Myocardial Contrast Echocardiography In Patients Research Articles

Microvascular perfusion and cardiac function after revascularization assessed by myocardial contrast echocardiography in patients with acute ST-segment elevation myocardial infarction

Objectives: To evaluate microvascular perfusion and left ventricular function in patients with acute ST-segment elevation myocardial infarction after revascularization using myocardial contrast echocardiography (MCE), and to explore clinical influencing factors of abnormal microvascular perfusion in these patients. Methods: This is a cross-sectional study. The analysis was performed among patients admitted to Peking University People's Hospital for acute ST-segment elevation myocardial infarction (STEMI) from June 2018 to July 2021. All patients underwent percutaneous coronary intervention (PCI) and completed MCE within 48 hours after PCI. Patients were divided into normal myocardial perfusion group and abnormal perfusion group according to the myocardial perfusion score. The echocardiographic indexes within 48 hours after PCI, including peak mitral valve flow velocity (E), mean value of early diastolic velocity of left ventricular septum and lateral mitral annulus (Em), left ventricular global longitudinal strain (GLS) and so on, were analyzed and compared between the two groups. Multivariate logistic regression analysis was used to evaluate the influencing factors of myocardial perfusion abnormalities. Results: A total of 123 STEMI patients, aged 59±13 years with 93 (75.6%) males, were enrolled. There were 50 cases in the normal myocardial perfusion group, and 73 cases in the abnormal myocardial perfusion group. The incidence of abnormal myocardial perfusion was 59.3% (73/123). The left ventricular volume index ((62.3±18.4)ml/m2 vs. (55.1±15.2)ml/m2, P=0.018), wall motion score index (WMSI) (1.59 (1.44, 2.00) vs. 1.24(1.00, 1.47), P<0.001) and mitral E/Em (17.8(12.0, 24.3) vs. 12.2(9.2, 15.7), P<0.001) were significantly higher whereas left ventricular global longitudinal strain (GLS) ((-10.8±3.4)% vs. (-13.8±3.5)%, P<0.001) was significantly lower in the abnormal myocardial perfusion group than those in the normal myocardial perfusion group. Multivariate logistic regression analysis showed that left anterior descending (LAD) as culprit vessel (OR=3.733, 95%CI 1.282-10.873, P=0.016), intraoperative no/low-reflow (OR=6.125, 95%CI 1.299-28.872, P=0.022), and peak troponin I (TnI) (OR=1.018, 95%CI 1.008-1.029, P=0.001) were independent risk factors of abnormal myocardial perfusion. As for ultrasonic indexes, deceleration time of mitral E wave (OR=0.979, 95%CI 0.965-0.993, P=0.003), mitral E/Em (OR=1.100, 95%CI 1.014-1.194, P=0.022) and WMSI (OR=7.470, 95%CI 2.630-21.222, P<0.001) were independently related to abnormal myocardial perfusion. Conclusions: The incidence of abnormal myocardial perfusion after PCI is high in patients with acute STEMI. Abnormal myocardial perfusion is related to worse left ventricular systolic and diastolic function. LAD as culprit vessel, intraoperative no/low-reflow and peak TnI are independent risk factors of abnormal myocardial perfusion.

Long-Term Prognostic Value of Myocardial Viability by Myocardial Contrast Echocardiography in Patients after Acute Myocardial Infarction: A Systematic Review and Meta-Analysis.

