title: Improvement of left ventricular function under cardiac resynchronization therapy goes along with a reduced incidence of ventricular arrhythmia.
abstract: OBJECTIVE
  The beneficial effects of cardiac resynchronization therapy (CRT) are thought to result from favorable left ventricular (LV) reverse remodeling, however CRT is only successful in about 70% of patients. Whether response to CRT is associated with a decrease in ventricular arrhythmias (VA) is still discussed controversially. Therefore, we investigated the incidence of VA in CRT responders in comparison with non-responders.
  
  
  METHODS
  In this nonrandomized, two-center, observational study patients with moderate-to-severe heart failure, LV ejection fraction (LVEF) ≤35%, and QRS duration >120 ms undergoing CRT were included. After 6 months patients were classified as CRT responders or non-responders. Incidence of VA was compared between both groups by Kaplan-Meier analysis and Cox regression analysis. ROC analysis was performed to determine the aptitude of LVEF cut-off values to predict VA.
  
  
  RESULTS
  In total 126 consecutive patients (64±11 years; 67%male) were included, 74 were classified as responders and 52 as non-responders. While the mean LVEF at baseline was comparable in both groups (25±7% vs. 24±8%; P = 0.4583) only the responder group showed an improvement of LVEF (36±6% vs. 24±7; p<0.0001) under CRT. In total in 56 patients VA were observed during a mean follow-up of 28±14 months, with CRT responders experiencing fewer VA than non-responders (35% vs. 58%, p<0.0061). Secondary preventive CRT implantation was associated with a higher likelihood of VA. As determined by ROC analysis an increase of LVEF by >7% was found to be a predictor of a significantly lower incidence of VA (AUC = 0.606).
  
  
  CONCLUSIONS
  Improvement of left ventricular function under cardiac resynchronization therapy goes along with a reduced incidence of ventricular arrhythmia.
authors.affiliation: Heinrich-Heine-University Duesseldorf, Medical Faculty, Department of Cardiology, Pulmology and Angiology, Dusseldorf, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Eickholt
authors.forename: Marcus
authors.initials: M
authors.lastname: Siekiera
authors.forename: Kiriakos
authors.initials: K
authors.lastname: Kirmanoglou
authors.forename: Astrid
authors.initials: A
authors.lastname: Rodenbeck
authors.forename: Nicole
authors.initials: N
authors.lastname: Heussen
authors.forename: Patrick
authors.initials: P
authors.lastname: Schauerte
authors.forename: Artur
authors.initials: A
authors.lastname: Lichtenberg
authors.forename: Jan
authors.initials: J
authors.lastname: Balzer
authors.forename: Tienush
authors.initials: T
authors.lastname: Rassaf
authors.forename: Stefan
authors.initials: S
authors.lastname: Perings
authors.forename: Malte
authors.initials: M
authors.lastname: Kelm
authors.forename: Dong-In
authors.initials: DI
authors.lastname: Shin
authors.forename: Christian
authors.initials: C
authors.lastname: Meyer
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000401:mortality / Q000503:physiopathology* / Q000628:therapy*; D058406:Cardiac Resynchronization Therapy; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000150:complications / Q000628:therapy; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D013318:Stroke Volume; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling