直接冠状动脉内支架对急性心肌梗死“心肌无复流”的影响

目的评价直接置入冠脉内支架对急性心肌梗死（AMI）血管再通后“心肌无复流”现象的影响。方法将100例ST段抬高型AMI随机分为直接置入冠脉内支架组（直接支架组）和球囊预扩张置入冠脉内支架组（预扩张支架组），应用单光子发射型计算机断层心肌灌注显像（SPECT）、心肌梗死溶栓治疗试验（TIMI）血流分级、心肌呈色分级（MBG）、肌酸激酶同工酶（CKMB）峰值和峰值时间及6个月临床随访来评价两种方法对AMI患者的心肌灌注情况及临床疗效。结果两组虽然术后即刻TIMI血流分级、术后24h内左室射血分数（LVEF）、左室舒张末期容积（LVEDV）及左室收缩末期容积（LVESV）差异无统计学意义分别为96％、（48．14±4．43）％、（96．38土10．31）ml、（49．52±4．91）ml出境 vs 92％、（47．94±4．47）％、（99．66±13．26）ml、（48．18±5．32）ml，P〉0．05]；但直接支架组与预扩张组比较，术后即刻MBG分级2～3级明显增高（90％VS74％，P〈0．05）、无复流发生率达10％ vs 26％（P〈0．05），术后24h内SPECT心肌灌注积分（MPDS）明显降低（3．68±1．52 vs 4．93±1．84；P〈0．05）、CK-MB峰值明显减少（217．2±96．86）U／L vs （260．22±97．78）U／L；P〈0．05）、CK-MB峰值时间明显提前（11．72±2．67）hVS（13．7±2．06）h；P〈0．05），而手术时间、X线曝光时间、造影剂用量显著减少分别为（40．48土7．18）min、（12．84±3．77）min、（134．82±55．05）ml vs （44．54±6．2）min、（15．82±5．08）min、（158．12±53．9）ml；P〈0．05]；随访6个月后，与预扩张组比较，直接支架组LVEF明显增高（52．19±3．36）％ vs （50．2±5．32）％；P〈0．05]，MPDS、LVEDV、LVESV显著减低分别为2．39士1．50、（92．2±5．8）ml、（44．76±3．28）ml vs 3．11±1．74、（95．41±7．79）ml、（47．05±5．54）ml；P〈0．05]、纽约心脏病学会（NYHA）心功能分级≥2级明显减少（8％ vs 24％，P〈0．05）。结论直接置入冠脉内支架可降低AMI血管再通后心肌无复流的发生、缩小梗死面积、减轻左室重构，并可改善远期心功能。

Effect of coronary stent implantation without predilation on myocardium no-reflow in acute myocardial infarction patients

Objective To determine the effect of direct coronary stenting on myocardium no-reflow （NR） after recanalization in patients with acute myocardial infarction（AMI）compared with stenting after balloon predilation. Methods A tolal of 100 AMI patients undergoing percutaneous coronary intervention （PCI） were randomly divided into direct stenting group（n= 50） and stenting after balloon predilation group（n= 50）. The effects were evaluated by single-photon emission computed tomography （SPECT）, thrombolysis in myocardial infarction （TIMI）, myocardial blush grading（MBG）, levels and time of peak creatine kinase-myocardial band（CK-MB） and the clinical outcome after 6 months. Results Immediate TIMI, left ventricular ejection fraction（LVEF）, left ventricular end-diastolic volume （LVEDV） and left ventricular end systolic volume（LVESV） in SPECT within 24 h after PCI were similar in direct stenting and stenting after balloon predilation groups96%, （48.14±4.43） %, （96.38±10. 31）ml, （49.52±4.91）ml vs 92%, （47.94±4.47）%, （99.66±13.26）ml, （48.18±5.32）ml, respectively, P〉0. 05]. However, immediate MBG 2-3 increased significantly after PCI （90M vs 74%, P〈0.05）, the rate of NR decreased significantly（10% vs 26%, P〈0.05） and myocardium perfusion defect score （MPDS） within 24 h after PCI decreased significantly（3.68±1.52 vs 4.93±1.84, P〈0.05） in direct stenting group compared with that of stenting after predilation group. The peak CK-MB levels and the peak CK-MB time were significantly different in direct stenting and stenting after balloon predilation groups（217.2±96.86）U/L, （11.72±2.67）h vs （260. 22±97.7）U/L, （13.7±2.06）h, respectively, P〈0. 05]. Direct stenting was associated with less procedural duration （40.48±7.18） min vs （44.54±6.2） min, P〈0.05], radiation exposure time（12.84±3.77）min vs （15. 28±5.08） min, P〈0. 05] and amount of contrast dye used（134.82±55.05）ml vs （158.12±53.9）ml, P〈0. 05]. MPDS, LVEDV and LVESV were significantly decreased and LVEF was significantly increased after 6 months in direct stenting group compared with that of predilation group2.39±1.50, （92.2±5.8）ml,（44.76±3.28）ml and （52.19±3.36）% vs 3.11±1.74, （95.41±7.79）ml, （47.05±5.54）ml and （50.2±5.32）%, respectively, P〈0. 05]. At the same time, the rate of New York Heart Association symptomatic classification ≥2 was significantly lower in direct stenting group during 6 months follow-up （8% vs 24%, P〈0.05）. Conclusion Direct stenting without predilation can decrease NR after recanalization, reduce the infarction area, attenuate left ventricular remodeling and improve clinical outcomes compared with stenting after balloon predilation in AMI patients.