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Listener feedback, urgent AF ablation, AF ablation as a stroke-reducing therapy, implantable loop recorder accuracy, and HF management in the setting of serious disease are the topics John Mandrola, MD, discusses in this week's podcast.
This podcast is intended for healthcare professionals only.
To read a partial transcript or to comment, visit:
https://www.medscape.com/twic
I Urgent AF ablations
II AF Ablation Is Not Likely a Good Therapy for Stroke Reduction
III Loop Recorders
IV Heart Failure Therapy when there is Cancer
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The Bob Harrington Show with the Stephen and Suzanne Weiss Dean of Weill Cornell Medicine, Robert A. Harrington, MD. https://www.medscape.com/author/bob-harrington
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You're listening to this week in Cardiology from the Heart.org medscape
Cardiology. This podcast is intended for health care professionals only. Any
views expressed are the presenters own and do not necessarily reflect the
views of Web MD or medscape. Hi everyone. This is John Mandrola from the Heart.org
medscape Cardiology and this is this week in Cardiology for March 6, 20, 26. This
week. Some really interesting listener feedback. Urgent AF-ablation. AF-ablation
as a stroke-reducing therapy. ILR, loop recorder accuracy, and heart failure
management in the setting of serious disease. So first is some listener feedback. I
received a nice email about my coverage of the provocative JAMA internal medicine
letter on patient preferences for statin therapy. This is a letter in which
authors from Japan surveyed people on what their smallest worthwhile
difference would be for accepting a daily statin prescription. I was struck by
the findings because when the authors surveyed about 500 adults from the U.S. and
Japan, they found that nearly one in four individuals would refuse statins even
if they could get risk reduction from 20% to zero. And that the smallest
worthwhile difference for patients is essentially three times more than the
actual risk reduction found in trials. I took from these observations that most
people tend to be minimizers. They want a lot more bang for their buck in
risk reduction if they were to accept a daily statin. Well, internist and
primary care doctor, Dr. Kuma, foams B from Russian University in Chicago wrote
to me to say that number one, the survey only included people who have never been
honest at. And that might select for minimizers. But more importantly, Dr.
Foams B wrote this sort of discussion probably hits different when it's done
in a personalized setting with physician patient continuity. While someone might
decline a medication when answering questions on a survey, if given the option
from a doctor they have known and trusted for years, the results would likely
be different. Suddenly, small effect sizes could feel larger. Okay, I really like
this comment because it highlights the concept of external validity of
evidence, doesn't it? That is how we generalize evidence from carefully controlled
studies, which are always special circumstances to everyday practice. And a
survey is certainly a special circumstance. Dr. Foams B's comment makes perfect
sense. If you're responding to a survey, you may be more apt to be purely
quantitative, but you're in the office of a trusted professional, you might feel
differently. Now, let me tell you an example. I felt this firsthand in my
urologist office. I was there for a specific issue that turned out to be
nothing. Thank goodness. But while I was there, I got the full court press on
PSA screening for prostate cancer. Now, I've studied screening. I've written
about screening. This includes PSA screening. I knew the data. And I had
decided that no doctor ever would check my PSA. But, but I trusted my
urologist. He was clearly an expert. He was also kind and professional. And he
spoke from his point of view of caring for utils of people with bad prostate
cancer. He gave me his best case. And I can't believe it. But I relented and let
him take a PSA. I mean, gosh darn it. And thankfully, it was okay. But that will be
the last PSA I get. But this experience underscores Dr. Foams B's excellent
point that an online questionnaire likely does not recapitulate conversation
with the trusted professional. That said, I still think statin drugs should be
available over the counter without a prescription in an aisle that has a risk
calculator and people can decide for themselves. All right. Next topic is Urgent
AF Oblations. Jackie P has published an observational study looking at the
use and safety of urgent AF Oblation in the US. That is an AF Oblation done in
patients hospitalized for something other than AF. Now, if you care for patients
with AF, the idea may have entered your brain too. That is, a patient comes in
with something say pneumonia, hypotension, heart failure, VTE, and they're
found to be an AFib. And you think crap, this AFib is new. It's causing trouble.