Background and Objectives: According to recent guidelines, myocardial contrast echocardiography (MCE) is recommended for detecting residual myocardial viability (MV). However, the long-term prognostic value of MV as assessed by MCE in identifying major adverse cardiac events (MACE) after acute myocardial infarction (AMI) remains undefined. Materials and Methods: We searched multiple databases, including PubMed, EMBASE, and Web of Science for studies on the prognostic value of MCE for clinical outcomes in AMI patients. The primary endpoints were MACEs during follow-up. Six studies that evaluated a total of 536 patients with a mean follow-up of 36.8 months were reviewed. Results: The pooled sensitivity and specificity of MCE for predicting MACEs were 0.80 and 0.78, respectively, and the summary operating receiver characteristics achieved an area under the curve of 0.84. The pooled relative risks demonstrated that the MV evaluated by MCE after AMI was correlated with a high risk for total cardiac events (pooled relative risk: 2.07; 95% confidence interval: 1.28–3.37) and cardiac death (pooled relative risk: 2.48; 95% confidence interval: 1.03–5.96). MV evaluated by MCE was a highly independent predictor of total cardiac events (pooled hazard ratio: 2.09, 95% confidence interval: 1.14–3.81) in patients after AMI. Conclusions: Residual MV evaluated by MCE may be an effective long-term prognostic tool for predicting MACE in patients after AMI that can provide moderate predictive accuracy. The assessment of MV by MCE may become an alternative technique with the potential to rapidly provide important information for improving long-term risk stratification in patients after AMI, at the bedside in clinical practice, especially for patients who cannot tolerate prolonged examinations. The PROSPERO registration number is CRD42020167565.

Assessment of no-reflow phenomenon by myocardial contrast echocardiography in patients with acute myocardial infarction with ST-segment elevation

Abstract Funding Acknowledgements Type of funding sources: None. Background The noninvasive assessment of myocardial perfusion by echo contrast agents in patients with acute myocardial infarction with ST-segment elevation (STEMI) after successful revascularization is becoming a relevant clinical reality. Perfusion imaging techniques with myocardial contrast echocardiography (MCE) remains the least studied and most promising ultrasound technology for the diagnosis of no-reflow phenomenon. Purpose To study the echocardiographic and angiographic characteristics of the no-reflow phenomenon detected by MCE in patients with STEMI. Methods The study included 43 patients aged from 40 to 82 years in acute stage of myocardial infarction. Patients were divided into two groups: 32 patients characterized by sufficient myocardial reperfusion after revascularization according to MCE results and 11 patients were with the impaired perfusion. Results The patients with impaired perfusion demonstrated a greater size of the left ventricular (LV) asynergy (40.1 ± 2.2% vs 27.4 ± 8.5%, p &amp;lt; 0.001). LV dilatation (LV end-systolic volume 67.3 ± 20.3 ml vs 51.8 ± 17.2 ml, p = 0.015), impaired LV ejection fraction (39.5 ± 3.4% vs 47.2 ± 4.9%, p &amp;lt; 0.001), and significant mitral regurgitation (45.5% vs 3.1%, p = 0.011) with a decrease in DP/DT (979.9 ± 363.4 mmHg/s vs 1565.7 ± 502.8 mmHg/s, p &amp;lt; 0.001) was more often detected in this group. In more than a quarter of these patients, coronary angiography showed no perfusion disorders after revascularization. In the group with impaired perfusion by MCE, the single-vascular lesions (46.9% vs 9.1%, p = 0.033), the lesions of the anterior interventricular artery (90.9% vs 40.6%, p = 0.004), and acute occlusion (100% vs 68.8%, p = 0.043) were more often determined. Conclusion According to the results of MCE, the echo signs of LV dysfunction were more pronounced after successful revascularization in patients with STEMI and myocardial perfusion disorders. The SYNTAX score was twice higher in these patients compared to the patients with recovered perfusion. In addition, no-reflow phenomenon by MCE was observed in the most patients with anterior interventricular artery lesion.

107 The long term prognostic value of dipyridamole stress myocardial contrast echocardiography in comparison with single photon emission tomography in patients with known or suspected coronary artery disease

BackgroundSingle photon emission computed tomography (SPECT) is a well-established method to evaluate patients with coronary artery disease (CAD). Myocardial contrast echocardiography (MCE) is an imaging technique that allows assessment of...

