Abstract
Introduction: To know whether cardiac pacemaker implantations
improve the functional capacity (FC) and affect the prognosis.
Methods and Results: We prospectively enrolled 621 de-novo
pacemaker recipients (age 76±9 years, 50.7% male) between April 2015
and September 2016. The FC was assessed by
the metabolic equivalents (METs)
during the implantation and periodically thereafter. The patients werea priori classified into a poor FC (<2 METs, n=40
[6.4%]), moderate FC (2< METs<4, n=239
[38.5%]), and good FC (> 4 METs, n=342
[55.1%]). Three months after
the pacemaker implantation, poor FC or moderate FC patients improved to
a good FC by 43%. The
distribution of the three FCs remained at those levels by the end of the
follow-up (p=0.18). During a median follow-up of 2.4 years, 71 patients
(11%) had cardiovascular hospitalizations and 35 (5.6%) all-cause
death. A multivariate Cox analysis revealed that a poor FC at baseline
was an independent predictor of both a cardiovascular hospitalization
(hazard ratio [HR] 2.494, 95% confidence interval [CI]
1.227-5.070, p=0.012) and all-cause death (HR 3.338, 95% CI
1.254-8.886, p=0.016). One year after the pacemaker implantation, the 19
patients whose poor FC improved to a good FC did not die, however, the 8
who remained with a poor FC had a high mortality rate of 37.5%
(p<0.01).
Conclusion: Approximately half of the poor or moderate FC
patients improved to a good FC 3 months after the pacemaker
implantation. The baseline FC predicted the prognosis, and patients with
an improved FC after the pacemaker implantation had a better prognosis.
Key words : arrhythmia, pacemaker, functional capacity,
prognosis.