Feature tracking CMR reveals abnormal strain in preclinical arrhythmogenic right ventricular dysplasia/ cardiomyopathy: A multisoftware feasibility and clinical implementation study

Background: regional right ventricular (rv) dysfunction is the hallmark of arrhythmogenic right ventricular dysplasia/cardiomyopathy (arvd/c),but is currently only qualitatively evaluated in the clinical setting. feature tracking cardiovascular magnetic resonance (ft-cmr) is a novel quantitative method that uses cine cmr to calculate strain values. however,most prior ft-cmr studies in arvd/c have focused on global rv strain using different software methods,complicating implementation of ft-cmr in clinical practice. we aimed to assess the clinical value of global and regional strain using ft-cmr in arvd/c and to determine differences between commercially available ft-cmr software packages. methods: we analyzed cine cmr images of 110 subjects (39 overt arvd/c [mutation+/phenotype+],40 preclinical arvd/c [mutation+/phenotype-] and 31 control) for global and regional (subtricuspid,anterior,apical) rv strain in the horizontal longitudinal axis using four ft-cmr software methods (multimodality tissue tracking,tomtec,medis and circle cardiovascular imaging). intersoftware agreement was assessed using bland altman plots. results: for global strain,all methods showed reduced strain in overt arvd/c patients compared to control subjects (p < 0.041),whereas none distinguished preclinical from control subjects (p > 0.275). for regional strain,overt arvd/c patients showed reduced strain compared to control subjects in all segments which reached statistical significance in the subtricuspid region for all software methods (p < 0.037),in the anterior wall for two methods (p < 0.005) and in the apex for one method (p = 0.012). preclinical subjects showed abnormal subtricuspid strain compared to control subjects using one of the software methods (p = 0.009). agreement between software methods for absolute strain values was low (intraclass correlation coefficient = 0.373). conclusions: despite large intersoftware variability of ft-cmr derived strain values,all four software methods distinguished overt arvd/c patients from control subjects by both global and subtricuspid strain values. in the subtricuspid region,one software package distinguished preclinical from control subjects,suggesting the potential to identify early arvd/c prior to overt disease expression. © 2017 the author(s).