梗死相关血管晚期开通对急性心肌梗死后左室功能的影响

目的探讨急性前壁心肌梗死后延迟经皮冠状动脉血运重建术(PCI)使梗死相关血管(IRA)开通对心梗晚期左室功能的影响。方法选择64例急性前壁、前间壁及广泛前壁Q波性心梗后病情稳定,发病10～21d冠脉造影证实左前降支完全闭塞者,依据是否接受成功PCI,分为成功PCI组和对照组,分别于急性期、术后2个月和6个月应用超声心动图随访左室腔大小、左室功能和室壁活动异常,并观察6个月期间心力衰竭事件的发生情况。结果心梗后2个月两组左室射血分数(LVEF)、左室收缩末期容积指数(LVESVI)、左室舒张末期容积指数(LVEDVI)和室壁活动异常(VWMA)积分与急性期相比无明显差异(P>0.05),急性期和2个月时两组上述各指标之间相比差异也无显著性(均P>0.05)。6个月时两组LVEF和VWMA积分与急性期和2个月相比无明显差异(P>0.05),但对照组LVEDVI和LVESVI较急性期明显增大(P<0.01,P<0.05),且与成功PCI组相比差异具有显著性(P<0.01,P<0.05)。6个月随访期间心力衰竭事件发生率对照组为19%,成功PCI组2%,但差异缺乏统计学意义(P>0.05)。结论急性前壁心梗后IRA延迟开通能明显减少心梗后晚期的左室重构,而对心梗后早期左室重构的影响不大。延迟PCI可能有利于减少心梗后远期心力衰竭事件的发生。     

急性前壁心肌梗死后梗死相关血管延迟开通对晚期左室重构的影响

目的探讨急性前壁心肌梗死后,延迟经皮冠状动脉血运重建术(PCI)使梗死相关血管(IRA)开通,对心梗晚期左室重构的影响.方法选择64例急性前壁、前间壁及广泛前壁Q波性心梗后病情稳定,发病10～21天冠脉造影证实左前降支完全闭塞者,依据是否接受成功PCI,分为成功PCI组和对照组,分别于急性期、术后2个月和6个月应用超声心动图随访左室腔大小、左室功能和室壁活动异常,并观察6个月期间心力衰竭事件的发生情况.结果心梗后2个月两组左室射血分数(LVEF)、左室收缩末期容积指数(LVESVI)、左室舒张末期容积指数(LVEDVI)和室壁活动异常(VWMA)积分与急性期相比无明显差异(P＞0.05),急性期和2个月时两组上述各指标之间相比差异也无显著性(均P＞0.05).6个月时两组LVEF和VWMA积分与急性期和2个月相比无明显差异(P＞0.05),但对照组LVEDVI和LVESVI较急性期明显增大(P＜0.01,P＜0.05),且与成功PCI组相比差异具有显著性(P＜0.01,P＜0.05).6个月随访期间心力衰竭事件发生率对照组为19%,成功PCI组2%,但差异缺乏统计学意义(P＞0.05).结论急性前壁心梗后IRA延迟开通能明显减少心梗后晚期的左室重构,而对心梗后早期左室重构的影响不大.延迟PCI可能有利于减少心梗后远期心力衰竭事件的发生.     

急性心肌梗死后延迟冠状动脉介入治疗对左室重构和远期预后的影响

目的探讨急性心肌梗死(AMI)后延迟经皮冠状动脉介入治疗(PCI)对左室重构(LVRM)和远期预后的影响。方法93例初次AMI患者分为PCI组(47例)和非PCI组(46例)。分别在心肌梗死后(23±10)d(术前)和术后6个月测量左心室容量指数、射血分数(LVEF)和异常室壁运动积分指数,并观察6个月期间主要不良心脏事件的发生情况。结果6个月时两组左室射血分数和室壁活动异常积分与术前相比差异无统计学意义,但对照组左室舒张末期容积指数(LVEDVI)和左室收缩末期容积指数(LVESVI)较术前明显增大(P<0.01,P<0.05),且与PCI组相比差异有统计学意义(P<0.01,P<0.05)。6个月随访期间主要不良心脏事件发生率对照组为11%,成功PCI组为4%,但差异无统计学意义。结论AMI后延迟PCI可抑制左室扩大,延缓慢性期左室重构,并显著减少心脏事件的发生。     

