心脏CT成像在评估心房颤动患者左心耳自发显影中的价值

Assessment of left atrial appendage spontaneous echo contrast in patients with atrial fibrillation using two-phase cardiac CT

目的研究心脏CT成像（CCT）定性及定量分析在左心耳自发显影（LAASEC）中的诊断价值。方法2014年1月至2016年3月于大连医科大学附属第一医院明确诊断心房颤动（房颤）且行CCT及经食管超声心动图（TEE）两项检查的住院患者245例。以TEE为金标准，计算CCT定性评估LAASEC的灵敏度、特异度、阳性预测值（PPV）、阴性预测值（NPV）及准确度。测量左心耳（LAA）、升主动脉（AA）和左心房（LA）CT值，计算LAA／AA及LAA／LA，并绘制LAA、LAA／AA及LAA／JJA的受试者工作特征（ROC）曲线。结果TEE诊断LAASEC0级113例，1级73例，2级19例，3级25例，4级15例。CCT示无LAASEC患者162例，LAASEC患者83例。2～4级LAASEC患者59例，CCT均为阳性。CCT定性检测LAASEC（≥1级）的灵敏度、特异度、PPV、NPV及准确度分别为56．8％、92．9％、90．3％、64．8％及73．5％。LAA、LAA／AA及LAA／LA的ROC曲线下面积分别为0．852、0．902、0．824。LAA／AA在最佳截断点为0．897，CCT定量检测LAASEC的灵敏度、特异度、PPV、NPV及准确度为87．9％、83．2％、85．9％、85．5％及85．7％。结论CCT在评估LAASEC尤其是2～4级LAASEC方面具有重要的临床价值。在定性分析基础上，结合定量分析尤其LAA／AA值能较大程度提高CCT诊断LAASEC的准确度。

Objective To evaluate the ability of cardiac CT（CCT） in detecting left atrial appendage spontaneous echo contrast （LAASEC） in patients with atrial fibrillation visually and quantitatively. Methods We studied 245 inpatients with atrial fibrillation who received both two-phase CCT and transesopha- geal echocardiography（TEE） examinations. LAASEC was visually identified in TEE and CCT. Taking TEE as the gold standard, CCT was analyzed visually by calculating sensitivity, specificity, positive predictive value （PPV） , negative predictive value （ NPV ） , and accuracy. In addition, LAA apex, left atrial （LA） body and as- cending aorta（AA） attenuation（ Hounsfield units）were measured on initial CCT and LAA/AA and LAA/LA at- tenuation ratios were calculated. The quantitative values of LAA, LAA/AA and LAA/LA were determined on the basis of the receiver operating characteristic （ROC） curve. Results In our study of 245 patients, TEE demon- strated that grade 0 LAASEC in 113 ,grade 1 in 73 ,grade 2 in 19 ,grade 3 in 25 ,and grade 4 in 15 patients,re- spectively. On CCT, 162 patients were found without LAASEC and 83 patients with LAASEC. A total of grade 2- 4 LAASEC in 59 patients were detected with CCT. Sensitivity, specificity, PPV, NPV and accuracy values of CCT for LAASEC （ ≥grade 1 ） were 56. 8% ,92. 9% ,90. 3% ,64. 8% and 73. 5% ,respectively. The area under the ROC curve for LAA, LAA/AA and LAA/LA were 0. 852,0. 902, and 0. 824, respectively. Quantitative identification of LAASEC （≥ grade 1 ） yielded a sensitivity of 87.9% , specificity of 83.2% , PPV of 85.9% , NPV of 85.5% and an accuracy of 85.7% when the optimal LAA/AA ratio was 0. 897. Conclusion Two-phase CCT is a promising noninvasive examination in detection of LAASEC （ especially for grade 2-4 ）. On the basis of CCT visual analysis, the accuracy for the detection of LAASEC can be improved with quantitative measurement.