直接PCI治疗急性心肌梗死出现“无血流”的剖析

目的　探讨直接经皮冠脉介入治疗 (PCI)治疗急性心肌梗死 (AMI)出现“无血流”(no flow ,NF)的发生率和临床意义。方法　 99例连续行直接PCI的AMI患者根据冠脉造影中有无NF现象分为NF组 (18例 )非NF组 (81例 ) ,计算NF的发生率 ,分析两组一般临床特征、blush分级、ST段抬高的变化、磷酸肌酸激酶的峰值 (CPK)、心功能和心血管事件的发生率。结果　NF组 18例患者 ,占所有直接PCI患者的 18.2 % ,既往心梗史、糖尿病、前壁梗死和多支血管病变的发生率方面明显增加 (P <0 .0 5 )。NF组blush分级和ST段抬高下降≥ 5 0 %者显著减少 ,CPK显著增加 [(32 38± 10 0 8)和 (2 4 5 1±112 4 ) ,P <0 .0 5 ],LVEF显著降低 [(0 .38± 0 .11)和 (0 .6 3+0 .10 ) ,P <0 .0 1];NF组总死亡率较非NF组有增加趋势 ,但无显著统计学意义 ;非致死性心衰 (2 1.4 %和 4 .8% ,P <0 .0 5 )和复合终点事件(4 2 .9%和 18.5 % ,P <0 .0 5 )的发生率无论住院期间还是随访 1年均明显增加 ,而两组在不稳定性心绞痛、非致死性再次心肌梗死、缺血性靶血管重建及总的心脏性死亡的发生率方面无显著降低 [(0 .5 8±0 .14 )和 (0 .6 3± 0 .10 ) ,P >0 .0 5 )。结论　直接PCI治疗AMI过程中NF的发生率为 18.2 % ;出现NF者心肌微循环灌注不良 ,梗死     

SPECT心肌灌注显像对急性心肌梗死急诊PCI的近期疗效评估

目的 :探讨单光子发射型计算机断层 (singlephotonemissioncomputedtomography ,SPECT)心肌灌注显像评估急性心肌梗死 (AMI)急诊经皮冠脉介入治疗 (PCI)后的心肌灌注状况的价值。方法 :采用99mTc tetrofosmin(P5 3)SPECT心肌灌注显像对 10 9例急诊PCI治疗的AMI患者评估心肌灌注情况 ,并记录 6个月心脏事件发生率。结果 :SPECT显示无复流 (no reflow ,NR)组 2 0例 ,有复流组 85例 ,两组在心梗史、糖尿病和多支血管病变的差异有显著性意义 (P <0 .0 5 )。NR组总死亡率较非NR组有增加趋势 ,但差异无显著性意义 ;非致死性心衰和复合终点事件的发生率无论住院期间还是随访 6个月差异均有显著性意义 (P <0 0 5 )。结论 :SPECT心肌灌注显像可对AMI患者梗死相关血管 (IRA)再通治疗疗效进行可靠的无创性评价 ,NR者预示心肌微循环灌注不良 ,心功能差 ,近中期预后差。     

多支血管病变急性心梗直接冠状动脉成形术后住院期间疗效观察

目的　比较单支与多支血管病变急性心肌梗死 (AMI)患者直接经皮冠状动脉介入 (PCI)后住院期间心功能和心脏事件的发生率。方法　 115例AMI患者 ,均于发病后 12h内直接PCI和支架术。根据急诊冠状动脉造影结果将患者分为单支血管病变组 (甲组 ) 6 6例和多支血管病变组 (乙组 ) 4 9例。询问有无梗死前心绞痛史 ,发病后 10d作二维心动超声检查 ,出院前记录心脏事件。结果　甲组 12例出现梗死前心绞痛 (12 / 6 6 ) ,乙组 18例 (18/ 4 9) ,P <0 .0 1;甲组PCI后平均左心射血分数为 (6 3.0 0±6 .76 ) % ,乙组为 (6 2 .18± 8.5 2 ) % ,P >0 .0 5 ;术后甲组心功能衰竭发生 6 / 6 6 ,乙组为 4 / 4 9,P >0 .0 5 ;甲组心绞痛发生 3/ 6 6 ,乙组为 2 / 4 9,P >0 .0 5 ;甲组恶性心律失常发生 2 / 6 6 ,乙组为 3/ 4 9,P >0 .0 5 ;甲组心源性死亡发生 2 / 6 6 ,乙组为 0 ,P >0 .0 5 ;甲组复合终点事件为 13/ 6 6 ,乙组为 9/ 4 9,P >0 .0 5 ,均无显著统计学差异。结论　无论单支或多支血管病变AMI后对梗死相关动脉行直接PCI均同样有效     

