Safety of dobutamine stress real-time myocardial contrast echocardiography

OBJECTIVES: The aim of this study was to determine the safety of dobutamine stress myocardial perfusion imaging (MPI) obtained by real-time contrast echocardiography (RTCE) and intravenous ultrasound contrast in a large cohort of patients with suspected coronary artery disease (CAD). BACKGROUND: Despite the increasing number of studies showing the potential clinical utility of myocardial contrast perfusion imaging with commercially available contrast agents, the safety of this technique in a clinical setting has not been demonstrated. METHODS: Over a four-year period, 1,486 patients underwent dobutamine stress RTCE with low mechanical index pulse sequence schemes after intravenous injections of commercially available contrast agents (35% Definity, Bristol Myers Squibb Medical Imaging Inc., North Billerica, Massachusetts; 65% Optison, GE-Amersham, Princeton, New Jersey). The hemodynamic and adverse effects of RTCE were compared with 1,012 patients who underwent conventional dobutamine stress echocardiography (DSE) without contrast. The feasibility of image analysis was defined as the ability to analyze MPI in at least two of the three standard segments in each left ventricular wall. RESULTS: No myocardial infarction or death occurred during dobutamine stress. There was no difference in the incidence of nonsustained ventricular tachycardia, sustained ventricular tachycardia, or supraventricular tachycardia during dobutamine infusion between RTCE and DSE. Myocardial perfusion imaging was considered feasible for analysis in 94% of the walls at baseline and 95% at peak stress. The anterior, lateral, and posterior walls were the most common regions in which MPI was not feasible. Myocardial perfusion imaging with RTCE had a higher accuracy for detecting patients with angiographically significant CAD than the analysis of wall motion (84% vs. 66%, respectively; p < 0.001). CONCLUSIONS: Dobutamine stress RTCE appears to be a safe and feasible technique for evaluating patients with known or suspected CAD.     

Accuracy of stress Tc-99m tetrofosmin myocardial perfusion tomography for the diagnosis and localization of coronary artery disease in women.

BACKGROUND: Earlier studies have suggested a modest accuracy of stress thallium 201 myocardial perfusion imaging (MPI) for the diagnosis of coronary artery disease (CAD) in women. The accuracy of stress MPI with technetium 99m tetrofosmin has not been studied in women. The aim of this study was to assess the accuracy of stress Tc-99m tetrofosmin MPI for the diagnosis and localization of CAD in women. METHODS AND RESULTS: We studied 88 women who underwent exercise or dobutamine stress Tc-99m tetrofosmin tomography and coronary angiography within 3 months. Significant CAD was defined as a stenosis 50% or greater in diameter in at least 1 major epicardial coronary artery. Myocardial perfusion abnormalities were detected in 44 of 53 patients with significant CAD and in 7 of 35 patients without significant CAD (overall sensitivity, 83% [95% confidence interval (CI), 73%-93%]; specificity, 80% [95% CI, 67%-93%]; and accuracy, 82% [95% CI, 74%-90%]). The sensitivity was 72% (18/25) in patients with single-vessel CAD and 93% (26/28) in patients with multivessel CAD. Perfusion abnormalities were detected in 2 or more vascular distributions in 20 of 28 patients with multivessel CAD and in 4 of 60 patients without multivessel CAD (sensitivity for the identification of multivessel CAD, 71% [95% CI, 55%-88%]; specificity, 93% [95% CI, 86%-98%]; and accuracy, 86% [95% CI, 79%-93%]). The sensitivity, specificity, and accuracy were 82%, 84%, and 83%, respectively, for the diagnosis of CAD in the left anterior descending artery; 77%, 84%, and 81%, respectively, for CAD in the right coronary artery; and 74%, 80%, and 78%, respectively, for CAD in the left circumflex artery. CONCLUSION: Stress Tc-99m tetrofosmin MPI is an accurate noninvasive technique for the diagnosis and localization of CAD in women.     

