Fu, Haixia

Introduction: Surgically implanted epicardial left ventricular (eLV) lead is an alternative approach when transvenous LV (tLV) lead implantation in CRT patients has failed. With advancement in surgical technique and free from limitations of cardiac venous anatomy, operators have the freedom to choose the most optimal LV pacing site. Recent literatures noted differential clinical response in tLV-CRT patients with different LV lead locations. However, to the best of the authors’ knowledge, no such analysis has been published for eLV-CRT patients. Hypothesis: We hypothesize that optimal LV lead location in eLV-CRT is similar to tLV-CRT and similar clinical response is expected. Methods: After unsuccessful attempt(s) of tLV-CRT implantation, 44 (Age 63±15, 28M) patients received eLV-CRT from UCSD and Mayo Clinics between 2002 and 2013. Two-view (PA, lateral) chest radiographs were used to determine lead location by blinded independent observers. 9 patients were partially excluded from lead location analysis due to congenital cardiac anomaly or unavailable lateral chest radiograph. eLV lead locations were classified as basal, mid, or apical on the PA view; and anterior, anterolateral, lateral, posterolateral, or posterior on the lateral view. Survival data were collected from the national death and location database. Results: During an average follow up of 65 months, 15 patients have died following eLV-CRT implant. No death was attributed to acute surgical complication to eLV-CRT implantation. Kaplan-Meyer survival estimate showed anterior and apical eLV lead positions had lower survival rate as compared to non-anterior (p<0.01, figure A) and non-apical location (p=0.07, figure B). Conclusion: In this two-center study, apical and anterior eLV lead locations were associated with significantly lower survival rate. The study implies apical and/or anterior locations should be avoided, if possible, during eLV-CRT implantation.