直接经皮冠脉介入治疗对有无梗死前心绞痛患者心肌存活性和心室收缩同步性的影响

目的　探讨直接经皮冠状动脉介入治疗 (PCI)对有无梗死前心绞痛的急性心肌梗死 (AMI)患者心肌存活性和心室收缩同步性的近期影响。方法　 87例首次AMI患者 ,按梗死前有无心绞痛分为 3组 :A组 :无心绞痛史 30例。B组 :梗死前 4 8h内有心绞痛史 39例。C组 :仅在梗死前 >4 8h有心绞痛史 18例。所有患者均在发病 6h内行直接PCI术。术后 1周、4周行99mTc MIBI心肌灌注断层显像 (SPECT)测定心肌存活性 ;术后 2周行99mTc心血池显像测定心室收缩同步性参数。结果　①B组肌酸激酶MB同功酶 (CK MB)峰值显著低于A组 (P <0 .0 1)。②B组放射性缺损面积 (MIA)小于A组 (P <0 .0 5 ) ;AMI后 4周与 1周比较 ,B组MIA显著缩小 (P <0 .0 1) ,病变区放射性计数显著增加 (P <0 .0 1)。C组和A组前后比较均无显著差异③心功能 :B组左室射血分数 (LVEF)高于A组 (P <0 .0 1) ;左室收缩同步性 :B组左室相角程(LPS)低于A组 (P <0 .0 5 )。以上各参数 ,C组和A组比较均无显著差异。结论　①首次AMI前 4 8h内心绞痛发作可导致心肌缺血预适应 (IschemicpreconditioningIP)的产生 ,并可缩小心肌梗死面积 ,保护心功能。②直接PCI可显著提高有IP的AMI患者的近期心肌存活性和心室收缩同步性 ,改善心功能。     

急性心肌梗死急诊经皮冠状动脉介入治疗近期疗效观察

目的　探讨直接经皮冠状动脉 (冠脉 )介入治疗 (PCI)对急性心肌梗死 (AMI)的疗效。方法　 6 3例AMI患者在发病 12h内接受梗死相关血管急诊PCI ,随访 1～ 14个月。结果　 6 3例患者中6 1例 (96 .8% )介入治疗获得成功。 3例行经皮冠脉腔内成形术 (PTCA) ,5 8例置入支架。全部获得TIMI 3级血流灌注。 5例发生无血流现象 ,行冠脉内尿激酶溶栓血流改善。 5例在术中发生室速、室颤 ,4例及时除颤转复窦性心律 ,1例死亡。 5例心原性休克患者有 2例住院期死亡。随访期主要事件发生率 17% (5 / 6 0 ) ,其中 2例猝死 ,1例再梗死 ,再次接受PCI成功 ,1例接受择期CABG。 1例因支架内再狭窄行再次PCI。结论　直接PCI治疗AMI可有效地使梗死相关冠脉再通 ,成功率高 ,住院病死率低 ,近期预后良好     