We're going to pursue rhythm control, perhaps with drugs like amiodarone,
procanomide, so do all the fetalide. Then you think, wait, wait, if we're going
to do all that, why not just take the patient down to the EP lap and do a quick
AF ablation while he or she is here? An observational study, first author,
Amnit Sandu, published in Jackie P, suggests perhaps you should resist that
urge. They used an AFib ablation registry, which compiled cases from
2016 to 2023 and compared urgent versus elective AF Oblation cases. They had
140,000 patients who had had their first AF ablation. About 2% or 2700
cases were labeled as urgent, 98% were elective, and so they had two
comparator groups. Urgent patients had higher rates of comorbid
conditions, such as diabetes, coronary disease, heart failure, which you'd
expect. Urgent AF Oblation was more often used among black patients, and
those presenting to the procedure for an urgent AF ablation were more often
in atrial fibrillation. Hospitals that did more AF ablation also did more
urgent AF ablation. And when they looked at the seven-year time period, the number
of urgent AF ablations were increasing over time from 0.5% to 2% at the end
of the study. And the main result, which is not surprising, was that the
adjusted procedure-related complication rate was significantly higher with
urgent AF ablation compared with elective 4.9 versus 2.4%. That p-value was
highly significant. And notable is that these are just inpatient complications.
The registry is likely an underestimate because it can't see complications
that occur after discharge, things like stroke, bleeding, pneumonia, etc. And
the authors concluded the only thing that they could conclude that urgent AF
ablation has increased over the past decade. It's done in sicker patients,
and it has a much higher complication rate even when risk adjusted. Okay, my
comments. The first thing to say is that this is a good use of observational
data. Science tells us what we can do, trials tell us what we should do, and
registries tell us what we are actually doing. And none of these status should
be surprising. Patients in whom a doctor is tempted to do ablation during a
hospitalization for something else would surely be inherently sicker, and
thus they're going to have a higher complication rate. This study is nearly
five percent complication rate for urgent AF ablation is strikingly high in
my mind. Now, I'm just going to move to mandrola opinion. Here it is. Doing
urgent AF ablation is almost always a bad idea. If the patient is in the hospital
for something else, it's best to treat that something else and bring the patient
back for an elective AF ablation after you've seen them in clinic and things
are stable. I can think of only a handful of situations where I have done an
urgent AF ablation. And that is one thing that pops into my mind is when they're
in a left-atrial flutter of some sort, and it's recalcitrant, and it's causing
heart failure, and you just can't get them out of it. And these slow flutters can
be especially bad because if a flutter is slow in the atrium, they are often
fast and the ventricle due to one-to-one conduction. But most often, you can
bridge the patient with some drugs. For instance, if they're really sick with
heart failure, you can use amiodarone and a cardioversion, and then you can bring
these patients back. And I call this getting that patient out of a hole, then
doing the ablation later when things are more stable. Recall that at least in the
US, AF ablation is done with general anesthesia, and we should respect the
dangers of that when patients are acutely medically ill. The observations in
this paper are not surprising, but I think it was a worthwhile exercise to show us
the dangers of urgent AF ablation. The authors don't tell us not to do
urgent AF ablation, but the data surely suggests that we should be cautious, and in
almost all cases, resist the urge. Alright, a little more on AF ablation. AF
ablation is probably not a good therapy for stroke reduction. Jamin neurology
has published the results of the stabled RCT from 45 sites in Japan. The
clinical question is what to do with a patient with AF who's had a schemic
stroke? Do you give DOAC alone, and in this case they use DDoxaban, or DOAC plus AF
ablation? Now adding AF ablation would diminish AF episodes, and maybe that would
reduce a schemic stroke going forward. This trial was conducted in 2018 to
2021, so it's pretty old ablation technology. It was only 250 patients
randomized one to one. These were older patients, age 72, 25% female, and split
nearly half into paroxysmal and persistent AF. The Chad's vascular was high,
because they've had prior stroke, 4.5. The trial did exclude patients with
severe stroke. Media and follow-up was very good at nearly four years. The
primary endpoint was a composite of recurrent schemic stroke, systemic
embolism, all caused death, or heart failure hospitalization. So they're really
catching all important endpoints. The primary composite endpoint occurred in
22 patients in both groups. So the hazard ratio 1.11 clearly not significant.
Major bleeding was three in the standard arm, eight in the ablation arm. That
hazard ratio was three times greater in the ablation arm, but again the
conference intervals were 0.79 to 11, so not significant. A schemic stroke
occurred in 14 versus 10 patients, and these were obviously not significantly
different. And the author's conclusion reads, quote, in patients with atrial
fibrillation in the recent stroke history standard therapy, plus catheter
ablation did not significantly reduce the risk of the primary composite endpoint.
