Mar 06 2026 This Week in Cardiology

You're listening to This Week in Cardiology from org Medscape For healthcare professionals only. Any views expressed are the presenter's own and do not necessarily reflect the views of WebMD or Metal. Hi everyone, this is John Mandrola from the Heart.org Medscape Cardiology, and this is This Week in Cardiology for March 6, 2026. 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 was 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 five hundred adults from the US and Japan, they found that nearly one in four individuals would refuse statins even if they could get risk reduction from twenty percent 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 Folmsby from Rush University in Chicago, wrote to me to say that. Number one, the survey only included people who have never been on a statin, and that might select for minimizers. But more importantly, Doctor Folmsby 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. doctor Folsomsey's comment makes perfect sense. If you are responding to a survey, you may be more apt to be purely quantitative, but you're v 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 oodles 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 on me, gosh darn it. And thankfully it was okay, but that will be the last PSA I guess. But this experience underscores doctor Folmesy's excellent point that an online questionnaire likely does not recapitulate a conversation with a 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 ablations. Jackie P has published an observational study. Looking at the use and safety of urgent AF ablation in the U.S., that is an AF ablation done in patients hospitalized for something other than AF. Now, if you care for patients with EF, 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, procanamide, sodolol, dolphetolide. Then you think, wait, wait, if we're gonna do all that, why not just take the patient down to the EP lab and do a quick AF ablation while he or she is here?

An observational study first author M. Neat Sandu published in Jackie P suggest perhaps you should resist that urge. They used an AFib ablation registr registry which compiled cases from 2016 to 2023 and compared urgent versus elective AF ablation cases. Now they had 140,000 patients who had had their first AF ablation. About two percent or twenty seven hundred cases were labeled as urgent, ninety-eight percent were elective, and so they had two comparator groups.

Urgent patients had higher rates of comorbid conditions such as diabetes, coronary disease, heart failure, what you'd expect. Urgent afhoblation 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 aflation. And when they looked at the seven year time period, the number of urgent AF ablations were increasing

over time, from point five percent to two percent 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 four point nine versus two point four percent.

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, etcetera. 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 this data should be surprising. Patients in whom a doctor is tempted to do ablation during a hospitalization for something else will surely be inherently sicker and thus they're gonna have a higher complication rate.

This study's 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 him 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'em out of it.

And these slow flutters can be especially bad because if a flutter is slow in the atrium, they are often fast in the ventricle due to one to one conduction. But most often you can bridge the patient with some drugs. Uh for instance, if they're really sick with heart failure, you can use amioderone and a cardioversion, and then you can bring these patients back. And I call this getting that patient out of a hole. Then doing 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. 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 forty five sites in Japan. The clinical question is what to do with a patient with AF who's had ischemic 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 ischemic stroke going forward.

This trial was conducted in 2018 to 2021, so it's pretty old ablation technology. These were older patients, age seventy-two, twenty-five percent female, and split nearly half. f into paroxysmal and persistent AF, the Chad's VAS score was high because they've had prior stroke, uh four point five. The trial did exclude patients with severe stroke. Median follow-up was very good at nearly four years.

The primary endpoint was a composite of recurrent ischemic stroke, systemic embolism, all caused death, or heart failure hospitalization. So they're really catching all important endpoints. The primary composite end point occurred in twenty two patients in both groups, uh so the hazard ratio one point one one, 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 confidence intervals were zero point seven nine to eleven, so not significant. Ischemic strokes occurred in fourteen and versus ten 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 ACET AF trial where a rhythm control strategy, A in this case AF ablation, is being tested not so much as an AF episode reducer. But a hard outcome reducer. Recall that in 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 uh important outcomes. And it was the same in this trial. In fact, the authors of the stabled RCT don't even provide results on AF burden of 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 no. 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 thirteen percent incidence of the primary endpoint, but then assumed that ablation would reduce events by fifty percent. Fifty percent. That is way too optimistic because the control arm would be on DOAX.

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 uh ablation versus no ablation trials are always gonna have crossover, and this makes it even harder to find signal from noise. For instance, sixteen of the hundred twenty four patients in the standard arm had ablation and nineteen patients in the ablation arm did not have ablation, crossing over to the standard arm.

