Qualitative and quantitative real time myocardial contrast echocardiography for detecting hibernating myocardium

Background: Real time myocardial contrast echocardiography (RTMCE) is an emerging imaging modality for assessing myocardial perfusion that allows for noninvasive quantification of regional myocardial blood flow (MBF). Aim: We sought to assess the value of qualitative analysis of myocardial perfusion and quantitative assessment of myocardial blood flow (MBF) by RTMCE for predicting regional function recovery in patients with ischemic heart disease who underwent coronary artery bypass grafting (CABG). Methods: Twenty‐four patients with coronary disease and left ventricular systolic dysfunction (ejection fraction <45%) underwent RTMCE before and 3 months after CABG. RTMCE was performed using continuous intravenous infusion of commercially available contrast agent with low mechanical index power modulation imaging. Viability was defined by qualitative assessment of myocardial perfusion as homogenous opacification at rest in ≥2 segments of anterior or ≥1 segment of posterior territory. Viability by quantitative assessment of MBF was determined by receiver‐operating characteristics curve analysis. Results: Regional function recovery was observed in 74% of territories considered viable by qualitative analysis of myocardial perfusion and 40% of nonviable (P = 0.03). Sensitivity, specificity, positive and negative predictive values of qualitative RTMCE for detecting regional function recovery were 74%, 60%, 77%, and 56%, respectively. Cutoff value of MBF for predicting regional function recovery was 1.76 (AUC = 0.77; 95% CI = 0.62–0.92). MBF obtained by RTMCE had sensitivity of 91%, specificity of 50%, positive predictive value of 75%, and negative predictive value of 78%. Conclusion: Qualitative and quantitative RTMCE provide good accuracy for predicting regional function recovery after CABG. Determination of MBF increases the sensitivity for detecting hibernating myocardium. (Echocardiography 2011;28:342‐349)     

Value of rapid beta-blocker injection at peak dobutamine-atropine stress echocardiography for detection of coronary artery disease

OBJECTIVES: We studied the value of a rapid beta-blocker injection at peak dobutamine-atropine stress echocardiography (DASE) for the detection of coronary artery disease (CAD). BACKGROUND: The presence of tachycardia and hyperdynamic wall motion may make it difficult to recognize a new wall motion abnormality (NWMA) at peak stress. METHODS: We studied 101 patients (mean age 58.2 +/- 9.8 years) who underwent effective DASE and coronary angiography. All patients received a rapid intravenous injection of metoprolol immediately after peak DASE image acquisition. Positivity in combined peak plus post-metoprolol images was defined when there was only peak NWMA, maintenance of peak NWMA, or NWMA detected only after metoprolol injection. Significant CAD was defined as >or=50% stenosis by quantitative angiography. RESULTS: There were 37 patients without and 64 with CAD. The sensitivity, specificity, accuracy, and positive and negative predictive values for the detection of CAD at peak stress were 84%, 92%, 87%, 95%, and 77%, respectively. Five patients with CAD had negative peak images that became positive only after metoprolol. Extension of peak NWMA during metoprolol was observed in 14 patients, and multivessel CAD was detected in 10 of them. The sensitivity, specificity, accuracy, and positive and negative predictive values for peak plus metoprolol images were 92%, 89%, 91%, 94%, and 87%, respectively. CONCLUSIONS: The use of metoprolol injected at peak of dobutamine infusion improved the detection of CAD by DASE.     

