Gleditsch Jostein, Jervan Øyvind, Tavoly Mazdak, Geier Oliver, Holst René, Klok Frederikus A, Ghanima Waleed, Hopp Einar
Department of Radiology, Østfold Hospital, Kalnes, Norway.
Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
Int J Cardiol Heart Vasc. 2021 Dec 28;38:100935. doi: 10.1016/j.ijcha.2021.100935. eCollection 2022 Feb.
Persistent dyspnea is a common symptom after pulmonary embolism (PE). However, the pathophysiology of persistent dyspnea is not fully clarified. This study aimed to explore possible associations between diffuse myocardial fibrosis, as assessed by cardiac magnetic resonance (CMR) T1 mapping, and persistent dyspnea in patients with a history of PE.
CMR with T1 mapping and extracellular volume fraction (ECV) calculations were performed after PE in 51 patients with persistent dyspnea and in 50 non-dyspneic patients. Patients with known pulmonary disease, heart disease and CTEPH were excluded.
Native T1 was higher in the interventricular septum in dyspneic patients compared to non-dyspneic patients; difference 13 ms (95% CI: 2-23 ms). ECV was also significantly higher in patients with dyspnea; difference 0.9 percent points (95% CI: 0.04-1.8 pp). There was no difference in native T1 or ECV in the left ventricular lateral wall. Native T1 in the interventricular septum had an adjusted Odds Ratio of 1.18 per 10 ms increase (95% CI: 0.99-1.42) in predicting dyspnea, and an adjusted Odds Ratio of 1.47 per 10 ms increase (95% CI: 1.10-1.96) in predicting Incremental Shuttle Walk Test (ISWT) score < 1020 m.
Septal native T1 and ECV values were higher in patients with dyspnea after PE compared with those who were fully recovered suggesting a possible pathological role of myocardial fibrosis in the development of dyspnea after PE. Further studies are needed to validate our findings and to explore their pathophysiological role and clinical significance.
持续性呼吸困难是肺栓塞（PE）后的常见症状。然而，持续性呼吸困难的病理生理学尚未完全阐明。本研究旨在探讨通过心脏磁共振（CMR）T1 mapping评估的弥漫性心肌纤维化与有PE病史患者的持续性呼吸困难之间的可能关联。
对51例有持续性呼吸困难的患者和50例无呼吸困难的患者在PE后进行了CMR检查，包括T1 mapping和细胞外容积分数（ECV）计算。排除已知患有肺部疾病、心脏病和慢性血栓栓塞性肺动脉高压（CTEPH）的患者。
与无呼吸困难的患者相比，有呼吸困难的患者室间隔的固有T1更高；差异为13毫秒（95%可信区间：2 - 23毫秒）。有呼吸困难的患者的ECV也显著更高；差异为0.9个百分点（95%可信区间：0.04 - 1.8个百分点）。左心室侧壁的固有T1或ECV没有差异。室间隔固有T1每增加10毫秒，预测呼吸困难的校正比值比为1.18（95%可信区间：0.99 - 1.42），预测递增往返步行试验（ISWT）得分<1020米的校正比值比为每增加10毫秒1.47（95%可信区间：1.10 - 1.96）。
与完全康复的患者相比，PE后有呼吸困难的患者的间隔固有T1和ECV值更高，提示心肌纤维化在PE后呼吸困难的发生中可能起病理作用。需要进一步的研究来验证我们的发现，并探索其病理生理作用和临床意义。