择期PCI对急性心肌梗死患者心功能的影响

目的观察择期经皮冠状动脉介入治疗(PCI)对急性心肌梗死(AMI)患者心功能的影响。方法选择KillipⅠ~Ⅲ级AMI住院患者68例,AMI后10~14 d行冠状动脉造影证实梗死相关动脉(IRA)完全闭塞,依据是否行PCI将入选患者分为PCI组和对照组,并在住院和随访期间行C反应蛋白(CRP)、脑钠素(BNP)及超声心动图检查,测量两组术后1个月、6个月左室射血分数(LVEF)、左室舒张末期容积指数(LVEDVI)、左室收缩末期容积指数(LVESVI),测定两组AMI后7 d及6个月时CRP及BNP水平。结果 AMI后1个月,两组各项心功能参数无显著差异(P0.05),6个月时成功PCI组LVEF、LVESVI、LVEDVI明显改善(P0.05),而对照组心功能下降,两组间差异有统计学意义(P0.05),治疗6个月后,PCI组CRP、BNP降低,与AMI 7 d时及对照组同期比较,差异有统计学意义(P0.05)。结论 AMI后择期PCI,开通IRA,可明显改善心功能及临床预后。     

急性心肌梗死择期PCI对左室重构及远期预后的影响

目的评价急性心肌梗死择期经皮冠状动脉介入治疗(PCI)对左室重构及远期预后的影响。方法选择71例首次AMI患者,冠状动脉造影证实梗死相关动脉(IRA)完全闭塞(TIMI0~1级)。依据是否成功行PCI分为成功行PCI组和对照组,分别于术后1个月和6个月行ERNA和99mTc-MIBI心肌灌注显像,评价心功能及心肌灌注情况,对比分析两组Cortina积分和室壁瘤形成的比率、核素心肌灌注心肌梗死范围(MIA)、ERNA的心功能指标〔左心室峰射血时间(LVTPER)、左心室峰射血率(LVPER)、左心室峰充盈时间(LVTPFR)、左心室峰充盈率(LVPFR)、射血分数(EF)〕以及左心室舒张末期容积指数(LVEDVI)、左心室收缩末期容积指数(LVESVI)。并观察1年内主要心脏事件的发生情况。结果AMI后1个月,两组之间各项心功能参数及LVEDVI、LVESVI无显著性差异。6个月时成功PCI组各项心功能参数较1个月有改善趋势。对照组EF、LVPER、LVPFR较前下降,LVTPER、LVTPFR较前增加,有统计学意义,提示心功能下降。成功PCI组较对照组各项心功能参数明显改善。成功PCI组LVED-VI和LVESVI变化不明显,而对照组两指标较前明显增大,提示发生了心室重构。两组间LVEDVI和LVESVI相比差异有统计学意义。1年随访期间,成功PCI组无死亡及再次心肌梗死事件发生,在对照组中的发生较成功PCI组高,但无统计学意义。心力衰竭及心绞痛的发生对照组均明显高于成功PCI组。结论AMI后行择期PCI,开通IRA,可阻抑左室重构,改善心功能,从而改善预后,减少主要心脏事件的发生。     

