress test used for the diagnosis and assessment of prognosis in coronary heart disease, but may also prove valuable in valvular heart disease. The stressors used include physical exercise, pharmacological agents (dobutamine, vasodilators) and pacing stress, most often with the use of a permanent pacemaker. Two operators should perform the test: a physician experienced in stress echocardiography (at least 100 tests completed under supervision of an expert) and a trained nurse or another doctor. The laboratory should feature a defibrillator and a resuscitation kit with a set of pharmaceuticals, an intubation kit and an AMBU bag. Pacing stress echo requires an external programmer for the implanted permanent pacemaker. Exercise should be the preferred stressor for the diagnosis of ischemic heart disease with alternative of high-dose dobutamine test in cases of contraindications to physical stress. Pacing stress echo is recommended for patients with pacemakers, and dipyridamole test for the assessment of coronary flow reserve. Chest pain in patients with intermediate probability of coronary artery disease, inability to perform physical exercise and non-diagnostic resting or exercise electrocardiography are indications for stress echo. The test is also used in symptomatic patients after revascularization or patients qualified for revascularization for functional assessment of coronary artery stenosis. Low-dose dobutamine test is usually performed in patients after myocardial infarction or with moderate-to-severe left ventricular dysfunction to assess myocardial viability before potential revascularization.

Safety and efficacy of physiologist-led dobutamine stress echocardiography: experience from a tertiary cardiac centre

Background

Dobutamine stress echocardiography (DSE) services have traditionally been medically led. In some UK institutions, DSE lists are led by physiologists with medical support. In our tertiary cardiac centre at New Cross Hospital (NCH), the DSE service was established by a consultant echocardiographer. Following intensive training and assessment, the Trust approved drug administration by named senior cardiac physiologists. We believe this is the first report of a cardiac physiologist-managed DSE service, including physiologist drug administration. We have assessed the feasibility, safety and validity of this physiologist-led DSE service.

Methods

Retrospective analysis of 333 patients undergoing stress echocardiogram for inducible reversible ischaemia, myocardial viability and valvular heart disease over 6 months. Patients’ case notes review after 18–24 months.

Results

Overall, 92% of all cases (306) were performed by physiologists. In 300 studies, dobutamine was administered. The majority of the referrals were for coronary artery disease (CAD) assessment (281). In 235 cases, the study was uncomplicated. Sixty-seven patients developed dobutamine-related side effects. In 16 cases, complications led to early termination of the study. In two cases, urgent medical review was needed. Of the 281 studies for CAD assessment, 239 were negative for ischaemia, 28 were positive and 14 inconclusive. In 5 out of 28 cases with echocardiogram, evidence of inducible ischaemia, coronary angiography revealed unobstructed coronary arteries.

Conclusion

This study demonstrates the safety and effectiveness of this practice and provides potential for the expansion of the physiologists’ role and physiologist-led DSE services in other hospitals.

Feasibility of physiologist-led stress echocardiography for the assessment of coronary artery disease

BACKGROUND

Physiologist-led stress echocardiography (PLSE) services provide potential for expansion of SE services and increased productivity for cardiologists. There are however no published data on the feasibility of PLSE. We sought to assess the feasibility, safety and robustness of PLSE and cardiologist-led stress echocardiography (CLSE) for coronary artery disease (CAD) assessment.

METHODS

Retrospective analysis of 898 patients undergoing PLSE or CLSE for CAD assessment using exercise or dobutamine stress over 24 months. PLSE involved 2 cardiac physiologists (exercise) or 1 physiologist plus 1 cardiac nurse (dobutamine). A cardiology registrar was present in the echocardiography department during PLSE in case of medical complications. CLSE involved 1 physiologist and 1 trainee cardiologist who analysed the study and reviewed findings with an imaging cardiologist. Sixteen-segment wall motion scoring (WMS, WMSI) analysis was performed. Feasibility (stressor, image quality, proportion of completed studies, agreement with imaging cardiologist analysis) and safety (complication rate) were compared for PLSE and CLSE.

RESULTS

The majority of studies were CLSE (56.2%) and used dobutamine (68.7%). PLSE more commonly used exercise (69.2%). Overall, 96% of studies were successfully completed (>14 diagnostic segments in 98%, P = 0.899 PLSE vs CLSE). Commencement of PLSE was associated with an increase in annual SE's performed for CAD assessment. Complication rates were comparably very low for PLSE and CLSE (0.8% vs 1.8%, P = 0.187). There was excellent agreement between PLSE and CLSE WMS interpretation of 480 myocardial segments at rest (κ = 0.87) and stress (κ = 0.70) and WMSI (ICCs and Pearson's r >0.90, zero Bland-Altman mean bias).

