Real-time Myocardial Contrast Echocardiography Research Articles

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

ObjectiveThe 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...

Myocardial blood flow assessment in cardiac amyloidosis using myocardial contrast echocardiography

Cardiac amyloidosis (CA) patients may present with angina and coronary syndromes. Cardiac biomarkers are chronically elevated in some cases. Many proceed with coronary investigation which often reveals angiographically patent vessels. An explanation for their presentation is thought to be due to microvascular amyloid deposition resulting in microvascular dysfunction. We performed vasodilator myocardial contrast echocardiography (MCE) on a patient with CA to assess myocardial blood flow reserve (MBFR). She previously had patent epicardial coronary arteries on coronary angiography and a normal dobutamine stress echocardiogram. Real-time MCE was performed according to an established protocol using a commercial ultrasound machine and contrast agent. Images were recorded in the 3 apical views with low-power settings at a mechanical index of 0.1. Flash-impulse imaging at a high mechanical index (1.0) was performed to achieve complete myocardial bubble destruction, after which 10 end-systolic frames were recorded digitally in each view. Imaging was repeated after dipyridamole infusion. Background-subtracted plots of peak myocardial contrast intensity (representingmyocardial blood volume A) versus pulsing intervals (representing time) were constructed by QLab software to fit the monoexponential function conventional equation: y=A (1−e− t). From these plots, the slope of the replenishment curve was determined (representing myocardial blood velocity ). Per segment, the product of A and yielded rest MBF and post-dipyridamole MBFs (stress MBF), respectively. MBFR was calculated as the ratio of peak MBF to resting MBF. The results show a marked reduction in MBFR. This supports the hypothesis of microvascular dysfunction and adds to our pathophysiological understanding of this challenging condition.

The myocardial ischemia evaluated by real-time contrast echocardiography may predict the response to cardiac resynchronization therapy: a large animal study.

Evidence-based criteria for applying cardiac resynchronization therapy (CRT) in patients with ischemic cardiomyopathy are still scarce. The aim of the present study was to evaluate the predictive value of real-time myocardial contrast echocardiography (RT-MCE) in a preclinical canine model of ischemic cardiomyopathy who received CRT. Ischemic cardiomyopathy was produced by ligating the first diagonal branch in 20 beagles. Dogs were subsequently divided into two groups that were either treated with bi-ventricular pacing (CRT group) or left untreated (control group). RT-MCE was performed at baseline, before CRT, and 4 weeks after CRT. Two-dimensional speckle tracking imaging was used to evaluate the standard deviation of circumferential (Cir12SD), radial (R12SD), and longitudinal (L12SD) strains of left ventricular segments at basal as well as middle levels. Four weeks later, the Cir12SD, R12SD, and myocardial blood flow (MBF) of the treated group were significantly improved compared to their non-CRT counterparts. Furthermore, MBF values measured before CRT were significantly higher in responders than in non-responders to bi-ventricular pacing. Meanwhile, no significant differences were observed between the responder and non-responder groups in terms of Cir12SD, R12SD, and L12SD. A high degree of correlation was found between MBF values before CRT and LVEF after CRT. When MBF value>24.9 dB/s was defined as a cut-off point before CRT, the sensitivity and specificity of RT-MCE in predicting the response to CRT were 83.3% and 100%, respectively. Besides, MBF values increased significantly in the CRT group compared with the control group after 4 weeks of pacing (49.8±15.5 dB/s vs. 28.5±4.6 dB/s, p<0.05). Therefore, we considered that myocardial perfusion may be superior to standard metrics of LV synchrony in selecting appropriate candidates for CRT. In addition, CRT can improve myocardial perfusion in addition to cardiac synchrony, especially in the setting of ischemic cardiomyopathy.