依那普利对老年不同部位心肌梗死后左室重构的长期影响

目的　探讨依那普利对老年不同部位急性心肌梗死 (AMI)左室重构的长期影响。方法　 71例老年 AMI患者于发病后 2 4 h随机分为依那普利组 (n=36)和对照组 (n=35)。定期检查超声心动图 ,随访观察 1 2个月。结果　依那普利组左室舒张末期容量指数 (LVEDVI)和左室收缩末期容量指数 (LVESVI)从 1～ 1 2个月无明显增加 ,左室质量指数 (LVMIgl/ m2 )在 6～ 1 2个月时明显减少。而对照组 (n=35)上述指标明显增加伴左室射血分数 (LVEF% )降低。对照组前壁 AMI的 LVEDVI、LVESVI比下壁 AMI和治疗组前壁 AMI均显著增加 (P<0 .0 5～ 0 .0 1 )。结论　急性AMI后的左室重构主要影响前壁 ,表现为梗死区膨展 ,左室扩张及容量负荷增加。依那普利可减少 AMI后左室容量和质量指数 ,长期应用对左室重构的发生和发展有明显的防治作用。     

再血管化治疗对急性心肌梗死患者血浆激素水平和心功能的影响

目的:评价再血管化治疗对急性心肌梗死(AMI)患者神经内分泌激素水平及心功能的影响.方法:将68例AMI患者按是否行再血管化治疗分为急诊冠状动脉介入治疗(PCI)组20例,延迟PCI组26例,未行再血管化治疗的对照组22例,3组患者基础临床特征无统计学差异.于心肌梗死急性期和心肌梗死术后6个月分别采血检测血浆肾素活性(PRA)、血管紧张素Ⅱ(AngⅡ)浓度、血浆醛固酮(Ald)浓度、血浆去甲肾上腺素(NE)和肾上腺素(E)浓度,并测定左心室室壁运动指数(WMI)、左心室射血分数(LVEF)、左心室舒张末期容积指数(LVEDVI)和收缩末期容积指数(LVESVI)变化.结果:①无论急诊PCI组还是延迟PCI组,血浆肾素活性、血管紧张素Ⅱ、血浆醛固酮等激素水平术后6个月均有明显下降,而未行再血管化手术治疗的对照组激素水平无显著变化.②在急诊PCI组和延迟PCI组术后6个月与急性期比较左心室射血分数增加,左心室室壁运动指数减小;延迟PCI组术后6个月时的左心室收缩末期容积指数较急性期减小;急诊PCI组和延迟PCI组6个月的左心室收缩末期容积指数和室壁运动指数明显小于对照组,均有显著性差异(P＜0.05).结论:无论急诊PCI还是延迟PCI均可以降低心肌梗死后神经内分泌激素的过度激活,减缓左心室重塑,改善心功能.     

脑利钠肽对急诊冠状动脉介入治疗急性心肌梗死左室结构和功能的评估价值

目的:观察急性心肌梗死(AMI)患者接受急诊经皮冠状动脉介入(PCI)治疗前后的脑利钠肽(BNP)水平变化及其与左室功能,心室重构的关系,探讨BNP在急诊PCI治疗AMI患者预后评估中的作用.方法:入选2008-06-2009-02,发病后12 h内接受急诊PCI治疗的ST段抬高型急性心肌梗死(STEMI)患者120例,入院即时及出院时采用酶联免疫法测定患者血浆BNP水平,出院前行超声心动图检测左室射血分数,并根据PCI治疗后7 d的BNP水平将患者分为3组:A组<100 ng/L,B组为100～400 ng/L,C组>400 ng/L.所有患者术后6个月进行超声心动图检查,根据左室射血分数、左室舒张末期容积、左室收缩末期容积变化评估左室功能及心室重构.结果:BNP水平与AMI病变范围呈正相关,与左室射血分数呈负相关;PCI治疗后不同心肌梗死部位BNP水平较治疗前均明显下降;3组患者PCI治疗后6个月的超声心动图比较,患者左室射血分数、左室舒张末期容积、左室收缩末期容积B组、C组与A组相比差异有统计学意义(P<0.05),C组与B组比较差异也有统计学意义(P<0.05).结论:血浆BNP水平可反映AMI的严重程度;BNP增加的程度与梗死的范围呈正相关;AMI患者急诊PCI后BNP水平有显著下降趋势;BNP水平可能可以作为患者左室功能及心室重构的预测因子.     

