I don't understand what the poster is asking.:hmmm
He's been given the all clear to fly by his cardiologist and if he is referred back to him by his GP, then he will probably required an angiogram..... So at the moment it implies that he's not waiting for a clinic appointment with a cardiologist, and who knows when he is going to be referred back?.
It could be weeks, months or years, depending on his medical condition changing enough to warrant his GP to refer him back.
Also he doesn't tell us which country he's travelling to. If it's Europe, then like many of us with pre-existing conditions, we have to rely on our EHIC card when we can't get insurance to cover a particular condition on our insurance policy....... or if you manage to get it included, the insurance costs considerably more than the price of the holiday.
It seems to me that he is jumping the gun of what might or might not happen in the future. He's been given the all clear to fly and if his insurance company is aware that he has angina and his medication, they should decide whether to cover him or not.
Looking into a crystal ball and trying to forecast when a condition may change is no sound basis for making any decision.
Sanji x