Diagnostic value of routine clinical parameters in acute myocardial infarction: a comparison to delayed contrast enhanced magnetic resonance imaging

Aims: Contrast enhanced magnetic resonance imaging (ceMRI) has been shown to reliably identify irreversible myocardial injury. The aim of this study was to compare the findings on ceMRI with routine clinical markers of myocardial injury in patients with acute myocardial infarction (MI). Methods and results: Twenty-four patients with acute MI were investigated at 1.5 T. The global myocardial function was analysed with a standard cine MR protocol and a stack of short axis slices encompassing the entire left ventricle. Corresponding short axis slices were acquired for delayed ceMRI 15–20 min after the administration of 0.2 mmol gadolinium–DTPA/kg body weight. Mass of hyperenhancement and peak creatine kinase release (peak CK) was determined for each patient. The presenting 12-lead ECG was analysed for ST-elevation on admission and later development of Q-waves. Mass of hyperenhancement correlated moderately well to peak CK (r = 0.65, p < 0.01) and endsystolic volume index (r = 0.55, p < 0.01). Mass of hyperenhancement was inversely correlated to ejection fraction (r = –0.50, p = 0.02). Neither the presence of ST elevation on the admission ECG nor the later development of Q-waves did relate to the transmural extent of hyperenhancement and to the mass of hyperenhancement. Conclusion: Mass of hyperenhancement significantly correlates to global myocardial function and to peak CK. However, there is no relationship between the findings in ceMRI and 12-lead ECG abnormalities on admission suggesting an advantage of ceMRI in defining transmural extent and depicting small areas of necrosis.     

Myocardial SPECT perfusion defect size compared to infarct size by delayed gadolinium-enhanced magnetic resonance imaging in patients with acute or chronic infarction

BACKGROUND: Single photon emission computed tomography (SPECT) perfusion imaging has been considered a reference method for non-invasive estimation of infarct size in man. Recently, delayed gadolinium-enhanced magnetic resonance imaging (DE-MRI) has evolved as an accurate tool to quantify infarct size. Therefore, the present study was designed to compare perfusion defect size by SPECT to hyperenhanced volume by DE-MRI. METHODS: DE-MRI was performed in 30 patients. Fourteen were patients with revascularized first-time acute infarctions, eight revascularized chronic infarctions, and eight clinically referred non-revascularized patients. SPECT was performed in the same patients and analysed by a commercial package. RESULTS: The hypoperfused volume by SPECT was larger than the hyperenhanced volume by DE-MRI by 8 +/- 8 ml (6% +/- 5 percentage points), 10 +/- 18 ml (6% +/- 11 percentage points), and 26 +/- 30 ml (12% +/- 10 percentage points) in the acute, chronic and clinical populations, respectively. Left ventricle wall volume was smaller by SPECT in all settings. CONCLUSION: The SPECT perfusion defect size was comparable with but generally slightly larger than the hyperenhanced volume by DE-MRI in both absolute and relative terms in patients with acute and chronic infarction. The results may be related to systematic differences between modalities but could also be influenced by biological phenomena such as wall thinning or hypoperfused but viable myocardium.     

Stress radionuclide myocardial perfusion imaging detects more residual ischemia than stress echocardiography following acute myocardial infarction

OBJECTIVES: This investigation sought to compare the abilities of stress radionuclide myocardial perfusion imaging and stress echocardiography to detect residual ischemia in patients following acute myocardial infarction (MI). BACKGROUND: Stress radionuclide myocardial perfusion imaging and stress echocardiography are both commonly used to assess patients (patients.) in the immediate post MI period. However, the relative value of these techniques in identifying post MI ischemia remains unclear. METHODS: Eighteen patients. underwent both dipyridamole radionuclide perfusion imaging and dobutamine stress echocardiography on the same day or on consecutive days, 3-7 days following uncomplicated acute MI. Pts. who had an acute percutaneous intervention were excluded. Images were reviewed with clinical information available, but blinded to the opposing modality, for perfusion defects, wall motion abnormalities (WMA), and evidence of ischemia (reversible defect(s) on perfusion imaging, worsening WMA on stress echocardiography). Of the 18 patients, 11 subsequently underwent cardiac catheterization. RESULTS: Perfusion imaging identified defects in 16 (89%) patients, of whom 15 (83% of total) were found to be ischemic. Stress echocardiography identified a fixed wall motion abnormality in 17 (94%) and ischemia in 8 (44%, p < 0.05 compared with perfusion imaging ischemia). Among 11 patients who underwent catheterization, there was a trend towards perfusion imaging identifying more ischemia in the territory of an obstructed (> or = 70%) vessel--100% (11/11) vs. 64% (7/11) for stress echocardiography (p = 0.09). CONCLUSION: In the immediate post-infarction period, dipyridamole stress radionuclide myocardial perfusion imaging more often shows evidence of residual ischemia than dobutamine stress echocardiography.     

