I guess this one is kind of like asking "How big is the sky?" The answer really isn't important, except in the context of your own case. Some patients are diagnosed with stenosis as young children, then go on to live normal lives for many years. Others are diagnosed and are moved directly to surgery. There are too many variables for the general answer to mean very much to a single patient.
I think much has to do with your age at time of diagnosis. I was first diagnosed at age 51 or 52. I then went on to lead a rather normal life all through my 50's and up to age 63, when I decided that it was time for surgery. I "think" I was in The Waiting Room for over 10 years, which is a fairly long time to wait for someone diagnosed as late in life as was I. There are others here who waited longer than I, but if I remember them correctly, they were diagnosed earlier in their lives yet still were able to hold out until their 50's or later for surgery.
The other reason that this question is so hard (or may be impossible) to answer is the fact that for each patient, the condition progresses differently. Some patients are diagnosed, then their condition progresses very slowly. These patients are able to wait, as they are in no danger from their condition. Other patients are diagnosed and their condition progresses very rapidly, seemingly to go directly from a slight murmur to emergency surgery. There is no way to know for sure. Usually, the cardio's like to be able to evaluate sequential echo-cardiograms over several years to even begin to guess if their patient will be a long-term denizen of The Waiting Room or not.
I wish there was a way to definitively answer your question, but if there is a single answer, I don't know it.
