Abstract 12407: Three Dimensional and Doppler Echocardiographic Parameters Predict Response to Cardiac Resynchronization Therapy
Background: The evaluation of predictive parameters for response to cardiac resynchronization therapy (CRT) is the focus of several studies. Nevertheless, the exact reasons for lack of response are still unclear. The aim of this study was to evaluate the prognostic parameters of response to CRT.
Methods: 77 patients (male: 57, 41-83 years) with indication for CRT have been included. 3 dimensional Echocardiography (3DE) full-volume datasets of the left ventricle (LV) were obtained and analyzed to derive a systolic dyssynchrony index (SDI), calculated from the dispersion of time to minimal regional volume for all 16 LV segments. Moreover, doppler echocardiography (DE) was performed to calculate LV-RV-PEP-Delta, the difference of left and right ventricular pre-ejection periods, a parameter of inter-ventricular dyssynchrony. Echocardiography was performed in all patients for the evaluation of LV dimensions, ejection fraction (EF), SDI, LV-RV-PEP-Delta and NYHA class obtained before CRT and three months after biventricular pacemaker implantation and optimization of atrio-ventricular and ventricular-to-ventricular intervals. Patients with a reduction of at least one NYHA class were considered responders.
Results: In a logistic regression analysis enddiastolic and endsystolic volumes and LV-RV-PEP-Delta were predictive of clinical response (OR 0.992, p= 0.027, OR 0.990, p=0.028 and OR 2,800, p=0.025 respectively). Unexpectedly, baseline SDI was not predictive of response in these patients that received CRT optimization after implantation. Moreover, the cause of cardiomyopathy, QRS width, baseline EF and LV lead position were not predictive of response.
Conclusions: LV-RV-PEP-Delta, a simple parameter of interventricular dyssynchrony, was predictive of response to CRT and may be valuable in the selection process of patients for CRT, irrespective of QRS duration. Moreover, baseline EDV and ESV were predictive of response to CRT. This should be considered when selecting patients for CRT, as once a certain degree of adverse mechanical remodeling has occurred, electrical resynchronization may no longer be able to reverse this process.
- © 2012 by American Heart Association, Inc.