AVR stands for aortic valve replacement, a procedure that swaps out a damaged aortic valve for a new one. It is the most effective treatment for severe aortic stenosis (a narrowed valve) and aortic regurgitation (a leaky valve). Aortic stenosis is classified as severe when the valve opening shrinks below 1.0 square centimeters, roughly a third of its normal size. Without replacement, the prognosis for people with severe or symptomatic valve disease is poor.
Why the Aortic Valve Needs Replacing
The aortic valve sits between the heart’s main pumping chamber and the aorta, the large artery that delivers blood to the rest of the body. When this valve stiffens or narrows (stenosis), the heart has to work much harder to push blood through a smaller opening. Over time that extra strain weakens the heart muscle.
In aortic regurgitation, the valve doesn’t close properly, so blood leaks backward into the heart after each beat. Chronic regurgitation can be silent for decades because the heart gradually enlarges to compensate. Acute regurgitation is a different story: the heart has no time to adapt, blood pressure drops, fluid backs up into the lungs, and the situation can become life-threatening within hours.
Two Approaches: Open Surgery and Catheter-Based
There are two main ways to perform AVR. Surgical aortic valve replacement (SAVR) is traditional open-heart surgery. The surgeon opens the chest through the breastbone, stops the heart temporarily using a heart-lung machine, removes the damaged valve, and sews in the new one. This has been the standard approach for decades and remains the most common method for low- and intermediate-risk patients.
Transcatheter aortic valve replacement (TAVR) is a less invasive alternative. Instead of opening the chest, a cardiologist threads a compressed replacement valve through a large blood vessel, usually in the groin, and guides it into position inside the old valve. No heart-lung machine is needed, and many patients are awake or lightly sedated during the procedure.
TAVR carries a significantly lower risk of major bleeding, kidney injury, and new irregular heart rhythms in the weeks and months after the procedure compared to open surgery. However, it comes with a higher chance of needing a permanent pacemaker afterward, roughly 2.5 times higher than surgery, a risk that persists for years. It also carries a greater risk of vascular complications at the insertion site. At five years, survival rates for both approaches are essentially the same in low-risk patients: about 85% of people are alive five years after either procedure.
Mechanical vs. Tissue Valves
The replacement valve itself comes in two main types, and the choice between them is one of the biggest decisions in the process.
Mechanical valves are made from durable synthetic materials and come in two common designs: tilting-disc and bileaflet. Their major advantage is longevity, typically lasting 20 to 30 years, which means most people never need a second operation. The tradeoff is that mechanical valves require lifelong blood-thinning medication (warfarin) to prevent clots from forming on the valve. Warfarin means regular blood tests to keep the dosing in range, dietary adjustments, and a higher risk of bleeding complications.
Tissue valves (also called bioprosthetic valves) are made from animal tissue, most often pig or cow. They don’t require lifelong blood thinners because the biological material is less likely to trigger clot formation. Most patients take only a low-dose aspirin long term, with a short course of warfarin for the first three to six months after surgery. The downside is durability: tissue valves typically last 10 to 15 years before they begin to deteriorate. In a long-term study comparing the two types, no mechanical valves failed structurally over 11 years, while about 15% of bioprosthetic aortic valves did. For younger patients, that often means a second valve replacement later in life.
In general, mechanical valves tend to be recommended for younger patients who can tolerate decades of blood thinners, while tissue valves are often preferred for older patients or those who cannot safely take warfarin.
Blood Thinner Requirements by Valve Type
If you receive a mechanical valve, the target level of blood thinning depends on your specific valve design and personal risk factors. People with newer bileaflet mechanical valves and no additional clotting risks aim for a moderate level of anticoagulation. Those with older valve designs, a history of blood clots, or weakened heart function need a higher level. One specific newer-generation mechanical valve allows a lower anticoagulation target starting three months after surgery, combined with a daily low-dose aspirin.
For tissue valves, whether placed surgically or via catheter, the long-term requirement is typically just low-dose aspirin. Some surgeons prescribe warfarin for the first three to six months while the valve settles in and tissue grows over the sewing ring. Notably, the newer direct-acting blood thinners that many people take for other heart conditions are not safe for use with mechanical heart valves.
What Recovery Looks Like
After open-heart SAVR, the typical recovery period is four to eight weeks. During that time, you’ll gradually regain energy and start returning to normal activities. Most people spend several days in the hospital before going home. TAVR patients generally recover faster because there’s no chest incision to heal; hospital stays are often just one to three days.
After the initial recovery window, many patients go through a 12-week cardiac rehabilitation program involving supervised exercise, education, and monitoring. Even after rehab ends, it’s common to feel like full recovery takes longer than expected. The American Heart Association notes that after major heart surgery, many people find they’re adjusting to a “new normal” rather than snapping back to exactly how they felt before. This is typical, not a sign something went wrong.
Risks and Complications
Both types of AVR carry risks common to any major cardiac procedure: stroke, infection, bleeding, and kidney problems. Some complications are more specific to the type of procedure.
- Pacemaker requirement: TAVR patients are roughly two to three times more likely to need a permanent pacemaker than SAVR patients, because the catheter-delivered valve can press on the heart’s electrical system.
- Vascular injury: TAVR involves threading a large device through blood vessels, which carries about twice the risk of major vascular complications compared to surgery.
- Paravalvular leak: Small gaps between the new valve and surrounding tissue can allow blood to leak around the edges. This is more common with TAVR since the valve isn’t sewn into place.
- Bleeding: Open surgery carries a higher risk of major bleeding in the first 30 days.
- Valve infection (endocarditis): Any replacement valve, mechanical or tissue, carries a small ongoing risk of infection. People with prosthetic valves typically need antibiotics before certain dental procedures to reduce this risk.
Long-Term Outlook
Five-year data from a major trial published in the Journal of the American College of Cardiology found that about 85% of low-risk patients were alive five years after either TAVR or surgery, with no significant difference between the two. Rates of disabling stroke were also comparable.
The key long-term variable is valve durability. Mechanical valves rarely fail structurally, but the lifelong blood thinner requirement introduces its own set of risks over decades. Tissue valves avoid that burden but will eventually wear out. For someone who receives a tissue valve at age 55, there’s a meaningful chance they’ll need a second procedure in their late 60s or 70s. When that time comes, a new valve can often be placed inside the old one using a catheter-based approach, avoiding a repeat open-heart surgery.