Effects of Insulin Resistance on Myocardial Blood Flow and Arterial Peripheral Circulation in Patients with Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) is associated with increased risk for cardiovascular disease. We sought to evaluate the effects of insulin resistance (IR) on myocardial microcirculation and peripheral artery function in patients with PCOS. We studied 55 women (28 with PCOS without IR, 18 with PCOS and IR and 11 normal controls) who underwent laboratorial analysis, high-resolution vascular ultrasound and real time myocardial contrast echocardiography (RTMCE). Intima-media thickness (IMT) and brachial artery flow-mediated dilation (FMD) were evaluated by vascular ultrasound. The replenishment velocity (β), plateau of acoustic intensity (A) and myocardial blood flow reserve (MBFR) were determined by quantitative dipyridamole stress RTMCE. β reserve in group PCOS+IR was lower than control (2.34±0.55 vs. 3.60±0.6; P<0.001) and than PCOS without IR (2.34±0.55 vs. 3.17±0.65; P < 0.001). MBFR in patients with PCOS without IR did not differ from those of control (4.59±1.59 vs. 5.30±1.64; P =0.22) or from patients with PCOS+IR (4.59±1.59 vs. 3.70±1.47; P =0.07). When comparing with control group, patients with PCOS+IR had lower MBFR (5.30±1.64 vs. 3.70±1.47; P=0.01). No significant differences were found between control, PCOS without IR and PCOS+IR for FMD (0.18±0.05, 0.15±0.04 and 0.13±0.07; P =NS) or IMT (0.48±0.05, 0.47±0.05 and 0.49±0.07; P=NS). Women with PCOS and IR had depressed β and MBFR as demonstrated by quantitative RTMCE, but no alteration in endothelial dysfunction or IMT. PCOS without IR showed isolated depression in β reserve, probably an earlier marker of myocardial flow abnormality.

RELATIONSHIP BETWEEN HBA1C AND CORONARY FLOW RESERVE IN PATIENTS WITH TYPE 2 DIABETES MELLITUS: A REAL-TIME MYOCARDIAL CONTRAST ECHOCARDIOGRAPHY STUDY

We examined the relationship between glycosylated hemoglobin (HbA1c) and coronary flow reserve (CFR) in type 2 diabetes mellitus (DM) pts using real-time myocardial contrast echocardiography (RTMCE). We prospectively enrolled 24 pts (16 male; 66±12 yrs, DM duration 8±6 yrs, 42% smokers, 83% HTN,

QUANTITATIVE ASSESSMENT OF MYOCARDIAL BLOOD FLOW RESERVE USING DEFINITY DURING REGADENOSON VASODILATOR STRESS REAL-TIME MYOCARDIAL CONTRAST ECHOCARDIOGRAPHY FOR DETECTION OF LEFT ANTERIOR DESCENDING CORONARY ARTERY STENOSIS

To assess the feasibility and diagnostic accuracy of quantitative real-time myocardial contrast echocardiography (RTMCE) during regadenoson (Reg) (Astellas Pharma Inc) vasodilator stress for detection of significant Left anterior descending (LAD) stenosis (≥ 50% or ≥ 70% by quantitative coronary

Resting qualitative and quantitative myocardial contrast echocardiography to predict cardiac events in patients with acute myocardial infarction and percutaneous revascularization

Successful restoration of patency of the infarct-related artery is important in management of acute ST-segment elevation myocardial infarction (STEMI); however, it does not necessarily translate into the restoration of perfusion at the tissue level. In this study, we evaluate the prognostic role of qualitative and quantitative myocardial contrast echocardiography (MCE) in predicting cardiac events (after adjustment for cardiovascular risk factors) in STEMI patients undergoing reperfusion. Bedside resting real-time MCE using continuous infusion of diluted contrast agent (Definity) was performed within a median of 21.4 h from revascularization in STEMI. Myocardial perfusion on qualitative MCE was graded 1 = homogenous; 2 = partial/patchy; and 3 = absent. Perfusion score index (PSI) was calculated by adding the perfusion score in all segments divided by the total number of evaluable segments. Quantitative perfusion parameters [A, dB; β, sec(-1); and Aβ] were analyzed using a 17-segment model. Patients were followed for cardiac events including death; nonfatal myocardial infarction (MI); hospitalization for cardiac symptoms; coronary revascularization; or heart failure. Thirty-seven reperfused STEMI patients with a mean age of 64 years (range, 40-86 years) were enrolled and followed for a median of 1.4 years. Cardiac events occurred in 22 patients. Patients with cardiac events had a higher perfusion score index (PSI), and lower A, β and Aβ parameters compared to patients without events [1.84 ± 0.36 vs 1.39 ± 0.17 for PSI, P < 0.001; 0.57 ± 0.24 vs 0.85 ± 0.30 for A, P = 0.03; 0.34 ± 0.15 vs. 0.53 ± 0.17 for β, P = 0.002; and 0.21 ± 0.12 vs. 0.49 ± 0.32, for Aβ, P = 0.003; respectively]. A PSI value of 1.58 provided an area under the curve (AUC) of 0.873, while β of 0.423 and Aβ of 0.323 provided an AUC of 0.858 and 0.842, respectively. PSI and Aβ were independent predictors of cardiac events with an adjusted hazard ratio of 3.41 (1.19-12.27); and 4.19 (1.3-19.09), respectively. No contrast-related side effects were reported. Evaluation of perfusion in reperfused STEMI patients by qualitative and quantitative MCE (myocardial blood flow, Aβ) provides independent prediction of cardiac events.

