Let me be clear and say at the outset that I am not a doctor but this is a topic in which I have a fair amount of interest and have done a substantial amount of self-education. Per clinical and staging guidelines a valve area of 1.5 cm[SUP]2[/SUP] puts your degree of stenois severity right on the cusp of mild to moderate. Below 1.0 cm[SUP]2[/SUP] is severe. Where the valve area alone tells part of the story it does not tell the entire story; particularly in an individual with high cardiac output, large/tall body size or significant aortic insufficiency or regurgitation. Some other echo readings to pay attention to are ejection fraction, mean transvalvular gradient, aortic valve peak jet velocity, indexing the valve area to body surface area and AR pressure half time (indication of regurgitation). Get a copy of your echo report then do a quick web search for "aortic stenosis severity guidelines" as a way of getting a preliminary understanding of your degree of aortic stenosis severity. As others in this thread have said angina is an indication the heart is not getting enough oxygen; it would also be good to rule other other physiological reasons for angina such as coronary artery disease, even esophogeal reflux disease can mimic the symptoms of angina. If you have some time do a web search for "walk through angina". Is angina the only symptom or change that you've noticed? When considering the valve area alone it does not seem to be small enough at this time for that to be the sole reason for angina. You indicated that the stenosis is a result of a congenital disorder, it mght be good learn about other complications that may also be associated with the disorder that has resulted in the stenosis.
Again, I am not a doctor and I am also not 50+ but I may be able to provide some constructive input. I am a 48 year old enthusiastic mountain biker who just underwent aortic valve replacement 3.5 weeks ago for severe aortic stenosis. Aortic stenosis was a late term effect of radiation therapy in treatment for Hodgkin's Lymphoma 21 years ago. I first became aware of the condition about six years ago and at that time the valve opening was about 1.2 cm[SUP]2[/SUP], I continued riding a fair amount and had gone from viewing cycling as a means of recreation, riding 2 -3 times per week to over the past two years using cycling as a tool for fitness and health riding an average of 4.5 times per week with over 6600 miles last year and on track for that mileage range year to date this year. Over the years the valve area had reduced to an area of about .08 cm[SUP]2[/SUP] on the most recent echo in August of this year with an ejection fraction below 50% and my cardiologist as well as the surgeon viewing valve replacement as the best option at this point with no real net benefit in waiting any longer. It was only over the last nine months that I had really noticed some significant changes in my energy level and over the last three months I had modified my activity level to stay primarily in the aerobic zone as things started getting a little "funky" when I pushed toward maximal effort. Even with that I was still able to complete a 109 MTB race with 10,000 feet of climbing late summer, and in a respectable time.
Timing for valve replacement boils down to risk management. As you sit now there are known risks associated with your aortic valve in its present state. The risks associated with surgery are both known and unknown with, although a small risk, death being a worst case outcome. Optimal time for valve replacement is when the risk of not doing anything with the known condition outweigh the risks of surgery. Without clear cut symptoms or measurements in the severe category this can be subjective. I know because it was part of the process for me. Very early this year my cardiologist told me he thought it was time. He consulted with others in his practice and they all said they did not know what the right answer was but when he figured it out he should share it with them. Other reasons to wait include the reality that a prosthetic valve may have a smaller effective orifice area than the native valve even in its current diseased state. New prosthetic valve sizing will be dictated by the size of your aorta. A prosthetic valve is comprised of the active biological or mechanical valve structure plus the perimeter sewing ring that allows it to be fixed in place. Since the sewing ring is not part of the active valve structure it is not part of the effective orifice area allowing blood to move out of the left ventricle. For perspective a normal valve may have an opening of 3.0 - 4.0 cm[SUP]2[/SUP], my aortic valve was .8 cm[SUP]2[/SUP] when it was replaced last month. The new 23 mm St. Jude Trifecta tissue valve that I have now should have an effective orifice area around 1.8 cm[SUP]2[/SUP] but I will not know until I get an echo done sometime in the next two weeks. Mechanical valves will typically yield a larger effective orifice area and may last for a lifetime but they require anti-coagulation therapy for the rest of your life which requires regular monitoring and may make activities with potential for cuts, scrapes, broken bones or blunt force trauma riskier. Tissue valves will likely only last 10 - 15 years requiring re-operation in the future but recent advances in TAVR make percutaneous valve replacement through the femoral artery very likely as a replacement option at re-op time, eliminating the need for a sternotomy providing the installed bio-prosthetic valve is adequately sized In this case knowledge is power; selecting valve type is a very personal decision that you, and only you, have to live with. At what would be considered a young age for valve replacement, I chose a tissue valve knowing it would only last 10 - 15 years. A number of reasons for this including not wanting to management anti-coagulant therapy for the rest of my life, potential complication of same particularly later in life (have friends with parents on A/C therapy and issues) plus I did not want to give up activities or endeavors I am passionate about but which may not be advisable in an A/C therapy setting.
Having just recently been through valve replacement with a full sternotomy I can unequivocally say that the better shape you are going into it, the faster your recovery. I rode right up until the day I left for the hospital (went out of state to the Cleveland Clinic due to potential complications with radiation damage), six days before surgery I rode a trainer century just because I could. Surgery was on a Wednesday, skin closure in the OR was 12:15 PM that day and less than 72 hours later I was discharged from the hospital. One of the nurses on duty the last night I was in the hospital told me that in the year that they'd been on the unit it was the fastest they had seen anyone discharged after aortic valve replacement with a full sternotomy. Seriously... and I cannot stress this enough, go in as healthy and fit as you can. Luck favors the well prepared, prepare as best possible mentally and physically. I worked on core exercises for the past three months, engaged them when coughing or sneezing and it helped. Stronger core makes getting out of bed that much easier, you just do not realize how much you bend/twist/load/stress your sternum until it is completely cut and wired back together, even something as mundane as washing your hands becomes an interesting experience the first time after surgery. No driving for six weeks and no lifting anything over ten pounds for the same time period but both my cardiologist and surgeon told me I could get back on the trainer as soon as I wanted with no heart rate restrictions. Sternum heals completely in three months so sometime around 12 weeks should be able to ride outside again.
As for recovery progress, it has gone well. Discharge from the hospital day three after surgery, day five we drove 3.5 hours to Niagara Falls and spent the night, day six we walked around Buffalo, NY canalside and day eight my wife and I walked 10.5 miles through the Rocky River Recreation area south of Cleveland. Biking wise, I live in Anchorage, AK. and fall weather had not been the best so I spent a fair amount of time on a trainer indoors leading up to surgery keeping a pretty comprehensive ride log of speed and heart rate at 30 minutes into the activity. My trainer is a fluid trainer with no resistance settings but a very predictable resistance curve based on speed. I was back on the trainer at 12 days after AVR (aortic valve replacement) and within 2.5 weeks I was spinning at pre-surgery speed with a lower heart rate 30 minutes into the activity. Pre-surgery I was consistently about 14.3 MPH at 131 BPM, first day back on the trainer after surgery I was 11.8 MPH at 121 BPM with consistent gains and today's activity of 14.3 MPH at 119 BPM. To me that indicates that the disease had progressed to the point that it was impacting output and though I may not have been considered symptomatic, timing for surgery was probably spot on as recommended by the cardiologist and surgeon.
My apologies if this is long or rambling, when I started this reply I did not intend for it to be so verbose. If you have any questions fire away or send a PM. Good luck with your journey.