CONCLUSION

This to our knowledge is the first study of the feasibility of PLSE. PLSE performed by well-trained physiologists is feasible and safe in contemporary practice. PLSE and CLSE interpretation of stress echocardiography for CAD agree very closely.

The detection of viable myocardium by low-dose dobutamine stress speckle tracking echocardiography in patients with old myocardial infarction

PURPOSE

To explore the significance and value of speckle-tracking echocardiography (STE) associated with low-dose dobutamine stress echocardiography (LDDSE) for the detection of viable myocardium (VM) in patients with old myocardial infarction (OMI).

METHODS

We performed STE with LDDSE in 33 hospitalized patients with OMI and left ventricular systolic dysfunction. QLAB software was used to analyze strain (S) and strain rate (Sr). Percutaneous coronary intervention (PCI) was subsequently performed. The movement of each wall segment was observed by routine echocardiography before and after 1, 3, and 6 months of PCI, and improvement was regarded as the gold standard for diagnosing VM.

RESULTS

Compared with semi-quantitative wall-motion analysis combined with LDDSE, the sensitivity, specificity, and accuracy of c-STE (combining the three directions of S and Sr) at LDDSE were 91.6%, 79.5%, and 87.5%, respectively (p < 0.02). Among the deformation parameters, longitudinal strain (LS) and longitudinal strain rate (LSr) had the highest sensitivity, specificity, and accuracy. Upon combining LS and LSr at LDDSE to parallel tests, the sensitivity, specificity, and accuracy were 91.7%, 90%, and 90.6%, respectively. Compared with baseline, LVEF after PCI increased from 43.3% ± 2.6% to 47.3% ± 2.9% (p < 0.001).

CONCLUSIONS

Global strain at LDDSE is superior to semi-quantitative wall-motion analysis with LDDSE for the assessment of VM. When the multivariable analysis and the parallel tests are combined, LS combined with LSr can be considered an independent predictor of VM. LVEF is improved after PCI in patients with VM and OMI. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:545-554, 2016.

Effects of the glucagon-like peptide-1 receptor agonist liraglutide on systolic function in patients with coronary artery disease and type 2 diabetes: a randomized double-blind placebo-controlled crossover study

BACKGROUND

Patients with type 2 diabetes (T2D) and coronary artery disease (CAD) have increased risk of cardiac dysfunction. The diabetic heart is characterized by increased fatty acid oxidation and reduced glucose uptake resulting in reduced cardiac efficiency. Glucagon-like peptide-1 (GLP-1) has shown to increase myocardial glucose uptake and to improve myocardial function. We examined the effect of the GLP-1 receptor agonist, liraglutide, on the systolic function of the left ventricle (LV) in patients with T2D and stable CAD.

METHODS

In this placebo-controlled crossover study, 41 subjects with T2D and stable CAD were randomized to liraglutide or placebo and underwent dobutamine stress echocardiography (DSE) and exercise tolerance test at beginning and end of each intervention. The primary endpoint was changes in LV ejection fraction. Secondary endpoints were exercise capacity and other measures of systolic function: wall motion score index (WMSI), global longitudinal strain (GLS) and strain rate (GLSR).

RESULTS

Liraglutide, when compared to placebo, did not improve LV ejection fraction at rest (+0.54 %; 95 % CI 2.38-3.45), at low stress (+0.03 %; 95 % CI 3.25-3.32), at peak stress (+1.12 %; 95 % CI 3.45-5.69), or at recovery (+4.06 %; 95 % CI 0.81-8.93). No significant changes in WMSI were observed at any stress levels. GLS and GLSR at rest did not improve. The maximal exercise capacity estimated by metabolic equivalents was not affected by liraglutide.

CONCLUSION

In conclusion, liraglutide did not improve the systolic function of the left ventricle during DSE or the exercise capacity in patients with T2D and stable CAD. Clinical Trial Registration http://www.clinicaltrials.gov (unique identifier: NCT01595789).

Hypertension is strongly associated with false-positive bicycle exercise stress echocardiography testing results

INTRODUCTION

Exercise echocardiography is a reliable routine test in patients with known or suspected coronary artery disease. However, in ∼15% of all patients, stress echocardiography leads to false-positive stress echocardiography results. We aimed to investigate the impact of hypertension on stress echocardiographic results.

METHODS

We performed a retrospective study of patients with suspected or known stable coronary artery disease who underwent a bicycle exercise stress echocardiography. Patients with false-positive stress results were compared with those with appropriate results.

