title: Extraordinarily favorable left ventricular reverse remodeling through long-term cardiac resynchronization: super-response to cardiac resynchronization.
abstract: BACKGROUND
  Some chronic heart failure (CHF) patients show remarkable improvement in left ventricular (LV) remodeling after cardiac resynchronization therapy (CRT), for unclear reasons. This study aimed at identifying predictors of an extraordinarily favorable response to CRT.
  
  
  METHODS
  We studied 136 CRT patients (104 men, median 66 years, QRS 162 ms, left ventricular ejection fraction 24 ± 7%, 70% coronary disease, all left bundle branch block [LBBB]). We measured LV end diastolic diameter (LVEDD) before and after long-term (9.4 ± 6.3 months) CRT. At baseline, LV pre-ejection interval (LVPEI), interventricular mechanical delay (IVMD), LV dyssynchrony (standard deviation of electromechanical delays [SDEMD] in eight LV segments), exercise capacity (pVO(2)), and ventilatory efficiency (VE/VCO(2)) were assessed. Patients with a LVEDD reduction beyond the 80th percentile (high responders [HR]) were compared to low responders (LR).
  
  
  RESULTS
  In the HR group (n = 22), LVEDD was reduced from 71 to 52 mm (LR 64-61 mm, P < 0.001). HR had predominantly nonischemic heart disease (HR: 72%, LR: 44%, P = 0.019), tended to have a wider QRS (HR: 178 ms, LR: 162 ms, P = 0.066), had a longer LVPEI (HR: 179 ms, LR: 155 ms, P = 0.004), wider IVMD (HR: 60 ms, LR 48 ms, P = 0.05), larger LVEDD (P = 0.002), higher SDEMD (HR: 69 ms, LR: 46 ms, P = 0.044), but higher pVO(2) (HR: 17.5 mL/min/kg, LR: 13.5 mL/kg/min, P = 0.025) and lower VE/VCO(2) (HR: 31, LR: 35, P = 0.043), all compared to LR patients.
  
  
  CONCLUSIONS
  Extraordinarily favorable reverse LV remodeling through CRT in CHF and LBBB appears to require a particularly dilated LV due to nonischemic heart disease with pronounced electromechanical alteration, but with a fairly preserved functional capacity before CRT.
authors.affiliation: Department of Cardiology, Charité-Universitaetsmedizin Berlin-Campus Virchow-Klinikum, Berlin, Germany.
authors.forename: Özlem
authors.initials: Ö
authors.lastname: Çelebi
authors.forename: Thomas
authors.initials: T
authors.lastname: Knaus
authors.forename: Florian
authors.initials: F
authors.lastname: Blaschke
authors.forename: Dirk
authors.initials: D
authors.lastname: Habedank
authors.forename: Wolfram
authors.initials: W
authors.lastname: Döhner
authors.forename: Aischa
authors.initials: A
authors.lastname: Nitardy
authors.forename: Martin
authors.initials: M
authors.lastname: Stockburger
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000706:statistics & numerical data*; D015897:Comorbidity; D005260:Female; D005858:Germany / Q000453:epidemiology; D006333:Heart Failure / Q000453:epidemiology* / Q000517:prevention & control*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000453:epidemiology* / Q000517:prevention & control*; D020257:Ventricular Remodeling