RT3DE评价延迟PCI对急性心肌梗死患者心功能的影响

目的应用实时三维超声心动图(RT3DE)评价延迟经皮冠状动脉介入治疗(PCI)对急性心肌梗死(AMI)患者左心室功能的影响。方法选择首次AMI住院患者56例,根据是否行延迟PCI治疗,将患者分为PCI治疗组(30例)和药物治疗组(26例)。所有患者于治疗前和治疗后3个月、6个月分别进行RT3DE检查,对采集的三维超声图像进行脱机处理,得出左室舒张末期容积(LVEDV)、左室收缩末期容积(LVESV)及左心室射血分数(LVEF),比较两组患者左心功能的差异。结果PCI治疗组治疗后3个月、6个月较术前LVEDV、LVESV降低(P0.05),LVEF提高(P0.05)。药物治疗组治疗3个月、6个月时,各指标差异均无统计学意义。治疗后3个月及6个月时PCI治疗组与药物治疗组比较,LVEDV、LVESV、LVEF均有统计学意义(P0.05)。结论延迟PCI能明显改善AMI后左室重构,提高左心功能,改善患者预后。RT3DE可准确、方便的评价AMI患者左室整体心功能。     

急性心肌梗死急诊成功PCI时间对左室重构及远期预后的影响

目的评价急性心肌梗死急诊成功经皮冠状动脉介入治疗（PCI）时间对左室重构及远期预后的影响。方法选择91例首次急性心肌梗死（AMI）患者，冠状动脉造影证实梗死相关动脉（IRA）完全闭塞（TIMI0级～1级）。依据成功行PCI的时间分为3组。A组：6h内成功对罪犯血管施行PCI，29例；B组：6h～12h内成功对罪犯血管施行PCI，34例；C组：12h～24h内成功对罪犯血管施行PCI，28例。分别于术后即刻和6个月行冠状动脉造影及左心室造影，评价冠状动脉及心功能情况，对比分析3组Cortina积分和室壁瘤形成的比率、左心室造影的心功能指标：左心室舒张末容积（LVEDV）、左心室收缩末容积（LVESV）、左室射血分数（LVEF）、每分输出量（C0）、心脏指数（CI），并观察1年内主要心脏事件的发生情况。结果成功PCI即刻，3组之间各项心功能参数无统计学意义。6个月时A组和B组各项心功能参数较即刻有改善趋势；C组较前下降，但均无统计学意义。1年随访期间，3组无死亡及再次心肌梗死事件发生。心力衰竭及心绞痛的发生C组均明显高于A组、B组。结论AMI后尽早行PCI，开通IRA，可阻抑左室重构，改善心功能，从而改善预后，减少主要心脏事件的发生。     

Beneficial Effects of Delayed Opening the Infarct - related Artery on Late Phase Left Ventricular Function in Acute Anterior Myocardial Infarction

Objectives To assess the effect of delayed opening the infarct - related artery(IRA) by percutanous coronary intervention (PCI) on the late phase left ventricular function after acute anterior myocardial infarction. Methods 64 patients with initial Q -wave anterior myocardial infarction and the infarct- related arteries were total occluded conformed by angiogram at 2 to 14 days after onset were divided into successful PCI group and control group (not receiving PCI or the IRA not re - opened). 2 - DE was performed at early phase ( about 3 weeks) , 2 and 6months after onset of AMI respectively to detect the left ventricular function and left ventricular wall motion abnormality (VWMA). The total congestive heart failure events were recorded during 6 months follow-up. Results VWMA scores, left ventricular ejection fraction (LVEF), left ventricular end - diastolic and end-systolic volume indices (LVEDVI and LVDSVI)were similar in 2 groups at early phase and 2 months.There were no differences between early phase and 2months in each group too. VWMA scores and LVEF did not changed at 6 months in each group compared with the early phase and 2 months (P ＞ 0.05 ). But LVEDVI and LVESVI were significantly smaller in the successful PCI group than in the control group (P ＜0.01,P ＜ 0. 05 ). The congestive heart failure events were taken place in 19% of patients in control group compared with 2% in successful PCI group ( P ＞ 0.05 ).Conclusions Although the infarct size does not changed, delayed opening the IRA has beneficial effect to the late phase left ventricular dilatation after acute anterior myocardial infarction.     

