> Once women reach the age of 50, about the age of natural menopause, their risk for heart disease increases dramatically.

Wouldn't the hormonal changes associated with menopause be a more likely explanation for the increase in heart disease risk than the fact they are no longer losing blood periodically?

The correct answer is probably "both" rather than only one or the other. It's humans that like to create simple explanations and clear cut categories, not nature. Nature gives us egg-laying mammals because nature didn't ask our opinion beforehand.

How different is the increase of heart disease risk for men above 50?

A quick search indicates men actually see an increase after age 45. Some additional stats from the below source:

The average lifetime risk of developing cardiovascular disease was around 52% for men and 39% for women.

Lifetime risk jumped to 69% for men and 50% for women who had two or more cardiovascular risk factors by age 50.

Lifetime risk was just 5% among men and 8% among women who had optimal risk factors for cardiovascular disease at age 50.

https://www.webmd.com/heart-disease/news/20060206/how-great-...