Evaluating the Prognostic Value of Positron‐Emission Tomography Myocardial Perfusion Imaging Using Automated Software to Calculate Perfusion Defect Size

Background:

Myocardial perfusion imaging by positron‐emission tomography (PET MPI) is regarded as a valid technique for the diagnosis of coronary artery disease (CAD), but the incremental prognostic value of PET MPI among individuals with known or suspected CAD is not firmly established.

Hypothesis:

Myocardial perfusion defect sizes as measured by PET MPI using automated software will provide incremental prognostic value for cardiac and all‐cause mortality.

Methods:

This study included 3739 individuals who underwent rest‐stress rubidium‐82 PET MPI for the evaluation of known or suspected CAD. Rest, stress, and stress‐induced myocardial perfusion defect sizes were determined objectively by automated computer software. Study participants were followed for a mean of 5.2 years for cardiac and all‐cause mortality. Cox proportional hazards models were developed to evaluate the incremental prognostic value of PET MPI.

Results:

A strong correlation was observed between perfusion defect sizes assessed visually and by automated software (r = 0.76). After adjusting for cardiac risk factors, known CAD, noncoronary vascular disease, and use of cardioprotective medications, stress perfusion defect size was strongly associated with cardiac death (P < 0.001). Rest perfusion defects demonstrated a stronger association with cardiac death (P < 0.001) than stress‐induced perfusion defects (P = 0.01), yet both were highly significant. Similar patterns held for all‐cause death.

Conclusions:

The current study is the largest to date demonstrating PET MPI provides incremental prognostic value among individuals with known or suspected CAD. Automated calculation of perfusion defect sizes may provide valuable supplementary information to visual assessment. This work was partially funded by a predoctoral fellowship grant awarded to the first author by the American Heart Association's Founders' Affiliate. Additional funding was provided by Niagara Falls Memorial Medical Center, Positron Corporation, the University at Buffalo, and Niagara University. The authors have no other funding, financial relationships, or conflicts of interest to disclose.     

Prognostic value of treadmill exercise and dobutamine stress positron emission tomography

BACKGROUND:

Although positron emission tomography (PET) is routinely performed using vasodilator stress, exercise and dobutamine stress are available alternatives. Evidence suggests that vasodilator PET myocardial perfusion imaging (MPI) has prognostic value, but the prognostic value of treadmill exercise and dobutamine PET MPI is unknown.

OBJECTIVE:

To determine the potential prognostic value of nonvasodilator stress PET MPI.

METHODS:

Patients underwent treadmill exercise or dobutamine PET MPI. Images were assessed qualitatively and semiquantitatively. PET results were categorized as normal (summed stress score [SSS] of less than 4), abnormal (SSS of 4 or greater) or inconclusive (SSS of less than 4 and submaximal peak stress heart rate). Patient follow-up (cardiac death, nonfatal myocardial infarction [MI] and/or late revascularization) was performed.

RESULTS:

Of the 124 patients (mean follow-up period of 2.3±1.6 years), 46 patients (37%) had a normal study, 15 patients (12%) had an inconclusive study and 63 (51%) had an abnormal PET. Patients with a normal PET had no deaths or nonfatal MI. One patient with a normal PET underwent late revascularization (annual event rate of 1.7%). Patients with an abnormal PET had 15 cardiac events (one cardiac death, four nonfatal MIs and 10 late revascularizations), with an annual event rate of 13.0% (P=0.002).

CONCLUSIONS:

Although small, the present study suggests that defects seen on PET myocardial perfusion, resulting from stressors (treadmill exercise and dobutamine) that increase myocardial oxygen demand, may have prognostic value.     