急诊和择期冠状动脉介入治疗对急性心肌梗死左心室重构和功能的影响

目的评价急性心肌梗死(AMI)患者接受急诊和择期经皮冠状动脉介入(PCI)治疗对左心室重构和收缩功能的影响。方法对48例初次发病,发病时间在12h以内或12～24h之间的AMI患者行急诊PCI术;对27例AMI患者行择期PCI术。于术后2周、3个月和6个月行二维超声心动图测量左心室收缩末容积指数(LVESVI)、左心室舒张末容积指数(LVEDVI)、左心室射血分数(LVEF)和梗死区室壁运动指数(RWMI),并进行对比。结果术后2周、3个月急诊PCI组LVESVI、LVEDVI、LVEF和RWMI均显著优于择期PCI组。两组3个月和6个月时LVESVI、LVEDVI、LVEF及RWMI与2周时比较均有显著改善。至6个月时,两组间LVEDVI、LVEF和RWMI比较差异无统计学意义(P>0.05),而LVESVI差异有统计学意义(P<0.05)。两组间GWMI在各时间点统计差异无统计学意义。结论急诊PCI及择期PCI均可有效抑制左心室重构和改善左心室功能,急诊PCI更优于择期PCI。     

糖尿病和非糖尿病急性前壁心肌梗死晚期成功血运重建术后左室功能的变化及其与存活心肌的关系

目的:比较糖尿病和非糖尿病前壁急性心肌梗死(AMI)晚期成功血运重建术对心肌梗死后远期左室功能和预后的影响以及与存活心肌的关系.方法:选择依据病史、心电图和心肌损伤标志物等检查证实为首次发作的前壁AMI,并于发病后2周左右接受冠状动脉介入治疗术(PCI)的患者共计125例,其中参照WHO诊断标准确诊为并发糖尿病者(A组)43例,未并发糖尿病者(B组)82例.PCI前行超声心动图检查,了解左室功能和梗死相关区域存活心肌的情况.详细分析和记录PCI前后冠状动脉造影的结果.并分别于PCI前和术后6 h、24 h采取静脉血检测血清CK-MB和肌钙蛋白T水平.术后6个月重复超声心动图检查,了解左室功能和室壁活动异常的变化,并随访其间主要心血管事件的发生情况.结果:冠状动脉造影显示,与B组相比,A组PCI后即刻靶血管TIMI 2级血流所占的比例较多,TIMI 3级较少(分别为P<0.05和P<0.01).术后CK-MB和肌钙蛋白T增高者A组明显多于B组(25.6%∶9.8%,P<0.05).小剂量多巴酚丁胺超声负荷试验结果示A组中62.8%和B组中56.1%的患者有存活心肌,2组相比差异无统计学意义(P>0.05).急性期2组左室射血分数(LVEF)、左室舒张末期容积指数(LVEDVI)、收缩末期容积指数(LVESVI)以及室壁运动积分(WMS)基本相同(均P>0.05).术后6个月随访,B组WMS明显减少,LVEF明显增高;而A组LVEF和WMS均无明显改善,LVEDVI反而增加;2组相比LVEDVI、LVESVI、LVEF和WMS均有明显差异(分别P<0.05和P<0.01).随访期间2组主要心血管事件的发生率差异无统计学意义(18.6%∶11.0%,P>0.05).结论:糖尿病AMI晚期成功血运重建对远期左室功能的改善作用较非糖尿病者差,其结果可能与糖尿病患者晚期PCI后缺血心肌未能得到有效再灌注或再灌注加重心肌损伤有关,而术前存活心肌可能不是影响其疗效的主要原因.     

