@lewee It is person/physiology dependent. The good cardiologists conduct a thorough work up. If you don’t have genetic predisposition and no familial history, it’s stable based on serial imaging, and BP is controlled, a person can function for years at or below 5cm. It is a major surgery with risks, therefore the experts have developed guidelines to balance the risks. I was a huge weightlifter. I run and bike. My doc is confident that I can lift 135lb no problem as long as my exertion does not result in holding my breath. There are several forums that provide interviews with experts and share their experiences. I don’t want the surgery any sooner than necessary. There are many people below 5 that have been stable 20 years or more. For those less than 5 with family/genetic issues do tend to get surgery at less than 5, sometimes at 4.3 or 4.5.