For the incidence of stroke, the hazard ratio is zero point seven five, which is better for the Doeck arm, but the conference intervals went from zero point three three to one point seven zero. So standard therapy could have been sixty six percent better or seventy percent 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 Embolic strokes were the main strokes because less than ten percent of patients were taking antiplatelet drugs. then it's going to be very hard to improve on doac therapy uh using AVIB as a stroke reducer, because doac are so effective. So I would say in the end that no practice changes occur with this trial.

Uh AF ablation 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 AF ablation reducer stroke, you're going to need five to tie five to ten times more patients. And that's really not going to be feasible. Not because there aren't this 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 AF ablation have lower stroke rates. The authors cite a Swedish health registry study of more than three hundred thousand patients that finds that those who have ablation have lower stroke incidence. 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 syncope.

Say a patient has what I call stone cold sycopy. 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 Jack EP, and the authors set out to evaluate and compare the accuracy of currently used loop recorders.

From Medtronic, Boston, Biotronic, and Abbott, the database included a huge number of ECG verified episodes from sixty seven hundred patients. For the study, the authors selected a random sample of just one thousand hundred forty patients. Now the indications for ILR were the usual things like cryptogenic stroke, atrial fibrillation, syncope, palpitations, ventricotechardia.

The most common reason for alerts was AF, and for AF Boston Scientific had the highest positive predictive value, followed by Abbott and Medtronic, which had similar moderate a positive predictive value. 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 AFib, false positive burden overall was shockingly high at 51%. 51%.

Biotronic had the highest false positive rate at eighty nine percent, whereas other devices had comparable accuracy with false positive rates of like thirty nine, thirty five, and thirty two percent. Now, pause there and f 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 of zero point nine six.

Medtronic had the lowest at zero point three six. Pause detection action accuracy was lowest for Abbott. Their positive predictive value, and I hope this isn't a misprint, is zero point zero one and eighty percent of this is due to undersensing. The highest pause detection accuracy was Boston Scientific at zero point seven zero. So the authors concluded that ILRs demonstrate variable accuracy in arrhythmic 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 then put glue on it. Make sure there's a good R-wave signal. Then when reviewing the tracings 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 nominally or out of the box. One device I use is set out of the box to detect six minutes of AFib. This is ridiculous. No one cares about six minutes of AFib. I usually change it to one to two hours because if you're detecting six minutes of AFib, it's going to be much more likely to detect PACs while the patient's out walking or doing some other exercise.

And I 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 Impat Impathic, E M P A T I C C The goal was to assess typical heart failure therapy in patients with signs of both progression of heart failure 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 is the push to use heart fire therapy, I see people who should be eating cheeseburgers eating entresto 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 and 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 seventy, NT probe and P greater than six hundred, a high troponin, uh low EF. Uh L V mass loss greater than fifteen percent, transferrent saturation less than twenty percent, or just hef peth.

And ninety three patients were then randomized to get heart failure therapy, which could include saccubatril valsartan, empa, ivabradine, ferricoboxymaltose, 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, a pill or procedure, and the other group gets nothing. Uh 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. Uh the second composite on the hierarchy was ability to walk four meters, three, and a 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 win 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 uh get a reduced pro BNP. It increased the EF by 2.9%. and a very small improvement in the uh patient reported global assessment. So the authors include concluded in a population with advanced cancer receiving specialized palliative care and high early mortality, optimized heart failure therapy did not improve patient self care ability.

Now my comments, I realize 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 Heart Journal for publishing it. If I've said this once, I've said it a thousand times on this podcast. Guideline directed heart fire therapy was proven beneficial in trials that enrolled relatively healthy ambulatory patients, mostly recruited from heart fire 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 multimorbid 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 seccubitril sartin. So that's it for this week in cardiology. As always, I'm grateful that you listened. 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 uh you don't agree with, send me a note and we can do a listener feedback. Until next week, this is John Mandrola from the Heart.org Medscape Cardiography. listening to this week in cardiology.

org Medscape Cardiology. Any views expressed are the presenter's own. Yeah.