Abstract 12369: The Degree of Baseline Radial Dyssynchrony Predicts Long-Term Survival Following Cardiac Resynchronization Therapy
Introduction: The significance of echocardiographic dyssynchrony in patients undergoing cardiac resynchronization therapy (CRT) is unclear.
Methods: To test the hypothesis that the degree of radial dyssynchrony by speckle tracking strain predicts outcome following CRT, 207 consecutive patients were studied. All had ejection fraction (EF) ≤ 35%, QRS ≥ 120ms, and NHYA class III–IV. Their age was 65±12years, 31% female, QRS duration 159±26ms, EF 24±6%, and ischemic etiology 67%. Speckle tracking was performed at the mid-ventricular level with dyssynchrony defined as the time between anteroseptal to posterior wall peak radial strain. Long term unfavorable events were pre-specified as: death, transplant or ventricular assist device (VAD).
Results: Radial speckle tracking was feasible in 195 patients (94%). Using a predefined 130 ms cut-off for radial dyssynchrony, there were 147 patients (71%) that had radial dyssynchrony with an average value of 218±112ms. Patients with and without dyssynchrony had similar baseline characteristics, except QRS duration was longer in patients with dyssynchrony (161±26 vs 151±21 ms p= 0.03) Ischemic etiology was more common in patients without dyssynchrony (73% vs 52%, p-value= 0.02). There were a total of 65 events over 4 years: 50 deaths, 10 transplants, and 5 VADs. A receiver operator curve was generated to determine the ability of radial dyssynchrony to predict survival with a cutoff value of ≥200ms (AUC= 0.645 sensitivity= 65% specificity= 66% p-value= 0.0005). Patients with a radial dyssynchrony value of >200ms (n=104) had a significantly more favorable event-free survival than patients with radial dyssynchrony value between 130–200ms (n=42), or those without dyssynchrony <130ms (n=47).
Conclusions: A greater degree of radial dyssynchrony was associated with more favorable event-free survival after CRT compared with patients who had less or no dyssynchrony. These observations may have clinical implications.
- © 2010 by American Heart Association, Inc.