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

Abstract Objectives This study hypothesized that guided implants, in which the optimal left ventricular endocardial (LV ENDO ) pacing location was identified and targeted, would improve acute markers of contractility and chronic markers of cardiac resynchronization (CRT) response. Background Biventricular endocardial (BiV ENDO ) pacing may offer a potential benefit over standard CRT; however, the optimal LV ENDO pacing site is highly variable. Indiscriminately delivered BiV ENDO pacing is associated with a reverse remodeling response rate of between 40% and 60%. Methods Registry of centers implanting a wireless, LV ENDO 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 LV ENDO 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 BiV ENDO . 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.