Oct 7, 2022 This Week in Cardiology Podcast

John M. Mandrola, MD


October 07, 2022

Please note that the text below is not a full transcript and has not been copyedited. For more insight and commentary on these stories, subscribe to the This Week in Cardiology podcast on Apple Podcasts, Spotify, or your preferred podcast provider. This podcast is intended for healthcare professionals only.

In This Week’s Podcast

For the week ending October 7, 2022, John Mandrola, MD comments on the following news and features stories.

Post-Stent Antiplatelet Therapy

I’ve covered the post-coronary-stent strategy of preventing recurrent ischemia without increasing bleeding many times. It’s one of the most complicated spaces in all of cardiology. Before I tell you about a new paper in JAMA Cardiology, I want to remind all listeners that the reason we have these discussions is that stents aren’t free. The stented artery is not, exactly, fixed.

Once there is metal in the coronary artery, you have to block platelets. If you don’t, stents can thrombose. Abrupt 100% occlusions are worse than chronic 95% occlusions. Blocking platelets means taking a medication that increases the risk of bleeding. Make no mistake, if you are having a myocardial infarction (MI), the need for platelet-blockers after a stent is a great trade-off; if you have stable coronary artery disease (CAD), the tradeoff is far less clear.

I follow this space because I have oodles of patients with atrial fibrillation (AF) who also have stents. And the combination of oral anticoagulants (OAC) and antiplatelets is even more challenging.

As always, journalist Sue Hughes has excellent news coverage of a long-term extension of the SMART-CHOICE trial of two strategies of antiplatelet therapy after a stent:

  • One group got dual antiplatelet therapy (DAPT) and then monotherapy with a P2y12 inhibitor.

  • The other group got prolonged DAPT for 12 months or longer.

  • More than 90% of both groups received clopidogrel as their p2y12 inhibitor.

  • The initial trial was a 1-year noninferiority (NI) trial, but this report involves a 3-year extension.

  • At 1 year, there were similar and very low rates of major adverse cardiovascular and cerebrovascular events (MACCE), however, the short-duration DAPT had significantly lower rates of bleeding: 2.0% vs 3.4%.

  • In this most recent study, follow-up of 92% of the groups was continued for 3 years, which seems like a long time to continue DAPT.

  • MACCE occurred in 6.3% of the p2y12 monotherapy groups vs 6.1% in the DAPT group—so no difference.

  • Bleeding, however, was way lower in the monotherapy arm: 3.2% vs 8.2% in the DAPT arm.

On the surface, this seems like a clear picture; DAPT offers no advantage. But let’s first do a brief rundown of the background:

Point 1: Randomized controlled trials (RCTs) have consistently shown that shorter-duration and intensity of DAPT (in whatever form, different drugs, different durations) seem to produce similar rates of thrombotic events but less bleeding than longer duration DAPT.

Point 2: Guidelines trail this thinking a bit as there are still recommendations to continue DAPT for 3 to 6 months for stable CAD stent patients, and 6 to 12 months for those with stents done because of acute coronary syndrome.

Point 3: Another issue is that when DAPT is stopped, it has been the P2y12 inhibitor that is stopped, and the aspirin (ASA) that is continued. That has always struck me as weird, because ASA not only blocks platelets but also causes GI irritation.

The SMART-CHOICE data — same MACCE rates and higher bleeding with DAPT— comports with other trial data that also show that a P2y12 inhibitor alone may be better than DAPT. The problem is that any extended trial follow-up always comes with significant limitations. Limitations here include:

  • A roughly 8% dropout of patients;

  • Low event rates;

  • Loss of blinding;

  • Low adherence rates for DAPT over the 3 years.

Drs. Kirtane and Mehran, two eminent researchers in interventional cardiology, wrote the editorial and I highlight this quote:

“These data should lead clinicians to consider a strategy of monotherapy after a short period of DAPT as a viable one to mitigate bleeding risk,” adding the caveat that the extended follow-up study had limitations.

They emphasized something that seems super wise: This post-stent space is complex, and it allows for decision-making depending on individual patient features. They seem happy — as am I — that no algorithm or quality measure could ever work in this space.

It reminds me that what is needed in the post-stent space is the need to be a doctor, one who uses the best evidence, combined with clinical judgement, and patient preferences, to individualize care. This is exactly what the father of evidence-based medicine, David Sackett, would have recommended.

My final comment would simply be a reminder that none of these decisions need be considered if there was not a stent in the artery.