Role of dobutamine-atropine stress echocardiography in prognostic evaluation of 300 women

BACKGROUND: Dobutamine-atropine stress echocardiography (DASE) is a safe and accurate method to diagnose coronary artery disease (CAD), and can identify individuals at high risk for cardiac events such as myocardial infarction and cardiac-related death. The literature is limited regarding the prognostic value of DASE in women. OBJECTIVE: The objective was to determine the prognostic value of DASE in 300 women with known or suspected CAD. RESULTS: The 300 women underwent DASE and were followed up for 65 months (mean: 27 months). Ninety-five women had positive tests and 205 had negative tests. We demonstrated that women with negative tests had a 94% hard-event-free survival rate at follow-up (myocardial infarction and death), and in those with positive tests the event-free survival rate was 27% (P = 0.0003). The difference between women with positive and negative tests was also significant when minor events and total events were considered. Women with positive tests had 16.7 times more chance of having events than women with negative tests. Furthermore, women with positive tests but without cardiac events at follow-up (mean of peak WMSI - rest WMSI = 0.24 +/- 0.16) had less ischemic myocardium than women with positive tests and cardiac events at follow-up (mean of peak WMSI - rest WMSI = 0.34 +/- 0.26)(P < 0.04). CONCLUSION: Dobutamine-atropine stress echocardiography has good prognostic value for cardiac events in women. Women with negative tests have low probability for follow-up infarction or death. Women with positive tests and higher severity of induced ischemia have the highest incidence of cardiac events.     

Comparison of Two-Dimensional Echocardiography and Pulsed Doppler Tissue Imaging during Dobutamine-Atropine Stress Testing to Detect Coronary Artery Disease

In order to compare the diagnostic accuracy of two-dimensional (2-D) echocardiography and pulsed Doppler tissue imaging (pDTI) during dobutamine-atropine stress testing (DAST) to detect significant coronary lesions, 41 patients underwent DAST (up to 40 microg/k/min of dobutamine with additional atropine during submaximal heart rate responses) and coronary angiography. Pulsed Doppler tissue sampling of territories corresponding to the left anterior descending (LAD), left circumflex (LCx), and right coronary arteries (RCAs) were performed in the apical four-chamber plus aorta and two-chamber apical views. The measurements were repeated at rest, at low dose (10 microg/k/min), and at peak stress. Pulsed DTI measurements included peak early systolic (Vs), peak early diastolic (Ve), and peak late diastolic (Va) velocities. Harmonic 2-D echocardiography was recorded at rest, low dose, peak stress, and recovery, and compared with pDTI assessment. Positive 2-D echocardiography was considered as infarction or ischemic response. The results were evaluated for the prediction of significant coronary stenosis (50% luminal narrowing). Feasibility of pDTI was 100%, 95%, and 98% for the LAD, the LCx, and RCA territories, respectively. At rest, Vs in territories supplied by arteries with coronary artery disease (CAD) (6.3 +/- 2.0 cm/sec) was not different from those without (6.6 +/- 2.1 cm/sec). Vs increased less in territories supplied by arteries with than without CAD (75 +/- 107% vs 102 +/- 69%, P = NS). Ve was lower in territories with CAD at rest (6.0 +/- 2.1 cm/sec vs 8.2 +/- 3.4 cm/sec, P < 0.0001) and low dose (7.2 +/- 2.1 cm/sec vs 8.8 +/- 3.6 cm/sec, P < 0.01), but similar at peak stress (7.6 +/- 3.5 cm/sec vs 8.1 +/- 3.3 cm/sec). Ve increase was similar in territories with (36 +/- 74%) than without CAD (15 +/- 6 4%). Va was similar at rest and low dose in territories with and without CAD (9.2 +/- 2.7 cm/sec vs 9.1 +/- 2.3 cm/sec and 10.9 +/- 3.1 vs 10.3 +/- 3.6 cm/sec, respectively), but lower at peak stress in territories with CAD (13.3 +/- 4.6 cm/sec vs 15.3 +/- 4.5 cm/sec, P = 0.05). The Va increase was lower in territories with CAD (43 +/- 37% vs 77 +/- 72%, P < 0.05). In a territory-based analysis, a failure to achieve Vs > or =10.5 cm/sec at peak stress in the LAD and LCx, and > or =10.0 cm/sec in the RCA territory, was found to be the more accurate limit to detect CAD in the corresponding arteries: sensitivity (95% confidence intervals): 63% (55-71), P = NS vs 2-D echocardiography: 59% (51-67); specificity 76% (68-84), P < 0.01 vs. 2-D echocardiography: 95% (89-100); and accuracy 69% (63-75), P = NS vs 2-D echocardiography: 76% (70-82). Thus, pDTI is feasible during DAST but not more accurate than 2-D echocardiography for the detection of significant CAD in a territory-based study.     