Real-time dobutamine stress myocardial contrast echocardiography for detecting coronary artery disease: correlating abnormal wall motion and disturbed perfusion

BACKGROUND: Real-time myocardial contrast echocardiography (MCE) makes possible the simultaneous visualization of changes in perfusion imaging and wall motion. OBJECTIVES: To assess the accuracy of real-time MCE for detecting the presence and extent of coronary artery disease (CAD), and to evaluate the correlation between wall motion and myocardial perfusion by visual examination. METHODS: A total of 140 consecutive patients without resting wall motion abnormalities were screened to undergo dobutamine stress MCE with power modulation and coronary angiography. Significant coronary disease was defined by the quantification of over 50% stenosis in a major epicardial vessel. The visual identification of wall motion and myocardial perfusion abnormalities was determined by blind review. RESULTS: Eight patients were excluded due to suboptimal images (feasibility 94.3%). Myocardial contrast enhancement analysis and wall motion analysis were similar in terms of sensitivity (81.2% versus 83.5%, respectively) and specificity (76.5% versus 80.9%, respectively) in detecting the presence of CAD. Myocardial contrast enhancement analysis tended to have a greater sensitivity than wall motion analysis in detecting the ischemic extent over multiple vascular territories among patients with multiple-vessel disease (sensitivity 83.8% versus 71.4% [P=0.09], and abnormal segment length 54.7+/-21.1% versus 48.9+/-24.7% [P=0.03] for myocardial contrast enhancement and wall motion analysis, respectively). There was good concordance between the presence of myocardial ischemia and wall motion abnormality for the segment-by-segment analysis (89.7% agreement, kappa = 0.745). The correlation of the wall motion score and perfusion score at peak stress was also good (r=0.793, P=0.015). CONCLUSIONS: Dobutamine stress MCE with power modulation is similar in sensitivity and specificity to wall motion analysis for detecting the presence of CAD. However, it provides greater sensitivity in evaluating the extent of ischemia in patients with multiple-vessel disease.     

Prognostic implications of stress Tc-99m tetrofosmin myocardial perfusion imaging in patients with left ventricular hypertrophy.

BACKGROUND: Left ventricular hypertrophy (LVH) is associated with an increased risk of cardiac death. Data on the prognostic value of myocardial perfusion imaging (MPI) in patients with LVH are limited. The aim of this study is to assess the independent value of stress technetium 99m tetrofosmin MPI in predicting the long-term mortality rate in patients with LVH. METHODS AND RESULTS: We studied 177 patients (mean age, 59 +/- 12 years; 134 men) with LVH by electrocardiographic criteria who underwent dobutamine or exercise stress Tc-99m tetrofosmin MPI. Endpoints during follow-up were cardiac and all-cause death and hard cardiac events. A normal scan was detected in 42 patients (24%). Myocardial perfusion abnormalities were fixed in 59 patients (33%) and reversible in 76 (43%). Perfusion abnormalities were observed in a single-vessel distribution in 79 patients and in a multivessel distribution in 56. During a mean follow-up period of 5.5 +/- 2 years, 60 patients (34%) died. Death was considered cardiac in 42 patients (24%). Nonfatal myocardial infarction occurred in 10 patients (6%). The annual mortality rate was 1.4% in patients with normal perfusion, 3.2% in those with perfusion abnormalities in a single-vessel distribution, and 8% in those with a multivessel distribution. In a multivariate analysis independent predictors of death were age (risk ratio [RR], 1.05; 95% confidence interval [CI], 1.02-1.07), male gender (RR, 1.9; 95% CI, 1.1-3.6), hypercholesterolemia (RR, 1.7; 95% CI, 1.0-2.9), and abnormal perfusion (RR, 2.7; 95% CI, 1.5-4.8). CONCLUSION: In patients referred for stress MPI, LVH is associated with a high mortality rate, with approximately one third of patients dying over a period of 5 years. Stress Tc-99m tetrofosmin MPI provides independent information for predicting death in these patients.     

