64排螺旋CT冠状动脉造影诊断支架内再狭窄的价值

The Value of 64-detector Spiral CT Coronary Angiography in Assessment of Coronary InStent Restenosis

目的探讨采用64排螺旋CT冠状动脉造影(CTA)诊断冠状动脉支架内再狭窄(ISR)的价值。方法对41例(82枚支架)冠状动脉支架置入术后患者进行CTA和常规冠状动脉造影(CAG)检查,以后者为金标准,支架内狭窄程度≥50%视为ISR,评价CTA诊断冠状动脉支架内再狭窄的敏感性和特异性,并分析影响CTA图像质量的因素。结果本组82枚支架CAG检出10枚(12.2%)发生ISR,14枚支架因图像质量差CTA无法评价。在CTA可评估的68枚支架中,CAG检出6枚ISR,CTA发现7枚ISR,CTA对ISR的诊断敏感性、特异性、阳性预测值和阴性预测值分别为83.3%、96.8%、71.4%和98.4%,与CAG比较无显著性差异(p>0.05)。在可评估的68枚支架中:心率<70次/分钟有65枚(95.6%),支架直径≥3.0mm者54枚(79.4%),支架壁厚度<140μm者53枚(77.9%)。在不可评估的14枚支架中:心率≥70次/分钟有12枚(85.7%),支架直径<3.0 mm者12枚(85.7%),支架壁厚度≥140μm者13枚(92.9%)。患者心率、支架直径及支架壁厚度与支架的可评价性间有显著性差异(p<0.05)。结论 64排螺旋CT冠状动脉造影能准确评价冠状动脉支架内再狭窄,对慢心率、薄壁、大直径支架患者的可评估性更好。

Objective To evaluate the diagnostic value of coronary CT angiography（CTA） with 64-detector Spiral CT for the detection of coronary in-stent restenosis（ISR）. Methods A total of 41 consecutive patients with previous cononary stent implantation with 82 stents were included in this study. All the patients were performed by 64-detector Spiral CT for CTA and conventional coronary angiography（CAG）. The later is the ＂gold standard＂ for the diagnosis,and if the degree of stenosis ≥50% indicate the present of significant ISR, and to evaluate the sensitivity and specificity, and analyze the factors affecting image quality of CTA. Results Ten ISRs were diagnosised by CAG in the 82 stents, 14 stents could not be evaluated by CTA because of poor image quality. Of 68 stents which could be assessed by CTA, six ISRs were detected by CAG, and seven by CTA, including two false positive, one false negative.In evaluable stents, diagnostic sensitivity, specificity, positive predictive value and negative predictive value of ISR with CTA were 83.3%, 96.8%, 71.4% and 98.4%,and the difference was no statistically significant（P〈0.05） compared with CAG. In 68 evaluable stents, patents with the heart rate 70 beats per minute（bpm） were in 65 stents（95.6%）, stent diameter ≥ 3.0 mm in 54 stents（79.4%）, and stent wall thickness 140 μm in 53 stents（77.9%）. 14 stents were unevaluable, of which, 12 stents（85.7%） in patients with heart rate≥70 bpm and 12 in stent diameter 3.0 mm, 13 stents（92.9%） with wall thickness ≥140 μm. Conclusion64-detector Spiral CT Coronary Angiography can evaluate in-stent restenosis of coronary artery accurately, the patients with slow heart rate, thin-walled and large diameter stent can be better assessed.