心脏磁共振可评估急性心肌梗死患者的早期心功能状态

目的  探讨心脏磁共振对急性心肌梗死患者早期心功能状态评估价值。方法  选择2022年6月~2022年12月在我科住院并确诊的急性ST段抬高型心肌梗死患者24例,男性22例,女性2例,年龄55.3±11.3岁。所有患者均在入院后行冠状动脉介入手术,并在术后5~7 d行心脏磁共振检查。应用电影成像技术分析心功能状态、是否存在反向运动和室壁瘤;组织追踪技术分析心肌各节段的应变能力;延迟强化技术分析心肌梗死部位、梗死面积大小和是否存在微循环障碍。结果梗死节段心肌应变分析显示：24例患者中,21例患者径向应变下降,18例患者周向应变下降,21例患者纵向应变下降,16例患者三向应变均下降;整体心肌应变分析显示：15例患者径向应变下降,10例患者周向应变下降,20例患者纵向应变下降,9例患者三向应变均下降;梗死节段心肌平均径向应变和周向应变低于整体心肌平均径向应变和周向应变（P < 0.05）,梗死节段与整体心肌纵向应变的差异无统计学意义（P > 0.05）。13例患者出现心肌反向运动;左室射血分数（LVEF）下降者10例;LVEF未下降的14例中,心肌反向运动6例,梗死节段三向心肌应变下降6例,梗死区内微循环障碍7例,NT-proBNP水平升高7例。出现反向运动组患者LVEF、梗死节段心肌和整体心肌平均周向应变、纵向应变均小于未出现反向运动组患者（P < 0.05）。相关性分析显示：LVEF与心肌整体应变、梗死节段应变和左房射血分数呈正相关关系,与心肌梗死面积、左室收缩末期容积/体表面积比值、NT-proBNP水平和Genisini评分呈负相关关系（P < 0.05）。二元Logistic回归显示,梗死节段纵向应变的降低可以独立预测患者是否出现心肌反向运动。结论  心脏磁共振技术可以多角度评价心功能状态,对急性心肌梗死患者术后早期心功能评估、治疗和干预,改善患者的预后提供参考依据。     

Contrast-enhanced magnetic resonance imaging reveals early decrease of transmural extent of reperfused acute myocardial infarction

In patients with myocardial infarction infarct size and transmural extent are of high prognostic value for clinical outcome and recovery of contractile function of the affected myocardium either spontaneously or after revascularisation. Delayed contrast-enhancement magnetic resonance imaging (DCE-MRI) is a non-invasive imaging technique of high accuracy for determination of myocardial infarct size and transmural extent. As decisions whether revascularisation procedures are promising in patients with coronary artery disease are increasingly based on the transmural infarct extent assessed by DCE-MRI we sought to examine whether the timing of MRI after acute myocardial infarction would influence the transmural extent. We performed DCE-imaging on a clinical 1.5 T scanner in patients at day-1 and day-7 after reperfused STEMI. We assessed the total number of segments displaying DCE as well as differentiated by the transmural infarct extent. The total number of affected segments as well as the number of segments with only subendocardial DCE did not change between day-1 and day-7. In contrast, we observed a significant decrease of the number of segments with DCE of ≥75% transmurality and a significant increase of segments with DCE grade III (51%–75% transmurality). We conclude that the transmural infarct extent is not stable over the first days after STEMI which should be taken into account when assessing viability in clinical and research settings. C. Merten and H. Steen contributed equally     

Measurement of left ventricular volume after anterior myocardial infarction: comparison of magnetic resonance imaging,echocardiography, and radionuclide ventriculography

