title: Reverse remodeling and the mechanism of mitral regurgitation improvement in patients with dilated cardiomyopathy.
abstract: BACKGROUND
  Functional mitral regurgitation (MR) is a common finding in dilated cardiomyopathy. Left ventricular (LV) reverse remodeling with LV size reduction and improvement in LV function is a well recognized phenomenon. We aimed to evaluate the impact of LV remodeling on the mechanism leading to functional MR.
  
  
  METHODS
  Among 188 patients with non-ischemic dilated cardiomyopathy, 10 patients significantly improved their LV function, reduced LV size and MR severity during follow-up (RRMR). A comparison was made between their baseline and follow-up echocardiographic examinations and to a matched-control group of patients who did not improve (no RRMR). LV and left atrium (LA) dimensions and volumes, LV mass (LVM), LV ejection fraction (LVEF) (Simpsons), sphericity index (SI), mitral valve tenting area (TA) coaptation distance (CD), effective regurgitant orifice (ERO), and regurgitant volume were calculated. Multivariable analysis was performed in order to evaluate which echocardiographic parameters related to MR improvement in reverse remodeling.
  
  
  RESULTS
  LV and LA dimensions and volumes, LVM, SI, TA, CD, ERO and right ventricle, in the RRMR group significantly decreased at follow-up (p < 0.04 for all). When compared to no RRMR, despite a similar ERO (0.2 ± 0.05 vs. 0.2 ± 0.08, p = 0.13) and a larger regurgitant volume (38 ± 9 vs. 29 ± 8 mL, p = 0.05) and despite similar clinical characteristics and medical treatment we found significantly higher LVEF, smaller LV dimensions and volumes, smaller LVM and SI in the RRMR group (p < 0.05 for all). On multivariable analysis the SI was the sole predictor of RRMR (p = 0.04, OR = 0.76, CI 0.58-0.99).
  
  
  CONCLUSIONS
  Reverse remodeling characterized by improvement in LV function, reduction in LV size and an associated reduction in MR severity is related to LV SI at baseline.
authors.affiliation: Leviev Heart Institute, Sheba Medical Center, Sheba, Israel; Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel. rafikupe@gmail.com.
authors.forename: Rafael
authors.initials: R
authors.lastname: Kuperstein
authors.forename: Ido
authors.initials: I
authors.lastname: Blechman
authors.forename: Sagit
authors.initials: S
authors.lastname: Ben Zekry
authors.forename: Robert
authors.initials: R
authors.lastname: Klempfner
authors.forename: Dov
authors.initials: D
authors.lastname: Freimark
authors.forename: Michael
authors.initials: M
authors.lastname: Arad
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D016009:Chi-Square Distribution; D002648:Child; D015150:Echocardiography, Doppler; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008944:Mitral Valve Insufficiency / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D015999:Multivariate Analysis; D016017:Odds Ratio; D020127:Recovery of Function; D013997:Time Factors; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling; D055815:Young Adult