Jan 28, 2022 This Week in Cardiology Podcast

John M. Mandrola, MD


January 28, 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 only for healthcare professionals.

In This Week’s Podcast

For the week ending January 28, 2022, John Mandrola, MD comments on the following news and features stories.

AF Screening

This week JAMA published the latest US Preventive Services Task Force (USPSTF) systematic review on atrial fibrillation (AF) screening. AF screening by doctors, that is. After a review of 26 studies, USPSTF found that the current evidence is insufficient to assess the balance of benefits and harms of screening for AF.

USPSTF is a notable group because they are independent experts in critical appraisal. Think Neutral Martians not cardiologists looking at the evidence. USPSTF assigns grades of preventive services on an A-B-C-D-I system. For example, A = high certainty of net benefit and doctors should offer or provide the service, while D = high certainty of no net benefit and harms outweigh benefits thus doctors should not offer this service. ‘I’ means insufficient evidence.

My colleague Andrew Foy, from Penn State University, and I wrote an editorial on the review in JAMA-Internal Medicine. We mostly concurred with the USPSTF group but emphasized that a major trial published after their review suggested that screening for AF actually gets closer to a D grade.

Systematic reviews have to end at some point, and in this case, the review ended before publication of the LOOP study, which is arguably the best-case scenario for AF screening. I say that because LOOP used implantable loop recorders (ILRs), which are always on, require no action from the person, and detect AF with decent accuracy.

LOOP enrolled older adults and found:

  • The group with the recorder had 3-fold more AF discovered and nearly 3-fold more anticoagulant prescriptions.

  • Yet all that extra AF discovered and anticoagulant prescribed did not lead to a statistically significant reduction in stroke.

Now I know some of you will say, come on Mandrola, in LOOP, the screened group had a 20% reduction in stroke and the majority of the 95% confidence interval (CI) was actually < 1, so while it did not reach statistical significance, screening did appear to reduce stroke.

Here’s the problem with that interpretation: major bleeding was 26% higher in the screened arm. Again, this did not reach significance, but the majority of the 95% CI was above 1 suggesting a high probability of higher major bleeding in the screened arm.

Comments. USPSTF finds insufficient evidence for AF screening. LOOP, with its high-level screening using ILRs, finds no net benefit. Is this surprising? Foy and I argue, no it is totally expected. Three big reasons:

  • The first reason is that we don’t completely understand the relationship between AF and stroke. We wrote:

    Consider how AF screening compares with breast cancer screening. The goal of early detection of breast cancer is to reduce the death rate from breast cancer, and because it is a leading cause of death in women, to reduce overall mortality. Early AF detection is different because AF is but 1 cause of stroke. In fact, the majority of the strokes in patients with screen-detected AF may not be sensitive to anticoagulants.

  • The second reason we were not surprised by LOOP is that we don’t know how much AF warrants oral anticoagulation. In the old days, anticoagulants were proven to have a net benefit (stroke reduction > bleeding increase) in patients with “clinical” AF, that is, AF that prompted a doctor’s visit.

    But now we have devices that can detect AF lasting seconds to minutes. We don’t know if treating these short-duration episodes will reduce stroke more than it increases bleeding. Fortunately, two ongoing randomized trials are looking at this question.

  • The third reason AF screening could fail is the harms of downstream testing. A person with a smart watch who discovers an irregular heartbeat may meet a calm, wise doctor who does just the right amount of testing as well as counseling on reduction of AF risk factors, such as obesity, alcohol excess and sleep apnea. This would be a positive.

    But the asymptomatic (previously healthy) person with screen-detected AF may also meet a doctor who orders a slew of unnecessary tests—any of which could lead to harm. Doing oodles of testing is sometimes warranted but it nearly always medicalizes a problem. In 2022, however, AF screening is increasingly being done whether doctors like it or not.

The reality is that rhythm monitoring is increasingly done with consumer devices, such as watches and smartphone apps. Foy and I addressed this point in our closing: We will increasingly see patients present with the surrogate marker of screen-detected AF. As with any screening test, the question is whether this knowledge can guide management decisions that ultimately improve outcomes. The evidence to date suggests the answer is no.

The biggest lesson from the USPSTF review is as a thinking exercise about screening for disease, which is admirable in theory but full up with snags in real life. We have to help people — our patients — understand the limits of early detection of surrogate markers of disease, because the digital revolution will only lead to more detection of more dubious surrogate markers of disease.

