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SmartDelay Determined AV Optimization: A Comparison of AV Delay Methods Used in Cardiac Resynchronization Therapy (SMART‐AV): Rationale and Design
Author(s) -
STEIN KENNETH M.,
ELLENBOGEN KENNETH A.,
GOLD MICHAEL R.,
LEMKE BERND,
LOZANO IGNACIO FERNÁNDEZ,
MITTAL SUNEET,
SPINALE FRANCIS G.,
VAN EYK JENNIFER E.,
WAGGONER ALAN D.,
MEYER TIMOTHY E.
Publication year - 2010
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.2009.02581.x
Subject(s) - medicine , cardiac resynchronization therapy , cardiology , heart failure , randomized controlled trial , clinical endpoint , surrogate endpoint , ejection fraction
Background:The clinical benefit of cardiac resynchronization therapy (CRT) for patients with moderate‐to‐severely symptomatic heart failure, left ventricular systolic dysfunction, and ventricular conduction delay is established. However, some patients do not demonstrate clinical improvement following CRT. It is unclear whether systematic optimization of the programmed atrioventricular (AV) delay improves the rate of clinical response.Methods:SMART‐AV is a randomized, multicenter, double‐blinded, three‐armed trial that will investigate the effects of optimizing AV delay timing in heart failure patients receiving CRT + defibrillator (CRT‐D) therapy. A minimum of 950 patients will be randomized in a 1:1:1 ratio using randomly permuted blocks within each center programmed to either DDD or DDDR with a lower rate of 60. The study will include echocardiographic measurements of volumes and function [e.g., left ventricular end‐systolic volume (LVESV)], biochemical measurements of plasma biomarker profiles, and functional measurements (e.g., 6‐minute hall walk) in CRT‐D patients who are enrolled and randomized to fixed AV delay (i.e., 120 ms), AV delay determined by electrogram‐based SmartDelay, or an AV delay determined by echocardiography (i.e., mitral inflow). Patients will be evaluated prior to initiation of CRT, 3 and 6 months post‐implant. The primary endpoint is the relative change in LVESV at 6 months between the groups. Patient enrollment commenced in May 2008 and the study is registered at clinicaltrials.gov.Conclusion:SMART‐AV is a randomized, clinical trial designed to evaluate three different methods of AV delay optimization to determine whether systematic AV optimization is beneficial for patients receiving CRT for 6 months post‐implant. (PACE 2010; 54–63)