Quantitative myocardial contrast supine bicycle stress echocardiography for detection of coronary artery disease.

BACKGROUND: If compared with two-dimensional echocardiography (2DE), quantitative myocardial contrast echocardiography (MCE) improves detection of coronary artery disease (CAD) during pharmacological stress, but there is paucity of data regarding quantitative MCE performed during supine bicycle stress. OBJECTIVES: To determine the feasibility and accuracy of quantitative MCE and assess its incremental benefit over 2DE for detection of CAD during supine bicycle stress. METHODS: Sixty-one consecutive patients (47 males, 14 females, mean age 57 ± 12 years) with suspected CAD, who were scheduled for coronary angiography, underwent 2DE and MCE supine bicycle stress. The diagnosis of obstructive CAD (≥50% stenosis) was based on inducible wall-motion and myocardial perfusion abnormalities. For quantitative myocardial perfusion analysis, A, ß, and Aß reserve were derived from myocardial contrast replenishment curves. RESULTS: Quantitative coronary angiography revealed ≥50% stenosis in 41, ≥70% stenosis in 18, single vessel disease in 24, and multivessel disease in 17 patients. If compared with 2DE, quantitative MCE was more sensitive (71% vs. 93%; P < 0.05) and more accurate (74% vs. 89%; P < 0.05) to detect obstructive CAD. The sensitivity of 2DE and quantitative MCE was 61% and 91% (P < 0.05) in 50-69% stenosis, and 63% and 92% (P < 0.05) in single vessel disease. No difference in sensitivity between 2DE and quantitative MCE was found in subjects with ≥70% stenosis (83% vs. 94%, P = NS) and multivessel disease (82% vs. 94%, P = NS). CONCLUSIONS: Quantitative MCE enhances sensitivity and accuracy of supine bicycle stress 2DE for detection of obstructive CAD, and this incremental benefit is especially present in less severe disease.

Myocardial contrast echocardiography enhances long-term prognostic value of supine bicycle stress two-dimensional echocardiography.

BACKGROUND: The aim of this study was to determine the incremental prognostic value of myocardial contrast echocardiography (MCE) over two-dimensional echocardiography (2DE) in patients undergoing supine bicycle stress. METHODS: Eighty-four patients with known or suspected coronary artery disease who underwent supine bicycle stress with 2DE and MCE (mean age, 58.5 +/- 9.7 years; 68 men) were followed up for 48.3 +/- 8.9 months for cardiac death (n = 1), nonfatal myocardial infarction (n = 9), and revascularization (n = 20). RESULTS: In sequential Cox models, the predictive power of the clinical model was strengthened by 2DE (chi(2) = 7.73 vs 12.92, P = .02) and further improved by MCE (chi(2) = 19.04, P = .01). On multivariate analysis, the only independent follow-up event predictor was ischemia on MCE (hazard ratio, 6.79; 95% confidence interval, 2.02-22.82; P = .001). Among patients with normal results on 2DE, those with normal results on MCE had greater 4.5-year event-free survival than those with abnormal results on MCE (93% vs 69%, P = .01). CONCLUSIONS: MCE enhances the predictive power of supine bicycle stress 2DE and allows the risk stratification of patients with normal results on 2DE.

Percutaneous treatment of idiopathic chylopericardium.

Chylopericardium is a rare disease that may result from a variety of causes, such as cardiac surgery, trauma, obstruction of the thoracic duct near its drainage into the subclavian vein, or have no identifiable underlying cause. The present report describes a case of idiopathic chylopericardium in which percutaneous transabdominal occlusion of the thoracic duct was performed as an alternative to surgical duct ligation. The procedure was successful, resulting in a decrease in pericardial fluid accumulation. However, it failed to cure the patient, as constrictive pericarditis developed 2 months later, requiring surgical pericardectomy. Whether this could have been avoided by early (percutaneous) pericardial fenestration is unknown.

Impact of previous myocardial infarction on the incremental value of myocardial contrast to two-dimensional supine bicycle stress echocardiography in evaluation of coronary artery disease.

BACKGROUND: If compared to two-dimensional echocardiography (2DE), myocardial contrast echocardiography (MCE) improves detection of coronary artery disease (CAD) during pharmacological stress, but data on MCE vs. 2DE during supine bicycle stress is limited. Although previous myocardial infarction (MI) influences sensitivity of 2DE, its effect on MCE has not been evaluated. OBJECTIVES: The study sought to determine the incremental benefit of MCE over 2DE for evaluation of CAD during supine bicycle stress and to assess the impact of previous MI on diagnostic values of both methods. METHODS: We studied 103 consecutive patients scheduled for coronary angiography. Prior to coronary angiography, all patients underwent supine bicycle stress. 2DE and MCE were performed during this stress test. The diagnosis of obstructive CAD (> or =50% stenosis) was based on the presence of inducible wall motion and perfusion abnormalities. RESULTS: Quantitative coronary angiography revealed > or =50% stenosis in 53 of 77 patients without previous MI and in 21 of 26 patients with previous MI. If compared to 2DE, MCE was more sensitive (68% vs. 86%; p<0.001) and more accurate (73% vs. 86%; p < 0.001) to detect > or =50% stenosis. In patients without previous MI, 2DE and MCE yielded sensitivity of 65% and 85% (p < 0.01) and accuracy of 71% and 85% (p < 0.01), whereas in patients with previous MI sensitivity was 79% and 90% (p=NS) and accuracy 79% and 88% (p = NS), respectively. CONCLUSIONS: MCE enhances sensitivity and accuracy of 2DE in detection of obstructive CAD during supine bicycle stress. The incremental benefit of MCE is especially present in patients without previous MI.