Prognostic Value of Myocardial Perfusion Analysis in Patients with Coronary Artery Disease: A Meta-Analysis

Myocardial perfusion (MP) imaging during stress myocardial contrast echocardiography (MCE) improves the detection of coronary artery disease (CAD). However, its prognostic value to predict cardiac events in patients with known or suspected CAD is still undefined. A search was conducted for single- or multicenter prospective studies that evaluated the prognostic value of stress MCE in patients with known or suspected CAD. A database search was performed through June 2015. Effect sizes of relative risk ratios (RRs) with their corresponding 95% CIs were used to evaluate the association between the occurrence of total cardiac events (cardiac death, nonfatal myocardial infarction, coronary revascularization) and hard cardiac events (cardiac death and nonfatal myocardial infarction) in subjects with normal and abnormal MP measured by MCE. The Cochran Q statistic and the I2 statistic were used to assess heterogeneity. A comprehensive literature search of the MEDLINE, Google Scholar, Cochrane, and Embase databases identified 11 studies enrolling a total of 4,045 patients. The overall analysis of RRs revealed that patients with abnormal MP were at higher risk for total cardiac events compared with patients with normal MP (RR, 5.58; 95% CI, 3.64-8.57; P<.001), with low heterogeneity among trials (I2=48.15%, Q=7.71, P=.103). Similarly, patients with abnormal MP were at higher risk for hard cardiac events compared with patients with normal MP (RR, 4.99; 95% CI, 1.75-14.32; P=.003), with significant heterogeneity among trials (I2=81.48%, Q=21.59, P<.001). The results of this meta-analysis suggest that MP assessment using stress MCE is an effective prognostic tool for predicting the occurrence of cardiac events in patients with known or suspected CAD.

Comparison Between Coronary Flow Reserve Obtained by Doppler and Myocardial Blood Flow Reserve Obtained by Myocardial Contrast Echocardiography in Patients With Dilated Cardiomyopathy

Comparison Between Coronary Flow Reserve Obtained by Doppler and Myocardial Blood Flow Reserve Obtained by Myocardial Contrast Echocardiography in Patients With Dilated Cardiomyopathy

Prognostic value of real time dobutamine stress myocardial contrast echocardiography in patients with chest pain syndrome

The aims of this study were (1) to evaluate the prognostic value of negative wall motion (WM) and myocardial perfusion during contrast-dobutamine stress echocardiography (DSE), (2) to determine whether WM-myocardial contrast echocardiography (MCE) had incremental prognostic value over just WM during DSE in patients with chest pain in the emergency room (ER), and (3) to compare the prognostic value of negative DSE-WM, and DSE-WM-MCE to nuclear-myocardial perfusion imaging (N-MPI) in a similar patient population over the same time period. We retrospectively studied 569 patients with real time contrast DSE, and 147 patients underwent N-MPI for evaluation of chest pain. Follow-up for cardiac events was obtained between 12 and 25 months. The cumulative cardiac event-free survival was 94.5% in negative DSE-WM, 97.1% in negative DSE-WM-MCE and 96.7% in negative N-MPI group. Cardiac event-free survival of the negative DSE-WM-MCE group was significantly higher than the DSE-WM group (log rank P < 0.01), and similar in the DSE-WM-MCE group compared to the N-MPI group. Combined WM and perfusion during DSE was the strongest independent predictor for cardiac events. The negative predictive power of DSE-WM-MCE is superior to that of just negative DSE-WM and is comparable to that of N-MPI. Myocardial perfusion and WM analysis during DSE provide independent information for predicting cardiac events in patients with chest pain syndrome in the ER.

