64排螺旋CT冠状动脉成像对冠心病诊断准确性的影响因素分析

The influence factors of diagnostic accuracy of 64-detector spiral computed tomography coronary angiography for coronary heart disease

目的：评价冠状动脉（冠脉）钙化、平均心率、心率波动及性别差异对64排螺旋CT冠脉成像（64-DSCTCA）诊断准确性的影响。方法：226例确诊或疑似冠心病患者同时接受64-DSCTCA和有创的冠脉造影（CAG）检查。以钙化积分分为0~100、101~400、〉400HU这3组;以平均心率分为≤70及〉70次/min两组;以心率波动分为≤15及〉15次/min两组。以CAG结果作为金标准,分别计算各亚组之间64-DSCTCA评估冠脉狭窄≥50%敏感度、特异度、阳性预测值、阴性预测值及诊断符合率,并采用统计学方法对比分析。结果：钙化积分影响64-DSCTCA的诊断准确性（P〈0.05）,严重钙化组（〉400 HU）其特异度、阳性预测值、诊断符合率显著降低。平均心率对诊断准确性无影响。尽管心率波动对诊断准确性无显著影响,但心率波动〉15次/min组其特异度、阳性预测值、阴性预测值、诊断符合率降低。女性组的阳性预测值低于男性组（P〈0.05）。结论：基于冠脉节段评估,严重的冠脉钙化降低了多层螺旋CT（MSCT）冠脉成像的诊断准确性,诊断严重的冠脉钙化患者（〉400U）仍然是一个挑战。高心率下MSCT冠脉成像仍有良好的诊断性能;减少心率波动有利于提高诊断准确性;诊断女性冠心病患者阳性预测值低于男性。

Objective：To evaluate the effect of calcification,average heart rate,heart rate variability,and gen der difference on the diagnostic accuracy of 64-detector spiral computed tomography coronary angiography（64-DSCTCA）.Method：A total of 226 patients with coronary heart disease（CHD）or suspected CHD underwent both64-DSCTCA and CAG.Patients were divided into subgroups according to the Agatston calcium score（0-100,101-400,400HU）,average heart rate（≤70bpm,70bpm）,heart rate variability（≤15bpm,15bpm）and gender.The sensitivity,specificity,positive predict value,negative predict value and accuracy of 64-DSCTCA in diagnosis of coronary artery stenosis≥50% were calculated among subgroups respectively,by using an invasive coronary angiography as a gold standard.The diagnostic accuracy of 64-DSCTCA were analyzed among subgroups with statistical method.Result：Calcium score had some effect on diagnostic accuracy of 64-DSCTCA（P〈0.05）,showing that the specificity,positive predict value,accuracy of severe calcification（400 HU）were significantly reduced.Average heart rate had no effect on diagnostic accuracy.Heart rate variability showed no statistically significant impact on diagnostic accuracy.However,in the subgroup of heart rate variability15bpm,the specificity,positive predict value and negative predict value were reduced.The positive predictive value in female group is lower than that of those in male group（P〈0.05）.Conclusion：At a per-segment level,severe coronary calcification reduced diagnostic accuracy of MSCT coronary angiography.It is still a challenge to identify patients with severe coronary calcification（400 U）.The MSCT coronary angiography shows a high diagnostic performance with higher heart rate.Reducing heart rate variability is favorable for improving diagnostic accuracy.The positive predictive value of MSCT in the diagnosis of female patients with CHD is lower than in male patients.