Dobutamine-atropine stress echocardiography and dipyridamole sestamibi scintigraphy for the detection of coronary artery disease: limitations and concordance

OBJECTIVES: We sought to compare dobutamine-atropine stress echocardiography (DASE) and dipyridamole Technetium 99-m (Tc-99m) sestamibi single photon emission computed tomography (SPECT) scintigraphy (DMIBI) for detecting coronary artery disease (CAD). BACKGROUND: Both DASE and DMIBI are effective for evaluating patients for CAD, but their concordance and limitations have not been directly compared. METHODS: To investigate these aims, patients underwent multistage DASE, DMIBI and coronary angiography within three months. Dobutamine-atropine stress echocardiography and stress-rest DMIBI were performed according to standard techniques and analyzed for their accuracy in predicting the extent of CAD. Segments were assigned to vascular territories according to standard models. Angiography was performed using the Judkin's technique. RESULTS: The 183 patients (mean age: 60 +/- 11 years, including 50 women) consisted of 64 patients with no coronary disease and 61 with single-, 40 with two- and 18 with three-vessel coronary disease. Dobutamine-atropine stress echocardiography and DMIBI were similarly sensitive (87%, 104/119 and 80%, 95/119, respectively) for the detection of CAD, but DASE was more specific (91%, 58/64 vs. 73%, 47/64, p < 0.01). Sensitivity was similar for the detection of CAD in patients with single-vessel disease (84%, 51/61 vs. 74%, 45/61, respectively) and multivessel disease (91%, 53/58 vs. 86%, 50/58, respectively). Multiple wall motion abnormalities and perfusion defects were similarly sensitive for multivessel disease (72%, 42/58 vs. 66%, 38/53, respectively), but, again, DASE was more specific than DMIBI (95%, 119/125 vs. 76%, 95/125, respectively, p < 0.01). Dobutamine-atropine stress echocardiography and DMIBI were moderately concordant for the detection and extent of CAD (Kappa 0.47, p < 0.0001) but were only fairly (Kappa 0.35, p < 0.001) concordant for the type of abnormalities (normal, fixed, ischemia or mixed). CONCLUSIONS: Dobutamine-atropine stress echocardiography and DMIBI were comparable tests for the detection of CAD. Both were very sensitive for the detection of CAD and moderately sensitive for the extent of disease. The only advantage of DASE was greater specificity, especially for multivessel disease. Dobutamine-atropine stress echocardiography may be advantageous in patients with lower probabilities of CAD.     

Isometric handgrip exercise during dobutamine-atropine stress echocardiography increases heart rate acceleration and decreases study duration and dobutamine and atropine dosage

BACKGROUND: Dobutamine-atropine stress echocardiography (DASE) is an established test for the diagnosis and risk stratification of patients with coronary artery disease. Atropine use to attain target heart rate prolongs test time. HYPOTHESIS: The aim of this study was to assess the utility of isometric handgrip exercise (33% maximal voluntary contraction x 4 min) with DASE. METHODS: We prospectively evaluated 131 patients undergoing DASE randomized to handgrip exercise or no handgrip. Effect of handgrip exercise on endpoints: time to target heart rate (85% maximum predicted), recovery time, total test time, mean dobutamine and atropine dosage, and the number of ischemic responses were assessed. Effect of current beta-blocker medication use was also evaluated. RESULTS: Heart rate rose more quickly in the handgrip group. At 6-10 min (peak handgrip), mean heart rate rose 51 +/- 14 beats/min in the handgrip group compared with 38 +/- 18 beats/min in the no handgrip group (p < 0.0001). With handgrip, overall dobutamine study time was reduced by a mean of 4.3 min (16.4 +/- 6.9 vs. 20.7 +/- 8.4, p = 0.004) in all patients, and by a mean of 5.9 min in patients not on beta-blocker medication (p = 0.001). The handgrip group also had a lower mean dose of dobutamine (25.8 +/- 13.5 vs. 32.4 +/- 16.4 mg, p = 0.025). The mean atropine dose was also lower (0.2 +/- 0.4 vs. 0.4 +/- 0.5 mg, p = 0.04). Handgrip exercise, however, did not decrease endpoints in patients on beta-blocker medication. CONCLUSIONS: Use of isometric handgrip exercise with DASE decreases time to target heart rate, recovery time, overall study time, and mean dosage of dobutamine and atropine. In patients not on beta-blocker medication, handgrip exercise should be routinely incorporated into all DASE protocols.     