Abstract 9420: Detection Of No-Reflow Phenomenon by Three-Dimensional (3D) Myocardial Contrast Echocardiography in Patients with Acute Myocardial Infarction

Backgrounds: No-reflow phenomenon observed after percutaneous coronary intervention (PCI) determines clinical and functional outcomes in patients with acute myocardial infarction (AMI). Myocardial contrast echocardiography (MCE) is one of the established methods to detect no-reflow after AMI. However, MCE using 2D echocardiography has only limited view of left ventricle, and it might evaluate myocardial perfusion inappropriately. We investigated the feasibility of MCE using three-dimensional echocardiography (3D-MCE) to assess myocardial perfusion after AMI. Methods and Results: We performed MCE study in 50 patients with AMI 15 minutes after successful primary PCI, using iE33 (Philips Medical Systems). We injected 3 mL of sonicated contrast agent containing microbubbles into a culprit coronary artery, and recorded an apical 2D-MCE image. Then, we recorded a full-volume 3D-MCE image with another injection of contrast agent. We obtained 7 short axis (SAX) images from one 3D data set, as shown in Figure. Myocardial perfusion in each segment was scored as good=0, poor=1, no-reflow=2, and sum of the score was calculated as a perfusion defect (PD) score. We determined ejection fraction (EF) and wall motion score index (WMSI), as an average of segmental score (0=normokinesis to 4=dyskinesis), on echocardiography recorded at 7.4±4.6 month later. Myocardial perfusion was successfully evaluated in 673/767 (87.7%) segments within risk area in SAX images on 3D-MCE. PD score in 2D-MCE showed no correlation with CK-MB (R 2 =0.08, p=0.06), EF (R 2 =0.03, p=0.26) and WMSI (R 2 =0.04, p=0.19) on follow-up echocardiography. On the other hand, PD score on 3D-MCE was significantly correlated with CK-MB (R 2 =0.56, p&lt;0.0001), WMSI (R 2 =0.40, p&lt;0.0001). It was also weakly but significantly correlated with EF (R 2 =0.10, p=0.02). Conclusions: 3D-MCE detected no-reflow after PCI and predicted functional recovery in patients with AMI more precisely than 2D-MCE.

Acute Hypoglycemia Decreases Myocardial Blood Flow Reserve in Patients With Type 1 Diabetes Mellitus and in Healthy Humans

Hypoglycemia is associated with increased cardiovascular mortality, but the reason for this association is poorly understood. We tested the hypothesis that the myocardial blood flow reserve (MBFR) is decreased during hypoglycemia using myocardial contrast echocardiography in patients with type 1 diabetes mellitus (DM) and in healthy control subjects. Twenty-eight volunteers with DM and 19 control subjects underwent hyperinsulinemic clamps with maintained sequential hyperinsulinemic euglycemia (plasma glucose, 90 mg/dL [5.0 mmol/L]) followed by hyperinsulinemic hypoglycemia (plasma glucose, 50 mg/dL [2.8 mmol/L]) for 60 minutes each. Low-power real-time myocardial contrast echocardiography was performed with flash impulse imaging using low-dose dipyridamole stress at baseline and during hyperinsulinemic euglycemia and hyperinsulinemic hypoglycemia. In control subjects, MBFR increased during hyperinsulinemic euglycemia by 0.57 U (22%) above baseline (B coefficient, 0.57; 95% confidence interval, 0.38 to 0.75; P<0.0001) and decreased during hyperinsulinemic hypoglycemia by 0.36 U (14%) below baseline values (B coefficient, -0.36; 95% confidence interval, -0.50 to -0.23; P<0.0001). Although MBFR was lower in patients with DM at baseline by 0.37 U (14%; B coefficient, -0.37; 95% confidence interval, -0.55 to -0.19; P=0.0002) compared with control subjects at baseline, the subsequent changes in MBFR during hyperinsulinemic euglycemia and hyperinsulinemic hypoglycemia in DM patients were similar to that observed in control subjects. Finally, the presence of microvascular complications in the patients with DM was associated with a reduction in MBFR of 0.52 U (24%; B coefficient, -0.52; 95% confidence interval, -0.70 to -0.34; P<0.0001). Hypoglycemia decreases MBFR in both healthy humans and patients with DM. This finding may explain the association between hypoglycemia and increased cardiovascular mortality in susceptible individuals.

Visualization of myocardial hemorrhage with real-time three-dimensional myocardial contrast echocardiography in patients with acute myocardial infarction.

