Melo Rodrigo J L, Assunção Antonildes N, Morais Thamara C, Nomura Cesar H, Scanavacca Mauricio I, Martinelli-Filho Martino, Ramires Felix J A, Fernandes Fabio, Ianni Barbara M, Mady Charles, Rochitte Carlos E
From the Cardiovascular Magnetic Resonance and Computed Tomography Sector (R.J.L.M., A.N.A., T.C.M., C.H.N., C.E.R.), Arrhythmia Unit (M.I.S.), Artificial Cardiac Stimulation Unit (M.M.F.), and Cardiomyopathy Unit (F.J.A.R., F.F., B.M.I., C.M.), Heart Institute (Instituto do Coração), University of São Paulo Medical School, Av Dr Enéas de Carvalho Aguiar 44, Andar AB, Cerqueira Cesar, São Paulo 05403-000 SP, Brazil.
Radiol Cardiothorac Imaging. 2023 Jun 15;5(3):e220112. doi: 10.1148/ryct.220112. eCollection 2023 Jun.
To evaluate myocardial T1 mapping and extracellular volume (ECV) parameters in different stages of Chagas cardiomyopathy and determine whether they are predictive of disease severity and prognosis.
Prospectively enrolled participants (July 2013 to September 2016) underwent cine and late gadolinium enhancement (LGE) cardiac MRI and T1 mapping with a precontrast (native) or postcontrast modified Look-Locker sequence. The native T1 and ECV values were measured among subgroups that were based on disease severity (indeterminate, Chagas cardiomyopathy with preserved ejection fraction [CCpEF], Chagas cardiomyopathy with midrange ejection fraction [CCmrEF], and Chagas cardiomyopathy with reduced ejection fraction [CCrEF]). Cox proportional hazards regression and the Akaike information criterion were used to determine predictors of major cardiovascular events (cardioverter defibrillator implant, heart transplant, or death).
In 107 participants (90 participants with Chagas disease [mean age ± SD, 55 years ± 11; 49 men] and 17 age- and sex-matched control participants), the left ventricular (LV) ejection fraction and the extent of focal and diffuse or interstitial fibrosis were correlated with disease severity. Participants with CCmrEF and participants with CCrEF showed significantly higher global native T1 and ECV values than participants in the indeterminate, CCpEF, and control groups (T1: 1072 msec ± 34 and 1073 msec ± 63 vs 1010 msec ± 41, 1005 msec ± 69, and 999 msec ± 46; ECV: 35.5% ± 3.6 and 35.0% ± 5.4 vs 25.3% ± 3.5, 28.2% ± 4.9, and 25.2% ± 2.2; both < .001). Remote (LGE-negative areas) native T1 and ECV values were also higher (T1: 1056 msec ± 32 and 1071 msec ± 55 vs 1008 msec ± 41, 989 msec ± 96, and 999 msec ± 46; ECV: 30.2% ± 4.7 and 30.8% ± 7.4 vs 25.1% ± 3.5, 25.1% ± 3.7, and 25.0% ± 2.2; both < .001). Abnormal remote ECV values (>30%) occurred in 12% of participants in the indeterminate group, which increased with disease severity. Nineteen combined outcomes were observed (median follow-up time: 43 months), and a remote native T1 value greater than 1100 msec was independently predictive of combined outcomes (hazard ratio, 12 [95% CI: 4.1, 34.2]; < .001).
Myocardial native T1 and ECV values were correlated with Chagas disease severity and may serve as markers of myocardial involvement in Chagas cardiomyopathy that precede LGE and LV dysfunction. MRI, Cardiac, Heart, Imaging Sequences, Chagas Cardiomyopathy © RSNA, 2023.
评估恰加斯心肌病不同阶段的心肌T1映射和细胞外容积（ECV）参数，并确定它们是否可预测疾病严重程度和预后。
前瞻性纳入的参与者（2013年7月至2016年9月）接受了电影成像和延迟钆增强（LGE）心脏磁共振成像（MRI）以及使用预对比（天然）或对比后改良Look-Locker序列的T1映射。在基于疾病严重程度划分的亚组（不确定型、射血分数保留的恰加斯心肌病[CCpEF]、射血分数中等的恰加斯心肌病[CCmrEF]和射血分数降低的恰加斯心肌病[CCrEF]）中测量天然T1和ECV值。采用Cox比例风险回归和赤池信息准则来确定主要心血管事件（植入心脏复律除颤器、心脏移植或死亡）的预测因素。
在107名参与者（90名恰加斯病患者[平均年龄±标准差，55岁±11岁；49名男性]和17名年龄及性别匹配的对照参与者）中，左心室射血分数以及局灶性和弥漫性或间质纤维化程度与疾病严重程度相关。CCmrEF组和CCrEF组的参与者相较于不确定型、CCpEF组和对照组的参与者，整体天然T1和ECV值显著更高（T1：1072毫秒±34和1073毫秒±63，对比1010毫秒±41、1005毫秒±69和999毫秒±46；ECV：35.5%±3.6和35.0%±5.4，对比25.3%±3.5、28.2%±4.9和25.2%±2.2；均P<0.001）。远隔部位（LGE阴性区域）的天然T1和ECV值也更高（T1：1056毫秒±32和1071毫秒±55，对比1008毫秒±41、989毫秒±96和999毫秒±46；ECV：30.2%±4.7和30.8%±7.4，对比25.1%±3.5、25.1%±3.7和25.0%±2.2；均P<0.001）。不确定型组中12%的参与者出现远隔部位ECV值异常（>30%），且随着疾病严重程度增加。观察到19个联合结局（中位随访时间：43个月），远隔部位天然T1值大于1100毫秒可独立预测联合结局（风险比，12[95%CI：4.1，34.2]；P<0.001）。
心肌天然T1和ECV值与恰加斯病严重程度相关，可能作为恰加斯心肌病中心肌受累的标志物，早于LGE和左心室功能障碍出现。MRI、心脏、心脏成像序列、恰加斯心肌病 ©RSNA，2023年