Coronary flow reserve in the remote myocardium predicts left ventricular remodeling following acute myocardial infarction.

PurposeCoronary flow reserve (CFR) in the non-infarcted myocardium is often impaired following acute myocardial infarction (AMI). However, the clinical significance of CFR in the non-infarcted myocardium is not fully understood. The objective of the present study was to assess whether a relationship exists between CFR and left ventricular remodeling following AMI.Materials and MethodsWe enrolled 18 consecutive patients undergoing coronary intervention. Heart function was analyzed using real-time myocardial contrast echocardiography at one week and six months after coronary angioplasty. Ten subjects were enrolled as the control group and were examined using the same method at the same time to assess CFR. Cardiac troponin I (cTnI) levels were routinely analyzed to estimate peak concentration.ResultsCFR was 1.55±0.11 in the infarcted zone and 2.05±0.31 in the remote zone (p<0.01) at one week following AMI. According to CFR values in the remote zone, all patients were divided into two groups: Group I (CFR <2.05) and Group II (CFR >2.05). The levels of cTnI were higher in Group I compared to Group II on admission (36.40 vs. 21.38, p<0.05). Furthermore, left ventricular end diastolic volume was higher in Group I compared to Group II at six months following coronary angioplasty.ConclusionMicrovascular dysfunction is commonly observed in the remote myocardium. The CFR value accurately predicts adverse ventricular remodeling following AMI.

Myocardial Contrast Echocardiography for the Detection of Coronary Artery Disease in Patients with Global Hypokinesis Admitted for First-Onset Acute Heart Failure: Pilot Study

BackgroundThe non-invasive differentiation of ischemic and nonischemic acute heart failure (AHF) not resulting from acute myocardial infarction is difficult and has therapeutic and prognostic implications. The aim of this study was to assess whether resting myocardial contrast echocardiography (MCE) can detect coronary artery disease (CAD) in patients with decreased left ventricular (LV) systolic function and global hypokinesis presenting with AHF.MethodsTwenty-one consecutive patients underwent low-power real-time MCE based on color-coded pulse inversion Doppler. Standard apical LV views were acquired during contrast IV infusion of Definity®. Following transient microbubbles destruction, the contrast replenishment rate (β), reflecting myocardial blood flow velocity, was derived by plotting signal intensity vs. time and fitting data to the exponential function: y (t) = A (1 - e-β(t-t0)) + C.ResultsOf the 21 (mean age 56.6 ± 13.6 years) patients, 5 (23.8%) demonstrated flow-limiting CAD (> 70% of luminal diameter narrowing). The mean ± standard deviation of LV ejection fraction was 29.6 ± 8.6%. Quantitative MCE analysis was feasible in 258 of 378 segments (68.3%). There were no significant difference in "β" and "Aβ" in patients without and with CAD (0.48 ± 0.27 vs. 0.45 ± 0.25, p = 0.453 for β and 2.99 ± 2.23 vs. 3.68 ± 3.13, p = 0.059 for Aβ, respectively). No contrast-related side effects were reported.ConclusionResting quantitative MCE analysis in patients with AHF was feasible, however, the parameters did not aid in detecting of CAD.

GW24-e0061 Microvascular dysfunction in remote myocardium predict left ventricular remodelling in acute infarction

ObjectivesCoronary flow reserve in the non-infarcted myocardium has been reported to be impaired after the onset of myocardial infarction, however, the clinical significance of microvascular dysfunction in the non-infarcted myocardium...