急性前壁心梗经皮冠状动脉血运重建术后ST段持续抬高对心梗晚期左室功能的影响

目的　探讨急性前壁心肌梗死行直接经皮冠状动脉血运重建术 (PCI)后心电图ST段持续抬高对心梗后晚期左室功能和临床预后的影响。方法　选择因急性前壁心肌梗死入院接受急诊PCI的患者 72例 ,动态观察PCI术前后心电图ST段的变化 ,以PCI术后 1hST段下降大于 5 0 %为ST段下降组 ,相反为ST段抬高组。应用超声心动图测定心梗后早期 (2～ 3周 )和晚期 (5～ 6个月 )左室功能和室壁活动异常的变化 ,并随访其间心血管事件的发生率。结果　ST段下降组 5 3例 (74 % ) ,ST段抬高组 19例(2 6 % )。心梗后早期两组间左室功能和室壁活动异常无明显差异 ;晚期ST段抬高组LVEF明显低于ST段下降组 (P <0 .0 5 ) ,而LVEDVI、LVESVI和VWMA积分均明显高于ST段下降组 (P <0 .0 5 ,P <0 .0 1)。随访期间ST段抬高组主要心血管事件的发生率略高于ST段下降组 ,但差异无统计学意义。ST段下降组梗死前心绞痛和直接支架术的比例明显高于ST段抬高组 (P <0 .0 5 )。结论　急性前壁心肌梗死成功直接PCI后ST段持续性抬高者心梗后晚期左室功能较差。有梗死前心绞痛和直接支架术者PCI术后ST段持续性抬高的发生率可能较低     

梗死前心绞痛对急性心肌梗死患者PCI术后无再流现象的影响

目的　探讨梗死前心绞痛对急性心肌梗死 (AMI)患者冠状动脉介入治疗 (PCI)术后无再流现象的影响。方法　 10 0例首次AMI患者 ,均在发病 12h内行PCI术。无再流现象定义为PCI术后IRA远端血流≤TIMIⅡ级 ,无有意义的残余狭窄。所有患者按照无再流现象的有无分为 2组 :无再流组 (15例 )和再流组 (85例 )。监测心肌酶谱变化 ;放射性核素测定心功能 ;观察室壁瘤发生率和住院病死率。结果　①无再流组梗死前心绞痛发生率显著低于再流组 (2 0 %和 6 1% ,P <0 .0 1) ;而前壁梗死的发生率明显高于再流组(6 7%和 35 % ,P <0 .0 5 ) ;肌酸激酶同功酶峰值显著高于再流组 (4 0 3± 132和 2 77± 15 1,P <0 .0 1)。②无再流组放射性缺损面积显著大于再流组 (2 7.6± 9.1%和 2 0 .9± 9.4 % ,P <0 .0 1) ;左室射血分数显著低于再流组 (4 6± 8%和 5 3± 9% ,P <0 .0 1) ;室壁瘤发生率和死亡率均高于再流组 (2 0 %和 4 % ,P <0 .0 5 ;2 0 %和2 % ,P <0 .0 5 )。③多元Logistic回归分析结果显示 ,缺乏梗死前心绞痛是发生无再流现象的独立预测因素(OR =6 .12 ,P =0 .0 1)。结论　缺乏梗死前心绞痛是发生无再流现象的高危因素 ,而无再流现象与心功能衰竭和病死率增高密切相关     

直接经皮冠脉介入和静脉溶栓治疗急性心肌梗死的比较

目的　探讨直接经皮冠脉介入 (PCI)和静脉溶栓治疗急性心肌梗死 (AMI)的临床疗效。方法　采用不同时期连续 13个月收治AMI患者 ,静脉溶栓组 5 7例 ,直接PCI组 75例。比较两组的再灌注率 ,以及两组住院和随诊期间心脏事件发生的情况。结果　静脉溶栓组再灌注率为 5 7.9% ,直接PCI组为 96 %。超声心动图LVEF值静脉溶栓组和直接PCI组分别为 0 .5 9± 0 .12和 0 .6 3± 0 .10。两组在住院期间的心脏事件的发生率无显著差异 ,而随访期间的心脏事件的发生率有显著差异 :直接PCI和静脉溶栓的不稳定心绞痛发生率分别为 9.3%和 38.6 % ;非致死性心功能衰竭 4 .0 %和 14 .0 % ;病死率 0 %和 7.0 % ;复合终点事件 9.3%和 5 0 .9%。结论　直接PCI能更快、更满意地开通梗死相关血管 ,抢救濒临死亡的心肌 ,改善心功能 ,降低病死率 ,优于静脉溶栓治疗。     

