title: Effect of QRS Narrowing After Cardiac Resynchronization Therapy on Functional Mitral Regurgitation in Patients With Systolic Heart Failure.
abstract: The determinants of improvement in functional mitral regurgitation (FMR) after cardiac resynchronization therapy (CRT) remain unclear. We evaluated the predictors of FMR improvement and hypothesized that CRT-induced change in QRS duration (ΔQRS) might have an impact on FMR response after CRT. One hundred ten CRT recipients were enrolled. CRT response (≥ 15 reduction in left ventricular end-systolic volume) and FMR response (absolute reduction in FMR volume) were assessed with echocardiography before and 6 months after CRT. The study end points included all-cause death or hospitalization assessed in 12 ± 3 months (range 1 to 18). A total of 71 patients (65%) responded to CRT at 6 months. FMR response was observed in 49 (69%) of the CRT responders and 8 (20%) of the CRT nonresponders (p <0.001). Although the baseline QRS durations were similar, the paced QRS durations were shorter (p = 0.012) and the ΔQRS values were greater (p = 0.003) in FMR responders compared with FMR nonresponders. There was a linear correlation between ΔQRS and change in regurgitant volume (r = 0.49, p <0.001). At multivariate analysis, baseline tenting area (p = 0.012) and ΔQRS (p = 0.028) independently predicted FMR response. A ΔQRS ≥ 20 ms was related to CRT response, FMR improvement, and lower rates of death or hospitalization during follow-up (p values <0.05). In conclusion, QRS narrowing after CRT independently predicts FMR response. A ΔQRS ≥ 20 ms after CRT is associated with a favorable outcome in all clinical end points.
authors.affiliation: Cardiology Department, Medipol University Faculty of Medicine, Istanbul, Turkey. Electronic address: oguzkaraca@hotmail.com.
authors.forename: Oguz
authors.initials: O
authors.lastname: Karaca
authors.affiliation: Cardiology Department, Medipol University Faculty of Medicine, Istanbul, Turkey.
authors.forename: Mehmet Onur
authors.initials: MO
authors.lastname: Omaygenc
authors.affiliation: Cardiology Department, Medipol University Faculty of Medicine, Istanbul, Turkey.
authors.forename: Beytullah
authors.initials: B
authors.lastname: Cakal
authors.affiliation: Cardiology Department, Medipol University Faculty of Medicine, Istanbul, Turkey.
authors.forename: Sinem Deniz
authors.initials: SD
authors.lastname: Cakal
authors.affiliation: Cardiology Department, Medipol University Faculty of Medicine, Istanbul, Turkey.
authors.forename: Haci Murat
authors.initials: HM
authors.lastname: Gunes
authors.affiliation: Cardiology Department, Medipol University Faculty of Medicine, Istanbul, Turkey.
authors.forename: Irfan
authors.initials: I
authors.lastname: Barutcu
authors.affiliation: Cardiology Department, Medipol University Faculty of Medicine, Istanbul, Turkey.
authors.forename: Bilal
authors.initials: B
authors.lastname: Boztosun
authors.affiliation: Cardiology Department, Medipol University Faculty of Medicine, Istanbul, Turkey.
authors.forename: Fethi
authors.initials: F
authors.lastname: Kilicaslan
mesh_terms: D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D018450:Disease Progression; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D054143:Heart Failure, Systolic / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D013318:Stroke Volume / Q000502:physiology*; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000502:physiology*; D020257:Ventricular Remodeling / Q000502:physiology*