Value of left ventricle mechanical dyssynchrony and scar burden in
combined assessment of factors associated with cardiac resynchronization
therapy response
Abstract
Introduction: The cardiac resynchronization therapy (CRT)
improves outcome in patients with heart failure (HF). However
approximately 30% of patients are non-responsive to CRT. The purpose of
this study was to investigate the role of the left ventricle (LV)
mechanical dyssynchrony (MD) and scar burden assessment as predictors of
CRT response. Methods: We included in the study 56 sinus rhythm
patients (male 35 [62.5 %], mean age 57.0 ± 11.5 years) with
ischemic or nonischemic HF, and left bundle branch block with QRS
duration ≥ 150 ms who underwent CRT-D implantation. Echocardiography,
full physical examination, myocardial perfusion imaging (MPI) with
99mTc-methoxy-isobutyl-isonitrile and gated blood pool
single-photon emission computed tomography (gBPS) were performed at
baseline and at 6-month follow-up. Patients were grouped based on the
response to CRT assessed by echocardiography. Results:
Forty-five patients (80.3 %) were responder (RESP) and 11 (19.7 %)
were non-responder (non-RESP) to CRT. RESP patients had higher LV
anterior wall standard deviation (LV AW_SD) (p=0.0001) and lower summed
rest score (SRS) (p=0.018) than non-RESP subjects. In multivariate
logistic regression, LV AW_SD (adjusted odds ratio [OR] 1.5275;
95% confidence interval [CI] 1.1472-2.0340; p=0.0037), SRS (OR
0.7299; 95% CI 0.5627-0.9469; p=0.0178) and HF non-ischemic etiology
(OR 20.1425; 95% CI 1.2719-318.9961; p=0.0331) were independent
predictors of CRT response. Conclusion: Ventricle dyssynchrony
and scar burden assessed by cardiac gBPS and MPI are associated with
response to CRT. Further investigations of their predictive significance
are warranted.