BACKGROUND Syncope is a common problem in the elderly, and a permanent
pacemaker is a therapeutic option when a bradycardic etiology is
revealed. However, the benefit of pacing when no association of symptoms
to bradycardia has been shown is not dear, especially in the elderly.
OBJECTIVE The aim of this study was to evaluate the effect of pacing on
syncope-free mortality in patients aged 80 years or older with
unexplained syncope and “positive” invasive electrophysiologic
testing (EPT).
METHODS This was an observational study. A positive EPT for the purposes
of this study was defined by at least 1 of the following: a corrected
sinus node recovery time of >525 ms, a basic HV interval of >55 ms,
detection of infra-Hisian block, or appearance of second-degree
atrioventricular block on atrial decremental pacing at a paced cycle
length of >400 ms.
RESULTS Among the 2435 screened patients, 228 eligible patients were
identified, 145 of whom were implanted with a pacemaker. Kaplan-Meier
analysis determined that time to event (syncope or death) was 50.1
months (95% confidence interval 45.4-54.8 months) with a pacemaker vs
37.8 months (95% confidence interval 31.3-44.4 months) without a
pacemaker (log-rank test, P =.001). The 4-year time-dependent estimate
of the rate of syncope was 12% vs 44% (P <.001) and that of any-cause
death was 41% vs 56% (P =.023), respectively. The multivariable odds
ratio was 0.25 (95% confidence interval 0.15-0.40) after adjustment for
potential confounders.
CONCLUSION In patients with unexplained syncope and signs of sinus node
dysfunction or impaired atrioventricular conduction on invasive EPT,
pacemaker implantation was independently associated with longer
syncope-free survival. Significant differences were also shown in the
individual components of the primary outcome measure (syncope and death
from any cause). (C) 2017 Heart Rhythm Society. All rights reserved