Real time myocardial contrast echocardiography during supine bicycle stress and continuous infusion of contrast agent. Cutoff values for myocardial contrast replenishment discriminating abnormal myocardial perfusion.

BACKGROUND: Myocardial contrast echocardiography (MCE) is a new imaging modality for diagnosing coronary artery disease (CAD). OBJECTIVE: The aim of our study was to evaluate feasibility of qualitative myocardial contrast replenishment (RP) assessment during supine bicycle stress MCE and find out cutoff values for such analysis, which could allow accurate detection of CAD. METHODS: Forty-four consecutive patients, scheduled for coronary angiography (CA) underwent supine bicycle stress two-dimensional echocardiography (2DE). During the same session, MCE was performed at peak stress and post stress. Ultrasound contrast agent (SonoVue) was administered in continuous mode using an infusion pump (BR-INF 100, Bracco Research). Seventeen-segment model of left ventricle was used in analysis. MCE was assessed off-line in terms of myocardial contrast opacification and RP. RP was evaluated on the basis of the number of cardiac cycles required to refill the segment with contrast after its prior destruction with high-power frames. Determination of cutoff values for RP assessment was performed by means of reference intervals and receiver operating characteristic analysis. Quantitative CA was carried out using CAAS system. RESULTS: MCE could be assessed in 42 patients. CA revealed CAD in 25 patients. Calculated cutoff values for RP-analysis (peak-stress RP >3 cardiac cycles and difference between peak stress and post stress RP >0 cardiac cycles) provided sensitive (88%) and accurate (88%) detection of CAD. Sensitivity and accuracy of 2DE were 76% and 79%, respectively. CONCLUSIONS: Qualitative RP-analysis based on the number of cardiac cycles required to refill myocardium with contrast is feasible during supine bicycle stress MCE and enables accurate detection of CAD.

Diagnosis of ischaemic heart disease by myocardial contrast echocardiography during supine bicycle stress.

INTRODUCTION: Myocardial contrast echocardiography (MCE) is a new imaging modality for diagnosing ischaemic heart disease (IHD). AIM: The aim of this study was to assess 1) the feasibility of MCE during supine bicycle stress and 2) the value of this method in the diagnosis of IHD. METHODS: Supine bicycle stress was performed in 44 consecutive patients (pts) referred for coronary angiography with an intermediate pre-test probability of IHD. MCE was carried out at peak stress and during recovery (once the heart rate returned to the pre-exercise value). During MCE an ultrasound contrast agent (Sonovue) was administered intravenously in a continuous mode using an infusion pump (BR-INF 100, Bracco Research). The acquired images were qualitatively assessed for perfusion and wall motion abnormalities. The 18-segment division of the left ventricle was used in the analysis. Coronary angiography was performed in all pts within 15 days of the exercise test. A quantitative analysis of coronary artery stenoses was carried out using the CAAS system. RESULTS: MCE could not be performed in 2 pts due to technical difficulties. Coronary angiography revealed significant coronary artery stenosis in 25 pts. The sensitivity and specificity of MCE in the diagnosis of IHD were 92.0% and 82.4%, respectively. The positive and negative predictive values were found to be 88.5% and 87.5%, respectively, while the agreement between coronary angiography and MCE was 88.1% (kappa=0.75). CONCLUSIONS: MCE during supine bicycle stress and continuous intravenous administration of an ultrasound contrast agent is a feasible technique and allows accurate diagnosis of IHD in pts in whom the pre-test probability of the disease is intermediate.

Analysis of regional left ventricular function by cineventriculography, cardiac magnetic resonance imaging, and unenhanced and contrast-enhanced echocardiography: a multicenter comparison of methods.

