Dad did well on a stress test. but how are vulnerable plaques checked for? i heard these dont show up on stress test. and i want to make sure no risk

No such thing: It's hard to hear, but the truth: there is never a way to say there is "no risk". If you are worried about heart disease, then focus on prevention to reduce the risk. Heart disease is preventable with a healthy diet and not smoking. Every day is a chance to make healthier choices. Avoid red and processed meats. Limit cheese and dairy products. Get regular aerobic exercise. Don't smoke.