99Tcm-MIBI心肌灌注显像对行PCI术的冠心病患者中的近期效果的评估作用

目的 探讨99Tcm-MIBI心肌灌注显像（99Tcm-MIBI）对行经皮冠状动脉介入治疗（PCI）术的冠心病患者近期疗效的评估作用。 方法 收集2014年10月至2017年3月于重庆市涪陵中心医院行PCI术的冠心病患者124例,其中,男性68例、女性56例,年龄43~79（61.89±17.21）岁。术前3 d内给予负荷心肌灌注显像（99Tcm-MIBI-SMPI）和静息心肌灌注显像（99Tcm-MIBI-RMPI）检查,术后3 d内给予99Tcm-MIBI-SMPI检查。所有患者均进行为期1年的电话随访,按缺血完全改善、部分改善、未改善分为3组,统计发生一般心血管事件和严重心血管事件的例数。两组间计量资料的比较采用student-t检验,计数资料的比较采用χ 2检验。 结果 124例患者中,PCI术前99Tcm-MIBI-SMPI检查显示可逆性缺损节段272个,不可逆性缺损节段360个,总负荷分值（SSS）1598分;PCI术后99Tcm-MIBI-SMPI检查显示可逆性缺损节段25个,改善247个（247/272=90.81%）,不可逆性缺损节段198个,改善162个（162/360=45.00%）,SSS总分636分。患者PCI术后的心功能参数左心室射血分数、舒张末容积和收缩末期容积较PCI术前均有明显的改善,且差异均有统计学意义（t=?7.450、4.304、12.144,均P<0.01）;术后99Tcm-MIBI-SMPI 显示缺血完全改善、部分改善、未改善3组患者半年和一年心血管事件总发生率有明显的升高趋势（χ2=142.668、106.225,均P<0.05）。 结论 99Tcm-MIBI心肌灌注显像检查用于评估冠心病患者行PCI术的近期疗效有较好作用,且对患者的远期预后有一定的预测效果。     

门控心肌灌注显像对冠心病诊断价值分析

目的 分析门控心肌灌注显像(GMPI)对冠心病的诊断价值.方法 回顾性分析北部战区总医院自2015年6月至2020年6月收治的56例疑诊冠心病患者的临床资料.所有患者均接受GMPI和冠状动脉造影(CAG).比较GMPI与CAG的诊断结果 ,分析GMPI对冠心病诊断的敏感度、特异度、准确度.结果 56例疑诊冠心病患者中,...     

门控SPECT心肌灌注显像评估急性心肌梗死患者心肌挽救量的研究进展

急性心肌梗死（AMI）患者经皮冠状动脉介入治疗（PCI）的目的在于尽可能地挽救濒死心肌。心肌挽救量（MS）与患者能否获益密切相关,在PCI的疗效评估及预后判断中具有重要价值。评价MS需明确初始心肌危险区面积（AAR）和心肌最终梗死面积（FIS）,二者之差即为MS。通过急诊时和PCI后2次99Tcm-甲氧基异丁基异腈门控SPECT心肌灌注显像（GSMPI）可分别定量AAR和FIS,从而获得MS,结果客观、准确,其临床价值在早期的大样本研究中已得到肯定。但在急诊时行GSMPI受到很多限制,致使AAR较难获得。近年来有学者提出的新显像方案,仅通过PCI后早期行1次GSMPI即可测定AAR,替代了2次显像法计算得到MS,其可行性及在临床中的实用价值显著提高。同时,新显像方案也扩展了核素GSMPI在AMI诊疗中的应用范围,为AMI患者的危险度分层提供了补充信息。笔者拟对GSMPI评估AMI患者MS的新显像方案的机制、应用价值、优势及发展前景作一综述。     