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

Background: 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). Methods: 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. Results: 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). Conclusion: 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.     

美托洛尔在多巴酚丁胺-阿托品负荷超声心动图检测冠心病中的应用价值

目的评价美托洛尔静脉注射在多巴酚丁胺-阿托品负荷超声心动图（DASE）检测冠心病（CAD）中的应用价值。方法选择可疑CAD患者72例,在DASE检查达负荷心率后快速静脉注射美托洛尔（DASE—Meto）,DASE—Meto检查后2周内行冠状动脉造影（CAG）。分析DASE负荷心率时及美托洛尔静脉注射后室壁运动计分指数及血流动力学参数,将CAG结果与DASE、DASE—Meto结果进行比较分析。结果CAG阳性患者35例,阴性37例。DASE检测CAD的敏感性、特异性、准确性、阳性预测值、阴性预测值分别为65．7％、86．5％、76．4％、82．1％、84．6％,10例CAG阳性患者DASE负荷心率时为阴性,而在美托洛尔注射后出现节段性室壁运动障碍,故DASE—Meto检测的CAD的敏感性、特异性、准确性、阳性预测值、阴性预测值分别为94．3％、83．8％、88．9％、72,7％、93．9％。美托洛尔静脉注射后,使用多巴酚丁胺、阿托品所致不良反应减轻,恢复时间缩短。结论在DASE负荷心率时静脉注射美托洛尔可提高检测CAD的准确性、安全性。     

实时心肌声学造影对冠心病患者心肌灌注的定量评价

目的探讨实时心肌声学造影(RTMCE)定量分析冠心病患者心肌血流量的临床应用价值。方法对20例冠脉造影左前降支冠脉狭窄>75%以上的冠心病患者(观察组)和20例健康体检者(对照组)行静息状态下RTMCE检查,同时应用超声心动图检测造影剂峰值密度(A)、心肌血流速率(β)、心肌血流量(MBF,MBF=A×β)、左室舒张末期内径(LVEDD)、左室收缩末期内径(LVESD)、射血分数(EF)、舒张早期峰值血流速度(Emax)、舒张晚期峰值血流速度(Amax)。比较两组相应节段的心肌灌注情况和心脏功能。结果观察组β及MFB均显著低于对照组(P均<0.01),LVEDD、LVSED、EF、Emax、Amax、Emax/Amax、Dt等两组比较无明显差异。结论冠心病患者心肌血流速度减慢,存在心肌微循环损伤;RIMCE可定量评价缺血心肌的血流灌注状况。     

The elusive link between coronary lesion morphology and dobutamine stress echocardiography results