RESULTS

126 patients with suspected or known coronary artery disease were included in this retrospective study. 23 patients showed false-positive stress echocardiography results. Beside comparable age, gender distribution and coronary artery status, hypertension was more prevalent in patients with false-positive stress results (95.7% vs. 67.0%, p = 0.0410). Exercise peak load revealed a borderline-significance with lower loads in patients with false-positive results (100.0 (IQR 75.0/137.5) vs. 125.0 (100.0/150.0) W, p = 0.0601). Patients with false-positive stress results showed higher systolic (2.05 ± 0.69 vs. 1.67 ± 0.39 mmHg/W, p = 0.0193) and diastolic (1.03 ± 0.38 vs. 0.80 ± 0.28 mmHg/W, p = 0.0165) peak blood pressure (BP) per wattage. In a multivariate logistic regression test, hypertension (OR 17.6 [CI 95% 1.9-162.2], p = 0.0115), and systolic (OR 4.12 [1.56-10.89], p = 0.00430) and diastolic (OR 13.74 [2.46-76.83], p = 0.00285) peak BP per wattage, were associated with false-positive exercise results. ROC analysis for systolic and diastolic peak BP levels per wattage showed optimal cut-off values of 1.935mmHg/W and 0.823mmHg/W, indicating false-positive exercise echocardiographic results with AUCs of 0.660 and 0.664, respectively.

CONCLUSIONS

Hypertension is a risk factor for false-positive stress exercise echocardiographic results in patients with known or suspected coronary artery disease. Presence of hypertension was associated with 17.6-fold elevated risk of false-positive results.

Stress-echocardiography is underused in clinical practice: a nationwide survey in Austria

BACKGROUND

The wide area of application, including coronary artery disease, valvular heart disease, or pulmonary hypertension makes stress echocardiography (SE) a powerful, cost-effective imaging modality in cardiology. The role of this technique in clinical practice in Austria is unknown.

METHODS

A nationwide survey included all departments for cardiology and/or internal medicine in the years 2008 and 2013. By electronic questionnaire demographics, indication for the test, the numbers of examined cases per year, operators, and various applied techniques of SE were interrogated and completed by telephone interviews.

RESULTS

Data could be obtained from all 117 departments. In the year 2007 in 58 (50%) and in 2012 57 (49%) departments SE was available in Austrian hospitals. More than 100 SEs per year were performed by only four (7%) units in the year 2007 and by five (8%) in 2012. Physical exercise, dobutamine, and dipyridamole SE were available in 27 (46%), 52 (90%), and six (10%) units in 2007, and in 15 (27%), 52 (91%), and five (9%) units in 2012, respectively. In 2007 41 (71%) and in 2012 26 (46%) echo-labs administered contrast agents during SE. Transesophageal SE and 3D-echo was performed in one (2%) and three (5%) units in 2007, and in six (10%) and four (7%) echo-labs in 2012.

CONCLUSIONS

This representative survey demonstrates the underuse of SE in clinical practice in Austria. Even in established application fields performance is low, examination frequencies as recommended by the cardiology societies are fulfilled only by a minority of institutions.

Adding liraglutide to the backbone therapy of biguanide in patients with coronary artery disease and newly diagnosed type-2 diabetes (the AddHope2 study): a randomised controlled study protocol

INTRODUCTION

Newly diagnosed type 2 diabetes mellitus (T2DM) in patients with coronary artery disease (CAD) more than doubles the risk of death compared with otherwise matched glucose tolerant patients. The biguanide metformin is the drug of choice in treatment of T2DM and has shown to ameliorate cardiovascular morbidity in patients with T2DM and myocardial infarction (MI). The incretin hormone, glucagon-like peptide-1 (GLP-1) improves β-cell function, insulin sensitivity and causes weight loss and has been suggested to have beneficial effects on cardiac function. The GLP-1 receptor agonist (GLP-1RA), liraglutide, is currently used for treatment of T2DM but its potential effect on cardiac function has not been investigated in detail. We hypothesised that liraglutide added to metformin backbone therapy in patients with CAD and newly diagnosed T2DM will improve β-cell function and left ventricular systolic function during dobutamine stress.

METHODS AND ANALYSES

40 patients with CAD and newly diagnosed T2DM will receive the intervention liraglutide+metformin and placebo+metformin in this investigator-initiated, double blind, randomised, placebo-controlled, cross-over 12 plus 12 weeks intervention study with a 2-week washout period. The primary cardiovascular end point is changes in left ventricular ejection fraction during stress echocardiography. The primary endocrine end point is β-cell function evaluated during a frequently sampled intravenous glucose tolerance test. Secondary end points include heart rate variability, diurnal blood pressure, glucagon suppression and inflammatory response (urine, blood and adipose tissue).

