Pilz Guenter, Bernhardt Peter, Klos Markus, Ali Eman, Wild Michael, Höfling Berthold
Department of Cardiology, Clinic Agatharied, Academic Teaching Hospital of the University of Munich, St.-Agatha-Str. 1, 83734, Hausham, Germany.
Clin Res Cardiol. 2006 Oct;95(10):531-8. doi: 10.1007/s00392-006-0422-7. Epub 2006 Aug 16.
Real world cardiology is faced with a low diagnostic yield of coronary angiography (CXA) in patients presenting with ACC/AHA class II CXA indication. Our aim was to analyze the clinical implication of a Cardiac MR (CMR) protocol including adenosine stress perfusion in this patient population. We examined whether CMR could enhance appropriate CXA indication and thus reduce the rate of pure diagnostic CXA. In addition, we compared the relative impact of CMR exam components (perfusion, function and viability assessment) in achieving this target.
176 patients were referred for CXA with class II indication. 171 underwent complete additional CMR exam in a 1.5-T whole body CMR-scanner for myocardial function, ischemia and viability prior to CXA. The routine protocol for assessment of CAD consisted of functional imaging (long and short axes), adenosine stress- and rest-perfusion in short axis orientation and "late enhancement" imaging in long and short axes. Images were analyzed by two independent and blinded investigators. Interobserver differences were resolved by a third reader.
There was a high association between CMR results and subsequent invasive findings (chi square for CMR perfusion deficit and stenosis >70% in CXA: 113.7, p<0.0001). 109 (63.7%) of our patients had relevant perfusion deficits as seen by CMR and matching coronary artery stenosis >70%. Four (2.3%) patients had false negative CMR findings. In 58 patients (33.9%) no relevant coronary artery stenosis could be observed, correctly predicted by CMR in 48 cases; in 10 (5.8%) patients CMR provided false positive results. Sensitivity of CMR to detect relevant CAD (>70% luminal narrowing) was 0.96, specificity 0.83, positive predictive value 0.92 and negative predictive value 0.92. Of the CMR components, perfusion deficit was the strongest independent predictor (odds ratio 132.3, p < 0.0001).
In a great number of patients being referred to cath lab with ACC/AHA class II indication for CXA, CMR provides a high accuracy for decision making regarding appropriateness of the invasive exam. CMR prior to CXA could substantially reduce pure diagnostic coronary angiographies in patients with intermediate probability for CAD, in our patient-cohort from approximately 34% to 6%. Further studies are warranted to identify rare false negative CMR results.
在因美国心脏病学会/美国心脏协会（ACC/AHA）II类冠状动脉造影（CXA）指征就诊的患者中，现实世界中的心脏病学面临着冠状动脉造影诊断率较低的问题。我们的目的是分析在这一患者群体中，包括腺苷负荷灌注的心脏磁共振（CMR）检查方案的临床意义。我们研究了CMR是否可以增强CXA的合理指征，从而降低单纯诊断性CXA的比例。此外，我们比较了CMR检查各组成部分（灌注、功能和存活心肌评估）在实现这一目标方面的相对影响。
176例患者因II类指征接受CXA检查。171例患者在1.5T全身CMR扫描仪上，于CXA检查前进行了完整的CMR检查，以评估心肌功能、缺血和存活心肌情况。评估冠心病的常规检查方案包括功能成像（长轴和短轴）、短轴方向的腺苷负荷及静息灌注以及长轴和短轴的“延迟强化”成像。图像由两名独立且不知情的研究者进行分析。观察者间的差异由第三位阅片者解决。
CMR结果与随后的侵入性检查结果之间存在高度相关性（CMR灌注缺损与CXA中狭窄>70%的卡方检验值：113.7，p<0.0001）。我们的109例（63.7%）患者存在CMR显示的相关灌注缺损，且匹配的冠状动脉狭窄>70%。4例（2.3%）患者CMR结果为假阴性。58例患者（33.9%）未观察到相关冠状动脉狭窄，CMR正确预测了48例；10例（5.8%）患者CMR结果为假阳性。CMR检测相关冠心病（管腔狭窄>70%）的敏感性为0.96，特异性为0.83，阳性预测值为0.92，阴性预测值为0.92。在CMR各组成部分中，灌注缺损是最强的独立预测因素（比值比132.3，p<0.0001）。
在大量因ACC/AHA II类指征被转诊至导管室进行CXA检查的患者中，CMR对于判断侵入性检查的合理性具有较高的准确性。在我们的患者队列中，CXA检查前进行CMR可使冠心病可能性为中等的患者中单纯诊断性冠状动脉造影的比例从约34%大幅降至6%。有必要进一步研究以识别罕见的CMR假阴性结果。
