Echocardiographic Predictors of Long-Term Survival in Patients Undergoing Cardiac Resynchronization Therapy: What Is the Optimal Metric?
BACKGROUND
Multiple definitions of reverse ventricular remodeling (RVR) employing various changes in left ventricular end-systolic (LVESV) or diastolic volumes (LVEDVs) or left ventricular ejection fraction (LVEF) have been used in determining cardiac resynchronization therapy (CRT) response, making comparability across studies difficult. We compared different metrics to each other, and in combination, in terms of association with long-term outcomes.


METHODS
We collected clinical and echocardiographic data on 436 patients undergoing CRT. LVEF was assessed via a combined volumetric and visual assessment. Volumes were manually traced. Using a nested multivariate model of a priori determined predictors of long-term survival free of left ventricular assist device (LVAD) or heart transplant, multiple definitions of RVR were added to the model individually to determine which provided the best model fit.


RESULTS
Over a mean follow-up of 5.4 ± 2.3 years, there were 198 endpoints (10 LVADs, 15 heart transplants, and 173 deaths). When added to a nested model controlling for multiple potential confounders, all definitions of RVR were significantly associated with improved survival. Changes in LVEF and LVESV were superior to changes in LVEDV. A combination metric of an LVEF improvement ≥ 5% and LVESV reduction ≥ 10% was the best overall metric for model fit.


CONCLUSIONS
Changes in LVESV and LVEF are better predictors of long-term outcome following CRT compared to changes in LVEDV. Adding an assessment of LVEF to reduction in LVESV ≥ 10% provided the best overall definition for RVR in predicting CRT outcomes.
Division of Cardiology, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA.
John
J
Rickard
Division of Cardiology, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA.
Bryan
B
Baranowski
Division of Cardiology, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA.
W H
WH
Wilson Tang
Division of Cardiology, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA.
Richard A
RA
Grimm
Division of Cardiology, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA.
Mark
M
Niebauer
Division of Cardiology, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA.
Daniel
D
Cantillion
Division of Cardiology, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA.
Bruce L
BL
Wilkoff
Division of Cardiology, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio, USA.
Niraj
N
Varma
D000368:Aged; D001145:Arrhythmias, Cardiac / Q000000981:diagnostic imaging* / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D058406:Cardiac Resynchronization Therapy / Q000009:adverse effects / Q000401:mortality; D018572:Disease-Free Survival; D004452:Echocardiography / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D020127:Recovery of Function; D012189:Retrospective Studies; D012307:Risk Factors; D013318:Stroke Volume; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling
clinical: implantable devices--biventricular pacing/defibrillator