Background. Coronary lesion angiographic morphology of the complex type is associated to enhanced susceptibility to ischemia during vasodilator adenosinergic stress testing and attributed to the reduced vasodilatory capacity of the damaged endothelium. Whether coronary lesion morphology can also influence the results of adrenergic pharmacologic stress test remains unknown. The aim of our study was to assess the relationship between coronary plaque morphology and dobutamine-atropine stress echocardiography (DASE) results. Methods and results. We analyzed DASE (up to 40 mcg/kg/min plus atropine) and coronary angiography data of 42 patients with single vessel disease and no totally occluded vessel at angiography. 7 patients had angina, 35 had previous infarction. A diagnostic DASE was performed in all patients within 1–10 (mean 4.7 ± 3.4) days before coronary angiography. An angiographic lesion was considered complex when irregular borders and/or intraluminal lucencies, suggestive of ulcer and/or thrombus were present. According to the angiographic lesion morphology (Ambrose classification), 2 groups were identified: Group I, with simple lesion; Group II with complex lesion. The two groups were similar for number of patients (n= 21), age (I=55 ± 11 vs II=53 ± 7 years, p=ns), coronary stenosis severity expressed as% diameter reduction (I=77 ± 14 vs II=78 ± 15%, p=ns), presence of previous infarction (I=17 vs II=18 pts, p=ns). No difference was found in the prevalence of positivity between the two groups (I=72 vs II=62%, p=ns). The two groups achieved a similar peak dobutamine dose (I=32 ± 9 vs II=33 ± 9 mcg/kg/min, p=ns) and peak Wall Motion Score Index (I=1.5 ± 0.26 vs II=1.45 ± 0.28, p=ns). Conclusions. In patients with non occlusive single vessel disease, coronary morphology of complex type is not associated with greater vulnerability to dobutamine induced ischemia.     

Real time myocardial contrast echocardiography to predict left ventricular wall motion recovery after reperfused acute myocardial infarction

INTRODUCTION AND OBJECTIVES: Real time myocardial contrast echocardiography (RTMCE) is a recently developed method. We sought to determine: a) whether RTMCE predicts recovery of left ventricular function after acute myocardial infarction (AMI), and b) whether data obtained with this method are comparable to those obtained with 99mTc-sestamibi single photon emission computed tomography (SPECT) and magnetic resonance. PATIENTS AND METHOD: We studied 85 patients with AMI who underwent angioplasty. RTMCE was performed 7 (4) days after AMI. Two-dimensional echocardiography was performed at the time of the RTMCE study and at follow-up (10 [4] weeks). SPECT and magnetic resonance were performed after AMI in 18 and 32 patients, respectively. RESULTS: Follow-up two-dimensional echocardiography results were available for 82 patients, who were subdivided into 2 groups: recovery (n=49) and no recovery (n=33). Regional (AMI-related) wall motion score index improved from 1.75 (0.49) to 1.32 (0.36) (P< .001) in the recovery group, and worsened from 1.85 (0.39) to 1.95 (0.36) in the no recovery group (P< .001). RTMCE perfusion score was 0.8 (0.3) in the recovery group, and 0.6 (0.4) in the no recovery group (P< .001). Concordance between RTMCE and SPECT in a segmental analysis was 78% (P< .001; kappa=0.49), whereas concordance between RTMCE and hyperenhancement with delayed contrast magnetic resonance findings was 70% (P< .001; kappa =0.35). Independent predictors of recovery were peak creatine kinase (OR=1.4 per 1000 UI; 95% CI, 1.0-1.9; P< .05) and RTMCE score (OR=8.8; 95% CI, 1.9-39.3; P< .01). A RTMCE score > or = 0.60 had a positive predictive value of 73% and a negative predictive value of 69% (P< .001; area under the curve 0.70). CONCLUSION: RTMCE showed a modest predictive value for recovery of left ventricular function after reperfused AMI.     

Tolerability and infusion time of an accelerated infusion dobutamine echocardiography protocol

OBJECTIVES: A new, accelerated dobutamine-atropine stress echocardiography (DASE) protocol (baseline 20 mcg/kg/min; 40 mcg/kg/min) was compared with a standard protocol in patients with suspected coronary artery disease (CAD) to evaluate tolerability, length of infusion, and overall test times, as well as safety. METHODS: Patients received the DASE or the standard protocol on an alternating basis (n = 164). RESULTS: Total test time, including patient recovery (HR < 100 bpm), dropped from an average of 19:23-12:12 min (p < 0.0001). Average symptom duration decreased from 5:50 to 3:17 min (p < 0.01). Women had shorter total test times in both accelerated and standard protocols compared to that of men. CONCLUSIONS: The accelerated DASE protocol is a well tolerated alternative to standard dobutamine stress testing allowing practitioners to reduce test times without increasing the incidence of arrhythmias. Patients in the accelerated arm also had shorter duration of symptoms.     

