The potential clinical value of contrast-enhanced echocardiography beyond current recommendations.

BACKGROUND: Contrast agents are used in resting echocardiography to opacify the left ventricular (LV) cavity and to improve LV endocardial border delineation in patients with suboptimal image quality. If a wider use of contrast-enhanced echocardiography would be adopted instead of the current selective approach, diagnoses such as myocardial ischemia and LV structural abnormalities could potentially be detected earlier. The aim was therefore to retrospectively investigate if contrast-enhanced echocardiography beyond the current recommendations for contrast agent usage affects assessment of wall motion abnormalities, ejection fraction (EF) and detection of LV structural abnormalities. A secondary aim was to evaluate the user dependency during image analysis. METHODS: Experienced readers (n = 4) evaluated wall motion score index (WMSI) and measured EF on greyscale and contrast-enhanced images from 192 patients without indications for contrast-enhanced echocardiography. Additionally, screening for LV structural abnormalities was performed. Repeated measurements were performed in 20 patients by the experienced as well as by inexperienced (n = 2) readers. RESULTS: Contrast analysis resulted in significantly higher WMSI compared to greyscale analysis (p < 0.003). Of the 83 patients, classified as healthy by greyscale analysis, 55% were re-classified with motion abnormalities by contrast analysis. No significant difference in EF classification (≥55%, 45-54%, 30-44%, < 30%) was observed. LV structural abnormalities, such as increased trabeculation (n = 21), apical aneurysm (n = 4), hypertrophy (n = 1) and thrombus (n = 1) were detected during contrast analysis. Intra- and interobserver variability for experienced readers as well as the variability between inexperienced and experienced readers decreased for WMSI and EF after contrast analysis. CONCLUSIONS: Contrast-enhanced echocardiography beyond current recommendations for contrast agent usage increased the number of detected wall motion and LV structural abnormalities. Moreover, contrast-enhanced echocardiography increased reproducibility for assessment of WMSI and EF.

Does stress echocardiography add incremental value to baseline ejection fraction for the early identification of candidates for implantable defibrillators?

Objective: A reduction in left ventricular ejection fraction (EF) remains the strongest indicator of increased risk of sudden cardiac death after an acute myocardial infarction (AMI). Guidelines recommend that patients with an EF ≤35%, 6-12 weeks after AMI should be considered for implantable cardioverter defibrillator (ICD) therapy. Stress echocardiography is a safe method to detect viability in a stunned myocardium. The purpose of this study was to investigate if stress echocardiography early after AMI could identify ICD candidates before discharge. Methods: Ninety-six patients with EF ≤40% early after AMI were prospectively included in a cohort study, and investigated by baseline and stress echocardiography before discharge. Follow-up echocardiography was performed after 3 months. EF, mitral annular plane systolic excursion (MAPSE) and peak systolic velocity (PSV) were determined for each examination. Results: There were 80 (83%) patients who completed the baseline, stress and follow-up echocardiography. Among them there were 32 (40%) patients who met the ICD criteria of EF ≤35% at 3 months. For these patients, EF, MAPSE and PSV were significantly lower than for those patients who recovered. The area under the receiver operating characteristic curve (AUC) was 85% (95% CI 0.74 to 0.94) for baseline EF to predict non-recovery. None of the other variables had a higher AUC. Conclusion: Patients who met the ICD criteria of EF ≤35% at 3 months after myocardial infarction had lower EF, MAPSE and PSV on baseline and stress echocardiograph before discharge. Stress echocardiography did not add additional value in predicting non-recovery.

Method comparison for cardiac image registration of coronary computed tomography angiography and 3-D echocardiography.

Treatment decision for coronary artery disease (CAD) is based on both morphological and functional information. Image fusion of coronary computed tomography angiography (CCTA) and three-dimensional echocardiography (3DE) could combine morphology and function into a single image to facilitate diagnosis. Three semiautomatic feature-based methods for CCTA/3DE registration were implemented and applied on CAD patients. Methods were verified and compared using landmarks manually identified by a cardiologist. All methods were found feasible for CCTA/3DE fusion.

Combination of contrast-enhanced wall motion analysis and myocardial deformation imaging during dobutamine stress echocardiography.

BACKGROUND: The combination of deformation analysis with conventional wall motion scoring (WMS) has been shown to increase the diagnostic sensitivity of dobutamine stress echocardiography (DSE). The feasibility and diagnostic power of WMS is largely improved by contrast agents; however, they are not used in combination with deformation analysis, as contrast agents are generally considered to render strain measurement unfeasible. AIMS: To assess the feasibility of tissue velocity (TVI)- and 2D speckle tracking (ST)-based strain analysis during contrast-enhanced DSE; and to show whether there is an incremental value in combining deformation analysis with contrast-enhanced WMS. METHODS: DS echocardiograms containing native, tissue Doppler, and contrast-enhanced loops of 60 patients were analysed retrospectively. The feasibility of WMS, TVI-, and ST-strain measurement was determined in 40 patients according to pre-defined criteria. The diagnostic ability of a combined protocol integrating data from contrast-WMS and TVI-strain measurement was then compared with contrast-WMS alone in all 60 patients, using coronary angiograms as a gold standard. RESULTS: Both TVI- and ST-based strain analysis were feasible during contrast-DSE (feasibility at peak stress: 87 and 75%). At the patient level, the diagnostic accuracy of the combined method did not prove superior to contrast-WMS (82 vs. 78%); a trend towards improved sensitivity and specificity for detecting coronary artery disease in the right coronary artery circulation (sensitivity: 85 vs. 77%, P = NS; specificity: 96 vs. 94%) was, however, observed. CONCLUSION: Both TVI- and ST-based myocardial deformation analysis are feasible during contrast-enhanced DSE, however, our results fail to demonstrate a clear diagnostic benefit of additional strain analysis over expert WMS alone.