Abstract 9904: Ability of Comprehensive Assessment of Strain Dyssynchrony Index by Speckle Tracking Imaging to Predict Long-Term Outcome After Cardiac Resynchronization Therapy in Patients with Heart Failure
Background: We previously reported that a combined assessment of radial, circumferential, and longitudinal strain dyssynchrony index (SDI) can further enhance the ability of the method to predict left ventricular reverse remodeling short-term after cardiac resynchronization therapy (CRT).
Hypothesis: SDI can predict long-term outcome after CRT in patients with heart failure (HF).
Methods: We studied 64 HF patients who underwent CRT. SDI was calculated as the average difference between peak and end-systolic strain from 6-segment for radial and circumferential SDIs and 18-segment for longitudinal SDI using two-dimensional speckle-tracking strain. On the basis of our previous observations, pre-defined cutoff for significant dyssynchrony and residual myocardial contractility was radial SDI ≥6.5%, circumferential SDI ≥3.2%, and longitudinal SDI ≥3.6%. The pre-defined principal outcome variable was the combined endpoint of death from worsening HF and re-hospitalization for deteriorating HF. Long-term follow-up after CRT was tracked over 3.5 years.
Results: The primary endpoint of a pre-specified clinical event occurred in 15 patients (23%). Patients with significant radial, circumferential, and longitudinal SDIs were associated with favorable long-term outcome after CRT (p<0.001, <0.005, and <0.01 vs. patients without significant SDIs, respectively). Furthermore, long-term outcome after CRT in patients with positivity 3 of 3 types of SDIs was better than that in patients with positivity either 1 or none of 3SDIs (p<0.005 and <0.001). Cardiovascular event-free rate in patients with positivity 3 of 3 SDIs was also higher than that in patients with positivity none of 3SDIs (100% vs. 30%, p<0.001).
Conclusions: SDIs can successfully predict long-term outcome after CRT in HF patients. Moreover, the combined approach leads to more accurate prediction than using individual parameters, and these observations may have clinical implications in CRT patients.
- © 2011 by American Heart Association, Inc.