ETHICS AND DISSEMINATION

This study is approved by the Danish Medicines Agency, the Danish Dataprotection Agency and the Regional Committee on Biomedical Research Ethics of the Capital Region of Denmark. The trial will be carried out under the guidance from the GCP unit at Copenhagen University Hospital of Bispebjerg and in accordance with the ICH-GCP guidelines and the Helsinki Declaration.

TRIAL REGISTRATIONS NUMBER

Clinicaltrials.gov ID: NCT01595789, EudraCT: 2011-005405-78.

The risk of adverse events associated with atropine administration during dobutamine stress echocardiography in cardiac transplant patients: a 28-year single-center experience

BACKGROUND

Although dobutamine stress echocardiography (DSE) is performed in heart transplant patients, the safety profile of atropine administration in DSE in this setting is unclear.

METHODS AND RESULTS

We identified heart transplant patients who received atropine during DSE from January 1984 to August 2011 at our institution and compared them with a propensity-scored matched control group of heart transplant patients who underwent DSE without atropine. Adverse events were defined as significant arrhythmias (sinus arrest, Mobitz type II heart block, complete heart block, ventricular tachycardia, or ventricular fibrillation), hypotension requiring hospitalization, syncope or presyncope, myocardial infarction, and death. Forty-five heart transplant patients (median age 62 years, 82% male) received 0.2-1 mg atropine during DSE. Of these, 1 patient (2.2%) developed temporary complete heart block. No adverse events were identified in the control group of 154 patients who received dobutamine without atropine.

CONCLUSIONS

Our findings suggest that complete heart block can occur infrequently with the administration of atropine in heart transplant patients undergoing DSE. Therefore, patients should be appropriately monitored for these adverse events during and after DSE.

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.

Assessment of myocardial viability: comparison of echocardiography versus cardiac magnetic resonance imaging in the current era

Detecting viable myocardium, whether hibernating or stunned, is of clinical significance in patients with coronary artery disease and left ventricular dysfunction. Echocardiographic assessments of myocardial thickening and endocardial excursion during dobutamine infusion provide a highly specific marker for myocardial viability, but with relatively less sensitivity. The additional modalities of myocardial contrast echocardiography and tissue Doppler have recently been proposed to provide further, quantitative measures of myocardial viability assessment. Cardiac magnetic resonance (CMR) has become popular for the assessment of myocardial viability as it can assess cardiac function, volumes, myocardial scar, and perfusion with high-spatial resolution. Both 'delayed enhancement' CMR and dobutamine stress CMR have important roles in the assessment of patients with ischaemic cardiomyopathy. This article reviews the recent advances in both echocardiography and CMR for the clinical assessment of myocardial viability. It attempts to provide a pragmatic approach toward the patient-specific assessment of this important clinical problem.

Real-time three-dimensional dobutamine stress echocardiography for coronary artery disease diagnosis: validation with coronary angiography

OBJECTIVE

To compare real-time three-dimensional echocardiography (RT3DE) with two-dimensional dobutamine stress echocardiography (2DE) for the detection of myocardial ischaemia, with angiographic validation of the results.

METHODS

56 patients (mean (SD) age 64.5 (6.2) years, 38 males), referred for coronary angiography, were examined by 2DE and RT3DE during the same dobutamine stress protocol.

RESULTS

All 56 patients completed the stress protocol uneventfully. The mean (SD) acquisition time for the necessary views to evaluate all segments was 26.3 (2.5) s for RT3DE and 58.8 (3.7) s for 2DE (p<0.001). At peak stress, RT3DE had a higher wall-motion score index (1.25 (0.24) by 2DE, 1.30 (0.27) by RT3DE; p = 0.014). The regional wall-motion score for the four apical segments at peak stress was compared; it was 1.35 (0.55) by 2DE and 1.52 (0.69) by RT3DE (p = 0.003). The diagnostic parameters of 2DE versus RT3DE were: sensitivity 73% vs 78%, specificity 93% vs 89% and overall accuracy 86% vs 85%, respectively. In the left anterior descending artery territory, in particular, where RT3DE had higher regional wall-motion scores, it showed a tendency towards higher sensitivity (85% vs 78%), although this difference did not achieve statistical significance.

