Hi Catherine,  Unfortunately, I have to tell you that the answer is probably no.  What the research (the HERS study, in particular) shows is that women with any cardiac history should not be prescribed estrogen therapy.  If you had already been on estrogen for more than a year before your TIA, then there would be no reason to take you off.  However, there is an increased risk of cardiac events for you in the first year of therapy.  It goes down after that, but -since I'm assuming-- you've not been on it, I would recommend you not start. Depending on your symptoms, there are some alternative therapies that might be very helpful in making this a more comfortable period of change for you.  If your own provider is not a menopause expert, seek out someone in your area who is, so you get the best help available. Good luck to you, Sandy.