斑点追踪技术检测乳腺癌术后化疗药物对心肌的毒性作用

目的 采用斑点追踪成像技术（STE）检测心肌应变及心脏扭转获得心肌综合指数（MCI），探讨其对乳腺癌术后蒽环类药物化疗患者心肌毒性的临床检测价值。方法 选择2012年2月至2013年2月在同济大学附属东方医院肿瘤科就诊的33例女性乳腺癌术后辅助化疗患者纳入研究，并选择36名健康女性志愿者作为健康对照组。分别采集受试者在不同时点的常规超声心动图指标：左心室舒张末容积（EDV）、收缩末容积（ESV）、室间隔厚度（IVSTd）、左心室后壁厚度（PWTd）和左心室射血分数（LVEF），并用体表面积标化获得左心室舒张末容积指数（EDVI）、左心室收缩期末容积指数（ESVI）。采用STE技术获得左心室整体纵向应变（GLS）、整体径向应变（GRS）、左心室旋转角度（LVtw）和MCI。利用受试者操作特性（ROC）曲线分析各指标对乳腺癌患者化疗后心脏毒性的临床价值。结果 化疗组患者在完整5个化疗周期结束后同化疗前基础状态和健康对照组比较发现：（1）三组间的常规超声心动图参数EDV、ESV、IVSTd、PWTd和LVEF比较，差异无统计学意义（F=1.35、2.04、1.28、2.34、2.16，P均＞0.05），而三组间的ESVI和EDVI比较，差异有统计学意义（F=4.73、6.86，P均＜0.05）；（2）化疗组患者在完整5个化疗周期结束后ESVI和EDVI较化疗前基础状态和健康对照组减低，差异有统计学意义（同化疗前基础状态比较：t=6.10、5.13，同对照组比较：t=5.26、4.24，P均＜0.05）；（3）三组间的GRS比较，差异无统计学意义（F=1.23，P＞0.05），而三组间的GLS、LVtw和MCI比较，差异有统计学意义（F=4.29、5.02、12.35，P均＜0.05）；（4）化疗组患者在完整5个化疗周期结束后GLS、LVtw和MCI均较化疗前基础状态和健康对照组减低，差异有统计学意义（同化疗前基础状态比较：t=5.33、13.94，同健康对照组比较：t=4.97、4.46、7.18，P均＜0.05）；（5）MCI曲线下面积为0.894，MCI以-265.7（%×度）为乳腺癌化疗患者的截断值时，其敏感度为82.6%，特异度为78.7%。结论 采用STE技术检测乳腺癌化疗患者所获得的MCI，将心肌应变和心脏扭转结合起来，对早期检测化疗药物的心脏毒性作用具有较高的临床参考价值。

The role of speckle tracking echocardiography in identifying postoperative chemotherapeutic cardiotoxicity in patients with breast cancer

Objective To assess the potential clinical signiifcance of myocardial composite index （MCI） in the evaluation of left ventricular myocardial function in breast cancer patients with postoperative chemotherapy by speckle tracking echocardiography （STE）. Methods A total of 33 consecutive breast cancer patients with postoperative chemotherapy were prospectively enrolled in Shanghai East Hospital, Tongji University, from February 2012 to February 2013. Thirty-six female healthy volunteers were enrolled as the controls. Routine echocardiographic parameters left ventricular end diastolic volume （EDV）, end systolic volume （ESV）, interventricular septum thickness at diastole （IVSTd）, left ventricular posterior wall thickness （PWTd） and left ventricular ejection fraction （LVEF）] were obtained. EDV and ESV were corrected for body surface area, and then end diastolic volume index （EDVI） and end-systolic volume index （ESVI） were calculated. STE-derived parameters left ventricular global longitudinal strain （GLS）, global radial strain （GRS）, left ventricular twist （LVtw） and myocardial composite index （MCI）] were evaluated. All above data were obtained after 5 anthracycline-based chemotherapeutic cycles and compared with baseline measurements in controls respectively. Receiver operating characteristic （ROC） curves were constructed to determine optimal sensitivity and specificity of continuous variables for the prediction of future cardiotoxicity. Results （1）Changes in EDV, ESV, IVSTd, PWTd and LVEF showed no significant decreases compared with baseline and controls （F=1.35, 2.04, 1.28, 2.34, 2.16, P 〉0.05 for all）, while the changes in ESVI and EDVI showed statistically decreases （F=4.73, 6.86, P 〈0.05 for all）;（2）The changes in EDVI and ESVI showed signiifcant decreases compared with baseline （t=6.10, 5.13, P〈0.05 for all） and controls （t=5.26, 4.24, P〈0.05 respectively）;（3）The change in GRS showed no statistical signiifcance compared with baseline and controls （F=1.23, P〉0.05）, while change in GLS, LVtw and MCI showed statistical significances compared with baseline and controls （F=4.29, 5.02, 12.35, P〈0.05 for all）;（4）The changes in GLS, LVtw and MCI showed signiifcant decreases compared with baseline （t=5.33, 13.94, P〈0.05 respectively） and controls （t=4.97, 4.46, 7.18, P〈0.05 all）;（5）The area under receiver operating characteristics curve （AUC） of MCI was 0.894, and its optimal cut-off value was-265.7 （%×degree） with sensitivity of 82.6%and specificity of 78.7%. Conclusion MCI based on STE, combining myocardial strain and cardiac twist, may be an accurate predictor in identifying potential cardiotoxicity in postoperative chemotherapeutic survivors with breast cancer.