COVID Vaccine Myocarditis

Steve Stiles has excellent news coverage of multiple recent papers published on vaccine induced myocarditis, including one using the Vaccine Adverse Event Reporting System (VAERS). Do read Steve; he’s always excellent.


The World Heart Federation (WHF) has published a new policy brief that reports there is no safe amount of alcohol for the heart. The document tries to dispel the notion that a glass of wine per day is beneficial. The authors make the case that these old notions are based on observational data, which are heavily confounded.

I did not find any new sources of data but I have a few comments:

  • First, I think the negative effects of alcohol on the heart are underappreciated. So, in that sense I concur with the WHF. Surely people with heart disease or arrhythmias give themselves a better probability of improvement if they cut out alcohol. This is especially true for patients with AF and/or cardiomyopathy.

  • On the other hand, I hear my Italian colleague, Luigi DiBiasi, in my head. He has told me how important wine is to the Italian way of life. I get that, so it’s hard for me to be an anti-alcohol crusader.

Cycling is dangerous. Driving a car is dangerous. Skiing is dangerous. Life is full of risks and as clinicians we would do well to understand that people may not always make the most optimal health decisions.

Yes, it is unwise to recommend a glass of wine or spirits for the sake of health, but it is also hard to recommend that a healthy happy person give up their low dose alcohol intake.

Sports Related Sudden Death

The Journal of the American College of Cardiology (JACC) has published a paper from researchers at University of Paris, first author, Nicole Karam, that reports good news on the matter of survival from sports related sudden cardiac arrest (SrSCA). The authors used data from the French National Institute of Health and Medical Research, to study the evolution of incidence, prehospital management, and survival at hospital discharge of SrSCA among subjects aged 18 to 75 years, over six successive 2-year periods between 2005 and 2018.

  • The incidence of sudden death in sports was mostly unchanged over the time periods.

  • Most occur in middle-aged recreational athletes.

  • The frequency of bystander cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) use increased significantly and this was associated with a survival to hospital discharge of 66% in the last time period vs 24% in the first time period.

  • The authors conclude that the incidence of SrSCA remained relatively stable over time, and to them, that suggested a need for improvement in screening strategies.

  • Major improvements in on-field resuscitation led to a 3-fold increase in survival, underlining the value of public education in basic life support that should serve as an example for SCA in general.

I agree much more with the latter conclusion about the importance of public education and early intervention. I don’t so much agree with a need to improve screening, because of the absolute incidence. The incidence of sports related cardiac arrest is 6 to 7 per million. I may be wrong, and you can freely disagree, but I cannot see how any screening techniques could possibly modify an event with an incidence of 6 per million.

The data from this paper suggests the way to save lives from sports related sudden death is intervention, not prevention.

Physician vs Non-physician Care

I don’t know how it is in your neighborhood, but in ours, more and more care is delivered by nurse practitioners (NPs) and physician assistants (PAs). Two years ago, I wrote a column arguing that NP and PA care would not on average lead to worse outcomes. It’s counter-intuitive because docs have a lot longer training program. This past week I posted a 2-year update. I updated it because the growth of non-MD care has been incredible. And I came to the same conclusions. On average, I don’t see outcomes being much different. In the post, I gave the reasons why I believe this to be true. And then closed with three recommendations that may help ensure confidence in non-MD care. Take a look at the column and let me know what you think.

In Hospital Cardiopulmonary Resuscitation

Another feature article up on | Medscape Cardiology that’s worth taking a look at is from interventional cardiologist Jaya Mallidi. Dr Mallidi asks a question that I think about often – whether CPR as a default in the hospital is the correct default.

She notes that “In this country, we need permission to forego CPR. If there are no advanced directives or next of kin available to discuss end-of-life care, performing CPR is the default status for all hospitalized patients, irrespective of the underlying severity of the illness.”

In the column she tells the story of a man actively dying but no next-of-kin is available. CPR, she rightly argues, is an intervention that clearly has little benefit for this person. Then why is it the default? What follows is a nice discussion about the care of patients who are at end-of-life. It makes you think about a tough topic.

I suspect Jaya Mallidi’s views about in-patient CPR are similar to mine. You may disagree with me, but I see CPR as an extremely aggressive intervention that has benefits and harms. CPR and early defibrillation was the basis of the coronary care unit, and when used in patients with acute myocardial infarction, it is often life-saving.

But far too often CPR is used in patients with multi-organ failure who have little to no chance of meaningful survival. This is a tragedy. To me one of the most helpful things a cardiology or electrophysiology consultant can offer is permission to not recommend or default to CPR.

Good on Dr. Mallidi.


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