We have compared echocardiography (echo) and radionuclide ventriculography (RNV) with magnetic resonance imaging (MRI) for the measurement of left ventricular (LV) volume and ejection fraction. Seventy asymptomatic patients were studied up to 12 days after first Q wave anterior myocardial infarction and again after 6 months. Each patient had LV volume measured by all three techniques within 24 hours of each other on each occasion. LV end-systolic and end-diastolic volume index (LVESVI and LVEDVI) and LV ejection fraction (LVEF) were measured using the modified Simpson formula (echo), a counts-based method (RNV), and a multislice area summation method (MRI). Radionuclide volumes were measured both with and without correction for attenuation of isotope. Echocardiography overestimated LV volume compared with MRI. Mean (SD) differences (echo–MRI) were: LVEDVI + 10.6 ml/m² (16.8), LVESVI + 13.7 ml/m² (12.9), LVEF – 8.5% (11.2). RNV underestimated both volume and ejection fraction compared with MRI. Mean differences (RNV–MRI) were: LVEDVI –25.4 ml/m² (23.8), LVESVI – 5.0 ml/m² (18.6), LVEF – 13.8% (10.4). Variability in the difference between echo and MRI and between RNV and MRI was very similar for LVEF (coefficient of variation 23.9% echo, 22.2% RNV) but there was greater variability in the radionuclide than the echo measurements of absolute volume. Variability of the radionuclide measurements was reduced by not correcting for attenuation, and this finding may improve the radionuclide technique for serial measurements of percentage change in volume. Long-term inter-study reproducibility of MRI for LVEF (coefficient of reproducibility) was 10.9%, for echo it was 10.6%, and for RNV it was 14.6%. We conclude that measurements of LV volume depend on the method used and are not interchangeable. Echocardiography agrees more closely with MRI than RNV for the measurement of absolute volume, but the two techniques are similar for the measurement of LVEF.     

Myocardial contrast echocardiography for predicting functional recovery after acute myocardial infarction

Myocardial contrast echocardiography (MCE) is a promising diagnostic tool for detecting microvascular integrity. The aim of the study was to investigate the comparative specificity and sensitivity of intravenous MCE, technetium-99m Sestamibi single-photon emission computed tomography (SPECT) and dipyridamole–dobutamine (DIDO) stress echocardiography for predicting functional recovery after coronary revascularization in patients with acute myocardial infarction (AMI). Methods: In a prospective, observational study, 17 consecutive patients short after AMI who received successful treatment with primary percutaneous coronary angioplasty (PTCA) plus stent-implantation were examined with DIDO (dipyridamole with 0.28 mg/kg over 4 min plus dobutamine up to 10 mcg/kg/min), MCE (10 ml 4 g, 400 mg/ml Levovist^® intravenously; second harmonic power imaging) within 12–24 h and resting perfusion SPECT within 48–72 h after PTCA. Functional recovery of regional contractile function after 6-month follow-up was the gold standard to assess viability. Results: The rate of agreement between SPECT and MCE was 69% and between SPECT and a positive response to stress echo was 76% for combined DIDO. MCE showed a higher sensitivity (96%) in the identification of viability than SPECT (77%) and combined DIDO alone (79%). Specificity was lower for viability recognition with MCE (58%) compared with SPECT (93%) and DIDO (87%). Conclusions: The wall motion response during DIDO echocardiography is useful in the prediction of recovery of regional and global ventricular function after revascularization in patients after AMI. Combined intravenous MCE and DIDO is more accurate in the diagnosis of stunned myocardium than Tc-99m-MIBI SPECT alone.     