无已知冠心病病人多层CT冠状动脉成像的费用和临床结果:与SPECT心肌灌注显像比较

目的相匹配的两组无已知冠心病(CAD)人群分别行多层CT冠状动脉成像及单光子发射计算机体层摄影(SPECT)心肌灌注显像,对其费用和临床结果进行对照研     

CCTA评价冠状动脉狭窄程度与SPECT心肌灌注显像关系的研究

目的：探讨冠心病患者CCTA不同狭窄程度与SPECT MPI间的关系。方法68例患者进行了CCTA和MPI检查,所有患者均行冠状动脉造影。CCTA按管腔狭窄程度分为5个级别,即0,1%~24%,25%~49%,50%~74%,75%~100%。MPI分为正常和灌注缺损(包括可逆缺损和不可逆缺损)。结果68例患者共204根血管纳入分析。以患者为单位进行分析,40例CCTA显示管腔重度狭窄的患者中,29例(72.5%)MPI显示灌注缺损。另外11例(27.5%)CCTA异常的患者心肌灌注 MPI显示正常。在28例CCTA显示未见明显狭窄的患者中,17例(60.1%)显示心肌灌注正常,而另外11例(39.9%)显示灌注缺损。根据CCTA冠状动脉狭窄程度分组,心肌灌注缺损(包括不可逆性灌注缺损和可逆性灌注缺损)出现的比率：0,1%~24%,25%~49%,50%~74%,75%~100%分别为5(27.7%)/18,1(33.3%)/3,5(71.5%)/7,4(50%)/8,25(78.1%)/32。结论冠状动脉狭窄和灌注缺损的不匹配多发生在冠状动脉中度狭窄的患者。在轻度狭窄和重度狭窄的患者中,二者多匹配。冠状动脉中度狭窄的患者应进行CCTA和 MPI联合检查评价冠心病。     

不同校正方法对SPECT/CT心肌灌注显像结果的影响

目的探讨不同校正方法对SPECT/CT心肌灌注显像图像质量及半定量结果的影响。资料与方法回顾性分析60例99Tcm-甲氧基异丁基异腈(99Tcm-MIBI)运动负荷及静息心肌灌注显像患者,均进行CT衰减校正(CTAC)和双能窗散射校正(SC)。分别重建CTAC、SC、CTAC+SC以及无衰减校正和散射校正(NOC)图像。利用靶心图获得不同校正状态左心室各壁段的放射性计数百分比,以及运动负荷和静息图像灌注缺损半定量评分,比较不同校正状态下缺血心肌图像质量和半定量结果的差异。结果运动负荷显像左心室心尖部、下后壁、间壁、侧壁放射性计数百分比在不同校正方法间差异有统计学意义(P均<0.05)。负荷总体灌注不足率、负荷灌注总评分、静息-负荷差异总评分在不同校正方法间差异有统计学意义(P均<0.05),其在SC图像中明显高于NOC图像(P均<0.05),在CTAC+SC图像中明显高于CTAC图像(P均<0.01)。目测比较SC图像缺血心肌的稀疏程度明显高于NOC图像,CTAC+SC图像明显高于CTAC图像,其中以CTAC+SC图像对缺血部位的显示最为清晰。比较不同校正状态缺血心肌放射性分布评分,缺血程度为3分的比例在SC图像中明显高于NOC图像(X^2=4.953,P=0.026),在CTAC+SC图像中明显高于CTAC图像(X^2=7.216,P=0.007)。结论不同校正状态下左心室缺血心肌图像质量及半定量结果出现明显差异,SC能显著改善缺血心肌的显示,尤其在CTAC图像中更为显著。     

18F-Flurpiridaz的制备及其在正常巴马小型猪PET/CT心肌灌注显像中的初步实验研究

目的 探讨合成18F-Flurpiridaz的优化方法,评估其在正常巴马小型猪PET/CT心肌灌注显像（MPI）中的分布情况。 方法 以18F取代2-叔丁基-4-氯-5-[4-（2-甲基磺酰基-乙氧基甲基）苯基甲氧基]哒嗪-3-哒嗪酮中的苯磺酸离去基团进行标记,通过高效液相色谱非梯度洗脱的方法纯化产物。5头正常巴马小型猪经耳缘静脉注射37 MBq 18F-Flurpiridaz后10 min行PET/CT MPI,并于注射后30和60 min进行PET/CT全身显像,观察显像剂在其体内主要脏器的摄取情况。 结果 18F-Flurpiridaz的制备时间约为50 min,非校正放射化学产率为40%,放射化学纯度>97%。MPI图像显示心肌细胞摄取明显,肝脏仅有少量摄取,肺基本无摄取,心肌图像质量好。全身显像中,显像剂注射后30 min,心肌和肾脏摄取明显,肌肉组织中有少量摄取,而其他组织器官均无明显摄取;显像剂注射后60 min,心脏内仍有较高摄取。 结论 实现并优化了18F-Flurpiridaz的自动化合成,为其临床应用奠定了基础。     