术前负荷剂量rhBNP对急性前壁心肌梗死行急诊经皮冠状动脉介入时冠脉无复流的干预作用

 目的 探讨术前负荷剂量重组人脑利钠肽(recombinant human brain natriuretic peptide,rhBNP)对行急诊经皮冠状动脉介入(PCI)治疗的急性前壁心肌梗死患者冠脉无复流的干预作用。方法 序贯入选80例在武警天津总队医院行急诊PCI治疗的急性前壁心肌梗死患者,随机分为治疗组和对照组。治疗组PCI术前在常规药物治疗的基础上以1.5 μg/kg负荷剂量静推rhBNP;对照组单纯给予常规药物治疗;比较两组患者PCI术中冠脉无复流的发生情况。结果 治疗组在给药后冠脉无复流(2.5% vs 15.0%)及再灌注心律失常的比例明显低于对照组,差异有统计学意义。rhBNP相关的严重不良反应比较,两组住院期间主要心血管事件发生率无明显差异。结论 急性前壁心肌梗死患者急诊PCI术前应用负荷剂量rhBNP可显著改善冠脉血流,减少再灌注心律失常的发生。     

梗死心肌的MRI评价及病理对照实验研究

目的　通过MR影像与病理对照的方法明确心肌梗死后 7～ 10dMRI延迟强化区与梗死心肌的关系 ,以期为MRI评价心肌活性提供病理依据。方法　利用 6只猪无再灌注和再灌注的心肌梗死模型 ,行短轴面MR心肌延迟强化扫描。扫描结束后将心脏离体 ,沿短轴面将心脏切成断面行氯化三苯基四氮唑 (TTC)染色。比较心肌梗死区和正常对照区的延迟强化信号强度的差异 ;比较相应层面的MRI延迟强化区和TTC染色所示梗死区的关系。结果　在心肌梗死的 7～ 10d ,无论有无再灌注 ,MR延迟强化扫描均可见心肌梗死区信号较正常对照区明显升高 ,无再灌注组梗死区信号( 2 0 81± 6 49)是正常对照区 ( 2 68± 1 10 )的 7 76倍 (t =11 68,P <0 0 1) ,再灌注组梗死区信号( 14 2 8± 1 64)是正常对照区 ( 1 44± 0 52 )的 9 92倍 (t =3 1 69,P <0 0 1) ;无再灌注组的延迟强化区[占同层面左室面积的百分率为 ( 15 49± 6 0 7) % ]与梗死心肌 [( 14 95± 7 3 6) % ]一致 (t =-0 78,P>0 0 5) ,再灌注组的延迟强化区 [( 12 52± 5 93 ) % ]包括梗死区 [( 11 13± 5 81) % ]和梗死周围区 ,过度估计梗死心肌范围约 12 47% (t =-14 48,P <0 0 1)。结论　在心肌梗死的 7～ 10d ,MR延迟强化扫描可较准确地反映梗死心肌的范围     

冠状动脉介入治疗后心肌再灌注损伤与冠状动脉侧支循环关系的探讨

目的 :探讨冠心病患者经皮冠状动脉介入治疗 (PCI)前后血丙二醛 (MDA)、超氧化物歧化酶 (SOD)及左心室功能的变化及其与冠状动脉侧支循环的关系。方法 :选择接受PCI的 75例冠心病患者 ,根据冠状动脉造影结果分为无侧支循环组 (4 4例 )和侧支循环组 (31例 ) ,在术前及术后分别测定静脉血MDA、SOD水平 ,用超声心动图测定左心室射血分数(LVEF)及Tei指数。结果 :两组术后 2h静脉血MDA升高、SOD降低 (均P <0 .0 1) ,术后 2 4h无侧支循环组MDA回降、SOD上升 ,与术前比较仍有显著性差异 (P <0 .0 1) ;两组间PCI后MDA、SOD及Tei指数有显著性差异 (P <0 .0 5 ,P <0 0 1)。结论 :冠状动脉侧支循环能减轻冠心病患者PCI治疗后的心肌再灌注损伤。     

