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.