When I was 42 my gyn discovered my heart murmur. Went to the heart doctor and they did a echo and we kept an eye on it for 11 years then at 53, I had AVR in 2013. Heart surgeon discovered I had a 2 leaflet valve. They had never discovered that on all the echos I had every year. My on-x valve has been running now for 9 years and going strong.