三维超声心动图结合心肌超声造影评价2型糖尿病患者心肌功能障碍

目的 探讨实时三维超声心动图结合心肌超声造影对评价2型糖尿病（T2DM）患者心肌功能障碍的价值。方法 选取单纯糖尿病组（Ⅰ组）和糖尿病合并微血管并发症组（Ⅱ组）各29例,对照组（C组）32名,运用实时三维超声心动图获取左心室16节段、12节段及6节段达最小收缩容积时间的标准差（Tmsv16-SD、Tmsv12-SD、Tmsv6-SD）和最大时间差值（Tmsv16-Dif、Tmsv12-Dif和Tmsv6-Dif）及其心率校正值。通过心肌超声造影获得各室壁各节段的峰值强度A、充盈速度β并计算A·β,进行组间数据分析。结果 ①同步性运动评估：Ⅱ组除Tmsv6-Dif以外,其余左心室同步化指标均较C组延长（P均<0.05）;Ⅰ组Tmsv12-Dif、Tmsv12-SD、Tmsv12-Dif%和Tmsv12-SD%较C组延长（P均<0.05）。②心肌血流灌注整体评估：C组、Ⅰ组、Ⅱ组A、β、A·β均呈逐渐下降趋势,Ⅱ组A、β及A·β均低于C组（P均<0.05）;Ⅱ组β及A·β均低于Ⅰ组（P均<0.05）;Ⅰ组β及A·β均低于C组（P均<0.05）;3组内同一指标3个节段差异均无统计学意义（P均>0.05）。结论 单纯T2DM及合并血管并发症患者左心室运动均存在不同步现象;T2DM患者心肌灌注减低,呈弥漫性损害,随其他脏器微循环病变出现而加重。     

心脏磁共振延迟强化成像定量评价心肌梗死的研究

目的 研究计算机辅助测体积法(CAVM)与视觉评分法(VSM)在心脏磁共振延迟强化成像上评价梗死心肌大小的相关性,并探讨梗死心肌质量与室壁运动异常、左室功能的相关性.方法 采用多次屏气平衡稳态自由进动快速成像(FIESTA)序列,对21例心肌梗死患者行心脏电影MRI及钆喷替酸葡甲胺(Gd-DTPA)增强的延迟强化成像.①用CAVM及VSM分别评价患者的梗死心肌质量及梗死心肌范围程度.用VSM评价时根据延迟强化的透壁程度分为0～4分;0＝无强化,1＝1%～25%强化,2＝26%～50%强化,3=51%～75%,4=76%～100%强化;②评价患者的室壁运动异常及左室功能.结果 两种方法评价梗死心肌高度相关(r=0.825,P＜0.001);梗死心肌质量与室壁运动异常(r=0.740)、射血分数(r=-0.733)、收缩末期容积指数(r=0.702)、收缩末期容积(r=0.698)、舒张末期容积指数(r=0.657)、舒张末期容积(r=0.648)均密切相关(P≤0.001).结论 计算机辅助测体积法及视觉评分法均可准确定量梗死心肌,梗死心肌质量与室壁运动异常、左室功能有高度相关性.     

Relationship between function and perfusion early after acute myocardial infarction

To assess the relationship between baseline left ventricle function, functional reserve and resting myocardial perfusion in patients with acute myocardial infarction (AMI). After AMI the presence of dysfunctioning but viable myocardium plays a determinant role in clinical outcome. Regional ventricular function was evaluated by echocardiography both in resting conditions and during dobutamine infusion (10 g/kg/min). Perfusion was assessed by magnetic resonance imaging in a single slice approach where the first pass of an intravenously injected bolus of gadolinium-based contrast agent was followed through six regions of interest within the myocardium. In each patient a region with normal function was used as reference and the cross-correlation coefficient (CCC), which described the myocardial perfusion relatively to the reference region (CCC = 1 means equivalent perfusion), was obtained for the other five myocardial regions. Twenty-two patients were enrolled into the study. Sixty-one segments had normal function and normal perfusion (CCC = 0.92 ± 0.23). The perfusion deficit was more marked in the 29 regions with resting akinesia–dyskinesia than in the 20 hypokinetic regions (CCC = 0.71 ± 0.45 vs. 0.84 ± 0.23; p < 0.05). Out of the 29 regions with resting akinesia–dyskinesia the 13 segments which showed functional improvement following dobutamine had a higher resting perfusion than the 16 segments which were unresponsive to dobutamine (CCC = 0.83 ± 0.32 vs. 0.61 ± 0.52, p < 0.05). Similarly, out of the 20 regions with resting hypokinesia the 11 segments having functional reserve showed an higher resting perfusion than the segments which did not (0.96 ± 0.21 vs. 0.69 ± 0.19; p < 0.05). Early after AMI, the perfusion deficit reflects the severity of the mechanical dysfunction. In regions with baseline dyssynergy resting perfusion is, in general, higher when contractile reserve can be elicited by stress-echo.     

Quantification of myocardium at risk in myocardial perfusion SPECT by co-registration and fusion with delayed contrast-enhanced magnetic resonance imaging--an experimental ex vivo study

Background: Myocardial perfusion single‐photon emission computed tomography (MPS) can be used to assess myocardium at risk in occlusive coronary ischaemia. The aim was to develop a method to quantify myocardium at risk as perfusion defect size on ex vivo MPS using co‐registration and fusion with ex vivo magnetic resonance imaging (MRI). Methods: Pigs (n = 19) were injected 99mTc‐tetrofosmin prior to concluding 40 min of coronary artery occlusion, followed by reperfusion and MRI contrast injection. The excised heart was imaged with T1‐weighted MRI and MPS, and images were co‐registered using freely available software (Segment v1.8, http://segment.heiberg.se ). The left ventricle was semi‐automatically delineated in MRI and copied to MPS. The threshold for a MPS perfusion defect was defined as the mean counts in the MPS image at the MRI‐determined border between remote myocardium and air. The threshold was measured using count maxima set to the 100th–95th percentile of counts within the myocardium. The count maximum that gave the lowest threshold variability (SD) was considered the most robust. Results: A count maximum using the 100th percentile yielded a threshold of (mean ± SD) 55 ± 6·2%. This method showed the lowest SD compared to 99th–95th percentile count maxima (6·6–7·2%). Conclusions: We describe a method for objective quantification of myocardium at risk as perfusion defect size on MPS using knowledge of the anatomy of the myocardium from co‐registered MRI. This enables simultaneous quantification of myocardium at risk by MPS and infarct size by MRI for the evaluation of treatments for myocardial infarction.     

磁共振多序列诊断评价急性心肌梗死的应用进展

磁共振心血管检查技术为深入了解心脏结构和功能提供了无创的方法,具有较高诊断准确性,并且无电离辐射。灌注增强后的延迟显像技术能够对心肌梗死提供有价值的诊断和预后信息,但是对于心肌梗死的程度以及心肌弥漫性改变无法准确地评价。T1 mapping技术是一种能够定量评估心肌局限及弥漫性病变的新技术,其能定量地评估心肌梗死的程度及心肌水肿的范围,具有良好的诊断及预后价值,在临床实践中有更好的应用前景。     

延迟经皮冠状动脉介入治疗对急性心肌梗死患者心肌灌注及心功能的影响

目的：采用99 m 锝甲氧基异丁基异腈(99 m Tc-MIBI)门控静息心肌断层显像,研究延迟经皮冠状动脉介入(percutaneous coronary intervention,PCI)对急性心肌梗死(acute myocardial infarction,AMI)的疗效。方法选首次发病时间超过12小时但不超过72小时,未行溶栓治疗且无持续胸痛的 AMI 患者62例,随机分为对照组(n =31),只给予常规药物治疗,延迟 PCI 组(n =31)在常规药物基础上,发病后7~14天行 PCI 治疗。两组均于发病1周及治疗后4周行99 m Tc-MIBI 门控静息心肌断层显像,比较两组治疗前后左心室舒张末期容积(left ventricular end diastolic volume,LVEDV),左心室收缩末期容积(left ventricular end systolic volume,LVESV)、左心室射血分数(left ventricular ejection fraction,LVEF)、心肌缺血面积(ischemic area,IA)的变化。结果两组患者发病1周时的LVEDV、LVESV、LVEF 及 IA 差异无统计学意义。治疗4周后延迟 PCI 组 LVEDV、LVESV 明显下降,分别为(73.87±5.90)ml vs (81.20±7.14)ml,(26.51±3.51)ml vs (30.90±3.84)ml(P <0.01);与对照组比较 LVEF明显升高,(66.23±5.20)% vs (60.97±4.58)%(P <0.01)、IA 明显缩小(10.67±3.01)% vs (12.93±3.54)%(P <0.01)。结论对于 AMI 患者,延迟 PCI 可以更完全地血运重建,明显改善心肌灌注及恢复心室功能,可以改善预后;99m Tc-MIBI 门控静息心肌断层显像可以定量分析心肌灌注及心功能变化,可以准确评价延迟 PCI 治疗 AMI 效果。     