Relief of Symptoms in HF

It has been a good while since I discussed something that happens in every single one of our patients with heart failure (HF): death. One of my partners messaged me this week that she had discussed end-of-life goals of care with a patient with advanced HF whose time was short and they decided together to deactivate implantable cardioverter-defibrillator (ICD) therapies.

It was a notable message because it’s so uncommon. Yet, 99% of our patients with cardiac devices will die with the device in place and, as Atul Gawande famously wrote in Being Mortal, hope is not a plan.

Journalist Fran Lowry has news coverage of an observational study of home-based palliative care in Ontario. This was a comparison of patients who were referred for a collaborative and what sounds like comprehensive home-based palliative care and similar patients who did not receive this intervention.

The non-randomized retrospective study returned highly positive results for the home-based palliative care model.

  • Patients who received this intervention had a statistically significant, 48% lower risk of dying in the hospital, which was the primary endpoint.

  • Secondary endpoints also favored home-based palliative care: patients in the program spent more time at home and used the emergency department and intensive care unit less.

  • The authors did their best to match the groups. They did propensity matching, used only new referrals to palliative care, and conducted sensitivity analyses all of which suggested the groups were matched.

While I strongly believe that palliative care is vitally important, this sort of design is surely confounded by selection bias. Yet I am going to say something that I rarely say on #TWICPodcast: we don’t need randomized trials in this area.

My wife Staci, a palliative care physician, likes to say palliative care are pals for people with serious disease. Something like that need not be randomized.

  • The goal of palliative care is the relief of symptoms.

  • The goal of doctoring is relief of symptoms.

  • Symptom burden in HF is easy to forget in the academic HF space. Here, we talk so often of reduction of doctor-centric endpoints.

  • While lower rates of death and hospitalization are important, so is the relief of suffering.

I don’t think the relief of suffering needs to be proven in RCTs. The problem is that, unlike the makers of SGLT2 inhibitors, for example, there is no palliative care industry to partner with professional societies to provide educational support to doctors and patients.

So, please, my friends, when you care for patients with HF, always remember to think about relieving symptoms. This is every bit as important as the robotic use of guideline directed medical therapy. Let’s make heart failure care less heartless!

Left Atrial Appendage Occlusion Information on Hospital Websites

JAMA Internal Medicine has published a somewhat shocking research letter from a group of researchers at University of California San Francisco and Yale. They examined publicly available hospital web page content about percutaneous closure of the left atrial appendage (LAA) with Watchman.

They included the top 100 hospitals for cardiology from the 2021 US News and World Report. Each web page was assessed for indications and contra-indications as well as potential risks and benefits of the procedure.

They then used the Open Payments website to sort out general or research payments to the hospital or physicians who were quoted on the webpage and whether these payments were disclosed. Stop the treadmill, pull the car over, get off the bike, for the results:

  • Only 9% of webpages included at least one contra-indication;

  • Nearly all webpages and articles stated at least one Watchman-associated benefit, which was emphasized in 80% of webpages;

  • 20% of webpages included content from the Boston Scientific media kit;

  • Only 29% of web pages included at least one of 57 risks;

  • Of the 60 hospitals with Open Payment records, two-thirds received general or research payments from Boston Scientific. None of these payments were disclosed. None.

  • Of the 35 docs who were quoted on these web pages, 94% received general or research payments from Boston Scientific, and, less than 10% were disclosed.

Comments. I hardly need to say anything, but there is a podcast to produce. Here is a summary of what I sent Sue Hughes as e-mail comments for her news story.

  • These investigators have shown clear bias in the promotional materials for LAA closure.

  • They’ve bolstered their findings by also exposing the financial dualities of interest that pervade both hospital systems and individual physicians.

  • Two-thirds of hospitals receive funds from the manufacturer, and none were disclosed on their websites.

  • More than 90% of quoted physicians have received general or research funds from the makers of this device, but less than 10% disclosed these conflicts.

These are stark and sobering findings. I am not against industry collaboration, but these dualities should be disclosed.

From a patient perspective, LAA closure is one of the most complex decisions in all of cardiology. That is because it’s a preventive procedure that carries substantial upfront procedural risk in hopes of providing a probabilistic lower risk of stroke or bleeding in the future.

Even if you believe percutaneous LAA closure provided more benefit than risk, you have to agree it is a complex decision infused with uncertainty. These findings revealed very little to no uncertainty in the patient-facing web pages of hospitals. Patients deserve to see accurate unbiased educational materials. And these documents should be clear about disclosing financial dualities of interest.

The previous story on palliative care is a testament to dualities of interest in advertisements: I have yet to see a hospital web page promoting palliative care.

