Prediction of response to cardiac resynchronization therapy using simple electrocardiographic and echocardiographic tools.
OBJECTIVE
To predict response to cardiac resynchronization therapy (CRT) in patients with heart failure (HF) and intraventricular conduction delay.


RESULTS
The study population consisted of 82 consecutive HF patients with standard CRT indications. Patients were classified as responders, if they were alive without cardiac decompensation and experienced >or=15% decrease in left ventricular end-systolic volume. Sixty-eight percent of the enrolled patients responded to CRT. When compared with non-responders, responders had a wider baseline QRS width (P = 0.001), more marked QRS shortening (DeltaQRS) immediately after CRT (P = 0.001), and a better improvement in aortic velocity time integral (VTI) 24 h after CRT (P = 0.02). Moreover, there was a trend towards a greater baseline intraventricular dyssynchrony in the responder group (P = 0.07). By multivariable logistic regression, the baseline QRS width (OR: 0.95, 95% CI: 0.90-0.97, P = 0.001), DeltaQRS (OR: 1.038, 95% CI: 1.012-1.064, P = 0.003), and acute aortic VTI (OR: 0.81, 95% CI: 0.68-0.96, P = 0.017) emerged as independent predictors of response to CRT. Receiver operating characteristic curve analysis identified a QRS width >145 ms, DeltaQRS >20 ms, and aortic VTI >14 cm to predict responders.


CONCLUSIONS
A positive response to CRT was observed in 68% of the patients. Cardiac resynchronization therapy response is predictable using simple electrocardiographic and echocardiographic data.
1Department of Pacemaker and Electrophysiology, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Mellat Park, Vali-E-Asr Avenue, PO Box 15745-1341, Tehran 1996911151, Iran.
Hamid Reza
HR
Bonakdar
Mohammad Vahid
MV
Jorat
Amir Farjam
AF
Fazelifar
Abolfath
A
Alizadeh
Nozar
N
Givtaj
Niloofar
N
Sameie
Anita
A
Sadeghpour
Majid
M
Haghjoo
D002304:Cardiac Pacing, Artificial / Q000379:methods*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004452:Echocardiography / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000175:diagnosis* / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods*; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome