Thread by @AkivaRosenzveig

The #WorldCup2022 ⚽️ finals are set 🇦🇷vs🇫🇷 & is just a few days away, but don't forget about Christian Erikson 🇩🇰 and what happened to his heart in June of 2021.

A 🧵on Sudden Cardiac death (SCD) in athletes 💔….

with edits from @AHajduczok @MichaelEmeryMD and @CardioNerds

We will talk about:
⚡️Global incidence of SCD and sudden cardiac arrest (SCA) in the general and athlete populations
⚡️Etiologies implicated in SCD/SCA
⚡️If and how we can prevent SCD/SCA

Poll:
How do you feel about the following statement:

I feel comfortable with my knowledge of sudden cardiac death in athletes and the role prevention plays

First some definitions:

❤️‍🩹Sudden cardiac arrest (SCA):

Unexpected circulatory arrest➡️death➡️reversed by medical intervention

💔 Sudden cardiac death (SCD):

Sudden unexpected death due to cardiac causes or no other noted cause and Hx consistent with cardiac-related death

👉SCD is the most common medical cause of sudden death and is responsible for 56% of sudden death cases in athletes ≤39 years old😱😱

pubmed.ncbi.nlm.nih.gov/19221222/

It's difficult to determine the incidence of SCD but to give you a sense:

▶️ The estimated incidence of SCD in the general population is between 180,000-450,000 or 7-18% of total deaths.

pubmed.ncbi.nlm.nih.gov/21310315/

What about athletes⁉️⛹️🏋️‍♂️🏃‍♀️

❤️‍🔥All ages: ranges from 1/39,000 to 1/281,000

<40: 1-2/100,000

❤️‍🔥Male athletes have 3-5x ⬆️ incidence of SCD

❤️‍🔥Black athletes have 3x ⬆️ incidence

pubmed.ncbi.nlm.nih.gov/29284578/

Although most SCD occurs in general pop., intense exercise increases risk in those with underlying cardiac conditions

WHY⁉️

▶️ Intense exercise➡️⬆️ sympathetic activation ➡️ arrhythmias in PREDISPOSED individuals ⚡️💔

But what causes SCD in these individuals❓

So…hard to know because:

👉Post-mortem diagnosis lends bias to structural etiology
👉electrical abnormalities may be missed
👉large inter-provider variation among pathologists
👉7-44% of individuals remain without a declared etiology

Now that we got that out of the way, check out this nice table of the most common IDENTIFIABLE etiologies.

But, let’s break it down into:

❤️‍🔥Structural
❤️‍🔥Acquired
❤️‍🔥Electrical

Remember, the most common etiology is "sudden unexplained death" (see previous tweet)

Structural Abnormalities

⚡️Most cited etiology, although likely biased due to the nature of autopsies
⚡️Most common:

▶️Hypertrophic cardiomyopathy (HCM)
▶️Arrhythmogenic right ventricular cardiomyopathy (ARVC)
▶️Coronary artery abnormalities (CAA)

There is significant geographic 🌏variation likely reflecting the 🧬 component of these abnormalities

HCM:

▶️36% in US, 2-12% in Italy, UK, and France

ARVC:

▶️3-5% in US, 22% in Italy, and 10-12% in UK

Acquired Abnormalities

▶️Myocarditis is implicated in 2-9% of SCD

This is due to:

❤️‍🔥acute phase cardiac inflammation triggering electrical instability

❤️‍🔥 post-acute phase myocardial scar as an arrhythmogenic focus

▶️Commotio Cordis (blunt trauma to the chest resulting in SCD)

▶️implicated in 4% of sudden death cases

▶️ Other etiologies include heat stroke, illicit substances amongst others

Electrical Abnormalities

⚡️Pre-excitation syndromes (WPW)
⚡️Channelopathies (Brugada, LQTS)
⚡️Catecholamine polymorphic ventricular tachycardia

👉Least cited likely due to detection bias.

Genetic testing in 🧍‍♂️ with unexplained SCD/SCA found clinically sig. variant in 22-27%

Let’s talk about prevention‼️🛡️

Guideline Recommendations:

▶️ AHA/ACC endorses universal pre-participation examination (PPE) of Hx and PE
▶️ ESC endorses PPE including Hx, PE, and ECG
▶️ Italy and Israel MANDATE Hx, PE, and ECG

So what’s the evidence???

Some stats:

❤️‍🔥18-19% of athletes with SCD = prior Sx (chest pain, palpitations, syncope, dyspnea)
❤️‍🔥1 in 5 w/ PMHx such as murmur, diabetes, CHD, myocarditis, prior SCA
❤️‍🔥6.9% of young victims w/ family Hx of SCD
❤️‍🔥8% family Hx of death of 1st-degree relative <50

What do we do with these stats❓ Ask more about family Hx and do more physical exams!

The most commonly accepted tool is the AHA 14-point PPE (Class 1 recommendation by AHA)

American Academy of Pediatrics also released a PPE-5 in 2019 (nrotc.wisc.edu/wp-content/upl…)

The problem is that based on a meta-analysis:

Hx- Sens:20% Spec:94%

PE- Sens:9% Spec:97%

pubmed.ncbi.nlm.nih.gov/25701104/

Here enters the ECG controversy:

The same meta-analysis as above showed ECG to have sens:94% spec:93% in identifying conditions associated with SCD

But what really matters is does it prevent SCD⁉️

Evidence is based on a study in Italy:

👉84% reduction in SCD annually with ECG screening in ages 12-35

critique:

1⃣comparing 20 years after ECG screening to only 2 years prior

2⃣low event rate

These results have yet to be replicated

jamanetwork.com/journals/jama/…

▶️ECG screening has its technical limitations in athletes due to the physiologic adaptations of the heart

▶️There have been many iterations of criteria specific to athletes

▶️The most current is the International Criteria (2017)

What about Transthoracic Echocardiography (TTE)❓

👉Most major medical societies recommend against its use as a screening tool as no studies to date have shown it to be effective

Ultimately, screening needs to be personalized, maximizing the likelihood of detecting these conditions and minimizing the overall burden on the healthcare system

Therefore it is so important to develop emergency access plans 🦺with AEDs➡️ ⬆️ survival of OHCA with OR 1.75!!

Want to learn more❓

Check out this awesome review by @AHajduczok @max_ruge_md and @MichaelEmeryMD for all you want to know about SCD in athletes

pubmed.ncbi.nlm.nih.gov/35813032/

Let's reassess
How do you feel about the following statement:

I feel comfortable with my knowledge of sudden cardiac death in athletes and the role prevention plays

My sincerest thank you to @AHajduczok for the review article and phenomenal mentorship, @CardioNerds mentors @AmitGoyalMD @Gurleen_Kaur96 and @TDonisan for reviewing and editing, and #HouseThomas for the unending support, and of course @MichaelEmeryMD for his expert insight! 👋

Lastly, I will always be grateful to @ArjunKanwalMD for opening my eyes to the world of #SportsCardiology #CardioTwitter #ACCMedStudent @WMCCardsFellows