Study design
Between April 2012 and March 2019, we included 708 patients with HFrEF
who received a WCD (ZOLL Life Vest ™system, Pittsburgh, USA) at the
University Medical Centre in Mannheim, Heidelberg University, Department
of Cardiology, University Hospital Frankfurt, Department of Arrhythmias
& Invasive Cardiology, St. Georg Hospital Leipzig, and Department of
Cardiology, University Hospital of Zurich. This multicenter register is
designed as a retrospective cohort registry without any financial
support. Patients were treated according to the current European
guidelines for heart failure [11].
We divided the collective according to gender (male=579; female=129).
Furthermore, all patients were divided into age quartiles for analysis:
161 patients in 14-51 years old group, 375 patients in 52-72 years old
group, and 172 patients in 73-91 years old group. Baseline
characteristics such as indications for WCD use were gathered. Wear time
of WCD and WCD shocks during WCD use were documented. Echocardiographic
assessments were collected. The death rate due to a cardiovascular cause
during a 2-year-follow-up was evaluated. These data were assessed by
chart and/or telephone review at mean 2-year-follow-up. LVEF
> 35% led to stop WCD wearing and was recorded as an
improvement of the LVEF.
LVEF was calculated by using biplane Simpson’s method, using
echocardiography and/or cardiac MRI. This study was executed in
compliance with the fifth revision of the Declaration of Helsinki
regarding investigations in human subjects and the study protocol was
approved by the Ethics Committee in all involved centers [12].