The Value of Quantitative Real‐Time Myocardial Contrast Echocardiography for Detection of Angiographically Significant Coronary Artery Disease

Real-time (RT) myocardial contrast echocardiography (MCE) is a novel method for the assessment of regional myocardial perfusion. We sought to evaluate the feasibility and diagnostic accuracy of quantitative RT-MCE in predicting significant coronary stenosis, with reference to quantitative coronary angiography. RT-MCE can identify anatomically significant coronary artery stenosis in selected patients. RT-MCE is probably an effective method for detection of angiographically significant coronary artery stenosis. Thirty-five patients (mean age, 59.94 ± 10.63 years; 25 males) scheduled for coronary angiography underwent RT-MCE at rest, and shortly afterward underwent gated single-photon emission computed tomography (gated-SPECT). Coronary angiography was performed within 1 week after RT-MCE in all patients. The observing indexes included the images of RT-MCE that were analyzed quantitatively from microbubble replenishment curves for myocardial perfusion by using the Q-Lab software. The sensitivity and specificity of RT-MCE for quantitative detection of coronary artery disease (CAD) were obtained. The receiver operator characteristic (ROC) curves were used to assess the differences of accuracy in ischemic segments with A, β and A × β respectively. The sensitivity and specificity of gated-SPECT and RT-MCE for assessment of CAD were calculated using a 4-score method. A total of 513 segments among 595 segments in 35 patients were obtained. The cutoffs for A, β and A × β were 4.58, 0.64, and 2.73, and the sensitivity and specificity of quantitative RT-MCE for detection of CAD were 86.0%, 80.2%, 88.9%, and 84.1%, 64.6%, 79.9%, respectively. Meanwhile, the sensitivity and specificity of semiquantitative analysis for assessment of CAD were 66.7% and 61.8%. The ROC curve area of A and A × β was 0.91 and 0.90 in the middle segments. The ROC area of A was 0.52 in the base segments. The sensitivity and specificity of gated-SPECT for assessment of CAD were 84.8% and 82.7%, respectively. The sensitivity of multi-indexes RT-MCE increased. The sensitivity was 89.1%, 90.4%, and 96.3% by A + β, A + A × β, and β + A × β. Quantitative RT-MCE is an effective method for the detection of coronary artery stenosis. Quantitative RT-MCE is segmented for assessment to ischemic myocardium. RT-MCE with multi-indexes has a valuable application for assessment of CAD surpassing SPECT.

Patient Outcome Following 2 Different Stress Imaging Approaches: A Prospective Randomized Comparison

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.Myocardial perfusion imaging with RTMCE may improve the detection of coronary artery disease (CAD), and predict patient outcome.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.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.Perfusion imaging with RTMCE improves the detection of CAD during stress echocardiography, and identifies those more likely to undergo revascularization following an abnormal study.

Broken Heart Syndrome, Neurogenic Stunned Myocardium and Stroke

The diagnosis of stress cardiomyopathy is often made during coronary angiography. At this point hemodynamic parameters should be assessed; a right heart catheterization with measurement of cardiac output by Fick and thermodilution methods is helpful. Patients with acute neurologic pathology who develop left ventricular dysfunction (neurogenic stunned myocardium) may not be candidates for coronary angiography and in such cases real-time myocardial contrast echocardiography or nuclear perfusion scan can be used to exclude obstructive coronary disease. Hypotension and shock can be due to low output state or left ventricular outflow tract obstruction. Low output state can be managed with diuretics and vasopressor support. Refractory shock and/or severe mitral regurgitation may require an intra-aortic balloon pump for temporary support. In patients with intraventricular gradient intravenous beta-blockers have been used safely. Hemodynamically unstable patients should be managed in a critical care unit and stable patients should be monitored on a telemetry unit as arrhythmias may occur. An echocardiogram should be performed to look for intraventricular gradient, mitral regurgitation, or left ventricular thrombus. If left ventricular thrombus is seen or suspected anticoagulation with warfarin or low molecular weight heparin is generally advised until recovery of myocardial function and resolution of thrombus occurs. In patients with subarachnoid hemorrhage the use of vasopressors to reduce cerebral vasospasm may worsen left ventricular outflow tract gradient. In hemodynamically stable patients, a beta-blocker or combined alpha/beta blocker should be initiated. Myocardial function generally recovers within days to weeks with supportive treatment in most patients. The use of a standard heart failure regimen including an angiotensin-converting enzyme inhibitor or aldosterone receptor antagonist, beta-blocker titrated to maximal dose, diuretics, and aspirin is common until complete recovery of myocardial function occurs. Chronic therapy with a beta-blocker may be advisable. The underlying diagnosis that precipitated stress cardiomyopathy such as critical illness, neurologic injury, or medication exposure should be identified and treated.

