Investigation of a novel algorithm for synchronized left-ventricular pacing and ambulatory optimization of cardiac resynchronization therapy: Results of the adaptive CRT trial

Rationale and design of the AdaptResponse trial: a prospective randomized study of cardiac resynchronization therapy with preferential adaptive left ventricular‐only pacing

“…A total of 1100 patients experiencing a primary endpoint will generate 90% statistical power to demonstrate a significant reduction in the incidence of the primary endpoint, accounting for three equally spaced interim analyses (α = 0.05) and assuming a true intent‐to‐treat hazard ratio (HR) of 0.82 for ‘AdaptivCRT’ compared with ‘Conventional CRT’. With randomization of 3000 patients enrolled over 3 years and followed for 2.5 years, 1100 events are expected when the true control arm event‐free rate is 75% at 2 years (which is consistent with results from MADIT‐CRT,26 REVERSE,27 RAFT,28 Cleland's CRT meta‐analysis,29 and the adaptive CRT study18, 19). …”

“…The AdaptivCRT pre‐market approval study has demonstrated that AdaptivCRT‐optimized CRT is at least as effective as echo‐optimized BiV pacing determined by the CCS24 (73.6% improved in the AdaptivCRT arm vs. 72.5% in the echo‐optimized arm, P < 0.001 for non‐inferiority with a non‐inferiority margin of 12%18). Furthermore, in a post hoc sub‐analysis of this study, in patients with sinus rhythm, device‐determined normal AV conduction and presence of LBBB per medical history, more AdaptivCRT patients improved in their CCS compared with the echo arm (80.7% vs. 68.4%, P = 0.041 for superiority) 19.…”

“…to produce fusion of left‐ and right‐sided ventricular activation) when intrinsic AV conduction is normal or, alternatively, BiV pacing, when required. Preliminary studies have suggested that AdaptivCRT‐optimized resynchronization therapy results in improved clinical outcomes 18, 19, 20…”

2013 ESC Guidelines on Cardiac Pacing and Cardiac Resynchronization Therapy

“…Un pequeño estudio aleatorizado y algunas series de observación han mostrado mejorías significativas de los síntomas de IC y hospitalizaciones por IC después de optimizar los retrasos AV o VV 74,75,w134-w143 , sobre todo en pacientes con IC isquémi-ca w144 . Estos hallazgos no se confirmaron con los resultados de estudios multicéntricos más amplios [76][77][78][79][80][81][82][83] , lo que indica que optimizar sistemáticamente el retraso VV y AV tiene poco efecto en los resultados clínicos o ecocardiográficos obtenidos por quienes reciben TRC, en comparación con un retraso AV fijo de 100-120 ms y estimulación cardiaca biventricular (VD y VI) simultánea (tabla web 12). La selección del paciente, los tiempos del procedimiento y la metodología empleada (algoritmos de dispositivo, ECG o ecocardiografía) no fueron homogéneos entre todos los estudios, lo que impide obtener conclusiones firmes.…”

“…web 9). Se han propuesto varios métodos para optimizar el retraso AV y VV (tabla 13) [74][75][76][77][78][79][80][81][82][83] . Estos métodos pueden clasificarse en dos grupos principales: métodos basados en la ecocardiografía y no basados en la ecocardiografía.…”