Providence Hospital in Portland is world class and is a leading research center. I would have no problems going there or even nearby hospitals which usually have similar outcomes.
Of course bypass should not be taken lightly. The mortality is low, but depends on how healthy you are to begin with to some extent. But, this procedure is one of the miracles of modern medicine. You could easily make a full recovery and be better than ever.
With 90% blockage in a coronary artery
you have what is called a hemodynamically significant blockage, which means that blood flow is limited to the myocardium that the artery supplies. This is how you end up with permanent heart damage should this vessel clot. I have seen patient's with only 50% lesions form clots and blockages and cause heart attacks in front of my very eyes, even after being cleared by cardiologists for other surgeries. Do not put this off. In my facility we would have operated on you the next day, perhaps the same day if you were having symptoms such as chest pain
or shortness of breath
Should you get the bypass, make sure you take a shower the night before or the morning of surgery with hibiclens
to reduce the bacterial content of your skin and reduce any chance of infection.
I hope that you can find a solution that fits
your needs. Also, that you alter your lifestyle as much as possible after your chosen intervention. Take your meds, eat right, exercise, be happy, don't smoke.
Best of luck.