潘生丁负荷MR首次通过灌注显像评价心肌缺血

目的了解潘生丁负荷MR首过灌注(MRFP)显像在冠心病诊断中的临床意义.方法 42例拟诊冠心病的患者,按临床分为心肌梗死、心肌缺血、正常三组,行MRFP显像,其中25例行冠状动脉造影(CAG),并按冠脉狭窄程度分为狭窄<50%,50%～99%和100%三组.制定5分制标准,定性判断MRFP图像.分别分析临床分组和CAG分组的MR心肌灌注显像结果.结果定性判断MRFP图像对冠心病诊断的敏感性、特异性与准确性分别为90%、70%和80%.MRFP与临床分组的相关系数r=0.352(P=0.041);MRFP与CAG分组的相关系数r=0.402(P=0.001).出现灌注缺损的比例在临床分组中,分别为85.7%、61.1%和33.3%;在CAG分组中,分别为20%、60%和100%.结论 MRFP显像能够区分缺血和正常心肌,对冠心病诊断有一定意义.     

小剂量依替巴肽联合冠状动脉介入治疗对急性心肌梗死患者血流灌注及心功能的影响

目的 探讨小剂量依替巴肽联合冠状动脉介入治疗(percutaneous coronary interventions, PCI)对急性心肌梗死（acute myocardial infarction, AMI）患者血流灌注及心功能的影响。方法 2018年10月至2019年5月就诊并行急诊PCI的ST段抬高型心肌梗死(ST segment elevation myocardial infarction,STEMI)患者。符合纳入标准及排除标准的行急诊PCI的STEMI患者随机分为试验组和对照组。试验组静脉内给予1次（180 μg/kg）依替巴肽,后静脉泵入1 μg/（kg·min）;对照组不予注射及泵入。观察指标包括一般资料、心肌灌注及心功能指标及主要不良心脏事件（major adverse cardiac events, MACE）。结果 试验组ST段回落率优于对照组（P＜0.05）。试验组心肌声学造影中,峰值强度（peak intensity,PI）高于对照组,达峰时间(time to peak,TP)低于对照组（P＜0.05）。术后1个月, 试验组LVEF明显高于对照组, BNP水平明显低于对照组（P＜0.05）。结论 应用小剂量依替巴肽可以改善急性STEMI患者的心肌再灌注及心功能,且不增加MACE的发生率。     

经皮血栓吸除术治疗急性心肌梗死无复流的疗效观察

目的应用实时心肌声学造影（RT-MCE）评价经皮血栓吸除术治疗急性心肌梗死（AMI）无复流的疗效。方法将68例证实梗死相关动脉有血栓形成的急性ST段抬高型心肌梗死（STEMI）患者随机分为单纯急诊经皮冠状动脉介入治疗（PCI）组和PCI联合血栓吸除术组,每组34例。于PCI后24h和1周行RT-MCE,记录两组灌注对比积分指数（CSI）、室壁运动积分指数（WMSI）、透壁性对比缺损长度百分比（CDL/LV）和严重室壁运动异常长度百分比（WML/LV）。结果术后24h和1周PCI联合血栓吸除术组CSI、WMSI、CDL/LV和WML/LV较单纯PCI组明显降低,且1周时较24h降低更明显（P〈0.05或P〈0.01）。结论经皮血栓吸除术可明显减少术后无复流的发生,改善微循环以及心脏功能,使PCI对AMI更有效。     

心肌声学造影在急性心肌梗死中的临床应用

急性心肌梗死(AMI)的发生发展与心肌微循环障碍紧密相关,及时有效地评价微循环灌注情况对AMI的诊断、治疗和预后均有十分重要的意义。心肌声学造影是一种评估心肌微循环灌注的超声新技术,目前已成为临床评价AMI的重要方法。本文就心肌声学造影在AMI再灌注前后的应用、危险分层、疗效评估、存活心肌检测、造影剂安全性等方面进行综述。     