Acute oedema in the evaluation of microvascular reperfusion and myocardial salvage in reperfused myocardial infarction with cardiac magnetic resonance imaging

The accurate measurement of myocardial salvage is critical to the ongoing refinement of reperfusion strategies in acute myocardial infarction (AMI). Cardiac magnetic resonance imaging (CMR) can define the area at risk in AMI by the presence of myocardial oedema, identified by high signal intensity on T₂-weighted imaging with a short inversion time inversion-recovery (STIR) sequence. In addition, myocardial necrosis can be identified with CMR delayed contrast enhanced imaging. In this prospective study we examined the relationship of acute oedema and necrosis with impaired microvascular reperfusion. We also evaluated acute oedema as a marker of the area at risk in AMI, for the purposes of documenting myocardial salvage. CMR was performed on 15 patients with (AMI), within 24 h of successful percutaneous coronary intervention (PCI). Left ventricular (LV) systolic dysfunction was defined by a systolic thickening <40% (severe <20%). Microvascular reperfusion was evaluated during the acute phase of contrast wash-in. CMR was repeated 3 months post-PCI to evaluate recovery of LV function and final infarct size. Myocardial salvage was defined as the percentage of the area at risk that was not infarcted on follow up CMR. There was a significant correlation between impaired microvascular reperfusion and the extent of segmental oedema (R = 0.363, P < 0.01), but not myocardial necrosis (R = 0.110, P > 0.5). The extent of myocardial salvage correlated with recovery of systolic function (R = 0.241, P < 0.05), which was strongest in LV segments with severely reduced systolic function (R = 0.422, P < 0.01). Conclusions: In acutely reperfused AMI, oedema can be used to identify the area at risk for the purpose of calculating myocardial salvage. The correlation between myocardial oedema and reperfusion status suggests a pathological role of acute oedema in the impairment of microvascular reperfusion.     

PTCA对急性心肌梗死Q-T离散度影响

目的 :观察急性心肌梗死患者经皮冠状动脉成型术 (PTCA)后Q -T离散度的变化 ,探讨PTCA对Q -T离散度的影响。方法 :测定 3 0例急性心肌梗死患者PTCA术前、术后即刻、术后 2h、术后 2 4h的Q-T离散度。结果 :急性心肌梗死患者PTCA术后即刻Q -T离散度较术前明显延长 (P <0 .0 5 ) ,术后 2h、术后 2 4h的Q -T离散度较术前明显减小 (P <0 .0 5 ) ;心肌梗死部位 (前 /侧壁AMI与下 /后壁AMI相比 )对Q -T离散度无影响 (P >0 .0 5 )。结论 :经皮腔内冠状动脉成型术可以使急性心肌梗死患者Q -T离散度显著降低 ,减少心律失常发生 ,对降低急性心肌死患者死亡率有临床意义。     

Detection of infarct size safety threshold for left ventricular ejection fraction impairment in acute myocardial infarction successfully treated with primary percutaneous coronary intervention

Purpose

In acute myocardial infarction (AMI) treated by primary percutaneous coronary intervention (PCI), there is a direct relationship between myocardial damage and consequent left ventricular (LV) functional impairment. It is however unclear whether there is a safety threshold below which infarct size does not significantly affect LV ejection fraction (EF). The aim of this study was to evaluate the relationship between infarct size and LVEF in AMI patients treated by successful PCI using a specific statistical approach to identify a possible safety threshold.

Methods

Among patients with recent AMI submitted to perfusion gated single photon emission computed tomography (SPECT) to define the infarct size, the data of 427 subjects with sizable infarct size were considered. The relationship between infarct size and LVEF was analysed using a simple segmented regression (SSR) model and an iterative algorithm based on robust least squares (RLS) for parameter estimation.

Results

The RLS algorithm detected two break points in the SSR model, set at infarct size values of 11.0 and 51.5 %. Because the slope coefficients of the two extreme segments of the regression line were not significant, by constraining such segments to zero slope in the SSR model, the lower break point was identified at infarct size = 8 % and the upper one at 45 %.