OBJECTIVES: To define the use of cineventriculography, cardiac magnetic resonance imaging (cMRI), and unenhanced and contrast-enhanced echocardiography for detection of left ventricular (LV) regional wall motion abnormalities (RWMA). BACKGROUND: Detection of RWMA is integral to the evaluation of LV function. METHODS: In 100 patients, cineventriculography and unenhanced and contrast-enhanced echocardiography were performed. Fifty-six of the patients underwent additional cMRI. RWMA were assessed referring to a 16-segment model for cMRI, unenhanced and contrast echocardiography. Cineventriculography was evaluated on a 7-segment model. Hypokinesia in one or more segments defined presence of RWMA. Interobserver agreement among three readers was determined within each imaging modality. Intermethod agreement between imaging modalities was analyzed. A standard of truth for the presence of RWMA was obtained by an independent expert panel decision (EPD) based on clinical data, electrocardiogram, coronary angiography, and blinded information from the imaging modalities. RESULTS: Sixty-seven patients were found to have an RWMA by EPD. Interobserver agreement expressed as kappa coefficient was 0.41 (range 0.37 to 0.44) for unenhanced echocardiography, 0.43 (range 0.29 to 0.79) for cMRT, 0.56 (range 0.44 to 0.70) for cineventriculography, and 0.77 (range 0.71 to 0.88) for contrast echocardiography. Contrast enhancement compared to unenhanced echocardiography improved agreement of echocardiography related to cMRI (kappa 0.46 vs. 0.29) and related to cineventriculography (kappa 0.59 vs. 0.28). Accuracy to detect EPD-defined RWMA was highest for contrast echocardiography, followed by cMRI, unenhanced echocardiography, and cineventriculography. CONCLUSIONS: Analysis of RWMA is characterized by considerable interobserver variability even using high-quality imaging modalities. Interobserver agreement on RWMA and accuracy to detect panel-defined RWMA is good using contrast echocardiography.

Assessment of systolic left ventricular function: a multi-centre comparison of cineventriculography, cardiac magnetic resonance imaging, unenhanced and contrast-enhanced echocardiography.

AIMS: To assess the agreement of left ventricular ejection fraction (LVEF) determinations from unenhanced echocardiography, contrast-enhanced echocardiography, magnetic resonance imaging (MRI), and cineventriculography as well as the inter-observer agreement for each method. METHODS AND RESULTS: In 120 patients, with evenly distributed EF-groups (> 55, 35-55, < 35%), cineventriculography, unenhanced echocardiography with second harmonic imaging, and contrast echocardiography at low mechanical index with iv administration of SonoVue were performed. In addition, cardiac MRI at 1.5 T using a steady-state free precession sequence was performed in a subset of 55 patients. On-site, and two blinded off-site assessments were performed for unenhanced and contrast echocardiography, cineventriculography, and MRI according to pre-defined standards. Intra-class correlation coefficients (ICCs) were determined to assess inter-observer reliability between all three readers (i.e. one on-site and two off-site). EF was 56.2 +/- 18.3% by cineventriculography, 54.1 +/- 12.9% by MRI, 50.9 +/- 15.3% by unenhanced echocardiography, and 54.6 +/- 16.8% by contrast echocardiography. Correlation on EF between cineventriculography and echocardiography increased from 0.72 with unenhanced echocardiography to 0.83 with contrast echocardiography (P < 0.05). Similarly, correlation on EF between MRI and echocardiography increased from 0.60 with unenhanced echocardiography to 0.77 with contrast echocardiography (P < 0.05). The inter-observer reliability ICC was 0.91 (95% CI 0.88-0.94) in contrast echocardiography, followed by cardiac MRI (0.86; 95% CI 0.80-0.92), cineventriculography (0.80; 95% CI 0.74-0.85), and unenhanced echocardiography (0.79; 95% CI 0.74-0.85). CONCLUSIONS: Unenhanced echocardiography resulted in slight underestimation of EF and only moderate correlation compared with cineventriculography and MRI. Contrast echocardiography resulted in more accurate EF and significantly improved correlation with cineventriculography and MRI. Contrast echocardiography significantly improved inter-observer agreement on EF compared with unenhanced echocardiography. Inter-observer reliability on EF using contrast echocardiography reaches a level comparable to MRI and is better than those obtained by cineventriculography.

Echoscintigraphy: a new imaging modality for the reduction of color blooming and acoustic shadowing in contrast sonography.

The purpose of this study was to develop and evaluate a new imaging modality (echoscintigraphy) to reduce color blooming and acoustic shadowing in contrast sonography. After injection of various amounts (700 to 40,000 bubbles/mL) of the echo contrast agent SH-U 563A into a flow phantom, artificial vessels were insonated in the intermittent harmonic-power Doppler imaging (H-PDI) mode. The receive gain was varied from 50% to 75%. The cross-sectional area (CSA) of the tube was assessed using a new summation algorithm (echoscintigraphy) and a conventional single-frame analysis (S-FA) of the H-PDI-signals. Echoscintigraphy is based on the recording and summation of low-intensity signals that are emitted during the ultrasound (US)-induced destruction of microbubbles. Application of the summation algorithm at low-contrast concentration allowed a gain-independent automatic calculation of the CSA at medium and high gain settings. Using the S-FA method, the assessment of the vessel diameter and the CSA was gain-dependent and allowed correct measurements only from 60% to 65% gain. At a high receive-gain and high contrast concentration, S-FA resulted in an overestimation of the CSA up to 35.5%. Echoscintigraphy allows correct display of contrast-filled vessels over a wide range of gain settings at low contrast concentrations, where S-FA does not adequately display echo contrast. Thus, echoscintigraphy minimizes artefacts resulting from color blooming and acoustic shadowing.