Robert Steiner MRI Unit, MRC Clinical Sciences Centre, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK.
J Cardiovasc Magn Reson. 2012 Jun 21;14(1):41. doi: 10.1186/1532-429X-14-41.
Progressive heart failure due to remodeling is a major cause of morbidity and mortality following myocardial infarction. Conventional clinical imaging measures global volume changes, and currently there is no means of assessing regional myocardial dilatation in relation to ischemic burden. Here we use 3D co-registration of Cardiovascular Magnetic Resonance (CMR) images to assess the long-term effects of ischemia-reperfusion injury on left ventricular structure after acute ST-elevation myocardial infarction (STEMI).
Forty six patients (age range 33-77 years) underwent CMR imaging within 7 days following primary percutaneous coronary intervention (PPCI) for acute STEMI with follow-up at one year. Functional cine imaging and Late Gadolinium Enhancement (LGE) were segmented and co-registered. Local left ventricular wall dilatation was assessed by using intensity-based similarities to track the structural changes in the heart between baseline and follow-up. Results are expressed as means, standard errors and 95% confidence interval (CI) of the difference.
Local left ventricular remodeling within infarcted myocardium was greater than in non-infarcted myocardium (1.6%±1.0 vs 0.3%±0.9, 95% CI: -2.4% - -0.2%, P=0.02). One-way ANOVA revealed that transmural infarct thickness had a significant effect on the degree of local remodeling at one year (P<0.0001) with greatest wall dilatation observed when infarct transmurality exceeded 50%. Infarct remodeling was more severe when microvascular obstruction (MVO) was present (3.8%±1.3 vs -1.6%±1.4, 95% CI: -9.1% - -1.5%, P=0.007) and when end-diastolic volume had increased by >20% (4.8%±1.4 vs -0.15%±1.2, 95% CI: -8.9% - -0.9%, P=0.017).
The severity of ischemic injury has a significant effect on local ventricular wall remodeling with only modest dilatation observed within non-ischemic myocardium. Limitation of chronic remodeling may therefore depend on therapies directed at modulating ischemia-reperfusion injury. CMR co-registration has potential for assessing dynamic changes in ventricular structure in relation to therapeutic interventions.
重塑导致的进行性心力衰竭是心肌梗死后发病率和死亡率的主要原因。传统的临床影像学测量整体容量变化，目前尚无评估与缺血负担相关的局部心肌扩张的方法。在这里，我们使用心血管磁共振（CMR）图像的 3D 配准来评估急性 ST 段抬高型心肌梗死（STEMI）后缺血再灌注损伤对左心室结构的长期影响。
46 名患者（年龄 33-77 岁）在接受经皮冠状动脉介入治疗（PPCI）治疗急性 STEMI 后 7 天内接受 CMR 成像，并在 1 年后进行随访。功能电影成像和晚期钆增强（LGE）被分割并配准。通过基于强度的相似性来评估局部左心室壁扩张，以跟踪心脏在基线和随访之间的结构变化。结果表示为平均值、标准误差和差异的 95%置信区间（CI）。
梗死心肌内的局部左心室重构大于非梗死心肌（1.6%±1.0 比 0.3%±0.9，95%CI：-2.4% - -0.2%，P=0.02）。单因素方差分析显示，透壁性梗死厚度对 1 年时局部重构程度有显著影响（P<0.0001），当梗死透壁性超过 50%时，观察到最大的壁扩张。当存在微血管阻塞（MVO）时（3.8%±1.3 比-1.6%±1.4，95%CI：-9.1% - -1.5%，P=0.007）和当舒张末期容积增加超过 20%时（4.8%±1.4 比-0.15%±1.2，95%CI：-8.9% - -0.9%，P=0.017），梗死重构更为严重。
缺血损伤的严重程度对局部心室壁重构有显著影响，非缺血心肌仅观察到适度扩张。因此，慢性重构的限制可能取决于调节缺血再灌注损伤的治疗方法。CMR 配准有可能评估与治疗干预相关的心室结构的动态变化。
