Primary and Secondary Outcome
The primary outcome that we assessed was the development of PICM. Given the absence of an agreed-upon definition of PICM, we analyzed the incidence of PICM using two separate definitions: 1.) LVEF decrease of ≥10% and 2) ≥10% decrease in LVEF to an LVEF of <50%. The first definition commonly reports the highest incidence, and the second is the most referenced in the literature [3]. As a secondary outcome, we also assessed for worsening of tricuspid regurgitation based on echocardiographic data. When tricuspid regurgitation was present, the severity was reported from mild to severe, consistent with American Society of Echocardiography guidelines. Other secondary outcomes assessed were the effect of device implantation location on the LVEF and the effect of device implantation on QRS duration.