Dick Anastasia, Schmidt Björn, Michels Guido, Bunck Alexander C, Maintz David, Baeßler Bettina
Department of Radiology, University Hospital of Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
Department III of Internal Medicine, Heart Centre, University Hospital of Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
Eur J Radiol. 2017 Apr;89:72-80. doi: 10.1016/j.ejrad.2017.01.028. Epub 2017 Jan 30.
The present study aims at evaluating the feasibility and reproducibility of cardiac magnetic resonance (CMR) feature tracking (FT) derived strain and strain rate (SR) parameters of the left and right atrium (LA, RA) in patients with acute myocarditis as well as their potential to detect diastolic dysfunction. In addition, the diagnostic value of LA and RA strain parameters in the setting of acute myocarditis is investigated.
CMR cine data of 30 patients with CMR-positive acute myocarditis were retrospectively analyzed. 25 age- and gender-matched healthy individuals served as a control. Analysis of longitudinal strain and SR of both atria was performed in two long-axis views using a dedicated FT-software. LA and RA deformation was analyzed including reservoir function (total strain [ε], peak positive SR [SR]), conduit function (passive strain [ε], peak early negative SR [SR]) and booster pump function (active strain [ε], peak late negative SR [SR]). Intra- and inter-observer reproducibility was assessed for all strain and SR parameters using Bland-Altman analyses, intra-class correlation coefficients (ICCs) and coefficients of variation (CV).
FT analyses of both atria were feasible in all patients and controls. Reproducibility was good for reservoir and conduit function parameters and moderate for booster pump function parameters. Myocarditis patients demonstrated an impaired LA reservoir and conduit function when compared to healthy controls (LA ε: 32±17 vs. 46±13, p=0.019; LA SR: 1.5±0.5 vs. 1.8±0.5, p=0.117; LA SR: -1.3±0.5 vs. -1.9±0.5, p<0.001), while LA booster pump function was preserved. In logistic regression and ROC-analyses, LA SR proved to be the best independent predictor of acute myocarditis (AUC 0.80), and using LA SR with a cut-off of -1.6s resulted in a diagnostic sensitivity of 83% and a specificity of 80%. Changes in RA phasic function parameters showed a tendency to parallel those of the LA and showed no additional effect with respect to the diagnostic potential in acute myocarditis.
Myocarditis patients exhibit an impaired atrial reservoir and conduit function, what might be indicative of ventricular diastolic dysfunction. LA SR was the best predictor for the presence of acute myocarditis in our study, pointing towards the discriminative power of atrial strain analysis in the CMR-based diagnosis of acute myocarditis.
本研究旨在评估心脏磁共振成像（CMR）特征追踪（FT）得出的急性心肌炎患者左、右心房（LA、RA）应变及应变率（SR）参数的可行性和可重复性，以及它们检测舒张功能障碍的潜力。此外，还研究了LA和RA应变参数在急性心肌炎诊断中的价值。
回顾性分析30例CMR确诊的急性心肌炎患者的CMR电影数据。25例年龄和性别匹配的健康个体作为对照。使用专用FT软件在两个长轴视图中对两个心房的纵向应变和SR进行分析。分析LA和RA的变形，包括储存功能（总应变[ε]、峰值正向SR[SR]）、管道功能（被动应变[ε]、早期峰值负向SR[SR]）和增压泵功能（主动应变[ε]、晚期峰值负向SR[SR]）。使用Bland-Altman分析、组内相关系数（ICC）和变异系数（CV）评估所有应变和SR参数的观察者内和观察者间的可重复性。
对所有患者和对照进行的两个心房的FT分析均可行。储存和管道功能参数的可重复性良好，增压泵功能参数的可重复性中等。与健康对照相比，心肌炎患者的LA储存和管道功能受损（LA ε：32±17对46±13，p=0.019；LA SR：1.5±0.5对1.8±0.5，p=0.117；LA SR：-1.3±0.5对-1.9±0.5，p<0.001），而LA增压泵功能得以保留。在逻辑回归和ROC分析中，LA SR被证明是急性心肌炎的最佳独立预测指标（AUC 0.80），使用截断值为-1.6s的LA SR时，诊断敏感性为83%，特异性为80%。RA相位功能参数的变化显示出与LA平行的趋势，且在急性心肌炎诊断潜力方面没有额外作用。
心肌炎患者表现出心房储存和管道功能受损，这可能提示心室舒张功能障碍。在我们的研究中，LA SR是急性心肌炎存在的最佳预测指标，表明心房应变分析在基于CMR的急性心肌炎诊断中具有鉴别能力。