Comparison of safety and efficacy of the early injection of atropine during dobutamine stress echocardiography with the conventional protocol

Although dobutamine-atropine stress echocardiography (DASE) is an established method for evaluating patients who have coronary artery disease (CAD), it can increase test duration and a patient's exposure to large doses of dobutamine. New protocols, including the early injection of atropine during dobutamine stress echocardiography (EA-DSE), have been proposed to decrease test duration. This study compared the safety, efficacy, and accuracy of EA-DSE with those of DASE. We retrospectively evaluated 3,163 patients who underwent DASE and 1,664 patients who underwent EA-DSE over a period of 12 years. In EA-DSE, atropine at a dose 50% stenosis) was assessed in patients who underwent quantitative angiography 相似文献   

Endocardial border delineation during dobutamine infusion using contrast echocardiography

BACKGROUND: A significant percentage of pharmacologic stress echocardiograms produce suboptimal images despite the use of second harmonic imaging. Intravenous continuous infusion of myocardial ultrasound contrast may enhance endocardial border delineation during dobutamine-atropine stress echocardiography (DASE), improving wall-motion analysis. PATIENTS AND METHODS: We prospectively studied 68 patients (41 males and 27 females), mean age 58 years, with DASE during intravenous infusion of contrast using second harmonic imaging. Dobutamine was infused in scalar doses of 5 microg/kg/min to 40 microg/kg/min, and atropine was administered in doses of up to 1 mg. We diluted 0.1 mL of perfluorocarbon-exposed sonicated dextrose albumin (PESDA) microbubbles into 80 mL of saline solution, which was used for continuous intravenous infusion. Blinded reviewers used a 16-segment model at rest and peak DASE to analyze segmental wall delineation in two sets of images for each patient, with and without contrast. An endocardial delineation score of 0-3 (nondelineated to excellent delineation) was given to each segment. An endocardial delineation score index (EDSI), the number of endocardial delineation scores for each set of images divided by 16, was created. RESULTS: The analysis of the mean EDSI for the 2176 segments was 1.46 (+/- 0.43) at rest and 1.30 (+/- 0.48) at peak for noncontrast images and 2.22 (+/- 0.52) and 2.29 (+/- 0.52) for contrast images. Complete left ventricle opacification was obtained in all patients, with a mean dose of 4 mL/min, although in 15 (22%) patients, signs of apical bubble destruction occurred. There were 1768 (81%) of 2176 segments delineated without contrast enhancement and 2057 (95%) of 2176 with enhancement (P < 0.05). CONCLUSION: Continuous infusion of myocardial ultrasound contrast improves endocardial border delineation using second harmonic imaging in patients undergoing DASE.     

Prognostic Value of Real Time Myocardial Contrast Echocardiography after Percutaneous Coronary Intervention

Real time myocardial contrast echocardiography (RTMCE) is a cost‐effective and simple method to quantify coronary flow reserve (CFR). We aimed to determine the value of RTMCE to predict cardiac events after percutaneous coronary intervention (PCI). We have studied myocardial blood volume (A), velocity (β), flow indexes (MBF, A × β), and vasodilator reserve (stress‐to‐rest ratios) in 36 patients with acute coronary syndrome (ACS) who underwent PCI. CFR (MBF at stress/MBF at rest) was calculated for each patient. Perfusion scores were used for visual interpretation by MCE and correlation with TIMI flow grade. In qualitative RTMCE assessment, post‐PCI visual perfusion scores were higher than pre‐PCI (Z = ?7.26, P < 0.01). Among 271 arteries with TIMI flow grade 3 post‐PCI, 72 (36%) did not reach visual perfusion score 1. The β‐ and A × β‐reserve of the abnormal segments supplied by obstructed arteries increased after PCI comparing to pre‐PCI values (P < 0.01). Patients with adverse cardiac events had significantly lower β‐ and lower A × β‐reserve than patients without adverse cardiac events. In the former group, the CFR was ≥ 1.5 both pre‐ and post‐PCI. CFR estimation by RTMCE can quantify myocardial perfusion in patients with ACS who underwent PCI. The parameters β‐reserve and CFR combined might predict cardiac events on the follow‐up.     

