Myocardial Contrast Echocardiography Enhances Long-Term Prognostic Value of Supine Bicycle Stress Two-Dimensional Echocardiography

Long-term prognostic value of stress myocardial perfusion echocardiography in patients with coronary artery disease: a meta-analysis

AIMS

To evaluate the prognostic value of myocardial perfusion (MP) imaging during contrast stress echocardiography (cSE) in patients with known or suspected coronary artery disease (CAD).

METHODS AND RESULTS

A search in PubMed, Embase databases, and the Cochrane library was conducted through May 2019. The Cochran Q statistic and the I2 statistic were used to assess heterogeneity, and the results were analysed by RevMan V5.3 and Stata V15.1 software. Twelve studies (seven dipyridamole and five exercise/dobutamine) without evidence of patient overlap (same institution publishing results over a similar time period) enrolling 5953 subjects (47% female, 8-80 months of follow-up) were included in the analysis. In all studies, total adverse cardiovascular events were defined as either cardiac death, non-fatal myocardial infarction (NFMI), or need for urgent revascularization. Hazard ratios (HRs) revealed that a MP abnormality [pooled HR 4.75; 95% confidence interval (CI) 2.47-9.14] was a higher independent predictor of total events than abnormal wall motion (WM, pooled HR 2.39; 95% CI 1.58-3.61) and resting left ventricular ejection fraction (LVEF, pooled HR 1.92; 95% CI 1.44-2.55) with significant subgroup differences (P = 0.002 compared with abnormal WM and 0.01 compared with abnormal LVEF). Abnormal MP was associated with higher risks for death [Risk ratio (RR) 5.24; 95% CI 2.91-9.43], NFMI (RR 3.09; 95% CI 1.84-5.21), and need for coronary revascularization (RR 16.44; 95% CI 6.14-43.99).

CONCLUSION

MP analysis during stress echocardiography is an effective prognostic tool in patients with known or suspected CAD and provides incremental value over LVEF and WM in predicting clinical outcomes.

[Comparison of myocardial contrast stress-echocardiography and standard stress-echocardiography in detecting myocardial ischemia in patients with different severity of coronary artery stenoses]

AIM

To compare diagnostic value between standard stress-echocardiography and myocardial contrast stress echocardiography in detection of myocardial ischemia in patients with different severity of coronary artery stenoses.

MATERIALS AND METHODS

Myocardial contrast stress-echocardiography and standard stress-echocardiography were performed in 38 patients with coronary artery stenoses over 50% by angiography. Of all lesions 39 were intermediate (5075%) and 33 over 75% stenoses. Fractional flow reserve (FFR) was measured in 12 coronary arteries. During myocardial contrast stress-echocardiography wall motion and myocardial perfusion was assessed.

RESULTS

Adequate visualisation increased from 81.6% in unenhanced segments to 96.1% in contrast-enhanced segments. The sensitivity, specificity, and diagnostic accuracy of standard stress-echocardiography and myocardial contrast stress-echocardiography in intermediate (5075%) coronary stenoses were 44%, 83%, 56% and 56%, 94% и 64% respectively compare to angiography. Taking into account the 12 arteries with evaluated FFR, these parameters increased to 52%, 93% и 65% in standard stress-echocardiography and to 68%, 100% and 75% in myocardial contrast stress-echocardiography. In coronary stenoses over 75% the sensitivity, specificity, and diagnostic accuracy of standard stress-echocardiography and myocardial contrast stress-echocardiography were 78%, 88%, 80% and 86%, 100%, 92% respectively Conclusion. Use of contrast-enhanced stress-echorardiography significantly increased the diagnostic value of this method by improving endocardial border visualization and possibilities of myocardial perfusion assessment.

New Applications in Echocardiography for Ultrasound Contrast Agents in the 21st Century

Contrast echocardiography microbubbles are ultrasound-enhancing agents that were originally designed to help improve endocardial border definition, known as left ventricle opacification, and to enhance Doppler signals. Over time, contrast microbubbles are used to assess myocardial perfusion because they travel through the capillaries of the cardiac circulation. Current research provides good evidence that myocardial perfusion echocardiography improves comprehensive echocardiographic evaluations of ischemic heart disease. The approval of regulatory authorities and the availability of quantitative operator-independent analysis software will hopefully prompt physicians and sonographers to implement myocardial perfusion echocardiography into the daily workflow of echo laboratories. New diagnostic and therapeutic applications will result in improved patient care, especially in the area of sonothrombolysis, where preliminary data have already shown utilization in ST elevation myocardial infarction, improving left ventricular systolic function and reducing the need for implantable defibrillators at 6-mo follow-up. This review gives an overview of the applications of myocardial perfusion imaging with ultrasound. Each cited study had institutional review board/institutional animal care and use approval.

