Abstract 14116: Myocardial Viability and Left Ventricular Lead location as Predictors of Ventricular Arrhythmias in Cardiac Resynchronization Therapy (CRT) Recipients With Ischemic Cardiomyopathy
Background: Although left ventricular (LV) lead concordance to scar is associated with a poor response to cardiac resynchronization therapy (CRT), the impact of LV lead concordance to scar or ischemia as a predictor of incident device treated ventricular arrhythmia (VA) remains unclear.
Methods: We analyzed 121 patients with ischemic cardiomyopathy undergoing CRT. The anatomical location of the LV lead was assessed by coronary venography and chest-x-rays. Concordance of the LV lead to the zone of ischemia or scar on the 17-segment nuclear sestamibi scan was established in a blinded manner. The primary endpoint was time until first appropriately treated VA with a 3-year censor. Echocardiographic response was evaluated at baseline and 6 months.
Results: We divided 121 patients (age 71.2 ± 12.2 years; baseline LVEF 24.6 ± 6.9 %, NYHA 2.9 ± 0.4) into 3 groups based on concordance of LV lead to scar and ischemia (SI, n=19), normal myocardium (NM, n=50) and scar (SC, n=52). Baseline characteristics and the summed differential score (SDS) were similar between the groups except for the higher summed rest scores (SRS) and summed stress scores (SSS) in the SC group. On Kaplan-Meier analysis time to first VA was significant in the SI group (Figure 1, p=0.04). Echocardiographic response was similar across all groups. On multivariate Cox regression presence of LV lead on SI was an independent predictor of VA (adjusted HR 2.86, 95% CI: 1.14-7.19, p=0.02).
Conclusion: Pacing on an area of scar and ischemia is associated with a higher incidence of device treated ventricular arrhythmias compared to LV leads concordant to normal myocardium or scar. These results suggest that knowledge of the distribution of myocardial scar and ischemia may be important for optimal selection of LV lead location.
- © 2013 by American Heart Association, Inc.