I am not sure that your claim that "50% more likely to be misdiagnosed than men" is correct. I suspect that the figure is a misrepresentation of the data by the British Heart Foundation. This reported that for STEMI women had a 41% chance of being misdiagnosed, and for NSTEMI it was 59% chance of being misdiagnosed. The BHF simply combined these two to give 50%. Notwithstanding that, the source of the BHF's data was an article by Wu and Gale "Impact of initial hospital diagnosis..."

In this Wu argued that if you are a male patient suffering from a STEMI heart attack, then you have a 19% chance of being misdiagnosed. For a female it is higher at 24%. If you are a male patient and you are suffering a NSTEMI heart attack, then your chances of being misdiagnosed are 33%. For a female it is 41%. Thus, for both types of heart attack women are at greater risk of being misdiagnosed but based on Wu’s published data the difference is not 59% or 41%. It is 4% and 8%.