Mar 29, 2024 This Week in Cardiology Podcast

Intermittent fasting, anticoagulation decisions, heterogenous treatment effects, frailty in HF, the importance of the ECG, and industry conflicts are the topics John Mandrola, MD, covers this week.
www.medscape.c...
-- TRANSCRIPT --
In This Week’s Podcast
For the week ending March 29, 2024, John Mandrola, MD, comments on the following news and features stories: the Intermittent fasting paper, complicated anticoagulation decisions, heterogenous treatment effects, frailty in heart failure (HF), the importance of the ECG, and industry conflicts.
The Intermittent Fasting Brouhaha
No, Intermittent Fasting Won't Kill You
Dr Christopher Labos has a nice essay on theheart.org | Medscape Cardiology site about the recent intermittent fasting story. He is a great writer and thinker, but I have a bit of different take.
Perhaps you heard about this story. The American Heart Association (AHA) issued a press release in advance of the AHA EPI meeting detailing an observational study that found an association between people who self-reported intermittent fasting and a 91% higher rate of cardiovascular (CV) death. There was no simultaneous publication; it was just a poster.
This was about as flawed an analysis as there is. There were self-reported eating patterns (I can hardly recall what or how I ate yesterday, never mind weeks ago), and there were surely confounding variables - that is, people who self-report time-restricted eating may be different from those who do not. Dr Labos points out that the authors did 36 comparisons, so the play of chance was also likely. I could go on.
But this story has a special twist. One that really bugs me.
When the paper came out reporting that a popular pattern of eating was associated with harm, and mainstream media jumped on it, many of the Top People in medicine were outraged at the methodological flaws.
There was a backlash, and Twitter lit up with Top People telling us about the problems of non-random observational comparisons.
What bothers me about this is that many of these people remain silent when similarly flawed studies come out that find associations they like. Gulp, some of them even publish studies like the one they are publicly shredding.
My take is that nearly all of these sorts of studies are too flawed to have a) been done, b) been published, and c) been promoted or covered in the media.
What I try to do here is be neutral in my criticism of these studies. I don’t feel strongly about time-restricted eating, recent studies in the NEJM and JAMA find no real weight loss effects. What I would propose is that there be equal criticism for similarly flawed papers.
Today, I will discuss a number of observational studies that were done properly and add important findings to consider for the practice of clinical medicine.
Stroke Prevention with OAC in patients with AF
We have the simple idea that if stroke risk is high enough, we start oral anticoagulants (OACs). We determine stroke risk based on the simple CHADSVASC score. We estimate the untreated yearly stroke risk, then multiply it times 0.65, as 65% reduction is how much warfarin reduced stroke risk vs placebo or aspirin (ASA).
This is the prevailing thinking. It is what the guidelines say. It is the mainstay of decision aids for OACs.
But it’s super simple and makes assumptions that may not be true. One of the major assumptions is that there is no accounting for competing risk of death. Namely, if a patient dies of anything 1 or 2 or 3 years after starting OACs, there is blunting of the 5-year efficacy of stroke prevention.
The thing is, death is a common occurrence after a new diagnosis of atrial fibrillation (AF). Multiple observational studies report a 20% to 25% mortality in the first year after AF diagnosis.
Transcript in its entirety can be found by clicking here:
www.medscape.c...