My name is Parikshit Sharma.
I am an associate professor of medicine
at Rush University Medical Centre.
I'm also the section chief of cardiac electrophysiology,
and the director of the Rush Arrhythmia Centre
and the Rush EP lab, in Chicago Illinois.
So the study was aimed to evaluate
clinical outcome differences
between left bundle branch area pacing
as compared to traditional right ventricular
or atypical pacing.
The end points that we evaluated,
the primary composite endpoint was that
of a combination of mortality,
or the first hospitalisation for heart failure,
or need for upgrade to bi-ventricular pacing.
The secondary end points we evaluated
were the primary composite endpoint in patients
with greater than 20% and greater than 40%
ventricular pacing burden,
as well as individual co-primary end points
that were individually evaluated.
The study was a non-randomized prospective
observational evaluation of 703 patients at two sides,
which was the Geisinger health system,
as well as the Rush University Medical Centre cohort.
And we compared about 703 patients
with 321 patients in the left bundle area branch pacing arm,
and about 382 patients in the right ventricular
or conventional pacing arm.
So the findings of this study were very interesting
as we have known from observational data in the past,
his bundle pacing has demonstrated a better clinical
outcomes when compared to traditional RV pacing.
Left bundle branch pacing was along the same lines.
The primary composite endpoint was much lower
in the left bundle branch pacing arm,
as compared to the RV pacing arm with the outcome
of 10% in the left bundle branch pacing arm,
versus 23.3% in the right ventricular pacing arm
with a p-value of less than 0.001
and a hazards ratio of 0.46,
suggesting that left bundle branch pacing does overall
better in this cohort of patients,
further evaluation of patients with pacing burdens greater
than 20% and 40% suggested similar findings
with a statistically significant difference
in the primary composite outcome
between left bundle branch area pacing
and right ventricular pace with a p-value
of less than 0.01 and hazards ratio of 0.32.
When we looked at individual endpoints of mortality,
heart failure, and need for upgrade to biventricular pacing,
to our surprise,
there was a significant difference in the mortality,
whether we looked at the entire cohort or in subsets of
patients with a higher burden of ventricular pacing with
left bundle branch area pacing doing much better
as compared to right ventricular pacing.
Similarly, when looking at heart failure hospitalizations
as well, left bundle branch pacing, area pacing,
did much better than traditional right ventricular pacing
with a lower incidence of heart failure hospitalisation
in the left bundle branch area arm.
In the entire cohort, as well as in
the subsets of patients with a higher burden
of ventricular pacing.
So overall, left bundle branch area pacing
did much better than right ventricular pacing
when it came to the primary composite end points,
as well as individual co-primary end points based on our
evaluation in this cohort of patients.
I think that's very interesting, it's important to take
the findings of this study with a caveat that
this was a non-randomized clinical evaluation.
Given the fact that this was non-randomized,
it has its inherent challenges and biases,
such as selection bias that may be associated
with the selection of this patient cohort.
Although the groups were fairly evenly
matched with each other.
Before we can make this a mainstream strategy
for ventricular pacing,
I would think that more detailed evaluation in the form of a
randomised control multi-center study would be necessary
to further confirm these findings
and make this part of routine practice.
The findings of the study do provide a very strong signal
that suggests that left bundle branch area pacing
may be a much better alternative to pace the ventricles
in patients with need for pacemaker implantations
for bradycardia indications.
But like I said,
this needs further evaluation in large care,
randomised controlled trials.
It is important to bear in mind that the two sites that
included patients as part of this study were sites that have
been considered centres of excellence
for conduction system pacing, whether it is
his bundle pacing or left bundle branch area pacing.
So it's very important that individuals and operators that
are going to perform these procedures really do this the
right way for their patients before it becomes mainstream.
That's really critical. The other,
the other question that we don't really have
an answer to just yet is with regards
to the ability for lead extractions,
with leads implanted in the left bundle branch area.
And until we have more data on that,
we have to still be a little bit careful
with long-term performance of this particular technique
when compared to traditional RV pacing,
where we have information,
the lead extraction ability, and safety.