Author + information
- Received May 5, 2017
- Revision received November 13, 2017
- Accepted November 16, 2017
- Published online February 19, 2018.
- Emilce Trucco, MDa,b,c,
- José María Tolosana, MD, PhDa,b,d,
- Elena Arbelo, MD, PhDa,b,d,
- Ada Doltra, MD, PhDa,b,
- María Ángeles Castel, MD, PhDa,b,d,
- Eva Benito, MDa,b,
- Roger Borràs, BSca,b,
- Eduard Guasch, MD, PhDa,b,d,
- Silvia Vidorreta, RNa,b,
- Barbara Vidal, MD, PhDa,b,d,
- Silvia Montserrat, MD, PhDa,b,d,
- Marta Sitges, MD, PhDa,b,d,
- Antonio Berruezo, MD, PhDa,b,d,
- Josep Brugada, MD, PhDa,b,d and
- Lluís Mont, MD, PhDa,b,d,∗ ()
- aInstitut Clínic Cardio-Vascular (ICCV), Hospital Clínic, Universitat de Barcelona, Catalonia, Spain
- bInstitut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia, Spain
- cDepartment of Cardiology, Hospital Universitari Doctor Josep Trueta, Girona, Spain
- dCentro de Investigacíon Biomédica en Red Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
- ↵∗Address for correspondence:
Dr. Lluís Mont, Hospital Clínic de Barcelona, C/Villarroel 170, 6º, escala 3 08036 Barcelona, Spain.
Objectives The aim of this study was to compare patient response to cardiac resynchronization therapy (CRT) using fusion-optimized atrioventricular (AV) and interventricular (VV) intervals versus nominal settings.
Background The additional benefit obtained by AV- and VV-interval optimization in patients undergoing CRT remains controversial. Previous studies show short-term benefit in hemodynamic parameters; however, midterm randomized comparison between electrocardiogram optimization and nominal parameters is lacking.
Methods A group of 180 consecutive patients with left bundle branch block treated with CRT were randomized to fusion-optimized intervals (FOI) or nominal settings. In the FOI group, AV and VV intervals were optimized according to the narrowest QRS, using fusion with intrinsic conduction. Clinical response was defined as an increase >10% in the 6-min walk test or an increment of 1 step in New York Heart Association functional class. The left ventricular (LV) remodeling was defined as >15% decrease in left ventricular end-systolic volume (LVESV) at 12-month follow-up. Additionally, patients with LVESV reduction >30% relative to baseline were considered super-responders; by contrast, negative responders had increased LVESV relative to baseline.
Results Participant characteristics included a mean age of 65 ± 10 years, 68% male, 37% with ischemic cardiomyopathy, LV ejection fraction 26 ± 7%, and QRS 180 ± 22 ms. Baseline QRS was shortened significantly more by FOI, compared with nominal settings (−56.55 ± 17.65 ms vs. −37.81 ± 22.07 ms, respectively; p = 0.025). At 12 months, LV reverse remodeling was achieved in a larger proportion of the FOI group (74% vs. 53% [odds ratio: 2.02 (95% confidence interval: 1.08 to 3.76)], respectively; p = 0.026). No significant differences were observed in clinical response (61% vs. 53% [odds ratio: 1.43 (95% confidence interval: 0.79 to 2.59)], respectively; p = 0.24).
Conclusions Device optimization based on FOI achieves greater LV remodeling, compared with nominal settings. (ECG Optimization of CRT: Evaluation of Mid-Term Response [BEST]; NCT01439529)
Dr. Mont has received institutional research grants and lecture, consulting, and advisory board fees from Medtronic, Biotronik, Boston Scientific, Livanova, and Abbott. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
All authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received May 5, 2017.
- Revision received November 13, 2017.
- Accepted November 16, 2017.
- 2018 American College of Cardiology Foundation
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