High-dose dipyridamole and gated sestamibi SPECT imaging provide diagnostic resting and stress ejection fractions useful for predicting extent of coronary artery disease

A decline in ejection fraction at stress compared with rest images has been associated with increased severity of coronary artery disease (CAD) and suggests a poorer prognosis. Myocardial perfusion imaging (MPI) using high-dose dipyridamole (HDD) has been shown to more accurately detect CAD than either standard dose dipyridamole (SDD) or exercise-induced stress (EST), but has not been looked at to determine its usefulness in detecting changes in stress and rest ejection fractions. To determine the relationship between changes in left ventricular ejection fraction (LVEF) and the severity of CAD, 36 Individuals underwent gated single photon emission computed tomography (SPECT) MPI using HDD. In each case resting and stress LVEFs were determined along with MPI results. Subjects with single-vessel CAD demonstrated an increase in LVEF from 77.8% (sd +/-8.8%) to 85.6% (sd +/-8.4%) resulting in a statistically significant increase in LVEF of 7.8% (p = 0.009). Patients with two-vessel disease showed a smaller increase from 73.2% (sd + 8.3%) to 79.8% (sd + 9.8%) following HDD stress. This increase was statistically (p = 0.008) significant. Patients with triple-vessel CAD showed a reduction in LVEF from 67.4% (sd +/-14.07) to 65.1% (sd +/-16.5%) which represented a decrease in LVEF of 2.7% and approached (p = 0.25) but did not reach statistical significance. Both the resting and stress LVEFs were statistically lower (p<0.05) in patients with triple-vessel CAD. Changes in resting LVEF (REF) and HDD pharmacologically induced stress LVEF (SEF) provide a valuable diagnostic marker as to the number of significantly diseased coronary arteries and can be acquired from gated SPECT sestamibi images.     

Detection of coronary artery disease with a continuous infusion of definity ultrasound contrast during adenosine stress real time perfusion echocardiography

BACKGROUND: Myocardial perfusion imaging during adenosine stress is an accurate method of detecting physiologically relevant coronary artery disease. METHODS: Real time perfusion echocardiography (RTPE) was compared to nuclear scintigraphy (rest Thallium, stress Sestamibi) in 40 patients with intermediate to high pretest probability. RTPE was performed with a continuous infusion of intravenous microbubbles (Definity; Bristol Myers Squibb) and intermittent high mechanical index impulses, with visual examination of both the replenishment rate and plateau intensity of contrast. RESULTS: Of the 119 coronary artery territories compared, SPECT and RTPE were in agreement in 105 (88% agreement; kappa 0.67). In patients who went on to quantitative coronary arteriography (QCA), there were three who had normal appearing radionuclide SPECT during adenosine, but subendocardial perfusion defects with RTPE. In all three cases, QCA confirmed the presence of a >50% diameter stenosis in the abnormal territory. CONCLUSIONS: We conclude from this study that adenosine stress imaging with RTPE is an accurate method of detecting coronary artery disease. The higher resolution of RTPE may identify subendocardial defects that would otherwise have gone undetected with radionuclide imaging.     

Prognosis of negative adenosine stress magnetic resonance in patients presenting to an emergency department with chest pain.

OBJECTIVES: This study was designed to determine the diagnostic value of adenosine cardiac magnetic resonance (CMR) in troponin-negative patients with chest pain. BACKGROUND: We hypothesized that adenosine CMR could determine which troponin-negative patients with chest pain in an emergency department have coronary artery disease (CAD) or future adverse cardiac events. METHODS: Adenosine stress CMR was performed on 135 patients who presented to the emergency department with chest pain and had acute myocardial infarction (MI) excluded by troponin-I. The main study outcome was detecting any evidence of significant CAD. Patients were contacted at one year to determine the incidence of significant CAD defined as coronary artery stenosis >50% on angiography, abnormal correlative stress test, new MI, or death. RESULTS: Adenosine perfusion abnormalities had 100% sensitivity and 93% specificity as the single most accurate component of the CMR examination. Both cardiac risk factors and CMR were significant in Kaplan-Meier analysis (log-rank test, p = 0.0006 and p < 0.0001, respectively). However, an abnormal CMR added significant prognostic value in predicting future diagnosis of CAD, MI, or death over clinical risk factors. In receiver operator curve analysis, adenosine CMR was a more accurate predictor than cardiac risk factors (p < 0.002). CONCLUSIONS: In patients with chest pain who had MI excluded by troponin-I and non-diagnostic electrocardiograms, an adenosine CMR examination predicted with high sensitivity and specificity which patients had significant CAD during one-year follow-up. Furthermore, no patients with a normal adenosine CMR study had a subsequent diagnosis of CAD or an adverse outcome.     