Incremental Value of Perfusion over Wall‐Motion Abnormalities with the Use of Dobutamine–Atropine Stress Myocardial Contrast Echocardiography and Magnetic Resonance Imaging for Detecting Coronary Artery Disease

Recently, multimodality imaging has been demonstrated to improve the sensitivity of dobutamine stress for the diagnosis of coronary artery disease (CAD). We sought to determine the additional value of myocardial perfusion (MP) over wall-motion (WM) analysis for detecting CAD, using real time myocardial contrast echocardiography (RTMCE) and cardiovascular magnetic resonance (CMR), in the same group of patients. We studied 42 patients who underwent RTMCE and CMR during high-dose dobutamine stress with early injection of atropine. No difference was observed in the diagnostic accuracy of RTMCE and CMR for detecting angiographically significant CAD when considering WM analysis alone (73% [95% CI, 65-81] and 78% [95% CI, 70-84], respectively; P = NS) or combined analysis of WM and MP (80% [95% CI, 73-97] and 83% [95% CI, 77-90], respectively; P = NS). Combined analysis of WM and MP had higher sensitivity than the analysis of WM alone by RTMCE (88% [95% CI, 75-100] vs. 72% [95% CI, 54-90]) and by CMR (92% [95% CI, 81-100] vs. 80% [95% CI, 64-96]) with no differences in specificity. The association of abnormal WM and MP abnormalities during high-dose dobutamine-atropine stress had additional value for detecting CAD over the analysis of WM alone, both by RTMCE (χ(2) = 16.16-24.13; P = 0.005) and CMR (χ(2) = 12.73-27.41; P = 0.001). RTMCE and CMR using the same dobutamine-atropine stress protocol had comparable diagnostic accuracies for the detection of angiographically significant CAD. MP imaging had additional value over WM analysis for the diagnosis of CAD, both at RTMCE and CMR.

Prospective Randomized Comparison of Conventional Stress Echocardiography and Real-Time Perfusion Stress Echocardiography in Detecting Significant Coronary Artery Disease

Although retrospective studies have suggested that myocardial perfusion and wall motion analysis with real-time myocardial contrast echocardiography (RTMCE) improves the detection of coronary artery disease (CAD) during dobutamine or exercise stress echocardiography, a prospective randomized comparison with conventional stress echocardiography that did not use RTMCE has not been performed. A total of 1,776 patients with preserved resting left ventricular wall motion undergoing dobutamine or exercise stress echocardiography for suspicion of CAD were randomized to either non-RTMCE, for which contrast was used only for the approved indication of enhancing left ventricular opacification, or RTMCE, for which contrast infusion was used in all cases to examine both wall motion and myocardial perfusion. Comparisons in test positivity, and positive predictive value in those subsequently referred for quantitative coronary angiography, were performed. Patients randomized to RTMCE had significantly higher test positivity (22% for RTMCE vs 15% with non-RTMCE, P= .0002). The increased test positivity occurred without a difference in positive predictive value in predicting >50% diameter stenoses by quantitative coronary angiography (67% for non-RTMCE, 73% for RTMCE). The mechanism for increased detection of CAD with RTMCE was mostly due to the detection of subendocardial wall thickening abnormalities that would have gone undetected when examining transmural wall thickening. RTMCE improves the detection of CAD during dobutamine and exercise stress echocardiography, mainly by the detection of subendocardial ischemia.