Stress echocardiography in coronary artery disease: a practical guideline from the British Society of Echocardiography

Stress echocardiography is an established technique for assessing coronary artery disease. It has primarily been used for the diagnosis and assessment of patients presenting with chest pain in whom there is an intermediate probability of coronary artery disease. In addition, it is used for risk stratification and to guide revascularisation in patients with known ischaemic heart disease. Although cardiac computed tomography has recently been recommended in the United Kingdom as the first-line investigation in patients presenting for the first time with atypical or typical angina, stress echocardiography continues to have an important role in the assessment of patients with lesions of uncertain functional significance and patients with known ischaemic heart disease who represent with chest pain. In this guideline from the British Society of Echocardiography, the indications and recommended protocols are outlined for the assessment of ischaemic heart disease by stress echocardiography.

Clinical practice of contrast echocardiography: recommendation by the European Association of Cardiovascular Imaging (EACVI) 2017

Contrast echocardiography is widely used in cardiology. It is applied to improve image quality, reader confidence and reproducibility both for assessing left ventricular (LV) structure and function at rest and for assessing global and regional function in stress echocardiography. The use of contrast in echocardiography has now extended beyond cardiac structure and function assessment to evaluation of perfusion both of the myocardium and of the intracardiac structures. Safety of contrast agents have now been addressed in large patient population and these studies clearly established its excellent safety profile. This document, based on clinical trials, randomized and multicentre studies and published clinical experience, has established clear recommendations for the use of contrast in various clinical conditions with evidence-based protocols.

Prognostic value of dobutamine stress myocardial perfusion echocardiography in patients with known or suspected coronary artery disease and normal left ventricular function

Objective

We sought to determine the prognostic value of qualitative and quantitative analysis obtained by real-time myocardial perfusion echocardiography (RTMPE) in patients with known or suspected coronary artery disease (CAD).

Background

Quantification of myocardial blood flow reserve (MBFR) in patients with CAD using RTMPE has been demonstrated to further improve accuracy over the analysis of wall motion (WM) and qualitative analysis of myocardial perfusion (QMP).

Methods

From March 2003 to December 2008, we prospectively studied 168 patients with normal left ventricular function (LVF) who underwent dobutamine stress RTMPE. The replenishment velocity reserve (β) and MBFR were derived from RTMPE. Acute coronary events were: cardiac death, myocardial infarction and unstable angina with need for urgent coronary revascularization.

Results

During a median follow-up of 34 months (5 days to 6.9 years), 17 acute coronary events occurred. Abnormal β reserve in ≥2 coronary territories was the only independent predictor of events hazard ratio (HR) = 21, 95% CI = 4.5–99; p<0.001). Both, abnormal β reserve and MBFR added significant incremental value in predicting events over qualitative analysis of WM and MP (χ2 = 6.6 and χ2 = 24.6, respectively; p = 0.001 and χ2 = 6.6 and χ2 = 15.5, respectively; p = 0.012, respectively). When coronary angiographic data was added to the multivariate analysis model, β reserve remained the only predictor of events with HR of 21.0 (95% CI = 4.5–99); p<0.001.

Conclusion

Quantitative dobutamine stress RTMPE provides incremental prognostic information over clinical variables, qualitative analysis of WM and MP, and coronary angiography in predicting acute coronary events.

Contrast echocardiography: latest developments and clinical utility

Ultrasound enhancing agents (UEAs) are being utilized for a growing number of applications with real-time very low mechanical index (MI) techniques in clinical cardiology today. This article will review recent developments on the safety of UEAs and their effectiveness in myocardial perfusion imaging, three-dimensional quantification of left ventricular function, and vascular imaging. UEAs are now being utilized in all age groups, with new indications that add incremental value to the currently approved by the Food and Drug Administration. These include the incremental value in cardiac imaging, where the off-label analysis of myocardial perfusion observed with UEAs adds to the enhanced endocardial border delineation. In carotid artery imaging, UEAs improve the detection of plaque but also can examine plaque neovascularization. Vascular surgeons now utilize UEAs in the evaluation of endovascular repair to detect endoleaks without the need of ionizing radiation. Newer applications are emerging in the detection of left atrial appendage thrombi and quantification of myocardial blood flow and volume in transplant patients.

Differences in patient outcomes after conventional versus real time perfusion stress echocardiography in men versus women: a prospective randomised trial

OBJECTIVE

The purpose of our study was to determine whether sex affects the predictive value of perfusion and wall motion imaging obtained with real time myocardial contrast echocardiography (RTMCE) when compared with conventional stress echocardiography (CSE).

METHODS

We prospectively enrolled 1649 age-matched men and women with intermediate pretest probability of coronary artery disease (CAD) undergoing stress echocardiography for suspicion of CAD. Patients with known CAD were excluded. Those who consented to participate in the study were randomised to undergo either CSE or RTMCE. Events were defined as death, non-fatal myocardial infarction (MI) and need for revascularisation.