Visualization of myocardial hemorrhage with real-time three-dimensional myocardial contrast echocardiography in patients with acute myocardial infarction.

Stress-induced Myocardial Ischaemia – Perfusion Contrast Echocardiography to Evaluate Presence and Severity of Coronary Artery Disease

The development of stable transpulmonary ultrasound contrast agents (UCAs) has allowed the echocardiographic assessment of myocardial perfusion, a technique known as myocardial contrast echocardiography (MCE). MCE exploits the ultrasonic properties of UCAs, which consist of acoustically active gas-filled microspheres. These are intravascular agents that have a rheology similar to red blood cells and thus allow analysis of myocardial blood flow both at rest and after stress. The combined assessment of wall motion and myocardial perfusion provides significant diagnostic and prognostic information during stress echocardiography. Functional imaging tests, such as myocardial perfusion scintigraphy and stress cardiac magnetic resonance imaging, are also used for non-invasive assessment of coronary disease. The principal advantages of MCE are that it does not expose the patient to ionising radiation or radioactive pharmaceuticals, is not contraindicated in patients with an implanted metallic device or who suffer from claustrophobia and it can be performed at the bedside. The purpose of this article is to outline the physiological principles underpinning ischaemia testing with MCE before proceeding to review the evidence base for MCE in patients with known or suspected coronary artery disease.

Adenosine Stress Myocardial Contrast Echocardiography for the Detection of Coronary Artery Disease: A Comparison With Coronary Angiography and Cardiac Magnetic Resonance

To evaluate the accuracy of adenosine myocardial contrast echocardiography (MCE) in diagnosing coronary artery disease (CAD). Adenosine stress echocardiography is not routinely used in the assessment of CAD. Since ultrasound microbubble contrast agents enable improved wall motion analysis and simultaneous assessment of myocardial perfusion, we sought to evaluate the diagnostic performance of combined wall motion/perfusion imaging with adenosine MCE in patients with suspected CAD. We evaluated the accuracy of adenosine MCE in identifying 1) the presence of anatomic disease, as defined by X-ray angiography, and 2) the functional significance of CAD, as determined by high field-strength (3-T), multiparametric cardiac magnetic resonance (CMR) imaging. Sixty-five patients with suspected CAD were studied before angiography with MCE and CMR, at stress (140 μg/kg/min intravenous adenosine) and at rest. For MCE, 2-, 3- and 4-chamber long-axis images were acquired during intravenous sulfur hexafluoride infusion. For CMR, short-axis first-pass perfusion and delayed enhancement images were acquired following intravenous gadolinium-diethylenetriaminepentaacetic acid bolus injections (0.05 mmol/kg). Quantitative coronary angiography served as a reference standard for anatomic disease (significant CAD defined as ≥ 50% reference diameter in vessels with diameter ≥ 2 mm). Compared with X-ray angiography, MCE provided diagnostic accuracy of 82%, sensitivity of 85%, and specificity of 76% for detecting significant coronary stenosis. Disease location was also identified with reasonable accuracy (diagnostic accuracy 81% for left anterior descending disease, 77% for left circumflex artery disease, and 84% for right coronary artery disease). With CMR as the reference standard for functional assessment, MCE provided diagnostic accuracy of 79%, sensitivity of 85%, and specificity of 74%. Interobserver agreement for MCE was 79% (95% confidence interval: 67% to 88%). Adenosine MCE achieved favorable diagnostic performance in identifying the presence and functional significance of coronary stenosis. Adenosine MCE may be useful in the clinical setting for evaluating patients with suspected CAD.

Right ventricular absolute myocardial blood flow in complex congenital heart disease

ObjectiveA consequence in patients with d-transposition of the great arteries (d-TGA) and tetralogy of Fallot (TOF) is right ventricular hypertrophy (RVH) and right ventricular failure. Myocardial contrast echocardiography (MCE) permits...

