Read this thread with interest.
Several years ago, I suffered a weird fall while taking a picture.. believe it or not. Broke my left femur. While at a somewhat remote hospital awaiting surgery to repair it, they administered a "nuclear stress test," a drug mimicking your heart under physical stress. A blockage was revealed, but I never had symptoms. Decided to go ahead with the surgery as the alternative was a 2.5 hour ground ambulance ride to Marquette, which was not highly regarded at that time.
I was enrolled in a cardiac rehab session and a follow-up with a cardiologist. He, they, routinely prescribed nitro as part of the regimen, but have never used it. I was never instructed to use special handling.