Nijveldt Robin, Hofman Mark B M, Hirsch Alexander, Beek Aernout M, Umans Victor A W M, Algra Paul R, Piek Jan J, van Rossum Albert C
Departments of Cardiology and Physics and Medical Technology, VU University Medical Center, Amsterdam, the Netherlands.
Radiology. 2009 Feb;250(2):363-70. doi: 10.1148/radiol.2502080739. Epub 2009 Jan 22.
To evaluate which cardiac magnetic resonance (MR) imaging technique for detection of microvascular obstruction (MVO) best predicts left ventricular (LV) remodeling after acute myocardial infarction (MI).
This study had local ethics committee approval; all patients gave written informed consent. Sixty-three patients with first acute MI, treated with primary stent placement and optimal medical therapy, underwent cine MR imaging at 4-7 days and at 4 months after MI. Presence of MVO was qualitatively evaluated at baseline by using three techniques: (a) a single-shot saturation-recovery gradient-echo first-pass perfusion sequence (early hypoenhancement), mean time, 1.09 minutes +/- 0.07 (standard deviation) after contrast material administration; (b) a three-dimensional segmented saturation-recovery gradient-echo sequence (intermediate hypoenhancement), mean time, 2.17 minutes +/- 0.26; and (c) a two-dimensional segmented inversion-recovery gradient-echo late gadolinium enhancement sequence (late hypoenhancement), mean time, 13.32 minutes +/- 1.26. Contrast-to-noise ratios (CNRs) were calculated from the signal-to-noise ratios of the infarcted myocardium and MVO areas. Univariable linear regression analysis was used to identify the predictive value of each MR imaging technique.
Early hypoenhancement was detected in 44 (70%) of 63 patients; intermediate hypoenhancement, in 39 (62%); and late hypoenhancement, in 37 (59%). Late hypoenhancement was the strongest predictor of change in LV end-diastolic and end-systolic volumes over time (beta = 14.3, r = 0.40, P = .001 and beta = 11.3, r = 0.44, P < .001, respectively), whereas intermediate and late hypoenhancement had comparable predictive values of change in LV ejection fraction (beta = -3.1, r = -0.29, P = .02 and beta = -2.8, r = -0.27, P = .04, respectively). CNR corrected for spatial resolution was significantly superior for late enhancement compared with the other sequences (P < .001).
By using cardiac MR imaging, late hypoenhancement is the best prognostic marker of LV remodeling, with highest CNR between the infarcted myocardium and MVO regions.
评估哪种心脏磁共振（MR）成像技术在检测微血管阻塞（MVO）方面最能预测急性心肌梗死（MI）后左心室（LV）重构。
本研究获得当地伦理委员会批准；所有患者均签署了书面知情同意书。63例首次发生急性MI且接受了直接支架置入和最佳药物治疗的患者，在MI后4 - 7天及4个月时接受了电影MR成像检查。在基线时采用三种技术对MVO的存在进行定性评估：（a）单次激发饱和恢复梯度回波首过灌注序列（早期低强化）；造影剂注射后平均时间为1.09分钟±0.07（标准差）；（b）三维分段饱和恢复梯度回波序列（中期低强化），平均时间为2.17分钟±0.26；（c）二维分段反转恢复梯度回波延迟钆增强序列（晚期低强化），平均时间为13.32分钟±1.26。从梗死心肌和MVO区域的信噪比计算对比噪声比（CNR）。采用单变量线性回归分析来确定每种MR成像技术的预测价值。
63例患者中，44例（70%）检测到早期低强化；39例（62%）检测到中期低强化；37例（59%）检测到晚期低强化。晚期低强化是LV舒张末期和收缩末期容积随时间变化的最强预测指标（β = 14.3，r = 0.40，P = 0.001；β = 11.3，r = 0.44，P < 0.001），而中期和晚期低强化对LV射血分数变化的预测价值相当（β = -3.1，r = -0.29，P = 0.02；β = -2.8，r = -0.27，P = 0.04）。与其他序列相比，经空间分辨率校正后的晚期强化CNR显著更高（P < 0.001）。
通过心脏MR成像，晚期低强化是LV重构的最佳预后标志物，梗死心肌与MVO区域之间的CNR最高。
