腺苷负荷心肌灌注显像在老年冠心病患者诊断中的价值

目的评价腺苷负荷心肌灌注显像试验对老年人冠心病的诊断价值以及对病变血管部位、血管支数、狭窄程度所作的评估。方法选择116例可疑冠心病的老年患者,行腺苷负荷心肌灌注显像。腺苷注射液按140μg/(kg.min)在6min内匀速静脉泵入。当腺苷泵入3min时经三通管快速静推99m锝-2-甲氧基异丁基异腈(99mTc-MIBI);1.5h后进行心肌灌注断层显像。若显像异常,次日行静息心肌显像。所有患者腺苷负荷心肌灌注显像后行冠状动脉造影。结果在116例患者中,73例冠状动脉造影显示明显的冠状动脉狭窄病变,其中单支病变22例,两支病变32例,三支病变19例。腺苷负荷心肌灌注显像试验诊断冠心病的敏感度、特异度和准确度分别为87.7%、72.1%和65.5%。诊断单支、两支和三支冠状动脉病变患者的敏感度分别为59.1%、84.4%和89.5%(P0.05)。对管径狭窄为50%～75%组的敏感度为57.1%,管径狭窄≥75%组的敏感度为89.4%,两组间比较有统计学意义(P0.05)。无论是单支病变、两支病变还是三支病变,累及前降支血管病变的心肌核素的阳性率均高(P0.05)。行血管内超声检查的17例患者中,有7例病变斑块面积狭窄率50%或管腔面积4mm2,有偏心或不稳定性斑块,给予冠脉介入治疗,而此7例腺苷负荷心肌核素均为阳性。结论腺苷负荷心肌灌注断层显像诊断老年患者冠心病的敏感度与冠脉狭窄程度和病变支数相关。对重度狭窄和两支、三支病变的患者有较高的敏感度,但对轻中度狭窄和单支病变的患者敏感度较低。腺苷负荷心肌灌注断层显像预测左前降支病变的阳性符合率高于左回旋支和右冠状动脉,且对临界病变的预测有一定价值。

Adenosine stress myocardial perfusion tomographic imaging for diagnosis of coronary artery diseases in elderly patients

Objective To analyze the roles of adenosine stress myocardial perfusion tomographic imaging （ASMPTI） in diagnosis of coronary artery diseases （CAD） and its significance for evaluating the sites, numbers, and stenosis of involved vessels. Methods ASMPTI was performed in 116 elderly patients suspicious for CAD. Adenosine was infused intravenously within 6 rain [140 ug/（kg· min）]. At 3 rain after adenosine infusion, 740 MBq of 99mTc-methoxy-isobatyl-isonitrile （MIBI） was injected intravenously. Single photon emission computed tomography myocardial perfusin imaging was obtained 1.5h after adenosine infusion. If the findings were abnormal, rest myocardial perfusion imaging would be performed next day. Coronary angiography （CAG） was performed in all patients within 1 week after myocardial imaging. Results Among 116 cases, coronary artery stenosis was demonstrated by CAG in 73 patients, including 22 patients with single vessel lesions, 32 with double vessel lesions and 19 with triple vessel lesions. The sensitivity, specificity and accuracy of ASMPTI for CAD were 87. 7%, 72. 1% and 65. 5%, respectively. The sensitivity for diagnosing single, double and triple vessel lesions was 59. 1%, 84. 4% and 89.5% respectively （P〈0. 05）. The sensitivity for diagnosing 50%-75% diameter stenosis was 57.1%, and that for diameter stenosis ≥75% was 89.4%, with significant difference between the two groups（P〈0. 05）. The positive rate of ASMPTI was high for left anterior desending coronary artery involved coronary stenosis, either for single, double, or triple vessel lesions. As for 17 cases undergoing introvascular ultrasound, 7 cases had plaque area 〉50% or lumen area 〈4 mm2 , and had off-center or unstable plaque. They received percutaneous coronary intervention. The ASMP-TI was all positive in these 7 cases. Conclusion The sensitivity of ASMPTI is related to coronary artery stenosis degree and numbers of involved vessels. The sensitivity for serious stenosis and double or triple vessel lesions is high, while that for mild or moderate stenosis and single vessel lesions is low. The positive concordance rate of ASMPTI for left anterior descending coronary artery is higher than that for left circumflex coronary artery and right coronary artery. It also has some values in predicting the borderline lesions.