左心声学造影对STEMI病人PCI术后心肌灌注及预后的评估价值

目的 探讨心肌声学造影(MCE)对急性STEMI病人PCI术后评估心肌灌注及预后的价值。方法 纳入本院78例急性STEMI且行PCI手术患者的病例资料,且术后48h均行MCE,根据MCE结果分为A组(灌注充盈正常：心肌节段造影剂充盈均匀,完全显影)43例,B组(灌注充盈稀疏：心肌节段造影剂充盈不均匀或部分显影)20例,C组(灌注充盈缺损：心肌节段造影剂充盈缺损,完全不显影)15例。应用常规超声与MCE技术获取各组患者术后48h、1个月、3个月左心功能指标[左室射血分数(LVEF)、左心室舒张末期容积(LVEDV)、左心室收缩末期容积(LVESV)]。记录三组患者术后6个月、12个月、24个月的主要不良心血管事件(MACE)发生率,并应用Logistic向后逐步回归分析急性STEMI患者PCI术后发生MACE的独立危险因素。结果 与A组比较,B、C组LVEDV、LVESV均较高,Am、E、LVEF较低,差异均有统计学意义(均P＜0.05)。与B组比较,C组LVEDV、LVESV均较高,Am、E、LVEF较低,差异均有统计学意义(均P＜0.05)。与A组比较,B、C组PCI术后MACE发生率较高,差异均有统计学意义(均P＜0.05)。多因素Logistic回归分析结果显示,LVEDV、LVESV、LVEF、MCE结果均为影响急性STEMI患者PCI术后发生MACE的独立危险因素(P＜0.05)。结论 MCE可有效评估急性STEMI患者PCI术后心肌灌注情况,可独立预测术后MACE事件的发生,利于患者预后。     

Magnetic resonance perfusion imaging in patients with coronary artery disease: a qualitative approach

Although contrast-enhanced first pass magnetic resonance imaging (MRI) has potential to quantify blood flow through extensive image post-processing, clinical utility is likely to depend on rapid qualitative analysis. Aims: To investigate use of an on-line analytical approach for detection of coronary artery disease (CAD). Methods and results: Thirty subjects with CAD underwent contrast-enhanced rest/adenosine stress MRI with basal, mid-papillary and apical short-axis image acquisition. Each short axis was divided into eight regions of interest (ROI). Regional perfusion was visually classified as normal or impaired according to transmural distribution and defect reversibility. MRI and angiographic data were compared. Qualitative MRI reporting was possible for 98% ROI. Eighty-six coronary artery (CA) territories were assessed of which 71 (83%) had stenoses. Sensitivity and specificity for detection of stenoses were 93 and 60%, respectively. The proportion of hypoperfused ROI rose from 31% with <50% stenosis to 65% with occlusion. More transmural defects were seen in infarction-related territories (75 vs. 54%, p < 0.05). More ROI demonstrated defect reversibility in occluded rather than in stenosed infarction-related vessels (89 vs. 58%, p < 0.05). Occluded vessels with grade 2–3 collaterals contained a higher proportion of normal ROI (44 vs. 25%, p < 0.05). Conclusions: Qualitative MRI analysis had high sensitivity and moderate specificity for detecting CA stenoses. Additional information was obtained relating to lesion severity, previous infarction, myocardial viability and impact of collateral circulation. The technique has potential for de novo diagnosis of CAD and as a complementary modality to angiography to assess the significance of given angiographic lesions.     

Pulsed tissue Doppler imaging for the detection of myocardial ischaemia, a comparison with myocardial perfusion SPECT

In order to compare the diagnostic ability of pulsed tissue Doppler and myocardial perfusion Single Photon Emission Computed Tomography (SPECT) in patients with a history of unstable coronary artery disease, CAD, 26 patients, 22 men and four women, age 47-76 years, were investigated in a prospective study, 5-10 day after an episode of unstable angina. Tissue Doppler and two-dimensional echocardiography were performed during dobutamine stress testing and myocardial scintigraphy after bicycle exercise and at rest. Patients with a normal SPECT had higher peak systolic velocity during dobutamine infusion, 18.9 +/- 4.1 cm s(-1), than patients with ischaemia, 12.2 +/- 3.8 cm s(-1) (P<0.001) or scar, 8.8 +/- 3.0 cm s(-1) (P<0.01). In a territorial analysis the difference in peak systolic velocity between areas with a normal and abnormal SPECT was less apparent. Failure to achieve >/=13 cm s(-1) in mean-peak systolic velocity was the most accurate criterion for detection of significant CAD on SPECT. We conclude that pulsed tissue Doppler can be used for objective quantification of left ventricular wall motion during dobutamine stress testing and for identification of patients with CAD on SPECT but not for identification of regional ischaemia.