However, they write the observed event rate was lower than anticipated,
suggesting that the study was underpowered to detect clinically meaningful
differences. Alright, so my comments, this is a bit like the ASTAF trial,
where a rhythm control strategy, in this case, AF ablation is being tested,
not so much as an AF episode reducer, but a hard outcome reducer. Recall
that an East AF, it was early rhythm control versus rate control, and early
rhythm control wasn't just for control of AF, it was to reduce important
outcomes, and it was the same in this trial. In fact, the authors of the
stable dark CT don't even provide results on AF burden at two arms. And I think
the use of AF ablation to reduce outcomes, especially in clinically ill
patients, this case prior stroke, is a reasonable question, because intuitively
you would think that reducing AF burden with ablation would add to the
DOAC efficacy. And the top line results in this trial are null, no statistical
differences were noted, but this is a big but. This is one of the situations
where I would not, not conclude that ablation is an ineffective reducer of
stroke, heart failure, or death, because this trial was massively underpowered,
which was evident in the calculations of their sample size. They estimated a
13% incidence of the primary endpoint, but then assume that ablation would
reduce events by 50%, 50%, that is way too optimistic, because the control arm
would be on DOAC, which would severely reduce stroke rate. Death is unlikely
to be affected by either arm, and since these patients did not have heart
failure to begin with, you wouldn't expect heart failure hospitalization to be
much different either. What's more, they had a lot of crossover, and these
pragmatic ablation versus no ablation trials are always going to have crossover,
and this makes it even harder to find signal from noise. For instance, 16 of
the 124 patients in the standard arm had ablation, and 19 patients in the
ablation arm did not have ablation crossing over to the standard arm. For the
incidence of stroke, the hazard ratio is 0.75, which is better for the DOAC arm,
but the conference intervals went from 0.33 to 1.70, so standard therapy could
have been 66% better or 70% worse than ablation. I'm really surprised that a
trial like this gets approved by the IRBs, because you could have predicted
wide conference intervals, and you could have predicted that the trial would
have been uninformative from the beginning. I would say that if a stroke is due
to AFib, and presumably it was in this trial, because DOAC was the main
intervention in the standard arm, and I would also think that symbolic strokes
were the main strokes, because less than 10% of patients were taking anti-platelet
drugs, then it's going to be very hard to improve on DOAC therapy using a
Vib as a stroke reducer, because DOACs are so effective. So I would say in the
end that no practice changes occur with this trial. AFiblation remains an
intervention to improve quality of life by reducing AF burden. This is true for
patients with and without a history of stroke. If you want to show AFiblation
reduces stroke, you're going to need five to ten times more patients, and that's
really not going to be feasible. Not because there aren't as many patients, there
are, but because many patients with a history of stroke and AFib will likely
have symptoms, and they'll want their symptoms reduced. Now one warning I want to
say about this, my friends, do not be duped by observational studies, showing that
those who get AFiblation have lower stroke rates. The author's site, a Swedish
health registry study of more than 300,000 patients, that finds that those who
have ablation have lower stroke incidents. These are non-random comparisons
and they're flawed by selection bias, wherein healthier patients get ablated
versus not ablated. All right, loop recorders, let's talk
implantable loop recorders or ILRs. These devices can be handy for long-term
monitoring for arrhythmias. They can detect AF, it can tell us AF burden, but
perhaps their greatest use, and the reason I most often use them is for the
diagnosis of infrequent but severe syncopy. Say a patient has what I call stone
cold syncopy. I mean, they just out stone cold, but it happens only once every
few months. You want to know the diagnosis, but if you do a two-week monitor, it's
unlikely to capture the event. But, poorly recognized is that ILR recordings
are often not perfect. So this is a study from multiple authors published in
Jackie P and the authors set out to evaluate and compare the accuracy of
currently used loop recorders from metronic, Boston, biotronic, and avid.
The database included a huge number of ECG verified episodes from 6,700
patients. For the study, the authors selected a random sample of just 1140
patients. Now, the indications for ILR were the usual things like cryptogenic
stroke, atrial fibrillation, syncopy, palpitations, ventricutect cardia. The
most common reason for alerts was AF. And for AF, Boston scientific had the
highest positive predictive value followed by avid and metronic, which had
similar moderate, a positive predictive values. Whereas biotronic for this one
had the lowest positive predictive value. We're talking 0.73 at best and 0.23 at
worst. Also for AF, false positive burden overall was
shockingly high at 51%. 51% biotronic had the highest false positive rate at 89%
whereas other devices had comparable accuracy with false positive rates of
like 39, 35 and 32%. Now, pause there and just forget the comparisons amongst
companies for a moment and consider that at least one in three AFib alerts are
not AFib. For bradycardia, Boston scientific demonstrated the highest positive
predictive value at 0.96. Metronic had the lowest at 0.36. Pause detection
accuracy was lowest for avid. Their positive predictive value and I hope this
isn't a miss print is 0.01 and 80% of this is due to under sensing. The highest
pause detection accuracy was Boston scientific at 0.70. So the authors concluded