Impact of combined supine and prone myocardial perfusion imaging using an ultrafast cardiac gamma camera for detection of inferolateral coronary artery disease

Background

Although combined supine and prone acquisitions improve the detection of inferolateral obstructive coronary artery disease (CAD), the predictors of inaccurate detection of inferolateral ischemia have not been reported by using cadmium zinc telluride (CZT) myocardial perfusion imaging (MPI).

Methods and results

Vasodilator stress ^99mTc tetrofosmin MPI using CZT camera and coronary angiography was performed in 322 patients within an interval of 2 months. Prone MPI was performed immediately after supine MPI. Narrowing of the luminal diameter ≥ 75% was considered significant. The presence of an abnormality on both supine and prone images was considered significant. Combined supine and prone imaging, compared with supine-only quantification, was more specific (93% vs. 72%, respectively, p < 0.0001) and accurate (88% vs. 74%, p < 0.0001) without compromising sensitivity (82% vs. 68%, p = 0.10). The area under the curve for detecting inferolateral ischemia was 0.769 (95% CI 0.705–0.833) for supine imaging and 0.802 (95% CI 0.730–0.875) for combined supine and prone imaging (p < 0.05). Multivariable analysis revealed that previous inferolateral myocardial infarction was an independent predictor of a false diagnosis (odds ratio = 3.45, 95% confidence interval [CI] 1.62–7.37, p < 0.001).

Conclusions

Combined supine and prone quantitative CZT MPI enhances the detection of inferolateral CAD without adversely affecting its sensitivity. However, we recommend inferolateral ischemia be monitored in patients with a history of previous inferolateral MI because previous inferolateral MI is a predictor of inaccurate diagnosis.     

Diagnosis of coronary artery disease in patients with permanent cardiac pacemaker by dobutamine stress echocardiography or exercise thallium-201 myocardial tomography

This study evaluated the use of dobutamine stress echocardiography and exercise thallium-201 myocardial computed tomography (CT) in the diagnosis of coronary artery disease (CAD) in patients with permanent transvenous pacemaker with the electrode implanted in the right ventricle (RV). Twenty-nine consecutive patients with pacemaker underwent dobutamine stress echocardiography, exercise thallium-201 myocardial CT, and coronary arteriography over a period of 8 +/- 1 days. None of these patients had suffered a myocardial infarction (MI). The cardiac rhythm of every patient was electrically paced during echocardiography and tomography. Sixteen (55%) patients showed CAD on angiography (stenosis > or = 50% of the luminal diameter of a major epicardial vessel). The detection sensitivity for CAD was 94% for the tomography and 88% for the echocardiography (P = NS). The difference between the sensitivities of the two techniques in detecting CAD based on the affected coronary artery was not statistically significant. Of the 13 patients without CAD, tomography showed a positive result in nine cases, i.e., a specificity of 31%, whereas echocardiography showed a positive result in only one case, i.e., a specificity of 92% (P < 0. 01). Exercise thallium-201 myocardial computed tomography produces an increased rate of false-positive results in patients with permanent transvenous cardiac pacemaker (PCP) implanted in the right ventricle (RV). Dobutamine stress echocardiography can thus be used to reduce considerably the level of false-positive results in these patients and still retain a detection sensitivity for CAD equal to that of myocardial tomography.     

