Aromatase Inhibitors and Escalating Blood Pressure

Hi all, I've been taking AI Letrozole for 4.5 months. I switched from Anastrozole after 1 month since my BP was going up too fast. It was a slower uptick with Letrozole, but steadily upwards. Because of possibly strong family history of heart disease, I was normally at about 135/78 (on two BP drugs) before the diagnosis of a recurrence after 30 years cancer free.
About a month ago, I began to get BP "spikes" about once a week at night around 180/90. Then a week ago it became several spikes EVERY night in that range, that would wake me up. It was scary that I could not control that, so went to ER. They couldn't do much, so saw my Primary Doc, who said "you're BP is not well -controlled enough." So now I'm on a third BP drug, and I am so suspicious of the AI Letrozolel causing this that I just quit taking it 7 days ago, to see if BP improves. There are definitely studies that AI' s can cause cardiovascular problems in some people, hypertension being one type. At 75 I don't want to ruin my heart in an effort to prevent the spread of breast cancer. So far it's not metasticized. I'll let you know how this goes. Has anyone else had heart-related reactions like this taking AI's? It seems from reading here that most folks can be on AI's for years and not have adverse reactions.