title: Cine dyscontractility index: A novel marker of mechanical dyssynchrony that predicts response to cardiac resynchronization therapy.
abstract: To investigate whether magnetic resonance imaging (MRI) cine-derived dyssynchrony indices provide additional information compared to conventional tagged MRI (tMRI) acquisitions in heart failure patients undergoing cardiac resynchronization therapy (CRT).
  
  
  
  Patients scheduled for CRT (n = 52) underwent preprocedure MRI including cine and tMRI acquisitions. Segmental strain curves were calculated for both cine and tMRI to produce a range of standard indices for direct comparison between modalities. We also proposed and evaluated a novel index of "dyscontractility," which detects the presence of focal areas with paradoxically positive circumferential strain.
  
  
  
  Across conventional strain indices, there was only moderate-to-poor (R = 0.3-0.6) correlation between modalities; eight cine-derived indices showed statistically significant (P < 0.05) relations to CRT outcome compared to just two tMRI-based counterparts. The novel dyscontractility index calculated on basal slice cine images (cine dyscontractility index, "CDI") was the single best predictor of clinical response to CRT (area under the curve AUC = 0.81, P < 0.001). While poorly correlated to its tMRI counterpart (R = 0.33), CDI performed significantly better in predicting response to CRT (P < 0.005), and was also numerically better than all other tMRI indices (AUC 0.53-0.76, all P for AUC comparisons <0.17).
  
  
  
  Cine-derived strain indices offer potentially new information compared to tMRI. Specifically, the novel CDI is most strongly linked to response to cardiac resynchronization therapy in a contemporary patient cohort. It utilizes readily available MRI data, is relatively straightforward to process, and compares favorably with any conventional tagging index. J. Magn. Reson. Imaging 2016;44:1483-1492.
authors.affiliation: Institute of Radioelectronics and Multimedia Technology, Warsaw University of Technology, Warsaw, Poland.|Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw, Poland.
authors.forename: Konrad
authors.initials: K
authors.lastname: Werys
authors.affiliation: Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Petryka-Mazurkiewicz
authors.affiliation: Institute of Radioelectronics and Multimedia Technology, Warsaw University of Technology, Warsaw, Poland.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Błaszczyk
authors.affiliation: Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw, Poland.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Miśko
authors.affiliation: Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw, Poland.
authors.forename: Mateusz
authors.initials: M
authors.lastname: Śpiewak
authors.affiliation: Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw, Poland.
authors.forename: Łukasz A
authors.initials: ŁA
authors.lastname: Małek
authors.affiliation: Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw, Poland.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Mazurkiewicz
authors.affiliation: Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Miłosz-Wieczorek
authors.affiliation: Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Marczak
authors.affiliation: Institute of Radioelectronics and Multimedia Technology, Warsaw University of Technology, Warsaw, Poland.|Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Kubik
authors.affiliation: Cardiac Magnetic Resonance Unit, Institute of Cardiology, Warsaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Dąbrowska
authors.affiliation: Institute of Radioelectronics and Multimedia Technology, Warsaw University of Technology, Warsaw, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Piątkowska-Janko
authors.affiliation: Institute of Radioelectronics and Multimedia Technology, Warsaw University of Technology, Warsaw, Poland.
authors.forename: Błażej
authors.initials: B
authors.lastname: Sawionek
authors.affiliation: Division of Cardiovascular Medicine, Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, UK.
authors.forename: Rohan
authors.initials: R
authors.lastname: Wijesurendra
authors.affiliation: Division of Cardiovascular Medicine, Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, UK.
authors.forename: Stefan K
authors.initials: SK
authors.lastname: Piechnik
authors.affiliation: Institute of Radioelectronics and Multimedia Technology, Warsaw University of Technology, Warsaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Bogorodzki
mesh_terms: D000328:Adult; D015415:Biomarkers; D058406:Cardiac Resynchronization Therapy; D056966:Excitation Contraction Coupling; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000517:prevention & control*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000517:prevention & control*
chemical_list: D015415:Biomarkers
keywords: cardiac magnetic resonance imaging; cardiac resynchronization therapy; cine; dyssynchrony index; image registration; strain