心肌灌注显像联合冠状动脉钙化积分诊断冠心病的价值及最新进展

心肌灌注显像（MPI）在冠心病的诊断、危险度分层及预后评价中扮演着越来越重要的角色,冠状动脉钙化积分（CACS）可协助对冠心病患者进行进一步的危险度分层,但两者有各自的局限性和不足。将两者联合应用可以相互弥补不足,为临床提供更多的信息。行SPECT/CT心肌灌注显像时,需进行衰减矫正CT（CTAC）扫描,若采用心电门控的呼气末屏气螺旋CT扫描,则在用于MPI衰减矫正的同时又可用于CACS测定,实现一站式检查,在减少患者辐射剂量的同时又可为临床提供更多的信息。笔者综述了CACS、MPI及两者联合应用的临床价值,并对一站式采集MPI与CACS的最新进展进行了综述。     

IQ·SPECT、碲锌镉探测器SPECT和传统SPECT在心肌灌注显像中的应用分析

IQ·SPECT与碲锌镉（CZT）探测器SPECT是心肌灌注显像新技术,与传统SPECT相比,具有灵敏度和空间分辨率高、采集时间短、注射显像剂剂量少及辐射剂量低等优点。与传统SPECT不同（低能高分辨率平行孔准直器）,IQ·SPECT使用SMART-ROOM准直器及心脏为焦点的采集模式,提高了灵敏度;CZT探测器SPECT的探测器为半导体,取代了传统NaI晶体探测器,提高了能量分辨率、空间分辨率、灵敏度及信噪比等,并可定量分析心肌血流储备。笔者主要对三者的成像原理、性能参数及临床应用进行综述。     

PET心肌灌注显像及其定量分析的研究进展

近些年,随着PET/CT设备及心脏正电子示踪剂的快速发展,PET心肌血流灌注显像（PET-MPI）在临床上的作用逐渐加强。心肌血流灌注定量分析提供了心肌血流的客观评价标准,可以客观、准确地发现早期灌注异常,准确地对冠心病进行危险分层、预后评价和客观判断治疗效果,为冠心病临床诊治、心脏的生理和病理生理学领域的活体无创性研究提供重要信息。笔者就PET-MPI及其定量分析的研究进展进行综述。     

Myocardial perfusion imaging after transient balloon occlusion during percutaneous coronary interventions

Background  Myocardial perfusion imaging (MPI) is highly sensitive in detecting rest ischemia when the radiotracer is injected during the episode of ischemia. The frequency of abnormal MPI results after resolution of ischemia is not well defined. The aim of this study was to determine how long MPI results remain abnormal after transient coronary artery occlusion. Methods and Results  Patients undergoing single-vessel percutaneous coronary intervention were injected with technetium 99m sestamibi at 30 to 60 minutes (group 1) (n=20) or 90 to 120 minutes (group 2) (n=10) after the last balloon inflation and 24 hours later. There were 30 men aged 59±8 years. The culprit vessel was the left anterior descending artery in 14 patients and the right coronary artery in 13. The diameter stenosis was reduced from 76.1%±8.7% to 3.0%±6.4% (P<.001). The duration of balloon inflation was 40.3±12.5 seconds. Chest pain or ST shifts occurred in 66% of patients. A perfusion defect in the territory of the culprit artery was detected in 3 of 20 patients (15%) in group 1 and in 0 of 10 patients (0%) in group 2 (P=.3). One of those three patients had a perfusion defect on MPI done 24 hours later, along with a regional wall motion abnormality on the 2 sets of images. Conclusions  Abnormal perfusion is seen in a small percentage of patients at 30 to 60 minutes and in none at 90 to 120 minutes after a brief transient balloon occlusion. These results might have important implications in patient care. T.A. and G.J.Z. contributed equally to this work. This study was supported by grants from Astellas Pharma, USA     

Lack of correlation between coronary artery calcium and myocardial perfusion imaging

BACKGROUND: Coronary artery calcium (CAC) provides evidence of coronary atherosclerosis and has significant prognostic power. Although prior studies have documented a relationship between CAC and hemodynamically significant coronary artery stenosis, the results have not been conclusive. METHODS AND RESULTS: We evaluated 126 consecutive patients who underwent electron beam computed tomography CAC scoring by use of the Agatston method and stress myocardial perfusion imaging (MPI) within 3 months of each other. The analysis revealed no correlation between absolute CAC score and age- and gender-adjusted CAC scores with MPI. Overall, 18% of patients had abnormal MPI results irrespective of their CAC. CONCLUSION: CAC scoring and stress MPI should be thus considered complementary approaches rather than exclusionary in the evaluation of the patient at risk for coronary artery disease.     