应用腺苷负荷心肌灌注显像随访老年冠状动脉介入术后患者的临床研究

目的 观察腺苷负荷心肌灌注显像对老年经皮冠状动脉介入治疗(PCI)患者疗效评估包括心肌血运恢复及心功能恢复情况。 方法 选择怀疑冠心病和已明确诊断老年冠心病患者,常规完成冠状动脉造影,53例行PCI,于PCI前、后6个月进行腺苷负荷心肌灌注显像检查,并同时进行心血管主要不良事件随访,完成随访40例。腺苷负荷心肌灌注显像把心肌分为16节段,计算核素扫描总积分及测定心功能。 结果 心肌扫描总积分与冠状动脉总狭窄指数呈正相关(r=0.675,P＜0.01);PCI后心肌扫描总积分与治疗前比较明显减低,分别为（2.2±2.3）与（4.5±1.9）分,差异有统计学意义(t=7.348,P＜0.01);PCI术后心肌灌注改善总有效率86.8％(40/53);PCI术后左心室射血分数较术前明显改善,分别为(58.3±10.5)％与（53.8±10.3）％,差异有统计学意义(t=3.497,P＜0.01)。 结论腺苷负荷心肌灌注显像作为一种无创的检测方法可以准确判定老年PCI术后血流恢复及心功能恢复情况,对老年人PCI术后疗效评价具有一定优势。     

Relationship between noninvasive coronary angiography with multi-slice computed tomography and myocardial perfusion imaging.

OBJECTIVES: The aim of this study was to perform a head-to-head comparison between multi-slice computed tomography (MSCT) and myocardial perfusion imaging (MPI) in patients with an intermediate likelihood of coronary artery disease (CAD) and to compare non-invasive findings to invasive coronary angiography. BACKGROUND: Multi-slice computed tomography detects atherosclerosis, whereas MPI detects ischemia; how these 2 techniques compare in patients with an intermediate likelihood of CAD is unknown. METHODS: A total of 114 patients, mainly with intermediate likelihood of CAD, underwent both MSCT and MPI. The MSCT studies were classified as having no CAD, nonobstructive (<50% luminal narrowing) CAD, or obstructive CAD. Myocardial perfusion imaging examinations were classified as showing normal or abnormal (reversible and/or fixed defects). In a subset of 58 patients, invasive coronary angiography was performed. RESULTS: On the basis of the MSCT data, 41 patients (36%) were classified as having no CAD, of whom 90% had normal MPI. A total of 33 patients (29%) showed non-obstructive CAD, whereas at least 1 significant (> or =50% luminal narrowing) lesion was observed in the remaining 40 patients (35%). Only 45% of patients with an abnormal MSCT had abnormal MPI; even in patients with obstructive CAD on MSCT, 50% still had a normal MPI. In the subset of patients undergoing invasive angiography, the agreement with MSCT was excellent (90%). CONCLUSIONS: Myocardial perfusion imaging and MSCT provide different and complementary information on CAD, namely, detection of atherosclerosis versus detection of ischemia. As compared to invasive angiography, MSCT has a high accuracy for detecting CAD in patients with an intermediate likelihood of CAD.     

Myocardial Contrast Echocardiography in Assessment of Stable Coronary Artery Disease at Intermediate Dobutamine-Induced Stress Level