Angiotensin II Receptor Blocker, Valsartan, Increases Myocardial Blood Volume and Regresses Hypertrophy in Hypertensive Patients

Although a reduction in myocardial blood volume (MBV), an in vivo index of the myocardial microvasculature, measured by myocardial contrast echocardiography in patients with hypertension (HT), can be demonstrated, it is still unknown whether a decreased MBV can be improved by antihypertensive treatment. Eleven HT patients (mean age 58 years, 7 men) with left ventricular hypertrophy (LVH) and 10 age- and sex-matched normal controls were studied. Harmonic power Doppler images were acquired at end-diastole of every 6(th) beat and MBV was calculated as 10(X/10)x100%, where X (dB) is myocardial contrast intensity minus the contrast intensity of the adjacent intracavity blood pool. Baseline blood pressure (BP) and left ventricular mass index (LVMI) in the HT patients were higher and MBV was lower than in the controls (2.52 +/-0.37% vs 3.31 +/-0.61%, P<0.01). MBV did not correlate with mean BP, but was inversely correlated with LVMI (r=0.61, P<0.01). After treatment with valsartan for 6 months, LVMI significantly decreased and MBV increased (2.72 +/-0.26%, P<0.05 vs baseline) in the patients with HT. There was a significant inverse correlation between the changes in MBV and those of LVMI (r=0.62, P<0.05), but not between MBV and mean BP. Valsartan, an angiotensin II receptor blocker, corrected the decreased MBV in association with regression of LVH in patients with HT.

Abstract 4710: Diagnostic Accuracy of Myocardial Perfusion on Myocardial Contrast Echocardiography in Patients with Acute Coronary Syndrome: Results from the Assessment of Coronary Heart Disease with Myocardial Contrast Echocardiography 2 (ACTMCE2) Multicenter Trial

Background: Intravenous myocardial contrast echocardiography (MCE) at rest and during vasodilator stress is a reliable bedside technique for assessment of myocardial perfusion in patients with coronary artery disease. The aim of this study is to evaluate diagnostic accuracy of myocardial perfusion abnormalities using MCE at rest in patients with acute coronary syndrome (ACS). This study is the first MCE multicenter trial for the evaluation of ACS in Japan. Methods: We performed triggered MCE at rest in 102 patients (mean age: 65 ± 11 years) with suspected ACS. We obtained 1:1 and 1:6 end-systolic triggered MCE images at four- and two-chamber views. We detected myocardial ischemia by the appearance of myocardial perfusion abnormalities (defect or reduction) in 1:1 end-systolic triggered MCE image. We assessed the appearance of regional wall motion abnormality (RWMA) at the same time. Quantitative coronary angiography was performed in all patients within 1 week (2.6 ± 2.2 days) after MCE. Results: Eighty-four of 102 (82%) patients were diagnosed ACS (unstable angina: 70 patients; non-ST-segment elevation myocardial infarction: 11 patients; ST-segment elevation myocardial infarction: 3 patients) and demonstrated significant coronary artery stenosis (stenosis = or &gt;75%) that required coronary revascularization therapy. The sensitivity, specificity, and accuracy of myocardial perfusion abnormality by MCE at rest for diagnosing ACS were 79%, 86%, and 83%, respectively. On each coronary artery, the sensitivity, specificity, and accuracy of MCE for diagnosing ACS were 85%, 71%, and 79% in the left anterior descending artery; 70%, 92%, and 84% in the left circumflex artery; 77%, 89%, and 84% in the right coronary artery, respectively. The sensitivity, specificity, and accuracy of RWMA for diagnosing ACS were 49%, 90%, and 71%, respectively, and the sensitivity of MCE for diagnosing ACS was significantly higher than that of RWMA. Conclusion: Intravenous myocardial contrast echocardiography at rest without stress examination is a feasible noninvasive method for accurate diagnosis of ACS. In this multicenter study, MCE at rest improved the diagnostic accuracy of echocardiography for diagnosing ACS.

