Combined [¹⁸F]FDG PET-cardiac MRI imaging (PET/CMR) is a useful tool to assess myocardial viability and cardiac function in patients with acute myocardial infarction (AMI). Here, we evaluated the prognostic value of PET/CMR in a porcine closed-chest reperfused AMI (rAMI) model. Late gadolinium enhancement by PET/CMR imaging displayed tracer uptake defect at the infarction site by 3 days after the rAMI in the majority of the animals (group Match, n = 28). Increased [¹⁸F]FDG uptake at the infarcted area (metabolism/contractility mismatch) with reduced tracer uptake in the remote viable myocardium (group Mismatch, n = 12) 3 days after rAMI was observed in the animals with larger infarct size and worse left ventricular ejection fraction (LVEF) (34 ± 8.7 vs 42.0 ± 5.2%), with lower LVEF also at the 1-month follow-up (35.8 ± 9.5 vs 43.0 ± 6.3%). Transcriptome analyses by bulk and single-nuclei RNA sequencing of the infarcted myocardium and border zones (n = 3 of each group, and 3 sham-operated controls) revealed a strong inflammatory response with infiltration of monocytes and macrophages in the infarcted and border areas in Mismatch animals. Our data indicate a high prognostic relevance of combined PET/MRI in the subacute phase of rAMI for subsequent impairment of heart function and underline the adverse effects of an excessive activation of the innate immune system in the initial phase after rAMI.

[ ¹⁸ F]FDG PET-心脏 MRI 联合成像 (PET/CMR) 是评估急性心肌梗死 (AMI) 患者心肌活力和心脏功能的有用工具。在这里，我们评估了 PET/CMR 在猪闭胸再灌注 AMI (rAMI) 模型中的预后价值。 PET/CMR 成像的晚期钆增强显示，大多数动物（匹配组， n = 28）在 rAMI 后 3 天梗塞部位出现示踪剂摄取缺陷。在梗死面积较大且左侧情况更差的动物中观察到 rAMI 后 3 天，梗塞区域的 [ ¹⁸ F]FDG 摄取增加（代谢/收缩力不匹配），而远端存活心肌（组不匹配， n = 12）中的示踪剂摄取减少心室射血分数 (LVEF)（34 ± 8.7 vs 42.0 ± 5.2%），1 个月随访时 LVEF 也较低（35.8 ± 9.5 vs 43.0 ± 6.3%）。通过对梗塞心肌和边界区进行批量和单核 RNA 测序进行的转录组分析（每组n = 3 例，以及 3 例假手术对照）显示，梗死区和边界区存在强烈的炎症反应，单核细胞和巨噬细胞浸润。不匹配的动物。我们的数据表明，rAMI 亚急性期联合 PET/MRI 与随后的心功能损伤具有高度的预后相关性，并强调了 rAMI 后初始阶段先天免疫系统过度激活的不利影响。