Approximately one million pacemakers are implanted
annually, providing electrical stimulation to
regulate a patient's heartbeat. Conventional
pacemakers are surgically placed under the skin of a
patient's chest, with wires, or leads, stretching
from the shoulder vein and attaching to the heart.
These wires and the surgical implantation are the
most common source of complications, occurring in up
to 12 percent of device recipients, according to
previous research. Leadless pacemakers, by contrast,
do not need wires. The small self-contained devices
about 10 percent of the size of a traditional
pacemaker are placed directly into the heart using a
catheter passed through the femoral vein in the leg.
Leadless pacemakers were introduced in 2014, and the
first leadless pacemaker was approved by the FDA in
2016. The new multi-center study compared short- and
mid-term complications between 718 patients
receiving the Nanostim leadless pacemaker and 1,436
patients with conventional (transvenous) pacemakers.
Leadless pacemaker patient data was taken from the
LEADLESS II trial, a prospective, nonrandomized,
multicenter clinical trial. Transvenous patient data
were obtained from Truven Health MarketScan claims
databases for patients implanted with single-chamber
pacemakers between April 2010 and March 2014 and
more than 1 year of pre-implant enrollment data.
Statistical methods were used to match patients
between the two groups to compare the outcomes of a
leadless vs. traditional pacemaker with other key
clinical variables being equal. At one month, the
study found that patients receiving one type of
leadless pacemaker (Nanostim) overall had fewer
complications (5.8 percent vs. 9.4 percent).
Leadless pacemakers completely eliminated lead and
pocket complications, including infection. By
comparison, complications among traditional
pacemaker recipients included lead complications
(3.62 percent), pocket complications (0.42 percent)
and infection (1.74 percent). There were no
significant differences between the groups in regard
to rates of vascular complications, electrode
dislodgement and generator complications. However,
the study did find that those receiving leadless
pacemakers had an increased risk of developing
pericardial effusion bleeding between the heart and
the sac that surrounds the heart (1.53 percent vs.
0.35 percent). These complications were uncommon but
serious, and sometimes required surgery. Beyond one
month and up to 18 months of follow-up, leadless
patients continued to experience overall fewer
complications than transvenous patients (0.56
percent vs. 4.94 percent). In the conventional
pacemaker group, there were a number of
complications wholly absent from the leadless group,
including lead-related complications, electrode
dislodgement, infection and pocket complications. |