Diagnostic accuracy and prognostic value of dobutamine stress myocardial contrast echocardiography in patients with suspected acute coronary syndromes

BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.     

Comparative accuracy of real-time myocardial contrast perfusion imaging and wall motion analysis during dobutamine stress echocardiography for the diagnosis of coronary artery disease

OBJECTIVE: This study sought to compare the accuracy of myocardial contrast echocardiography (MCE) and wall motion analysis (WMA) during submaximal and peak dobutamine stress echocardiography (DSE) for the diagnosis of coronary artery disease (CAD). BACKGROUND: The relative merits of MCE and WMA for the detection of CAD during DSE have not been studied in a large number of patients. METHODS: We studied 170 patients who underwent dobutamine (up to 50 microg/kg/min)-atropine stress testing and coronary angiography. The WMA and MCE (using repeated boluses of Optison [Mallinckrodt, St. Louis, Missouri] or Definity [Bristol-Myers Squibb, New York, New York]) were performed at rest, at intermediate stress (65% to 75% of maximal heart rate), and at peak stress. The diagnosis of CAD (>/=50% stenosis in >/=1 coronary artery) was based on reversible wall motion and perfusion abnormalities. RESULTS: Coronary artery disease was detected in 127 (75%) patients. Sensitivity of MCE was higher than that of WMA at maximal stress (91% vs. 70%; p = 0.001) and at intermediate stress (84% vs. 20%; p = 0.0001). Specificity was lower for MCE compared with WMA (51% vs. 74%; p = 0.01). Overall accuracy was higher for MCE than for WMA (81% vs. 71%; p = 0.01). Sensitivity for detection of CAD based on abnormalities in >/=2 vascular regions was higher for MCE than for WMA (67% vs. 28%; p < 0.01). CONCLUSIONS: The majority of inducible perfusion abnormalities occur at an intermediate phase of the stress test, without wall motion abnormalities. Myocardial contrast echocardiography provides better sensitivity than WMA, particularly in patients with submaximal stress and in identifying patients with multivessel CAD.     

Enhanced detection of ischemic myocardium by transesophageal dobutamine stress echocardiography: comparison with simultaneous transthoracic echocardiography

The diagnostic accuracy of dobutamine stress echocardiography is limited in patients with poor transthoracic acoustic windows. Transesophageal echocardiography (TEE) overcomes these limitations and thus may increase the clinical usefulness of dobutamine stress echocardiography. The present study was designed to compare the diagnostic accuracies of transesophageal and transthoracic dobutamine stress echocardiography for the identification of coronary artery disease (CAD) in a cohort of patients with a higher incidence of poor acoustic windows. Forty-two male patients (mean age, 66 +/- 9 years) underwent dobutamine stress echocardiography with simultaneous transesophageal and transthoracic imaging. Coronary arteriography was performed in 28 patients (67%). Transesophageal imaging adequately visualized 99.6% of left ventricular segments compared with 76.2% visualized by transthoracic imaging (P < 0.0001). There was substantial agreement between the two techniques for segmental wall motion analysis at baseline (kappa 0.76; 95% CI, 0.70-0.82); however, at peak dobutamine dose, agreement was significantly reduced (kappa 0.62; 95% CI, 0.55-0.69). The sensitivity (88% vs 75%), specificity (100% vs 75%), and positive predictive value (100% vs 80%) for the identification of CAD were all superior for transesophageal imaging. Transesophageal imaging correctly identified 11 of the 12 patients (92%) with multivessel disease compared with 5 patients (42%) identified by transthoracic imaging (P < 0.03). There were no major complications. Transesophageal dobutamine stress echocardiography is a safe, feasible, and accurate technique for the identification and risk stratification of patients with CAD. Transesophageal imaging appears to be superior to transthoracic imaging for identifying both the presence and extent of CAD, specifically in patients with poor acoustic windows.     

