CT or catheter angiogram for possible stenosis?

I am male, 55 years old.  I get a frequent chest pains in the upper chest accompanied by mental confusion and general disorientation.  My cardiologist thinks I have nothing wrong, so he feels a catheter angiogram is of very low risk to me but I am not so sure.   Can anyone please advise.

My chest pains and confusion occur most days and have been getting worse for several years. The confusion is like I was haing a mini-stroke.  I’ve ignored pains at the top of my chest for years.

My cardiologist said I was ok because my recent ECG (EKG), the TREADMILL test, and my ECHOCARDIOGRAM were all fine.

Since then, I have had significant improvement as I increased my blood pressure tablets.  Also vasodilators  help noticeably (such as alcohol from a glass of wine or dietary supplements such as L-arginine.  The meds are Amlodipine and Losartan which got my blood pressure down to a respectable 120/80.  To help with the confusion I recently added Bisporolol 2.5mg (beta blocker) which now gets my blood pressure down to 105/65 and a pulse of 43 bpm.

When my chest pains were bad, I sometimes got PAINS DOWN BOTH MY ARMS which were shooting pains but could also be sustained for hours.  This doesn’t seem like conventional angina or Prinzmetal's angina.

A DOPPLER ULTRASOUND OF THE CAROTID arteries in the neck showed no problems. Could there be a narrowing of my VERTEBRAL ARTERIES (because I get visual and balance problems as part of my confusion).  Perhaps there’s a problem along part of the aortic arch where these arteries originate.

The cardiologist prefers a catheter angiogram because it gives a more definite result and uses less radiation than a CT angiogram. I am worried that if there turns out to be a problem (perhaps with the aortic arch or some arteries) then using a catheter might cause a nasty complication.  On the other hand a CT angiogram may not reveal enough information as a catheter angiogram.

I don’t know how to proceed.  Any advice would be welcome.