title: MRI-based multiparametric strain analysis predicts contractile recovery after aortic valve replacement for aortic insufficiency.
abstract: BACKGROUND
  Guidelines for referral of chronic aortic insufficiency (AI) patients for aortic valve replacement (AVR) suggest that surgery can be delayed until symptoms or reduction in left ventricular (LV) contractile function occur. The frequent occurrence of reduced LV contractile function after AVR for chronic AI suggests that new contractile metrics for surgical referral are needed.
  
  
  METHODS
  In 16 chronic AI patients, cardiac MRI tagged images were analyzed before and 21.5 ± 13.8 months after AVR to calculate LV systolic strain. Average measurements of three strain parameters were obtained for each of 72 LV regions, normalized using a normal human strain database (n = 63), and combined into a composite index (multiparametric strain z score [MSZ]) representing standard deviation from the normal regional average.
  
  
  RESULTS
  Preoperative global MSZ (72-region average) correlated with post-AVR global MSZ (R(2) = 0.825, p < 0.001). Preoperative global MSZ also predicts improvement of impaired regions (N = 271 regions from 14 AI patients, R(2) = 0.392, p < 0.001). Preoperative MRI-based LV ejection fraction (LVEF) is also predictive (r = 0.410, p < 0.001). Although global preoperative MSZ had a significantly higher correlation than preoperative LVEF with improvement of injured regions (p < 0.001), both measures convey the same phenomenon.
  
  
  CONCLUSIONS
  Global preoperative MRI-based multiparametric strain predicts global strain postoperatively, as well as improvement of regions (n = 72 per LV) with impaired contractile function. Global contractile function is an important correlate with improvement in regionally impaired contractile function, perhaps reflecting total AI volume-overload burden (severity/duration of AI).
authors.affiliation: Department of Surgery, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: Beckah D
authors.initials: BD
authors.lastname: Brady
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Knutsen
authors.forename: Ningning
authors.initials: N
authors.lastname: Ma
authors.forename: Rita
authors.initials: R
authors.lastname: Gardner
authors.forename: Ajay K
authors.initials: AK
authors.lastname: Taggar
authors.forename: Brian P
authors.initials: BP
authors.lastname: Cupps
authors.forename: Nicholas T
authors.initials: NT
authors.lastname: Kouchoukos
authors.forename: Michael K
authors.initials: MK
authors.lastname: Pasque
mesh_terms: D000328:Adult; D001022:Aortic Valve Insufficiency / Q000150:complications / Q000601:surgery*; D016022:Case-Control Studies; D002908:Chronic Disease; D003661:Decision Support Techniques; D005260:Female; D005500:Follow-Up Studies; D006305:Health Status Indicators; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D017410:Practice Guidelines as Topic; D013599:Systole; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology / Q000601:surgery