Young male hearts are vulnerable?
Young female hearts are stronger?
This was unexpected. While looking through emergency department data on the road to understanding the surge in resuscitations among the 20-44 year old age group, a pattern of acute myocardial infarctions showed up, whereby young males - aged 0 to 19 years - had eight times as many MIs as young females.
It is generally known that men have more heart attacks than women. What is not so generally known is that boys have more heart attacks than girls.
A perusal of the scientific literature shows some recognition of the sex ratio skew in adults, but this appears less recognized for children and young adults. This study from China found that young MI patients - defined as being 45 years old or less - was highly skewed toward males:
A US study of 123 adolescents who sustained acute MI found a 4:1 male:female sex ratio. They comment that 20% of the adolescents had a history of substance abuse, and that 12% were smokers.
Within the very small set of studies that address pediatric myocardial infarction, there are a few that do not demonstrate the skewed sex ratio. This study of 17 children aged 12 or less who had suffered MIs had 11 girls and 6 boys. This study of 99 children who had cardiac arrests found a 1:1 sex ratio. This study of approximately 30 neonatal MIs does not even mention the sex of the infants - presumably the authors had no expectation that patient sex would have any influence in cardiac disease.
MYOCARDITIS IN BOYS?
It appears that young males are more vulnerable not only to myocardial infarctions than young females, but also to myocarditis. This 2017 study states “Men are known to have a higher incidence of myocarditis than women in adults aged <50 years” and then analyses rates among children.
Their findings: “In children aged 0 to 5 years, there was no sex difference in the occurrence of myocarditis. Boys aged 6 to 10 years had a higher incidence rate compared with girls (72% boys; incidence rate ratio: 2.46; 95% confidence interval, 1.03–5.89; P=0.04). Sex difference further increased in children aged 11 to 15 years (80% boys; incidence rate ratio: 3.5; 95% confidence interval, 2.68–5.67; P<0.0001).” (emphasis mine)
SUMMARY
As many readers know, my focus in mRNA vaccine safety revolves primarily around myocarditis, where it has long been observed that young males are at increased risk. What appears increasingly likely is that male hearts are generally more vulnerable to inflammation and infarction than female hearts. Perhaps mRNA vaccines magnify this difference.
This pre-existing vulnerability raises some theoretical possibilities around treating mRNA myocarditis, meanwhile.
Testosterone is my first hypothesis. Presumably this should be seen in other waus, i.e. sex ratio in cases of sudden death, increased cardiac reports associated with testosterone use, decreased cardiac reports associated with androgen blockers.
On a closely related point, Brazilian MD/PhD Flavio Cadegiani and team identified an increased rate of severe covid in men with high androgen expression, and successfully trialed androgen blockers for the treatment of covid. Whether this means that severe covid was often impairing the heart, or whether there are other ways in which testosterone affects the body in severe illness, is subject of future research and post.