Viable Myocardium Impact on Left Ventricular Function after Late Revascularization of Infarct-related Artery in Acute Myocardial Infarction

Objectives The long-term benefit of late reperfusion of infarct-related artery (IRA) after acute myocardial infarction (AMI) is controversial, and the benefit mechanisms remain uncertain. Low dose dobutamine stress echocardiography (LDSE) can identify viable myocardium and predict improvement of wall motion after revascularization. Methods Sixty-nine patients with first AMI who did not received early reperfusion therapy were studied by LDSE at 5 to 10 days after AMI. Wall motion abnormality and left ventricular size were measured at the same time. Successful PCI were done in all patients at 10 to 21 days after AMI onset. Patients were divided in two groups based on the presence or absence of viable myocardium. Echocardiography was repeated six months later. Results There were 157 motion abnormality segments. 89 segments (57%) were viable during LDSE. 26 patients (38%) with viability and 43 (62%) without. In viable group, left ventricular ejection fraction (LVEF) was increased (P < 0.05), and left ventricular end systolic volume index (LVESVI) and wall motion score (WMS) were decreased (P < 0.05 and P < 0.01) significantly at 6 months compared with baseline. But in patients without viability, LVEF was decreased (P < 0.01), and LVESVI and left ventricular end diastolic volume index (LVEDVI) were increased (P<0.05) significantly after 6 months, and the WMS did not changed (P > 0.05). LVEF increased (P< 0.05) and WMS decreased (P < 0.05) on LDSE during acute phase in patients with viability, but they were not changed in the nonviable group. Conclusions Late revascularization of IRA in patients with presence of viable myocardium after AMI is associated with long-term preservation left ventricular function and less ventricular remodeling. Improvement of left ventricular systolic function on LDSE indicates late phase recovery of left ventricular function after late revascularization.     

经皮冠状动脉介入治疗对冠状动脉慢性完全闭塞病变患者左心室重构及心功能的影响

目的评价经皮冠状动脉介入治疗(PCI)对伴左心室收缩功能不全的冠状动脉慢性完全闭塞(CTO)患者左室重构及心功能的影响。方法选择该院心内科住院患者88例,经冠状动脉造影(CAG)证实均为伴左心室收缩功能不全的慢性冠状动脉闭塞病变,根据是否对CTO病变行PCI治疗,将患者分为PCI治疗组(n=48)和药物治疗组(n=40)。于CAG术前及术后1周、3个月、6个月分别进行超声心动图检查,计算校正的舒张末期容积指数(LVEDVI)、收缩末期容积指数(LVESVI)和左室射血分数(LVEF),比较两组患者左室重构及心功能的差异。结果两组CAG基线资料比较,差异无统计学意义。CAG术后1周时两组LVEDVI、LVESVI、LVEF比较,差异无统计学意义。3个月时PCI组LVEDVI较术前显著降低,LVEF显著提高;与药物治疗组相比,差异也有统计学意义。6个月时PCI组LVEDVI进一步降低,LVEF进一步提高。结论PCI能够改善伴左心室收缩功能不全的CTO患者左心室收缩功能,改善左心室重构。     