Background: Myocardial contrast stress echocardiography (stress MCE) is a novel method for diagnosing coronary artery disease (CAD). Few studies have compared the diagnosis of ischemia by stress MCE to angiographic CAD. Methods: Dobutamine stress MCE and SonoVue contrast infusion were performed before an elective percutaneous coronary intervention in 37 patients (8 women) aged 45–75 years with symptomatic CAD and at least one significant coronary artery stenosis measured by quantitative coronary angiography (QCA). The total and regional perfusion and wall motion (WM) were scored as normal or abnormal and attributed to the three main epicardial coronary arteries using a 17-segment left ventricular model. Results: An intermediate stress level was obtained in 29 (78%) patients, and 2 (5%) patients obtained peak stress. A perfusion defect was detected in 92% and WM abnormality in 57% of the patients at peak stress (P < 0.01). By perfusion, 70% of stenoses were both detected and correctly anatomically located, compared to 42% by WM (P < 0.01). All 21 patients with multivessel disease and/or proximal left anterior descending (LAD) stenosis measured by QCA were identified by stress-induced perfusion defects, while only 11 of them were identified by WM abnormalities (P < 0.01). Conclusion: Perfusion scoring is superior to WM scoring during stress MCE for diagnosing significant CAD in patients obtaining intermediate stress level, in particular, when multivessel disease or proximal LAD stenosis is present.     

Prediction of global left ventricular function after bypass surgery in patients with severe left ventricular dysfunction. Impact of pre-operative myocardial function, perfusion, and metabolism.

AIMS: Previous studies have compared the accuracy of various tests of viability for the prediction of recovery of regional left ventricular function; global left ventricular recovery has been less well studied, although it has important prognostic and functional ramifications. We sought to identify the relative contribution of ischaemia, regional and global contractile reserve, perfusion and metabolic function to changes in left ventricular volumes and global function after coronary artery bypass surgery in patients with severe left ventricular dysfunction. METHODS AND RESULTS: Dipyridamole stress Rb-82, fluorodeoxyglucose positron emission tomography and low and high-dose dobutamine-atropine stress echocardiography were obtained in 66 patients with left ventricular impairment. Myocardial segments were considered viable if ischaemia or either metabolic or contractile reserve were present, on positron emission tomography or dobutamine echocardiography. Resting left ventricular function was reassessed after surgery (mean 10+/-3 weeks) in the 59 patients who had not suffered a major peri-operative event; functional improvement was defined by a 5% increment of ejection fraction. Myocardial viability was found in 37 (63%) patients using positron emission tomography and in 42 (71%) patients using dobutamine echocardiography; post-operative functional improvement was noted in 28 (47%) patients. In univariate analyses, predictors of global post-operative functional recovery included: the extent of viability according to positron emission tomography [OR (odds ratio): 2.08 for each additional viable segment, 95% CI (confidence interval): 1.33-3. 25, P=0.001] or dobutamine echocardiography (OR: 2.06 for each additional viable segment, 95% CI: 1.28-3.30, P=0.003) and the increase in ejection fraction with low-dose dobutamine (OR: 1.9 for each 1% increase in ejection fraction with low dose dobutamine, 95% CI 1.39-2.61, P<0.0001). In a multivariate model which included evidence of viability by either technique, and change in ejection fraction with low-dose dobutamine echocardiography, only change in ejection fraction with low-dose dobutamine echocardiography was predictive of post-operative left ventricular functional recovery (adjusted OR: 1.81, 95% CI: 1.30-2.52, P=0.0005). CONCLUSION: Among patients with severe left ventricular dysfunction who are referred for surgical revascularization, the overall accuracies of positron emission tomography and dobutamine echocardiography for the prediction of post-operative myocardial recovery are comparable. However, the strongest predictor of overall improvement of post-operative left ventricular function is an increase of ejection fraction with a low-dose dobutamine infusion.     

多巴酚丁胺负荷超声心动图结合组织多普勒应变率成像技术诊断老年人冠心病的研究

目的探讨多巴酚丁胺负荷超声心动图(DSE)结合组织多普勒应变率成像技术(SRI)诊断老年人冠心病的临床价值。方法 98例老年疑诊冠心病的患者行DSE+SRI检查,测定不同多巴酚丁胺负荷剂量时各心室壁中段收缩期心肌峰值应变率(SRpeak),2周内完成冠状动脉造影(CAG),对比分析SRpeak和CAG对老年人冠心病的诊断价值。结果与CAG相比,SRpeak诊断老年人冠心病敏感度、特异度、准确度分别为71.7%、82.2%、78.0%;SRpeak在不同多巴酚丁胺负荷剂量时诊断的敏感度和特异度不同,在40μg·kg~(-1)·min~(-1)负荷剂量时最高,分别为75.0%、90.4%;对于三支冠状动脉血管的定位诊断均表现为高特异度。结论多巴酚丁胺负荷定量应变率成像是一项安全、有效、无创诊断老年人冠心病的方法。     

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.     

