Abstract 12135: Acute Reduction in Strain Dyssynchrony Index with Cardiac Resynchronization Therapy Predicts Mid-Term Left Ventricular Reverse-remodeling and Long-Term Outcome: Using Two-dimensional Speckle-tracking Study
Background: We previously reported 2-dimensional speckle-tracking strain dyssynchrony index (SDI), which was a marker of both dyssynchrony and residual myocardial contractility, can predict response to cardiac resynchronization therapy (CRT). Our objective was to test the hypothesis that acute reduction in SDI after CRT can predict mid-term left ventricular (LV) reverse remodeling and long-term outcome.
Methods: We studied 75 CRT patients. Radial SDI was calculated as the average difference between peak and end-systolic speckle-tracking strain from 6-segment using mid-LV short-axis view before and 1-week after CRT. Mid-term responder was defined as ≥15% decrease in LV end-systolic volume 6-month after CRT. Long-term outcome events were pre-specified as death or hospitalization due to deteriorating heart failure and tracked over 5 years.
Results: Acute reduction of SDI in responder (n=49) was larger than that in non-responder (n=26) (p<0.001). Acute reductions in SDI ≥1.5% predicted mid-term responders (p<0.001, AUC=0.91). Mid-term response rate in patients with acute reduction in SDI≥1.5% were higher than that in patients with acute reductions in SDI<1.5% (82% vs. 25%, p<0.001). Moreover, acute reduction in SDI correlated with reduction of LV end-systolic volume at 6-month (r=0.69, p<0.001). The primary endpoint of pre-specified cardiac events occurred in 15 patients (20%). Importantly, patients with acute reductions in SDI ≥1.5% were associated with favorable long-term outcome after CRT than those with acute reductions in SDI<1.5% (event-free rate 86% vs.44%, p<0.001). Furthermore, there were 13 patients with acute increases in SDI, and this group had the lowest event-free rate (34%), and 92% of them were mid-term non-responders.
Conclusions: The acute changes in SDI after CRT was associated with mid-term LV reverse remodeling and long-term outcome. This approach may have clinical implications for predicting ‘true’ responders and patient’s care.
- © 2012 by American Heart Association, Inc.