Atorvastatin Treatment Improves Myocardial and Peripheral Blood Flow in Familial Hypercholesterolemia Subjects without Evidence of Coronary Atherosclerosis

Hypercholesterolemia induces early microcirculatory functional and structural alterations that are reversible by cholesterol reduction. Real time myocardial contrast echocardiography (RTMCE) and vascular ultrasound evaluate the effects of hyperlipidemia on peripheral and central blood flow reserve. This study investigated the effects of lipid-lowering therapy on coronary and peripheral artery circulation in patients with familial hypercholesterolemia (FH). RTMCE and vascular ultrasound were performed in 10 healthy volunteers (validation group) at baseline and after 12-week clinical observation, and in 16 age- and sex-matched FH patients without obstructive coronary artery disease (CAD) by computed tomography angiography at baseline and after 12-week atorvastatin treatment. Indexes of relative myocardial blood flow (MBF) were obtained at rest and during adenosine infusion. In validation group, there was no significant difference between flow-mediated dilation (FMD) at baseline and after 12 weeks (0.15 ± 0.02 vs. 0.14 ± 0.03; P = 0.39). Similarly, no differences were observed in MBF reserve at baseline and after 12 weeks (3.31 ± 0.63 vs. 3.48 ± 0.89; P = 0.89). FMD was blunted in FH patients, at baseline, as compared with validation group (0.08 ± 0.04 vs. 0.15 ± 0.02; P < 0.001) and became similar to that group (0.13 ± 0.05 vs. 0.14 ± 0.03; P = 0.07) after treatment. MBF reserve was blunted at baseline in FH patients in comparison with the validation group (2.78 ± 0.71 vs. 3.31 ± 0.63; P = 0.003). After treatment, MBF reserve values were no longer different (3.43 ± 0.66 and 3.48 ± 0.89; P = 0.84, respectively, for FH and validation groups). Patients with FH and no obstructive CAD have blunted MBF reserve and lower FMD values as compared with healthy volunteers. Both FMD and MBF reserve were normalized after atorvastatin treatment.

Clinical usefulness of low‐dose dobutamine stress real‐time myocardial contrast echocardiography for detection of viable myocardium

To evaluate and compare the diagnostic accuracy of semi-quantitative and quantitative real-time myocardial contrast echocardiography (RT-MCE) with low-dose dobutamine stress echocardiography (LD-DSE) in detecting viable myocardium. Thirty in-patients with coronary artery disease and regional wall motion abnormalities underwent RT-MCE without and with LD-DSE. Percutaneous coronary intervention was performed within 1 week after RT-MCE in all patients. Myocardial perfusion was evaluated from A, β, and A × β indices from microbubble replenishment curves. The motion of each myocardium segment was observed by routine echocardiography 1, 3, and 6 months after percutaneous coronary intervention and its improvement over time was the criterion of viable myocardium. RT-MCE sensitivity and specificity for the assessment of viable myocardium were 71.7% and 69.8%, rising to 81.3% and 76.7% (p < 0.05) when combined with LD-DSE. Using quantitative RT-MCE with cutoff values of A, β, and A × β, the sensitivity and specificity were 75.6%, 78.8%, 82.1%, and 82.4%, 77.9%, 78.6%, respectively. When combined with LD-DSE, the sensitivity and specificity were 86.0%, 83.2%; 88.9% and 84.1%; 89.6%, 79.9%, respectively. Quantitative RT-MCE analysis yielded higher sensitivity and specificity than semi-quantitative RT-MCE with or without LD-DSE for the detection of viable myocardium.

Clinical Usefulness of Myocardial Contrast Echocardiography to Detect Stress-Induced Cardiomyopathy in the Emergency Department

The purpose of this study was to investigate the clinical usefulness of myocardial contrast echocardiography (MCE) to distinguish stress-induced cardiomyopathy (SCMP) from acute myocardial infarction (AMI) in the emergency department (ED). We investigated 51 patients (62±13 years, 29 women) who had suspected SCMP in the ED with acute chest pain and showed apical wall motion abnormality on 2-dimensional echocardiography. All patients were assessed by real-time MCE and the perfusion status and quantitative myocardial perfusion parameters were analyzed. After MCE, coronary angiography was performed within 24h. Of 51 patients, 27 had significant perfusion defects (group A) and 24 had preserved perfusion at the apex (group B) by MCE. In group A, 25 patients showed significant luminal stenosis in the left anterior descending artery (LAD) and 2 patients showed no critical luminal stenosis. In group B, 20 patients showed no luminal stenosis and 4 patients showed moderate LAD stenosis. Sensitivity, specificity, positive and negative predictive values of MCE for detection of SCMP were 91%, 86.2%, 83%, and 93%, respectively. Quantitative MCE parameters were significantly decreased in group A compared with group B. Myocardial perfusion measured by MCE is relatively preserved in patients with SCMP compared with those with AMI. Therefore, real-time MCE may be a useful noninvasive diagnostic tool to distinguish SCMP from AMI in the ED.