CONCLUSION

RT3DE identifies wall-motion abnormalities more readily in the apical region than 2DE, which may explain the tendency towards higher sensitivity in the left anterior descending artery territory. RT3DE results were validated using angiography as reference and findings indicate diagnostic equivalence to 2DE, with the advantage of considerable shorter acquisition times.

Left atrial systolic reserve in idiopathic vs. ischaemic-dilated cardiomyopathy

PURPOSE

There are studies indicating more pronounced left atrial (LA) systolic dysfunction at rest in idiopathic (IDDC) than in ischaemic-dilated cardiomyopathy (ISDC). It was hypothesized that the findings would be similar with regards LA systolic reserve.

METHODS

Twenty-six patients with IDDC, 28 with ISDC and 25 normal controls underwent low-dose dobutamine stress echocardiography (5-10 microg kg(-1) min(-1) IV). Left atrial volumes were echocardiographically determined at rest and during stress at the mitral valve opening (maximal, Vmax), electrocardiographic P wave (onset of atrial systole, Vp) and mitral valve closure (minimal, Vmin) from the apical 4- and 2-chamber views (biplane area-length method). Left atrial systolic function was assessed with the LA-active emptying volume (ACTEV) = Vp-Vmin and fraction (ACTEF) = ACTEV/Vp.

RESULTS

Vmax at rest was similar in IDDC and ISDC and greater than in the controls (54.2 +/- 12 vs. 48.5 +/- 18 vs. 27.1 +/- 6.3 cm(3) m(-2), respectively, P < 0.001) and did not change with stress (53.9 +/- 13.8 vs. 46.9 +/- 16.2 vs. 25.8 +/- 5.9 cm(3) m(-2), P < 0.001). The ACTEV at rest was similar in IDDC and ISDC and greater than in the controls (8.6 +/- 3.5 vs. 9.7 +/- 2.9 vs. 6.1 +/- 2.2 cm(3) m(-2) P < 0.01), whereas during the dobutamine infusion it remained unaltered in IDDC (10.8 +/- 4.6 cm(3) m(-2), P = NS vs. rest) and increased in ISDC (11.8 +/- 3.3 cm(3) m(-2), P < 0.05) and the controls (13.1 +/- 3.2 cm(3) m(-2), P < 0.01). The ACTEF was lower in IDDC than ISDC and the controls at rest (20 +/- 10% vs. 33 +/- 8% vs. 36 +/- 10%, P < 0.01). Dobutamine infusion was associated with no significant increase in ACTEF in IDDC (25 +/- 12%, P = NS vs. rest), and with an increase in this variable in ISDC (39 +/- 10%, P < 0.05) and the controls (49 +/- 12%, P < 0.01).

CONCLUSIONS

Dobutamine infusion is associated with an increase in LA ACTEV and fraction in ISDC and no significant change in these indices in IDDC. These findings indicate a reduced LA systolic reserve in IDDC.

Safety and cardiac chronotropic responsiveness to the early injection of atropine during dobutamine stress echocardiography in the elderly

OBJECTIVE

To determine the safety and cardiac chronotropic responsiveness to early atropine dobutamine stress echocardiography (DSE) in the elderly.

DESIGN

Retrospective study of 258 patients >or= 70 years who underwent early atropine DSE and 290 patients >or= 70 years who underwent conventional DSE. In the early atropine protocol, atropine was started at 20 microg/kg/min of dobutamine if heart rate was < 100 beats/min, up to 2 mg. The cardiac chronotropic responsiveness in the elderly was compared with a control group of patients < 70 years matched for sex, myocardial infarction, diabetes, and treatment with beta blockers and calcium channel blockers.

RESULTS

The dose of dobutamine given to elderly patients was lower during early atropine than during conventional DSE (mean (SD) 29 (7) v 38 (4) microg/kg/min, p = 0.001). Early atropine DSE resulted in diminished incidence of ventricular extrasystoles, non-sustained ventricular tachycardia, bradycardia, and hypotension compared with conventional DSE. In comparison with patients < 70 years, elderly patients required lower doses of dobutamine and atropine and achieved a higher percentage of predicted maximum heart rate (92 (9)% v 88 (10)%, p = 0.0001). Except for more common hypotension (16% v 10%, p = 0.004), no other difference in adverse effects was observed between patients >or= 70 and < 70 years.

CONCLUSIONS

Early atropine DSE is a safe strategy in the elderly resulting in lower incidence of minor adverse effects than with the conventional protocol. Elderly patients presented adequate cardiac chronotropic responsiveness to early injections of atropine, requiring lower doses of drugs to reach test end points.