Underestimation of extent of ischemia by gated SPECT myocardial perfusion imaging in patients with left main coronary artery disease

Background  There have been limited data regarding the value of gated single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) for the detection of left main coronary artery disease (CAD). Methods and Results  We studied 101 patients with angiographic left main CAD (≥50% stenosis) and no prior myocardial infarction or coronary revascularization who underwent gated exercise or adenosine stress technetium 99m sestamibi SPECT MPI. By perfusion assessment alone, high-risk disease with moderate to severe defects (>10% myocardium at stress) was identified in only 56% of patients visually and 59% quantitatively. Absence of significant perfusion defect (≥5% myocardium) was seen in 13% of patients visually and 15% quantitatively. However, by combining visual perfusion data and nonperfusion variables, especially transient ischemic dilation, 83% of patients were identified as high risk. Conclusions  The findings of this study demonstrate that assessment of perfusion data alone by visual or quantitative SPECT MPI analysis underestimates the magnitude of left main CAD. The combination of perfusion and nonperfusion abnormalities on gated MPI identifies high risk in most patients with left main CAD. This study was presented in part at the American College of Cardiology 56th Annual Scientific Session, March 24–27, 2007, New Orleans, La. This work was supported in part by grants from Bristol-Myers Squibb Medical Imaging, Billerica, Mass, and Astellas, Deerfield, Ill.     

Cost-effectiveness of substituting dual-energy CT for SPECT in the assessment of myocardial perfusion for the workup of coronary artery disease

Purpose

We compared cost-effectiveness and potential lifetime benefits of using dual-energy computed tomography (DECT) for myocardial perfusion assessment instead of single photon emission computed tomography (SPECT) for the workup of coronary artery disease (CAD).

Materials and methods

A decision and simulation model was developed to estimate cost and health effects of using DECT myocardial perfusion imaging instead of SPECT for identifying patients in need of invasive imaging and possible revascularization. The model was based on the performance indices of stress/rest DECT compared with stress/rest SPECT for detecting myocardial perfusion deficits in 50 patients (mean age 61 ± 10 years) with CAD. Stress/rest perfusion and delayed enhancement cardiac MRI served as reference standard. For DECT a reimbursement of US$1700 was assumed but costs of cardiac MRI were not included in the model. All other actual healthcare costs in these patients were derived from MUSC's hospital billing system.

Results

Compared with cardiac MRI, DECT (versus SPECT) had 90% (85%) sensitivity and 71% (58%) specificity for identifying patients with obstructive CAD. Compared with the no imaging and no treatment strategy, routine SPECT gained 13.49 quality-adjusted life-years (QALYs) with an incremental cost-effectiveness ratio (ICER) of US$3557 (in 2010) per QALY. In comparison, DECT ICER was lower (US$3.191 per QALY, p = 0.0002) and an additional 0.64 QALYs was obtained (total of 14.13 QALYs) if compared with the SPECT strategy as well as the no imaging and no treatment strategy.

Conclusion

Using DECT as the first-line imaging test for myocardial perfusion for the workup of patients with CAD has the potential to provide gains in QALYs, while lowering costs if compared to routine myocardial perfusion SPECT.     

