BACKGROUND Myocardial recovery after primary percutaneous coronary intervention in acute myocardial infarction is variable and the extent and severity of injury are difficult to predict. We sought to investigate the role of cardiovascular magnetic resonance T1 mapping in the determination of myocardial injury very early after treatment of ST-segment elevation myocardial infarction (STEMI). METHODS STEMI patients underwent 3 T cardiovascular magnetic resonance (CMR), within 3 h of primary percutaneous intervention (PPCI). T1 mapping determined the extent (area-at-risk as %left ventricle, AAR) and severity (average T1 values of AAR) of acute myocardial injury, and related these to late gadolinium enhancement (LGE), and microvascular obstruction (MVO). The characteristics of myocardial injury within 3 h was compared with changes at 24-h to predict final infarct size. RESULTS Forty patients were included in this study. Patients with average T1 values of AAR ≥1400 ms within 3 h of PPCI had larger LGE at 24-h (33% ±14 vs. 18% ±10, P = 0.003) and at 6-months (27% ±9 vs. 12% ±9; P < 0.001), higher incidence and larger extent of MVO (85% vs. 40%, P = 0.016) & [4.0 (0.5-9.5)% vs. 0 (0-3.0)%, P = 0.025]. The average T1 value was an independent predictor of acute LGE (β 0.61, 95%CI 0.13 to 1.09; P = 0.015), extent of MVO (β 0.22, 95%CI 0.03 to 0.41, P = 0.028) and final infarct size (β 0.63, 95%CI 0.21 to 1.05; P = 0.005). Receiver-operating-characteristic analysis showed that T1 value of AAR obtained within 3-h, but not at 24-h, predicted large infarct size (LGE > 9.5%) with 100% positive predictive value at the optimal cut-off of 1400 ms (area-under-the-curve, AUC 0.88, P = 0.006). CONCLUSION Hyper-acute T1 values of the AAR (within 3 h post PPCI, but not 24 h) predict a larger extent of MVO and infarct size at both 24 h and 6 months follow-up. Delayed CMR scanning for 24 h could not substitute the significant value of hyper-acute average T1 in determining infarct characteristics.

中文翻译：

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超急性心血管磁共振 T1 映射可预测 ST 抬高型心肌梗死患者的梗死特征。


背景急性心肌梗死初次经皮冠状动脉介入治疗后的心肌恢复情况各不相同，损伤的程度和严重程度难以预测。我们试图研究心血管磁共振 T1 映射在 ST 段抬高型心肌梗死 (STEMI) 治疗后早期确定心肌损伤中的作用。方法 STEMI 患者在初次经皮介入治疗 (PPCI) 后 3 小时内接受 3 T 心血管磁共振 (CMR)。 T1 映射确定了急性心肌损伤的范围（左心室百分比，AAR 的危险区域）和严重程度（AAR 的平均 T1 值），并将这些与晚期钆增强 (LGE) 和微血管阻塞 (MVO) 相关。将3小时内心肌损伤的特征与24小时内的变化进行比较，以预测最终的梗塞面积。结果 本研究纳入了 40 名患者。 PPCI 3 小时内 AAR 平均 T1 值≥1400 ms 的患者在 24 小时（33% ±14 vs. 18% ±10，P = 0.003）和 6 个月（27% ±9 vs. 12% ±9；P < 0.001)，MVO 发生率较高且范围较大（85% vs. 40%，P = 0.016）& [4.0 (0.5-9.5)% vs. 0 (0-3.0)%，P = 0.025]。平均 T1 值是急性 LGE（β 0.61，95% CI 0.13 至 1.09；P = 0.015）、MVO 范围（β 0.22，95% CI 0.03 至 0.41，P = 0.028）和最终梗死面积的独立预测因子（ β 0.63，95%CI 0.21 至 1.05；P = 0.005）。接受者操作特征分析表明，AAR 的 T1 值在 3 小时内获得，但不是在 24 小时内获得，可预测大梗塞面积 (LGE > 9.5%)，在最佳截止值 1400 时具有 100% 阳性预测值ms（曲线下面积，AUC 0.88，P = 0.006）。 结论 AAR 的超急性 T1 值（PPCI 后 3 小时内，但不是 24 小时）可预测 24 小时和 6 个月随访时更大范围的 MVO 和梗塞面积。延迟24小时的CMR扫描不能替代超急性平均T1在确定梗死特征方面的显着价值。