Presentation on theme: "Primary Results from the SMART AV DELAY Trial: A Randomized Trial Comparing Empiric, Echocardiographic Guided and Algorithmic AV Delay Programming in Cardiac."— Presentation transcript:
Primary Results from the SMART AV DELAY Trial: A Randomized Trial Comparing Empiric, Echocardiographic Guided and Algorithmic AV Delay Programming in Cardiac Resynchronization Therapy (CRT) Kenneth A. Ellenbogen, MD, Michael R. Gold, PhD, MD, Bernd Lemke, MD, Ignacio F. Lozano, MD, Timothy E. Meyer, PhD, Suneet Mittal, MD, Jagmeet P. Singh, MD, Frank G. Spinale, PhD, MD, Kenneth M. Stein, MD, Jennifer E. Van Eyk, PhD, Alan D. Waggoner, MHS for The SMART-AV Trial Investigators.
Presenter Disclosure Information Kenneth A. Ellenbogen, MD Primary Results from the SMART AV DELAY Trial (Boston Scientific) FINANCIAL DISCLOSURE: Research Grants: Boston Scientific, Medtronic, St. Jude Medical, Biosense Webster, Sanofi Consulting / Advisory board: Boston Scientific, Biotronik, Medtronic, St. Jude Medical, Sorin Group, Sanofi, Cardionet, Atricare, EBR Lectures: Boston Scientific, Biotronik, Medtronic, St. Jude Medical, Sorin Group, Sanofi Stock Options: None; Salary Support: None; Speaker Bureau: None UNLABELED/UNAPPROVED USES DISCLOSURE: None All devices used in the SMART-AV trial were Boston Scientific
SMART-AV (Background) In patients with heart failure and prolonged QRS duration, cardiac resynchronization therapy (CRT) reduces heart failure hospitalizations and prolongs survival compared with optimal medical therapy (OMT). Achieving the optimal outcome from CRT may be dependent on proper programming of the optimal atrioventricular (AV) delay. However, large scale randomized trials establishing the overall efficacy of CRT have differed widely in their approach to AV optimization. CONTAK CD – No optimization CARE-HF and MIRACLE – Doppler echocardiography of transmitral flow COMPANION – algorithm based on the intrinsic AV interval and baseline QRS The ASE proposed a mitral inflow method for routine AV optimization after CRT.
Objectives To compare three alternative AV optimization techniques and to assess the hypotheses that: 1) systematic AV delay optimization using echocardiography and/or the SD algorithm is superior to a fixed nominal AV delay as demonstrated by improved LV geometry after 6 months and 2) that programming according to SD is non-inferior to using echocardiography-determined AV delay optimization.
Methods SMART-AV Inclusion NYHA class III or IV EF < 0.35 QRS >120ms Expected to be in sinus rhythm at the time of implant Willing and capable of undergoing a device implant and participating in all testing Receiving OPT SMART-AV Exclusion Complete heart block or unable to tolerate pacing at VVI-40-RV for up to 14 days Previously received CRT Primary Endpoint: LVESV at 6 months Secondary Endpoints: 6 min walk, EF, NYHA Class, LVEDV, QOL (MLWHF) Statistics: Continuous outcomes: general linear model - F test Categorical outcomes: risk difference of proportions – Chi- squared test Applicable to primary, secondary and subgroup analyses
SMART-AV – Study Design Enrollment and Implant CRT-D with SmartDelay Program device to VVI-40-RV Enrollment and Implant CRT-D with SmartDelay Program device to VVI-40-RV Post-Implant Visit (1 to 14 days post-implant) (1:1:1 Randomization, Programmed to DDD(R)60) Post-Implant Visit (1 to 14 days post-implant) (1:1:1 Randomization, Programmed to DDD(R)60) Echo (Iterative) SmartDelay Fixed (120/0) 3- month Visit 6- month Visit 3- month Visit 6- month Visit 3- month Visit Stein KM, et al. Pacing Clin Electrophysiol. 2010;33(1):54-63
Baseline Patient Characteristics Characteristics SD (n=332) Echo (n=323) Fixed (n=326) p-value Age (yrs) 66 ± 11 ns Gender (% male) 71% 68%65%ns Resting heart rate (bpm)71 ± 1272 ± 1371 ± 13ns Ejection fraction (%)25 ± 724 ± 725 ± 7ns QRS duration (ms)152 ± 21153 ± 20 ns History of ventricular fibrillation 2%1%2%ns History of paroxysmal atrial fibrillation11% 14%ns LBBB/RBBB/IVCD (%)79/11/972/16/1079/11/9ns Ischemic cardiomyopathy57% 56%ns NYHA FC II/III/IV heart failure4/92/4%2/96/2%2/95/3%ns mean ± SD Continuous variables are expressed as mean ± SD
SMART-AV – Patient Flow Implanted n=1014 Implanted n=1014 Randomized n=980 Randomized n=980 Fixed (120/0) n=325 Fixed (120/0) n=325 SmartDelay n=332 SmartDelay n=332 Withdrawn, LTFU or Missing data n=49 Withdrawn, LTFU or Missing data n=49 Evaluable Data n=283 (85%) Evaluable Data n=283 (85%) Echo (Iterative) n=323 Echo (Iterative) n=323 Withdrawn, LTFU or Missing data n=41 Withdrawn, LTFU or Missing data n=41 Evaluable Data n=282 (87%) Evaluable Data n=282 (87%) Withdrawn, LTFU or Missing data n=44 Withdrawn, LTFU or Missing data n=44 Evaluable Data n=281 (86%) Evaluable Data n=281 (86%) Enrolled n=1060 Enrolled n=1060
Summary & Conclusion The change in LVESV for the SD arm was no different than either the Echo or Fixed arms. There were no significant differences in the secondary structural or functional endpoints by optimization group. Patients with a wide QRS duration, LBBB, non-ischemic cardiomyopathy, and female gender responded more favorably to CRT therapy. In post-hoc analysis, females optimized with SD and Echo responded more favorably than females randomized to the Fixed arm. The routine use of AV optimization techniques as assessed in this trial is not warranted. However, this data does not exclude possible utility in selected patients who do not respond to CRT.