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.     

Women with high exercise tolerance and the role of myocardial perfusion imaging

BACKGROUND: Myocardial perfusion imaging (MPI) provides incremental diagnostic and prognostic information, even in patients with high exercise tolerance. HYPOTHESIS: Myocardial perfusion imaging provides significant diagnostic value, specifically in women with high exercise tolerance. METHODS: Our study population consisted of all women who underwent exercise MPI in our Department from January 1992 to June 1996 and reached at least Stage IV in the Bruce protocol. Patients were divided into those with known and those with possible coronary artery disease (CAD). All patients were followed for 3 years from the performance of MPI. RESULTS: Of 4,803 women who underwent myocardial perfusion imaging, 3,183 had exercise stressing, and of those, 311 reached at least Stage IV in the Bruce protocol. Of these 311 MPI scans, only 23 (7.4%) were abnormal (reversible, fixed, or mixed) and the remaining 288 (92.6%) were normal. Of the 82 patients with known CAD, 13 (15.8%) had an abnormal MPI, while only 10 (4.4%) of the 229 patients with possible CAD. No myocardial infarction or cardiac death occurred within 3 years; one patient with normal MPI needed revascularization. CONCLUSION: In women with high exercise tolerance, especially in those without already known CAD, the yield of MPI is very low. Women with high exercise tolerance have an excellent prognosis.     

Characteristics and outcome of octogenarian population referred for myocardial perfusion imaging: comparison with non-octogenarian population with reference to gender

BACKGROUND: Octogenarian patients referred for stress myocardial perfusion imaging (MPI) differ from younger (non-octogenarian) patients in that they have lower prevalence of risk factors for CAD, but more frequent ischemic events and higher cardiac mortality. HYPOTHESIS: The purpose of this study was to investigate the efficacy of MPI in octogenarian men and women compared with that in the younger population, and to compare the prognostic value of stress MPI in both populations. METHODS: We studied 162 consecutive patients aged > or = 80 years who were referred for stress MPI, and compared them with 253 consecutive patients aged < 80 years. Patients completed a questionnaire encompassing information about the existence of coronary risk factors, cardiac symptoms, coronary artery disease (CAD), myocardial infarction, coronary artery bypass graft, percutaneous transluminal coronary angioplasty, and results of stress MPI. The patients were followed up for cardiac mortality for a mean of 45 +/- 12 months. RESULTS: There were 61 women and 101 men (17% of all referrals) with a mean age of 83 +/- 3 (range 80-90). Parameters of octogenarian patients demonstrated a significantly lower prevalence of non-insulin-dependent diabetes mellitus (p < 0.02), hypercholestrolemia (p < 0.001), and smoking (p = 0.001) compared with non-octogenarian patients. The prevalence of known CAD was similar, but the prevalence of abnormal resting electrocardiogram, left ventricular (LV) dilatation, and stress-induced ischemia was significantly higher in octogenarians (p < 0.002). Cardiac mortality rate per year was 4.3% in octogenarians versus 1.3% in the younger population (p < 0.0001). The independent predictors according to MPI of cardiac death were LV dilatation and presence of ischemia in octogenarians, and severity of ischemia in non-octogenarians. CONCLUSIONS: The octogenarian population referred for stress single-photon emission computed tomography differed from the non-octogenarian group in that it had a lower prevalence of risk factors for CAD, but more frequent ischemic events and higher cardiac mortality; however, MPI variables predict adverse outcome in both populations.