Absence of baseline echocardiographic dyssynchrony was associated with significantly less favorable event-free survival after cardiac resynchronization therapy, especially with QRS 120-150 ms (P=0.002).
Cohort (n=229)
Does the presence of baseline echocardiographic dyssynchrony predict improved long-term event-free survival in heart failure patients undergoing cardiac resynchronization therapy?
The presence of baseline echocardiographic dyssynchrony, particularly measured by radial strain and Yu Index, independently predicts better long-term event-free survival in heart failure patients receiving CRT.
p-value: p=0.003
BACKGROUND: The ability of echocardiographic dyssynchrony to predict response to cardiac resynchronization therapy (CRT) has been unclear. METHODS AND RESULTS: A prospective, longitudinal study was designed with predefined dyssynchrony indexes and outcome variables to test the hypothesis that baseline dyssynchrony is associated with long-term survival after CRT. We studied 229 consecutive class III to IV heart failure patients with ejection fraction ≤35 and QRS duration ≥120 milliseconds for CRT. Dyssynchrony before CRT was defined as tissue Doppler velocity opposing-wall delay ≥65 milliseconds, 12-site SD (Yu Index) ≥32 milliseconds, speckle tracking radial strain anteroseptal-to-posterior wall delay ≥130 milliseconds, or pulsed Doppler interventricular mechanical delay ≥40 milliseconds. Outcome was defined as freedom from death, heart transplantation, or left ventricular assist device implantation. Of 210 patients (89) with dyssynchrony data available, there were 62 events: 47 deaths, 9 transplantations, and 6 left ventricular assist device implantations over 4 years. Event-free survival was associated with Yu Index (P=0.003), speckle tracking radial strain (P=0.003), and interventricular mechanical delay (P=0.019). When adjusted for confounding baseline variables of ischemic origin and QRS duration, Yu Index and radial strain dyssynchrony remained independently associated with outcome (P<0.05). Lack of radial dyssynchrony was particularly associated with unfavorable outcome in those with QRS duration of 120 to 150 milliseconds (P=0.002). CONCLUSIONS: The absence of echocardiographic dyssynchrony was associated with significantly less favorable event-free survival after CRT. Patients with narrower QRS duration who lacked dyssynchrony had the least favorable long-term outcome. These observations support the relationship of dyssynchrony and CRT response.
Gorcsan et al. (Tue,) conducted a cohort in Class III to IV heart failure (n=229). Echocardiographic dyssynchrony assessment vs. Absence of echocardiographic dyssynchrony was evaluated on Freedom from death, heart transplantation, or left ventricular assist device implantation (p=0.003). Absence of baseline echocardiographic dyssynchrony was associated with significantly less favorable event-free survival after cardiac resynchronization therapy, especially with QRS 120-150 ms (P=0.002).