Advantages of an Early Aortic Valve Replacement
Research suggests that replacing or repairing a stenotic aortic valve may have greater long-term benefits for patients, even if there are no symptoms.
Once you find out you have a heart condition, your first impulse may be to “fix” it as soon as possible. But some problems are better served by monitoring them and taking a “watchful waiting” approach to see if the problem ever progresses. If there are no symptoms and there is no change in the condition, surgery or other interventions may not be necessary.
This approach was recently examined in the case of aortic valve stenosis, a condition in which the valve fails to open properly. In a study published in JACC: Cardiovascular Interventions, Japanese researchers found that replacing the valve in patients with severe aortic valve stenosis but no symptoms led to significantly better outcomes instead of taking a watch-and-wait approach. For example, at five years, the rate of hospitalizations for heart failure was 3.8 percent among patients who underwent aortic valve replacement (AVR), compared to 19.9 percent among patients who were on watchful waiting.
But this aggressive approach to asymptomatic patients needs to be evaluated carefully, explains Samir Kapadia, MD, section head of Invasive/≠Interventional Cardiology at Cleveland Clinic. He noted that many factors need to be considered, including whether the patient is symptomatic.
“Many patients don’t know if they are symptomatic,” he says. “Sometimes we do a stress test to assess this. If aortic stenosis is very severe, it is unlikely that the asymptomatic state will last for long.”
To understand the severity of aortic valve stenosis, doctors have several tests that can help them reach a diagnosis.
Because aortic valve stenosis means the valve can’t open fully, the result is a reduction in blood being pumped through the aorta≠—the body’s biggest blood vessel—to the rest of the body.
A stress test reveals how the heart functions during exertion. If blood flow through the aorta is limited or the heart is pumping harder to compensate, that may be revealed in a stress test.
Your doctor may also look for signs of significant left ventricular hypertrophy, a condition in which the wall of the heart muscle around the left ventricle has become thickened due to the additional pumping demands caused by the valvular disease.
Dr. Kapadia adds that a measurement of B-type natriuretic-peptide (BNP) is also useful in determining whether aortic valve stenosis is developing into heart failure. BNP is released by the venticles in response to pressure changes within the heart.
“Concurrent coronary artery disease may also tip the balance for more aggressive therapy for these patients,” Dr. Kapadia adds.
When AVR is necessary
If the severity of your aortic valve stenosis gets to a point where replacement is the only option, there are some key things to keep in mind.
For example, AVR in adults is usually done with open surgery. However, in recent years a procedure called transcatheter aortic valve replacement (TAVR) has become more widely used. It’s still limited primarily to patients for whom traditional surgery isn’t an option. TAVR is a percutaneous procedure, which means it uses a catheter. The catheter delivers a prosthetic valve to the heart, where it can replace the failing natural valve. The pool of possible TAVR candidates may expand in the years ahead, but for now it’s essentially just for those who are unfit for surgery.
But even before the type of procedure is determined, several factors must be in place before a patient must receive a new valve.
A patient with severe aortic stenosis is likely to need a new valve if he or she has symptoms such as shortness of breath, angina, syncope (fainting) due to a drop in blood pressure), or ventricular dysfunction.
Patients undergoing open heart surgery for other reasons, who have moderate aortic stenosis, may also be good candidates for replacement.
“The prognosis is similar to the general population,” Dr. Kapadia says. “In other words, it’s excellent. For low-risk patients, mortality of surgery is less than one percent.”
Even though an individual may be a candidate for surgery, timing is still critical. “One should be monitored by an expert to decide the timing of AVR (surgical or percutaneous) to maximize risk benefit,” he says. “The replaced valve also has finite life, and therefore very early replacement is not recommended.”
Paying attention to symptoms
If you’ve been diagnosed with valve stenosis, but you have no obvious symptoms, talk with your doctor about what symptoms you should be on the lookout for, and what tests you should have done periodically, Dr. Kapadia says.
If you’re not active, a stress test can see how your heart is functioning.
If you are active and asymptomatic, follow-up should be done of factors such as ventricular hypertrophy, aortic stenosis severity, heart disease, and left venticular function.