Suggest Treatment For Chest Discomfort With Unstable Angiogram

Hi, I'm 36 with a 20yr history of smoking, and diabetes type 2 and moderately overweight. I was going up and down the stairs and got some mild chest discomfort. It went away, and have not experienced it again. I went to a scheduled routine appointment with my PCP who did an ekg and found some nonspecific changes and sent me to the hospital. The ekgs were negative and they ruled me out for an MI, then went to a cardiologist and told me eventhough the ekg is neg. he think im having unstable angina and said i need an emergent cath based on my risk factors and one episode of chest discomfort a week prior, he said he does not trust a stress test as it can kill me with unstable angina. I have not experience the pain ever since, and im afraid he may be jumping the gun with a cath....I am concerned that he also a stent happy type of guy. I tried to find possible alternatives such as 64 CTA, but he says I may die if I wait and have to have the angiogram. I know cath is the gold standard, but cta has a comparable negative predictive value. Other studies such as a conventional pulmonary angiogram is the gold standard to rule out pulmonary embolism, but nowadays a pulmonary angiogram is almost never ordered to exclude a pulmonary emboli. Am I being unreasonable to consider alternatives or is a cath is absolutely needed STAT?