title: Predictive parameters of left ventricular reverse remodeling in response to cardiac resynchronization therapy in patients with severe congestive heart failure.
abstract: BACKGROUND
  Cardiac resynchronization therapy (CRT) is useful for the treatment of severe congestive heart failure. Unfortunately up to 30% of patients could be non-responders. The aim of our study was to find parameters to predict responsiveness to CRT.
  
  
  METHODS
  Fifteen patients (9 males, 6 females, mean age 67.3 +/- 7.8 years, range 52-83 years) with dilated cardiomyopathy, NYHA functional class III-IV, left ventricular (LV) ejection fraction < 35% and QRS > or = 110 ms, underwent CRT. All the patients had echocardiographic evidence of systolic dys-synchrony.
  
  
  RESULTS
  One patient died of electromechanical dissociation. The remaining 14 patients maintained biventricular stimulation at 6 months; mean QRS width decreased from 156 to 132 ms (p < 0.001). Ten patients (71%) were considered responders because of a reduction in LV end-systolic volume > 15%. In non-responders (4 patients, 29%) LV end-systolic volume was stable in 3 patients and increased in 1. LV ejection fraction significantly increased only in responders (p < 0.001). Responders had more severe pre-pacing dyssynchrony than non-responders (p < 0.001). Inter- (p = 0.002) and intraventricular dyssynchrony (p = 0.003) did significantly reduce after CRT only in responders. On multiple regression analysis there were two independent predictors of reverse remodeling after pacing: the baseline mitral QS-tricuspid QS (QSm-QSt) time (B = -1.7, p = 0.005) and the intraventricular dyssynchrony index (B = -1.55, p = 0.007). Pre-implant QSm-QSt of 38 ms correctly identified the two groups: responders had a value > 38 ms and non-responders < 38 ms. The pre-implant intraventricular dyssynchrony index of 28 ms was the cut-off value: responders had an index > 28 ms, non-responders < 28 ms.
  
  
  CONCLUSIONS
  In the literature a tissue Doppler imaging index of intraventricular dyssynchrony evaluated before implantation is used to select responders to CRT. In our work we studied interventricular and intraventricular dyssynchrony, and both the QSm-QSt time and the standard deviation of the 12 LV segment QS time were correctly able to identify responders.
authors.affiliation: Unit of Cardiology, Electrophysiology and Cardiac Stimulation, Spedali Civili, Brescia, Italy. e.demaria@inwind.it
authors.forename: Elia
authors.initials: E
authors.lastname: De Maria
authors.forename: Paolo
authors.initials: P
authors.lastname: Gallo
authors.forename: Michele
authors.initials: M
authors.lastname: Damiano
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Scognamiglio
authors.forename: Ciro
authors.initials: C
authors.lastname: De Simone
authors.forename: Salvatore
authors.initials: S
authors.lastname: Nilo
authors.forename: Pasquale
authors.initials: P
authors.lastname: Guarini
authors.forename: Giosuè
authors.initials: G
authors.lastname: Mascioli
authors.forename: Antonio
authors.initials: A
authors.lastname: Curnis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000628:therapy; D002304:Cardiac Pacing, Artificial; D002311:Cardiomyopathy, Dilated / Q000628:therapy; D015150:Echocardiography, Doppler; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D013318:Stroke Volume; D016896:Treatment Outcome; D020257:Ventricular Remodeling