Conclusion

Using a rigorous statistical approach, it is possible to demonstrate that below a threshold of 8 % the infarct size apparently does not affect the LVEF and therefore a safety threshold could be set at this value. Furthermore, the same analysis suggests that the relationship between infarct size and LVEF impairment is lost for an infarct size > 45 %.     

急性心肌梗死院前与院内溶栓治疗的疗效比较

目的探讨院前溶栓治疗急性心肌梗死的必要性及安全性。方法对象为2005年1月—2008年1月的急性心肌梗死患者72例,其中35例由我院急诊科进行院前溶栓治疗,37例进行院内溶栓,并将两者对比分析。结果发病至溶栓治疗时间,院前溶栓组为(108.29±29.05)min,院内溶栓组为(179.38±45.67)min。再通率院前组为71.43%,院内组为45.95%。心脏事件发生率院前组为11.43%,院内组为32.43%。两组相比差异有统计学意义(P(0.05)。结论对急性心肌梗死患者进行院前溶栓治疗能缩短发病至开始溶栓的时间,提高冠脉再通率,降低心脏事件发生率,是必要可行和安全的。     

Cardiac sympathetic dysfunction contributes to left ventricular remodeling after acute myocardial infarction

To investigate the role of the cardiac sympathetic nervous system in left ventricular remodelling, 50 patients with first-time acute myocardial infarction (AMI) and patency of the infarct-related artery after reperfusion underwent quantitative iodine-123 metaiodobenzylguanidine (MIBG) imaging at 4 days and 4 weeks (n=42), and quantitative technetium-99m tetrofosmin imaging at 2 days after AMI. They also underwent both ventriculography and coronary angiography on admission and about 4 weeks after AMI. On the basis of left ventricular end-systolic volume (LVESV), patients were divided into two groups. Patients with LVESV dilatation (n=20) had a significantly lower ejection fraction (P<0.003) and a significantly higher severity score of 99mTc-tetrofosmin (P<0.04), and total severity (P<0.01), delta extent (P<0.007) and delta severity (P<0.0008) scores of MIBG than patients without LVESV dilatation (n=30). delta severity score of MIBG was directly correlated with change in LVESV at 4 weeks (r=0.63, P<0.0001). Stepwise linear discriminant function analysis showed that delta severity score of MIBG (P<0.0002) was the only discriminator of LVESV dilatation. Patients with LVESV dilatation had higher regional washout rates in both the infarct and the non-infarct zones than patients without such dilatation. Furthermore, no MIBG parameters changed significantly between 4 days and 4 weeks after AMI. In reperfused AMI, delta severity score of MIBG was related to the degree of ventricular dilatation and was the only powerful discriminator of ventricular dilatation. These results suggest that cardiac sympathetic nervous abnormality might contribute to left ventricular remodelling in reperfused AMI. MIBG imaging may allow identification of reperfused AMI patients at high risk for left ventricular remodelling.     

Scintigraphic evaluation of routine filterwire distal protection in percutaneous coronary intervention for acute ST-segment elevation myocardial infarction: a randomized controlled trial

Aim

Distal embolization during primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) may result in reduced myocardial perfusion, infarct extension and impaired prognosis. In a prospective randomized trial, we assessed the effect of routine filterwire distal protection on scintigraphic estimated infarct size.

Methods and results

The effect of routine filterwire distal protection was evaluated in 344 patients with STEMI <12 hours undergoing primary PCI. Patients were randomized to distal protection with a filterwire or standard PCI. The primary endpoint was myocardial infarct size measured by Sestamibi SPECT after 30 days (%). Secondary endpoints included myocardial salvage, ST-segment resolution (STR), myocardial biomarker release and major adverse cardiac and cerebral events. Baseline characteristics including area at risk (estimated by Sestamibi SPECT) were similar. Final infarct size was not statistically different in the distal protection and the control groups (median [IQR], 6% [1-19] and 5% [1-14], P = .23). Also, secondary endpoints were similar in the two treatment groups.

Conclusion

Distal protection with a filterwire performed as routine therapy in primary PCI for STEMI did not reduce myocardial infarct size. The study does not support routine use of distal protection in primary PCI.