Assessment of myocardial perfusion by the microbubble replenishment parameters of real-time myocardial contrast echocardiography

Objective To assess myocardial perfusion by the end-systolic and end-diastolic replenishment parameters of real-time myocardial contrast echocardiography (MCE).Methods Twenty-one patients with myocardial infarction(MI) and normal control group of 6 cases underwent intravenous realtime myocardial contrast echocardiography via slow and homogeneous venous injections of SonoVue.MCE images were obtained from the apical 4-chamber,2-chamber,and long-axis views.According to the exponential function:y(t) =A [1 - e-kt] + B,the time intensity curves were obtained.By an off-line ECG triggering and curve fitting,the replenishment parameters A value,k value,A × k value were obtained separately from end-systolic and end-diastolic images.Results In normal control group,the end-systolic replenishment parameters A value,k value,A × k value were all lower than that of the end-diastolic replenishment parameters[(6.21 ± 2.69)dB vs (7.93 ± 3.66)dB,P ＜0.05；0.36 ± 0.15 vs 0.42 ± 0.19,P ＜ 0.01 ;2.88 ± 1.29 vs 3.39 ± 1.61,P ＜0.05,respectively].The end-diastolic replenishment parameters were found significantly greater variability than the end-systolic values (variation coefficient CV:A value 46.2％ vs 43.3％,k value 45.2％ vs 41.4％,A× k value 47.5％ vs 44.8％,all P ＜0.05).In 21 patients,the end-systolic replenishment parameters in myocardial segments supplied by infarct-related coronary artery were significantly lower than that in myocardial segments supplied by non - infarct - related coronary artery.Conclusions The end-systolic and end-diastolic replenishment parameters of real time myocardial contrast echocardiography can assess myocardial perfusion.The variability of the end-systolic replenishment parameters is smaller than that of the end diastolic parameters.Significant variability in k-value suggests that this parameter is best suited for before-after study in the same patient. Key words: Echocardiography; Myocardial infarction; Myocardial reperfusion

Real-time myocardial contrast echocardiography as a useful tool to select candidates for coronary revascularization among patients with end-stage renal disease – a 3-year follow-up study

To evaluate a real-time myocardial contrast echocardiography (MCE) as a tool to select candidates for coronary revascularization among patients with ESRD and to assess the rate of revascularization and mortality. 58 ESRD patients were screened for CAD using MCE. We analyzed the rate of coronary revascularization during 3-year follow-up. Patients with and without perfusion disturbances on MCE were compared. CAD was found in 46.2% patients out of 39 who underwent coronary angiography. 11 (39.3%) patients out of 28 from the group with perfusion defects on MCE underwent revascularization procedure (21.4% - PCI, 17.9% - CABG). No one from the group without perfusion defects had revascularization procedure. Perfusion defect (OR 1.37 CI 1.37-1.86, p=0.022) was related to revascularization in multivariant analysis (OR 12.87, CI 1.86-89.21, p=0.025). There was no difference in mortality between the group which underwent invasive procedures and treated conservatively (p=0.6643). In ROC analysis defects on MCE and CAD on angiography were equally good in anticipating combined end-point (AUC 0.716, CI 95% 0.544-0.851 and AUC 0.747, CI 95% 0.577-0.875, p=0.701) and death (AUC 0.752, CI 95% 0.582-0.878 and AUC 0.729, CI 95% 0.558-0.861, p=0.805). Our results indicate that MCE is a safe and uncomplicated method which may help along with other methods to select candidates for coronary revascularization among ESRD patients. In our study coronary revascularization procedures were successful but they did not improve patients' survival on 3-year follow-up.