Differential Clinical Outcome in Cardiac Resynchronization Therapy Via Surgically Implanted Epicardial Left Ventricular Leads in DCM and ICM Patients

Backgrounds: Surgically implanted epicardial left ventricular (eLV) lead has been used as an alternative approach when implantation of transvenous LV (tLV) lead in patients requiring cardiac resynchronization therapy (CRT) has failed. Recent literatures noted similarities in clinical response in CRT patient with eLV lead and tLV lead. However, comparison between CRT patients with ischemic (ICM) and dilated cardiomyopathy (DCM) is lacking in those with eLV lead. Methods: Of 1032 patients who underwent CRT implantation using tLV lead at UCSD and Mayo Clinics between May 2002 and August 2012, 38 (Age 64615, 24M) had failed tLV lead placement and received eLV leads for CRT. Electronic Medical Records of these patients were reviewed. NYHA class and echocardiograph were assessed before and after CRT implantation. Results: Following CRT implantation with eLV lead, improvements were noted in LVEF (26% vs. 31%, p ! 0.01), mean QRS duration (180ms vs. 166ms, p ! 0.01) and LVESD (58mm vs. 53mm, p 5 0.03). In patients with DCM (n515), the NYHA class (3.0 vs. 2.4, p5 0.01), LVEF (24.8% vs. 30.2%, p 5 0.02) and LVESD (58.7mm vs. 53.2mm, p 5 0.06) had significantly improved following CRT implantation compared to baseline. There were no statistically significant changes in NYHA class, LVEF and LVESD observed in patients with ICM (all p O 0.05). Conclusion: In this two-center study, eLV-CRT patients with DCM benefit significantly after CRT, as compared to patients with ICM. Although larger scaled studies are needed to confirm our result, eLV-CRT may be considered a viable alternative to tLV-CRT in patients with DCM.