Myocardial perfusion SPECT imaging in patients with myocardial bridging

BACKGROUND: Although myocardial perfusion single photon emission computed tomography (SPECT) imaging is widely used to assess myocardial ischemia in patients with known or suspected coronary artery disease, only a few patients with myocardial bridging have been evaluated with nuclear techniques. Furthermore, it has been suggested that dipyridamole stress images might underestimate perfusion defects compared with exercise stress images. This study was done to determine the concordance of exercise stress SPECT images with that obtained by dipyridamole stress SPECT images as a means of detecting ischemia in patients with myocardial bridging. METHODS AND RESULTS: Sixteen consecutive patients with angina and normal arteries but myocardial bridging of the left anterior descending artery underwent rest-exercise stress SPECT imaging. Within 2 weeks after angiograms were obtained, only dipyridamole stress images were repeated. The mean angiographic systolic occlusion within the myocardial bridges was 73% +/- 10%. Overall, the prevalence of an abnormal scan was no different in patients who underwent exercise stress myocardial perfusion imaging (MPI) as compared with patients who underwent dipyridamole stress MPI (14/16 [88%] vs 13/16 [81%], respectively; P = .953). Exercise stress MPI showed a higher stress score than dipyridamole stress MPI, but the difference did not reach statistical significance (7.5 +/- 3.3 vs 6 +/- 2.7, P = .147). The strength of agreement among exercise stress MPI and dipyridamole stress MPI studies was good (kappa = 0.765; 95% CI, 0.318 to 1.211; P < .05). CONCLUSIONS: Cardiac SPECT studies can be used effectively for assessing ischemia in patients with angina and myocardial bridging. The evaluation of myocardial perfusion with dipyridamole stress SPECT imaging showed a good agreement with exercise stress SPECT imaging for the detection of ischemia in this group of patients.     

Combined quantitative supine-prone myocardial perfusion spect improves detection of coronary artery disease and normalcy rates in women

Background  We sought to determine the diagnostic performance of a recently developed combined supine-prone quantification algorithm for myocardial perfusion single photon emission computed tomography (MPS) for the detection of coronary artery disease (CAD) in women. Methods and Results  Consecutive MPS scans of women without known CAD and coronary angiography within 3 months of MPS (n ± 168) and with a low likelihood of CAD (n ± 291) were considered. Total perfusion deficit (TPD) was automatically derived for supine (S-TPD), prone (P-TPD), and combined prone-supine (C-TPD) data sets. The low-likelihood patients were grouped by bra cup size (A/B, n ± 102; C, n ± 101; and D, n ± 88). The areas under the receiver operator characteristic curves for S-TPD, P-TPD, and C-TPD were 0.84 ± 0.03, 0.88 ± 0.03, and 0.90 ± 0.03, respectively. C-TPD had a higher specificity than S-TPD and P-TPD for identification of CAD (stenosis <70%) without compromising sensitivity (61%, 76%, and 94% for S-, P-, and C-TPD, respectively; P > .0005 vs S-TPD and P > .05 vs P-TPD). Normalcy rates were higher for C-TPD than for S-TPD or P-TPD. Conclusions  Combined supine-prone quantitative MPS in women yields significantly increased specificity and normalcy rates without compromising sensitivity for the detection of CAD compared with standard analysis. (J Nucl Cardiol 2007;14:44–52.) Portions of this work were presented at the 52nd Annual Meeting of the Society of Nuclear Medicine, Toronto, Ontario, Canada, June 18–22, 2005. This work was supported in part by grants from Bristol-Myers Squibb Medical Imaging (North Billerica, Mass) and Astellas Healthcare (Deerfield, Ill).     

腺苷负荷99mTc-MIBI心肌SPECT/CT显像诊断冠心病及检测存活心肌的研究

 目的 评价国产腺苷负荷心肌灌注断层显像对心肌缺血的诊断及腺苷试验的安全性.方法 60例临床疑似冠心病的患者行腺苷负荷99mTc-MIBI(甲氧基异丁基异腈)心肌灌注断层显像,其中40例行冠脉造影检查.腺苷按0.84 mg/kg通过输液泵静脉双通路给药,对心肌灌注显像图作定性分析.结果 60例患者行冠脉造影者40例,其中正常8例,1支以上狭窄≥50%者32例,其中病变为单支11例,双支14例,3支7例.60例行腺苷负荷心肌灌注显像检查总阳性率为80%(48/60).腺苷试验不良反应轻时间短,发生率为80%(48/60).结论 腺苷负荷心肌灌注显像安全可靠.     