静脉应用重组人B-型利钠肽对急性心肌梗死冠状动脉介入术后心室重塑和收缩同步性的影响

目的:研究静脉应用重组人B-型利钠肽(rhBNP)对急性心肌梗死冠状动脉(冠脉)介入术后患者心室重塑和收缩同步性的影响.方法:选择48例12 小时内发病的急性前壁心肌梗死冠脉介入术后患者,随机分为rhBNP组25例和常规治疗组23例,分别于治疗后1周、4周和24周采用二维超声心动图测定舒张末期容积指数、收缩末期容积指数、左心室射血分数、左心室质量指数,梗死区的局部室壁运动指数.于治疗后1周、24周时行平衡法核素心室造影,了解心室收缩同步性参数.结果:①治疗后1周时,rhBNP组左心室收缩末期容积指数较常规治疗组降低、左心室射血分数较常规治疗组升高 (P<0.05).治疗后4周、24周时,rhBNP组左心室舒张末期容积指数、左心室收缩末期容积指数、左心室射血分数较常规治疗组差异均有统计学意义.治疗后24周时,rhBNP组的左心室质量指数,梗死区的局部室壁运动指数较常规治疗组明显下降,差异均有统计学意义 (P<0.05).②治疗后1周时心室相角程、半高宽、峰相位标准差在两组患者间差异无统计学意义 (P>0.05),治疗后24周时rhBNP组上述3项指标较常规治疗组差异有统计学意义(P<0.05).结论:冠脉介入术后在常规治疗的基础上应用rhBNP可进一步阻抑急性前壁心肌梗死后心室重塑,提高心室收缩同步性,改善左心功能.     

急性心梗心电图QRS波终末变形与左室功能变化的研究

目的探讨急性心肌梗死患者心电图QRS波终末变形情况与左心室功能变化的关系。方法根据入院心电图将急性心梗患者分成QRS终末变形阳性(QRS+)组(n=22)与QRS终末变形阴性(QRS-)组(n=46),于经皮冠状动脉介入术后2周与6个月时行超声心动图检查。结果术后6个月时QRS-组左心室舒张末期容积指数(LVEDVI)、左室收缩末期容积指数(LVESVI)及室壁活动异常积分(VWMA)明显小于QRS+组p<0.05),而左室射血分数(LVEF)显著高于QRS+组(p<0.05)。结论心电图QRS终末变形可作为急性心梗后左室重构和左室功能变化的预测因子之一。     

Late percutaneous coronary intervention for the totally occluded infarct‐related artery: A meta‐analysis of the effects on cardiac function and remodeling

Background : Late percutaneous coronary intervention (PCI) of a totally occluded infarct‐related artery (IRA) in stable patients is currently not recommended based on the lack of clear clinical benefits in randomized controlled trials. We sought to perform a systematic review and meta‐analysis of randomized controlled trials comparing PCI with optimal medical therapy in patients with IRA occlusion more than 12 hr after onset of acute myocardial infarction (AMI), focusing on left ventricular function and remodeling. Methods and Results : PubMed, CENTRAL, and mRCT were searched for eligible studies. Studies were included in the analysis if they were randomized controlled trials comparing conservative medical management with PCI performed at least 12 hr after the onset of symptoms of AMI, and data on left ventricular ejection fraction (LVEF) at baseline and follow‐up were available. Studies were excluded if randomization occurred less than 12 hr after symptom onset, or if patients were hemodynamically unstable. Change in LVEF was the primary outcome of interest, with changes in left ventricular end‐diastolic volume index (LVEDVI) and end‐systolic volume index (LVESVI) analyzed as secondary endpoints. We retrieved five studies in which baseline and follow up LVEF data were available enrolling a total of 648 patients: 342 patients randomized to PCI and 306 to medical treatment. There was a statistically significant difference in LVEF changes over time favoring PCI (+3.1%, 95% CI +1.0 to +5.2, P = 0.0004). In addition, there were statistically significant differences changes in both LVEDVI (?5.1 ml in favor of PCI, 95% CI of ?9.4 to ?0.8, P = 0.020) and LVESVI (?5.3 ml in favor in PCI, 95% CI of ?8.3 to ?2.4, P = 0.0005). Conclusions : This meta‐analysis suggests that late revascularization of an occluded IRA may improve left ventricular systolic function and remodeling, supporting the “open artery hypothesis.” The reason why these changes have not resulted in clinical benefits in large clinical trials is subject to debate. © 2008 Wiley‐Liss, Inc.