Myocardial Perfusion After Percutaneous Transluminal Septal Myocardial Ablation as Assessed by Myocardial Contrast Echocardiography in Patients with Hypertrophic Obstructive Cardiomyopathy

Microvascular dysfunction in hypertrophic obstructive cardiomyopathy (HOCM) depends on a complex interplay of functional and anatomic mechanisms. We used myocardial contrast echocardiography in 16 consecutive patients with HOCM (mean age 49 +/- 15 years; 11 men) referred for percutaneous transluminal septal myocardial ablation to assess myocardial perfusion before and 6 months after the procedure. Myocardial contrast echocardiography was performed using real-time imaging during intravenous injection of SonoVue. Myocardial blood velocity (beta) and a semiquantitative assessment of blood volume were obtained in the apical 4-chamber views at midapical septum. Twelve healthy individuals served as control subjects. In patients with HOCM, beta was lower either before (0.17 +/- 0.04 vs 0.50 +/- 0.34 s(-1), P = .006) or after (0.23 +/- 0.07 vs 0.50 +/- 0.34 s(-1), P = .02) successful percutaneous transluminal septal myocardial ablation compared with control subjects. A patchy perfusion pattern was seen in all the patients with HOCM either before or after the procedure. In patients with HOCM percutaneous transluminal septal myocardial ablation improves, but does not normalize microvascular function.

746 The diagnostic value of stress real-time myocardial contrast echocardiography in patients with no history of myocardial infarction

746 The diagnostic value of stress real-time myocardial contrast echocardiography in patients with no history of myocardial infarction

Usefulness of Real-Time Myocardial Perfusion Imaging to Evaluate Alterations of Myocardial Blood Flow in Patients With Stable Angina Pectoris Undergoing Elective Percutaneous Coronary Interventions

Release of cardiac enzymes has been reported in patients with stable angina who undergo elective percutaneous coronary intervention (PCI) and has been associated with adverse clinical outcomes. The aim of the present study was to investigate whether impaired microvascular integrity can be detected using myocardial contrast echocardiography in patients undergoing elective PCI, and whether it is related to the extent of postprocedural troponin T elevation. We investigated consecutive patients with stable angina (n = 19) who were scheduled for elective angioplasty with stent placement. Myocardial contrast echocardiography was performed before and 2 to 4 hours and 24 hours after coronary intervention. Contrast images were analyzed visually and quantitatively measuring the peak signal intensity (A) and the slope of the signal intensity rise (beta) in 16 myocardial segments. The product of A x beta was calculated in each segment to estimate the regional myocardial blood flow. Troponin T was collected serially before and 2 to 4 hours and 24 hours after PCI. Five patients (26%) had elevated troponin T 24 hours after PCI (range 0.03 to 0.46 microg/L). Eight patients (42%), including all 5 patients with elevated troponin T levels, demonstrated impaired microvascular integrity 2 to 4 hours after PCI in >or=2 myocardial segments (range 2 to 4) within the perfusion territory of the target vessel. Of the 11 patients without evidence of impaired myocardial perfusion by myocardial contrast echocardiography, none had elevated troponin T levels at follow-up. Quantitative analysis of myocardial blood flow showed that impaired perfusion after PCI was partially reversible. Thus, A x beta had decreased significantly at 2 to 4 hours after PCI (3.4 +/- 1.6 vs 8.8 +/- 3.4 dB/s baseline, p <0.01), reincreased after 24 hours (6.4 +/- 2.3 dB/s at 24 hours vs 3.4 +/- 1.6 dB/s at 2 to 4 hours, p <0.01), but did not return to baseline (8.8 +/- 3.4 dB/s at baseline vs 6.4 +/- 2.3 dB/s at 24 hours, p <0.01). The perfusion defect size 2 to 4 hours after PCI was closely related to the troponin T levels after 24 hours (r(2) = 0.80, p <0.0001). In conclusion, impaired microvascular integrity is partially present in patients with stable angina who undergo elective PCI, is partially reversible, and is closely related to the release of troponin T. Because judgment of interventional success has shifted downstream to tissue level perfusion, myocardial contrast echocardiography may be useful to monitor such alterations in myocardial tissue perfusion.

