Thread by @han_francis

Team it's time to address the Hoeg et al preprint on post-COVID vaccine myocarditis. How am I qualified to speak about myocarditis? I am board certified in paediatric cardiology and currently have patients recovering from this condition. TLDR: They are doing quite well. #MRI

What is the premise of that article? directly scanning VAERS data will result in capturing more cases of myocarditis, and therefore the "conclusion" that COVID vaccine generates a higher risk of myocarditis than COVID disease. But - cardiologists have diagnostic criteria. #heart

All that bleeds troponin is **not** myocarditis. I cite my professional society, the American College of Cardiology: #myocarditis #COVID19 #vaccination #VaccinesWork

Myocarditis is defined by @MayoClinicCV as: "an inflammation of the heart muscle (myocardium). The inflammation can reduce your heart's ability to pump and cause rapid or abnormal heart rhythms (arrhythmias)." Many things can cause myocarditis, and most of these are viruses.

Is all myocarditis of the same severity? Absolutely not. Is any cardiologist I'm aware of trying to downplay myocarditis when it is bad, or overcall myocarditis when it is mild? **Absolutely not**. Each patient with myocarditis deserves subspecialty care.

The most definitive test is always a pathological specimen, but this technique is plagued with false negatives, and the need to involve an interventional cardiologist. It is difficult to justify taking a snippet of a teenager's heart when s/he's recovering nicely.

I am aware of the 13yo who died after COVID vaccination, and deeply empathize with the pain that family is going through - however I eagerly await the report from the physicians who **directly** saw that patient. I will not hypothesize on his formal cause of death without data.

This is where Advanced Cardiac Imaging faculty can be useful - we can detect myocarditis by cardiac magnetic resonance imaging, and my wonderful colleagues at @scmrchd are doing just that. This snaps pictures of the heart and shows the inflammation/ injury (with no Xrays).

Why do we have MRI criteria for myocarditis? To avoid accidentally diagnosing every troponin positive teenager with myocarditis (and cry wolf). You release troponin just from exercise - mdpi.com/1660-4601/17/3… ; Every soccer player doesn't go home with a myocarditis dx.

A cardiologist's job is to put all the data together to make a holistic assessment, then give the diagnosis of myocarditis / no myocarditis. We also follow MRIs over time, and the result of that long term followup has resulted in patients recovering pediatrics.aappublications.org/content/early/…

30 000 ft view? PICU admissions are accelerating across the US due to COVID delta. Kid's aren't getting sicker, but more of them are landing in the hospital: cdc.gov/mmwr/volumes/7… #Pediatrics

Those who are eligible for vaccination deserve a chance to improve their odds of staying out of the hospital. Yes, kids don't die as much as adults with COVID, but outcomes aren't binary. PICU admit = negative impact on quality of life.

Long COVID = negative impact on quality of life. theconversation.com/do-kids-get-lo… Hospital admission post COVID vaccination = most kids are getting out in less than a week with minimal symptoms.

Remember VAERS is designed as a research hypothesis generating tool, not a diagnostic tool, and most **definitely** not a tool to seek causation. Physician review of VAERS reports really matters. Cardiologists assessing patients for myocarditis using formal criteria matters.

I have yet to witness (and have asked my colleagues too) one post-vaccine myocarditis child go on life support. Have I heard of post-#COVID19 disease children get on life support, and MISC kids go on life support? Absolutely.

In the end - vaccination with COVID in those who are eligible trades in a significant risk with a much smaller risk. That's what counts in the end.

@ENirenberg @gorskon @risahoshinoMD I would of course be grateful for any feedback that you can think of to communicate these concepts better. I stand with all my #tweetiatrician in shielding as many kids as possible from COVID.

Addendum: This is some data on the Paris experience on how bad COVID disease myocarditis/ shock/ MISC can be: pubmed.ncbi.nlm.nih.gov/32488505/ .