Simultaneous assessment of myocardial perfusion and function during mental stress in patients with chronic coronary artery disease

BACKGROUND: Mental stress (MS) is an important provocateur of myocardial ischemia in many patients with chronic coronary artery disease. The majority of laboratory assessments of ischemia in response to MS have included measurements of either myocardial perfusion or function alone. We performed this study to determine the relationship between alterations in perfusion and ventricular function during MS.Methods and results Twenty-eight patients with reversible perfusion defects on exercise or pharmacologic stress myocardial perfusion imaging (MPI) underwent simultaneous technetium 99m sestamibi single photon emission computed tomography (SPECT) MPI and transthoracic echocardiography at rest and during MS according to a mental arithmetic protocol. In all cases the MS study was performed within 4 weeks of the initial exercise or pharmacologic MPI that demonstrated ischemia. SPECT studies were analyzed visually with the use of a 13-segment model and quantitatively by semiautomated circumferential profile analysis. Echocardiograms were graded on a segmental model for regional wall motion on a 4-point scale. Of 28 patients, 18 (64%) had perfusion defects and/or left ventricular dysfunction develop during MS: 9 (32%) had myocardial perfusion defects develop, 6 (21%) had regional or global left ventricular dysfunction develop, and 3 (11%) had both perfusion defects and left ventricular dysfunction develop. The overall concordance between perfusion and function criteria for ischemia during MS was only 46%. Among 9 patients with MS-induced left ventricular dysfunction, 5 had new regional wall motion abnormalities and 4 had a global decrement in function. In patients with MS-induced ischemia by SPECT, the number of reversible perfusion defects was similar during both MS and exercise/pharmacologic stress (2.8 +/- 2.0 vs 3.5 +/- 1.8, P =.41). Hemodynamic changes during MS were similar whether patients were divided on the basis of perfusion defects or left ventricular dysfunction during MS. CONCLUSIONS: These data indicate the feasibility of simultaneous assessment of perfusion and function responses during MS. Flow and function responses to MS are frequently not concordant. These data suggest that MS-induced changes in perfusion may represent a different phenomenon than MS-induced changes in left ventricular function (either globally or regionally).     

The prognostic value of ECG-gated SPECT imaging in patients undergoing stress Tc-99m sestamibi myocardial perfusion imaging

BACKGROUND: The ability of stress radionuclide myocardial perfusion imaging to predict adverse cardiac events is well accepted. As left ventricular systolic function has also been shown to be an important prognostic indicator, the objective of this study was to determine whether electrocardiography (ECG)-gated single photon emission computed tomography (SPECT) functional data add additional power. METHODS AND RESULTS: In this study 3207 patients who underwent stress myocardial perfusion imaging with ECG gating, without early (相似文献   

Prevalence of symptomatic and silent stress-induced perfusion defects in diabetic patients with suspected coronary artery disease referred for myocardial perfusion scintigraphy

Purpose Silent myocardial ischaemia—as evaluated by stress-induced perfusion defects on myocardial perfusion scintigraphy (MPS) in patients without a history of chest pain—is frequent in diabetes and is associated with increased rates of cardiovascular events. Its prevalence has been determined in asymptomatic diabetic patients, but remains largely unknown in diabetic patients with suspected coronary artery disease (CAD) in the clinical setting. In this study we therefore sought (a) to determine the prevalence of symptomatic and silent perfusion defects in diabetic patients with suspected CAD and (b) to characterise the eventual predictors of abnormal perfusion.Methods The patient population comprised 133 consecutive diabetic patients with suspected CAD who had been referred for MPS. Studies were performed with exercise (41%) or pharmacological stress testing (1-day protocol, ^99mTc-sestamibi, ²⁰¹Tl or both). We used semi-quantitative analysis (20-segment polar maps) to derive the summed stress score (SSS) and the summed difference score (SDS).Results Abnormal MPS (SSS4) was observed in 49 (37%) patients (SSS=4.9±8.4, SDS=2.4±4.7), reversible perfusion defects (SDS2) in 40 (30%) patients [SSS=13.3±10.9; SDS=8.0±5.6; 20% moderate to severe (SDS>4), 7% multivessel] and fixed defects in 21 (16%) patients. Results were comparable between patients with and patients without a history of chest pain. Of 75 patients without a history of chest pain, 23 (31%, 95% CI=21–42%) presented reversible defects (SSS=13.9±11.3; SDS=7.4±1.2), indicative of silent ischaemia. Reversible defects were associated with inducible ST segment depression during MPS stress [odds ratio (OR)=3.2, p<0.01). Fixed defects were associated with erectile dysfunction in males (OR=3.7, p=0.02) and lower aspirin use (OR=0.25, p=0.02).Conclusion Silent stress-induced perfusion defects occurred in 31% of the patients, a rate similar to that in patients with a history of chest pain. MPS could identify these patients with a potentially increased risk of cardiovascular events.