RESULTS

Median follow-up was 2.6 years (927 women, 722 men). Mean age was 58±13 years in both sexes. There were a total of 62 deaths, 12 MIs and 85 revascularisations with a 2-year event rate of 3.5% (95% CI 2.7% to 4.7%). Male sex was a significant independent predictor of adverse outcome (death, non-fatal MI) in both CSE and RTMCE (CSE HR 2.07, 95% CI 1.07 to 4.02, RTMCE HR 2.14; 95% CI 1.04 to 4.33). Higher 2-year event rates were noted in men in comparison with women after a normal CSE (men 5.4%, women 1.6%, p=0.02), but not after a normal RTMCE (men 5.8%, women 3.7%, p=0.41). Event rates were also significantly higher in men after an abnormal RTMCE (men 34.8%, women 16.4%, p=0.02) but no difference in outcome between sexes was observed after an abnormal CSE (men 17.8%, women 18.6%, p=0.90).

CONCLUSIONS

The addition of perfusion imaging with RTMCE improves the predictive value of stress echocardiography in men with no known CAD, but does not improve the predictive value in age-matched women.

Patient outcome following 2 different stress imaging approaches: a prospective randomized comparison

OBJECTIVES

The study sought to prospectively compare patient outcome after stress real-time myocardial contrast echocardiography (RTMCE) versus conventional stress echo (CSE), where contrast is used to optimize wall motion (WM) analysis.

BACKGROUND

Myocardial perfusion imaging with RTMCE may improve the detection of coronary artery disease (CAD), and predict patient outcome.

METHODS

Patients with intermediate to high pre-test probability referred for dobutamine or exercise stress echocardiography were prospectively randomized to either RTMCE or CSE. Definity contrast was used for CSE only when endocardial border delineation was inadequate (63% of studies). Studies were interpreted by either an experienced contrast reviewer (R1; n = 1257), or 4 Level 3 echocardiographers (R2) with basic contrast training (n = 806). Death, nonfatal myocardial infarction (MI), and revascularizations were recorded at follow-up.

RESULTS

Follow-up was available in 2,014 patients (median 2.6 years). Mean age was 59 ± 13 years (53% women). An abnormal RTMCE was more frequently observed than an abnormal CSE (p < 0.001), and more frequently resulted in revascularization (p = 0.004). Resting WM abnormalities were also more frequently seen with RTMCE (p < 0.01), and were an independent predictor of death/nonfatal MI (p = 0.005) for RTMCE, but not CSE. The predictive value of a positive study, whether with CSE or RTMCE, was significant for both R1 and R2 reviewers in predicting the combined endpoint, but R1 was better than R2 at predicting patients at risk for death or nonfatal MI.

CONCLUSIONS

Perfusion imaging with RTMCE improves the detection of CAD during stress echocardiography, and identifies those more likely to undergo revascularization following an abnormal study.

Computed tomography coronary angiography and invasive coronary angiography demonstrate high correlation for area stenosis quantification in noncalcified and mixed plaques

We compared the variance of area and diameter significant stenosis measurement between quantitative computed tomography coronary angiography (QCTA) and quantitative invasive coronary angiography (QCA). Fifty patients presenting 65 significant coronary artery stenoses (≥70% area stenosis) in QCTA and QCA were included. Spearman's rank correlation revealed that area stenosis measurement by QCTA and QCA yields higher correlation than diameter stenosis and is highest for noncalcified and mixed lesions.

Contrast stress-echocardiography predicts cardiac events in patients with suspected acute coronary syndrome but nondiagnostic electrocardiogram and normal 12-hour troponin

BACKGROUND

No large study has demonstrated that any stress test can risk-stratify future hard cardiac events (cardiac death or myocardial infarction) in patients with suspected acute coronary syndromes (ACS), nondiagnostic electrocardiographic (ECG) findings, and normal troponin levels. The aim of this study was to test the hypothesis that combined contrast wall motion and myocardial perfusion echocardiographic assessment (cMCE) during stress echocardiography can predict long-term hard cardiac events in patients with suspected ACS, nondiagnostic ECG findings, and normal troponin.

METHODS

A total of 545 patients referred for contrast stress echocardiography from the emergency department for suspected ACS but nondiagnostic ECG findings and normal troponin levels at 12 hours were followed up for cardiac events. Patients underwent dipyridamole-atropine echocardiography with adjunctive myocardial perfusion imaging using a commercially available ultrasound contrast medium (SonoVue).

RESULTS

During a median follow-up period of 12 months, 25 cardiac events (4.6%) occurred (no deaths, 12 nonfatal myocardial infarctions, 13 episodes of unstable angina). Abnormal findings on cMCE were the most significant predictor of both hard cardiac events (hazard ratio, 22.8; 95% confidence interval, 2.9-176.7) and the combined (cardiac death, myocardial infarction, or unstable angina requiring revascularization) end point (hazard ratio, 10.7; 95% confidence interval, 3.7-31.3). The inclusion of the cMCE variable significantly improved multivariate models, determining lower Akaike information criterion values and higher discrimination ability.

CONCLUSIONS

cMCE during contrast stress echocardiography provided independent information for predicting hard and combined cardiac events beyond that predicted by stress wall motion abnormalities in patients with suspected ACS, nondiagnostic ECG findings, and normal troponin levels.