Diagnostic Accuracy and Prognostic Value of Dobutamine Stress Myocardial Contrast Echocardiography in Patients with Suspected Acute Coronary Syndromes

Both early stress testing and cardiac troponin I (cTnI) measurements are useful in assessing the prognosis of patients with acute coronary syndrome (ACS). We sought to determine the accuracy and prognostic value of wall motion analysis (WMA) and myocardial perfusion analysis (MPA) with real-time myocardial contrast echocardiography (RTMCE) during dobutamine stress in this patient population. We performed dobutamine stress RTMCE to assess perfusion in 158 consecutive patients (mean age: 61 +/- 13 years) with chest pain and possible ACS. Of these, 119 had normal cTnI, while 39 had isolated elevations of cTnI (range: 0.5-9.0 ng/ml). Quantitative angiography was performed within 1 month of RTMCE in 61 patients. Patients were followed for 16 months (range: 6-46 months). Cardiac events included death, nonfatal myocardial infarction, recurrent unstable angina, or need for urgent revascularization. The sensitivity, specificity, and accuracy of MPA for detecting a >50% coronary stenosis were 92%, 77%, and 88%, respectively, while they were 62%, 85%, and 67% for WMA. Three-year event-free survival was 87% in patients with negative WMA and MPA, 49% in those with positive WMA and MPA, and 51% in patients with negative WMA but positive MPA. Age-adjusted multivariate analysis demonstrated that the only independent predictors of cardiac events were a positive MPA (hazard ratio = 3.23; 95% CI = 1.23-8.49) and male sex (hazard ratio = 3.29; 95% CI = 1.21-8.97). In patients suspected of having an ACS, RTMCE improved the accuracy of dobutamine stress echocardiography for detecting coronary artery disease, and was an independent predictor of outcome.

Usefulness of Real-Time Myocardial Perfusion Imaging to Evaluate Tissue Level Reperfusion in Patients With Non–ST-Elevation Myocardial Infarction

Microvascular integrity is a prequisite for functional recovery in patients who have myocardial infarction after recanalization of the infarct-related coronary artery. In this study, we investigated whether impaired myocardial perfusion is present in patients who have non-ST-elevation myocardial infarction and whether the extent and time course of myocardial tissue reperfusion as assessed by myocardial contrast echocardiography (MCE) are related to functional recovery. Consecutive patients (n = 32) who presented with a first non-ST-elevation myocardial infarction were included in our study. MCE was performed on admission, 1 to 4 hours after angioplasty, and at 24 hours, 4 days, and 4 weeks of follow-up. Contrast images were analyzed visually and quantitatively. Myocardial blood flow was estimated by calculating the product of peak signal intensity and the slope of signal intensity increase. Improvement of wall motion on follow-up echocardiograms after 4 weeks served as a reference for functional recovery of impaired left ventricular function. Of 496 segments available for analysis, 128 (26%) were initially dysfunctional and 96 (75%) recovered at 4 weeks of follow-up. Myocardial tissue reperfusion occurred gradually, expanding over the first 24 hours after percutaneous coronary intervention (myocardial blood flow of 0.4 +/- 0.3 initially, 0.6 +/- 0.4 at 24 hours, and 1.6 +/- 0.7 dB/s at 4 weeks of follow-up, p <0.001). Extent of tissue reperfusion was closely related to grade of improvement of global ejection fraction (r2 = 0.76, p <0.001). MCE predicted functional recovery with a sensitivity of 81%, a specificity of 88%, and accuracy of 83% on a segmental level. Thus, impaired microvascular integrity is suggested by MCE in patients who present with non-ST-elevation myocardial infarction. Improvement of regional tissue perfusion after revascularization is closely related to functional recovery. This information may aid risk stratification and allow monitoring of the effectiveness of reperfusion therapy in these patients.