Huge kudos to the authors who have done US healthcare a great service. As with other important studies, their work has shown that there is much more work to be done. I also hope this works stimulates more research into healthcare promotion in other areas. My suspicion is that LAA closure is not an outlier. 

An addendum to this story: The senior author on this paper is Rita Redberg, the editor-in-chief of JAMA Internal Medicine. This week it was announced that she was stepping down as editor-in-chief.

I want to take a brief moment to congratulate Dr. Redberg in accomplishing something special. During her leadership, JAMA Internal Medicine has become an outlier in academic publishing — an outlier in the most positive way. JAMA Internal Medicine has consistently published research and editorials that challenge the status quo in Medicine.

The journal made a name for itself because of its emphasis on shared decision making, reducing low-value care, especially in the most frail and vulnerable patients, and it gave substantial space to the wonders of doing less vs more.

Of course, the New England Journal of Medicine and the Lancet, get the biggest RCTs, but for those who make a living seeing patients rather than writing papers and making speeches, JAMA Internal Medicine was the best journal to read.

Best wishes, Rita, and thank you for all that you have done. Your successors have their work cut out for them.

Hypertrophic Cardiomyopathy and Exercise

Because hypertrophic cardiomyopathy (HCM) can predispose to ventricular fibrillation, and because everyone knows about famous athletes who have died on the field, the question of exercise comes up often in patients with HCM. Old thinking had exercise as scary in patients with HCM. New thinking is moving toward less exercise restriction.

The Journal of the American College of Cardiology (JACC) has published a research letter from the famous group at St George’s in London in which they report on outcomes and changes in phenotypic expression of HCM in 53 consecutive athletes who continued to participate in competitive sport.

Athletes were seen at 6 to 12-months; assessments including electrocardiogram (ECG), echocardiogram, cardiopulmonary exercise testing, holter monitoring, and cardiac magnetic resonance (CMR) imaging. For the comparison, they used an athlete’s first tests against his last (98%).

Half of these athletes were professionals. The most common sport was cycling, then football, running, and rugby.

About a quarter were diagnosed with symptoms; 6 athletes had a family history of sudden cardiac death (SCD).

All 53 athletes were considered to have a “low” European Society of Cardiology (ESC) 5-year SCD risk score for HCM (mean SCD risk was only 1.9%). The ESC risk score uses age, maximum left ventricular wall thickness, left atrial diameter, left ventricular outflow tract gradient, family history of SCD, non-sustained ventricular tachycardia, and unexplained syncope.

  • Over nearly 5 years, and no detraining, all athletes remained free of cardiac symptoms. No deaths, no sustained ventricular tachycardia (VT), or syncope.

  • Four athletes showed new nonsustained VT, one of whom had an ICD because his risk score increased to as high as 4.9% on the basis of new late gadolinium enhancement on CMR.

  • One athlete had short run of AF.

  • There was no change in the electrical, structural, or functional phenotype as evidenced by ECG, echocardiography, and cardiopulmonary exercise testing.

The authors estimated the annual rate of SCD in the general HCM population as 0.5% to 1% per year. Therefore, they argue, that over the course of 4.5 years, you’d expect between 1.2 to 2.4 SCD events in this population. But there were none.

“Our findings suggest that the mortality rate in low-risk athletes with HCM who continue to exercise are no greater than in the general population.”

They mention their small sample size but emphasize that it is larger than previous reports and one-half were pro athletes and 17% were Black athletes, who are perceived to be at higher risk.

Comments. HCM is uncommon so sample sizes are always going to be small. First, the upside: This is encouraging data; I like athletics, and I find restricting those who love sport from doing sport is a big deal. It’s also reassuring that unlike arrhythmogenic right ventricular cardiomyopathy, competitive high-level exercise does not seem to progress the phenotype.

Yet I would emphasize some of the limitations:

  • First, they selected athletes who were already playing sports, so by definition, they would be low risk; a sort of survivor bias.

  • Second, few regular cardiologists have the expertise of the group led by Professor Sanjay Sharma. It’s unclear to me if athletes had CMR every 6 months to a year, but this would not be feasible in most centers

  • Third, SCD is a rare but terrible event. The ESC risk score is reasonable, and gets patients into a ballpark risk, but low risk does not equate to no risk. And all it would take is one of the 53 athletes to have cardiac arrest and the conclusions of this paper could change.

Two Previews

I wrote a column that will likely publish next week on the California misinformation law regarding doctors. I hope you read it and let me know what you think.

For the podcast, next week, there was a super important paper that reported on the FDA Duplicate project. This looked at the ability of very high-quality observational studies to simulate RCT results. It’s hugely important but I need more time to evaluate it fully.


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