Guidance for Optimal Site Selection of a Leadless Left Ventricular Endocardial Electrode Improves Acute Hemodynamic Response and Chronic Remodeling.

OBJECTIVES: This study hypothesized that guided implants, in which the optimal left ventricular endocardial (LVENDO) pacing location was identified and targeted, would improve acute markers of contractility and chronic markers of cardiac resynchronization (CRT) response. BACKGROUND: Biventricular endocardial (BiVENDO) pacing may offer a potential benefit over standard CRT; however, the optimal LVENDO pacing site is highly variable. Indiscriminately delivered BiVENDO pacing is associated with a reverse remodeling response rate of between 40% and 60%. METHODS: Registry of centers implanting a wireless, LVENDO pacing system (WiSE-CRT System, EBR Systems, Sunnyvale, California); John Radcliffe Hospital (Oxford, United Kingdom), Guy's and St. Thomas' Hospital (London, United Kingdom), and The James Cook University Hospital (Middlesbrough, United Kingdom). Centers used a combination of preprocedural imaging and electroanatomical mapping the identify the optimal LVENDO site. RESULTS: A total of 26 patients across the 3 centers underwent a guided implant. Patients were predominantly male with a mean age of 68.8 ± 8.4 years, the mean LV ejection fraction was 34.2 ± 7.8%. The mean QRS duration was 163.8 ± 26.7 ms, and 30.8% of patients had an ischemic etiology. It proved technically feasible to selectively target and deploy the pacing electrode in a chosen endocardial segment in almost all cases, with a similar complication rate to that observed during indiscriminate BiVENDO. Ninety percent of patients met the definition of echocardiographic responder. Reverse remodeling was observed in 71%. CONCLUSIONS: Guided endocardial implants were associated with a higher degree of chronic LV remodeling compared with historical nonguided approaches.