Supine bicycle echocardiography improved diagnostic accuracy and physiologic assessment of coronary artery disease with the incorporation of intermediate stages of exercise.

OBJECTIVES: The purpose of this work was to assess whether the incorporation of intermediate stages during supine bicycle exercise echocardiography (BEE) improves the accuracy of detection of coronary artery disease (CAD) through the evaluation of a biphasic response. BACKGROUND: Exercise echocardiography allows cardiac imaging throughout exercise. METHODS: Exercise echocardiography was performed in 104 patients (mean age 57 +/- 11 years, 37 women), 91 of whom underwent coronary angiography. The BEE protocol started at 25 W with increments of 25 W every 3-min stage. Images were digitized at rest, 25 W, 50 W, and peak exercise. Two experienced observers and 1 less experienced observer interpreted rest and peak exercise images, with and without the intermediate stages. RESULTS: Imaging during intermediate stages improved the sensitivity for detection of all individual vessel stenoses (78% vs. 58%, p < 0.001) and patients overall (94% vs. 74%, p = 0.001). The specificity was unchanged (all vessels: 83% vs. 81%, all patients: 64% vs. 60%). A change in left ventricular end-systolic volume from intermediate stage to peak exercise of >10% predicted CAD (sensitivity 94%, specificity 74%) and was more marked than changes observed from rest to peak exercise. The severity of coronary stenosis related to the double product achieved at the onset of ischemia during exercise (r = -0.61, p < 0.001) better than that at maximal exercise (r = -0.31, p < 0.01). CONCLUSIONS: During BEE, the acquisition and interpretation of intermediate stages of exercise in addition to peak exercise improves the detection of CAD and allows a better physiologic evaluation of the severity of coronary stenosis.     

Stress echocardiography is superior to exercise ECG in the risk stratification of patients presenting with acute chest pain with negative Troponin.

OBJECTIVE: To compare exercise electrocardiography (ExECG) and stress echocardiography (SE) in the risk stratification of patients presenting to hospital with cardiac-sounding chest pain, non-diagnostic ECGs and negative cardiac Troponin. METHODS: Patients presenting with acute chest pain were prospectively randomised to early ExECG or SE. A post-test likelihood of CAD was determined by the pre-test likelihood and the result of the stress test. Patients with a low post-test likelihood of CAD were discharged; those with a high post-test probability were considered for coronary angiography. All others were managed according to standard hospital protocols. RESULTS: A total of 302 patients underwent either ExECG or SE. SE identified significantly more patients with a low post-test probability of CAD (80% vs 31%, p<0.0001) and significantly fewer patients with an intermediate post-test likelihood of CAD compared to ExECG (3% vs 47%; p<0.0001). Significantly fewer patients undergoing SE were referred for further tests to exclude or refute the diagnosis of CAD (16% vs 52%; p<0.0001). In total, 36 (12%) had flow limiting CAD demonstrated by coronary angiography. Significant CAD was seen in fewer patients with a positive ExECG than with a positive SE (56% vs 84% (p=0.12)). Event rates were low for both modalities in patients with low post-test probability (3.5% for SE vs 5.1% for ExECG; p=ns) though the number of patients identified as low risk was higher if SE was performed. CONCLUSION: Despite negative cardiac Troponin, 12% of patients with acute chest pain had significant CAD. SE is superior to ExECG in discriminating between those patients with a low and intermediate risk of CAD and correctly identified patients with significant CAD, as well as conferring an excellent prognosis in those considered low risk. SE significantly reduces the requirement for further tests to diagnose CAD compared to ExECG.