I was diagnosed with microvascular angina last year!
I take 60mg of Imdur (isosorbide mononitate) once a day in the morning. This widens the tiny vessels around the heart & prevents the angina symptoms that I was getting with exertion. Apparently the body can get use to this drug, so I only have it in the morning- this means I'm more likely to get the angina pains during the evening.
I also carry a nitroligual pump spray for emergencies but since I've been on the Imdur, I very rarely need it. My blood pressure is normal & my arteries are like a 14 year old so I'm told- so I go to the Gym & lead a pretty normal life.
My cardiologist said that it isn't a particularly serious condition in that I'm no more likely to have a heart attack than anyone else.
However the pain means that that heart is under stress, so needs to be controlled. Hope this helps!