Introduction
Patients with bradyarrhythmias undergo ≈1 million de novo pacemaker
implantations annually worldwide.1Since the first
pacemaker implantations almost 60 years ago, permanent cardiac pacemaker
therapy has evolved remarkably, becoming a minimally invasive treatment,
improving the quality of life and reducing the mortality.1-3 Device implantations are now indicated not only
for young and middle-aged individuals who need to maintain physical
activity, but also for elderly patients and those with a reduced
physical function. There is wide recognition that the FC in patients
with various cardiovascular diseases is an important risk factor for
worsening heart failure and an increased risk of mortality,4, 5 however, there are limited data on whether
pacemaker implantations improve the FC, and whether changes in the FC
affect the outcomes.
In Japan, there is a system that exempts patients with serious diseases
from medical expenses as handicapped disabled patients. In the case of
patients with an initial pacemaker implant, the handicapped disability
levels can be divided into three levels depending on the indication of
the pacemaker implantation defined by the Japanese Circulation Society6 and their FC is determined by the metabolic
equivalents (METs). Currently,
three years after implanting a
pacemaker, the disability level is recertified based on the FC at that
time. However, it is not known how the FC changes over time after the
initial pacemaker implantation, and therefore, the optimal time for the
recertification should be determined by prospective studies. Therefore,
the aim of this study was to
examine the temporal trends in the
FC after a pacemaker implantation and the relationship between the FC
and prognosis in patients receiving a de novo pacemaker
implantation.