that ILRs demonstrate variable accuracy and arrhythmia detection with a
substantial burden of false positive alerts across all vendors despite AI based
and other algorithmic enhancements. Further improvement of alert algorithms to
reduce clinic burden is needed and I would say that is so. So my comments I
don't think we need to get too bogged down on device to device comparisons although
some are clearly worse for specific issues. The key point in in this report is
that loop recorders like so many things in medicine require attention to
detail. Yes, these loop recorders are super easy to insert like two minutes. Yes
they're very lucrative not only for the initial implant but it's recurring
income every 30 days. So my take of this is to spend a few moments in with proper
insertion. Use an oblique angle over the heart then don't just put it in and
put glue on it make sure there's a good our wave signal. Then when reviewing the
tracing's in clinic take a moment to review the electrograms to exclude these
false positives. And I strongly urge programming a longer AF detection time
than what comes out normally or out of the box. One device I use is set out of the
box to detect six minutes of a fib. This is ridiculous. No one cares about six
minutes of a fib. I usually change it to one to two hours because if you're
detecting six minutes of a fib it's going to be much more likely to detect
PACs while the patient's out walking or doing some other exercise. And I wonder
I mean I don't know what you all think but maybe people with arrhythmia
knowledge should be the one inserting these monitors. All right last topic is
heart failure therapy when there is a serious disease like cancer. The European
heart journal has published results of a trial called empathic EMPAT ICC. The goal
was to assess typical heart failure therapy in patients with signs of both
progression of heart fire and advanced cancer. Now you might not think such a
trial is necessary because most doctors would forego heart failure therapy so as
to maximize comfort in a patient with one to six months life expectancy. But you
would be wrong. So strong as to push to use heart fire therapy. I see people
who should be eating cheeseburgers eating in Tresto instead. Well German
authors led by a group at Charity Hospital in Berlin decided to study it in
an RCT form. It's a small modest study but it's worth talking about. Patients
had to have stage four solid tumors in low life expectancy and already be
taking palliative care. They also had to have functional limitations from
heart failure and at least two cardiovascular risk criteria for instance heart rate
greater than 70 and T pro B&P greater than 600 a high-troponin low EF. LV
mass loss greater than 15% transfer and saturation less than 20% or just
heft path. At 93 patients were then randomized to get heart failure therapy which
could include secubitrile valsartan, empathy, evabrdine, ferrocoboxymaltoes or
placebo in a double blind setting. The placebo here is a nice feature because
it's always better than one group getting active treatment of pill or
procedure and the other group gets nothing. Placebo arms avoid subtraction
anxiety bias so good on them. The primary endpoint was also a strong endpoint,
hierarchical endpoint. Days alive and able to wash oneself. That's a new one for
me. Second composite on the hierarchy was ability to walk four meters, three,
and self-reported global assessment of subjective well-being during the 30-day
placebo-controlled phase. So the results. The primary endpoint did not differ
between groups. The wind ratio was 0.95 with conference intervals going from
0.57 to 1.58, a p value of 0.8. Overall mortality was 32% at 30 days and that
did not differ between groups. The heart failure arm did get a reduced
pro-BNP. It increased the EF by 2.9% and a very small improvement in the patient
reported global assessment. So the authors concluded in a population with
advanced cancer receiving specialized palliative care and high early mortality
optimized heart failure therapy did not improve patient self-careability.
Now my comments. I realized that this trial will not win any of these authors
the Nobel Prize for medicine but kudos to them for gathering empirical data and
kudos to the European hard journal for publishing it. If I've said this once
I've said it a thousand times on this podcast. Guideline directed heart
failure therapy was proven beneficial in trials that enrolled relatively
healthy, ambulatory patients mostly recruited from heart failure clinics, not
hospital beds, not cancer centers. The primary problem that patients in
heart failure trials have is a bad ventricle. They are sick from LV dysfunction but
many patients with these other diseases are sick with LV dysfunction. For these
latter patients we would be wise to avoid therapies that don't improve quality
of life especially when time is limited. I see frail patients with multi-morbid
conditions who are unfortunate enough to get an echocardiogram and then they
receive all manner of non-beneficial heart failure interventions. The
empathic trial enrolled cancer patients but I'd extend the null trial results to
patients with dementia, CKD, COPD, frailty and other life limiting
conditions. For these patients ignore the shadows that you see on the echocardiogram
and give these patients only things that improve their quality of life. Things
like hamburgers, french fries, ice cream, not secubitral, falsartane. So that's
it for this week in cardiology. As always I'm grateful that you listen. Thank
you and remember if you like this podcast please take the time give us a
rating, write us a review. If you find something that you don't agree with send
me a note we can do a listener feedback. Until next week this is John
Mandrola from theheart.org medscape cardiology. You're listening to this week in
cardiology from theheart.org medscape cardiology. This podcast is intended for
healthcare professionals only. Any views expressed are the presenter's own and
do not necessarily reflect the views of web MD or medscape.
