Aortic valve repair requires a choice: mechanical or tissue

DEAR DR. ROACH: My brother, who is 48, has a leaky aortic valve. It is a birth defect in his bicuspid valve. His health is otherwise excellent. We have lined up a good surgeon. The problem is that my brother does not know which type of valve to get: mechanical or tissue. The doctor will put in either kind, but he has done a lot of tissue valves because when it needs to be replaced, he uses the valve-in-valve technique and can replace it without another surgery.

The tissue valve does not have the clotting problems that the mechanical valve has, but the tissue valves don’t last forever. If the tissue valve lasts 20 years and the replacement lasts 20 more, he still might need another. Our parents passed away at 93 and 90.

The surgeon uses the On-X valve for mechanical valves. We know that it is better, but it still has clotting potential. Do you have any new information on this? -- J.S.

ANSWER: There are pros and cons to both mechanical and bioprosthetic (tissue) aortic valves. While I can’t tell you which is better for your brother, I can compare the two generally.

A major advantage to mechanical valves is that the newest generation of valves are expected to last a lifetime. Of course, there are no guarantees, but that is the expectation. However, even valves like the On-X -- which has less clotting, as you mention -- still require lifelong anticoagulation. The only medication available for this right now is warfarin (Coumadin), which is taken every day and requires periodic blood testing. (The newer oral anticoagulants are not effective in people with mechanical heart valves.) This is easy for some people and hard for others. In addition, you can hear these valves, and while some people have no trouble shutting out the noise, others find this difficult to live with. (When I took my medical-school admission test, the person next to me had a mechanical heart valve, and it was very distracting.)

Bioprosthetic heart valves, usually made from bovine or porcine pericardium, can last 10-20 years and do not require anticoagulation. They are very quiet.

I heard a talk from and spoke with Dr. Aresh Salemi at Cornell, a cardiothoracic surgeon who has been doing research on replacing aortic valves using a catheter, rather than doing open-heart surgery. The data shows that this technique, which uses bioprosthetic valves, has superior results to open-heart surgery in high-risk and moderate-risk patients. It may be superior in low-risk and average-risk people as well. Further, if the valve fails, it can be replaced in the same way (which is the valve-in-valve technique you mentioned). As cardiac surgeons across the country become more expert in this technique, it may (and I expect will) be that catheter-based replacement will largely supersede open-heart surgical valve replacement.

DEAR DR. ROACH: My father is 94 years old and in relatively good health. Lately he has developed a fast pulse rate that is around 125. What can cause such a high pulse rate in someone who has not had cardiac issues during his life? Are there any dietary changes he could make to bring down his pulse rate? -- L.B.

ANSWER: A sudden change in heart rate can indicate a serious medical issue, such as an infection (urine and lung infections are notoriously silent, and thus hard to diagnose, in the very old). Many medicines can cause it. Not drinking enough is another cause. Several kinds of heart problems can contribute to it. He needs to see his doctor. Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med. cornell.edu or request an order form of available health newsletters at 628 Virginia Dr., Orlando, FL 32803. Health newsletters may be ordered from www.rbmamall.com