Abstract 13431: Global Longitudinal Strain Combined With Radial Strain Delay Before Cardiac Resynchronization Therapy is Associated With Long Term Survival
Introduction: Identifying factors related to nonresponse in cardiac resynchronization therapy (CRT) remains clinically important. The interaction of factors of global longitudinal strain (GLS), as an associated marker of scar burden, and radial strain delay, as a mechanical dyssynchony marker remains unclear.
Hypothesis: Our aim was to test the hypothesis that GLS by speckle tracking echocardiography (STE) combined with positive radial strain delay have prognostic utility in CRT patients.
Methods: We studied 128 heart failure patients with routine CRT indications according to current clinical guidelines (ischemic 68%, age 64.9 ± 11.7 years, QRS width 159.3 ± 29.5 ms, left ventricular (LV) ejection fraction (EF) 23.9 ± 5.4%). GLS was determined with speckle tracking as the average of the segmental values from routine 2D apical views. Baseline radial strain delay was assessed by speckle tracking radial strain with positive (+) pre-defined as anteroseptal to posterior wall delay ≥130 ms. Response was defined as an increase in LV end-systolic volume (ESV) ≥15% at 6-months follow up. Pre-specified outcome events were death, heart transplant or LV assist device (LVAD) over 4 years. We evaluated long term survival in four subgroups which were defined based on GLS cut-off value and radial strain delay.
Results: Responders had GLS values indicative of lower scar burden compared to non-responders (GLS -9.8 ± 3.1% vs. -7.9 ± 2.4%, p = 0.0003), as well as a higher prevalence of baseline radial strain delay (78% vs. 58%, p<0.0001). There were 57 events during a 4 years follow-up period: 42 deaths, 8 transplants and 7 LVADs. When subgroups were analyzed, patients with + GLS (≤ -9%) and + radial strain delay had a more favorable outcome than any other group (p=0.01).
Conclusion: Quantification of baseline GLS by speckle tracking echocardiography combined with radial strain delay assessment provided important long term prognostic information in patients undergoing CRT.
Author Disclosures: A. Delgado-Montero: None. B. Tayal: None. K. Ryo: None. A. Goda: None. D. Schwartzman: Research Grant; Modest; Medtronic, Boston Scientific. S. Saba: Research Grant; Modest; Medtronic, Boston Scientific, St Jude. J. Gorcsan: Research Grant; Modest; Biotronik, GE, Toshiba, Medtronic, St Jude Medical.
- © 2014 by American Heart Association, Inc.