Choosing between the two is a very hard decision to make, says Dr. Andrew Hurwitz, a cardiovascular surgeon at Glendale Memorial Hospital. Younger patients often opt for the mechanical valve because a biological one might need to be replaced when they get older and are less able to bounce back from surgery. In elderly patients, the biological valve is likely to last the rest of their lifetime.
Unfortunately, many people in need of a new valve are too elderly or sick to go under the knife. The risk of serious complications or death goes up with age, and patients with valve trouble often have other heart problems as well.
"At the current time, almost half of the patients with aortic stenosis don't get treated," Makkar says.
Makkar and Cedars-Sinai are participating in trials of a technique that is less risky for older patients. Edwards Lifesciences in Irvine manufactures a collapsible valve. Surgeons can thread this valve, scrunched down to pencil-width, through the femoral artery in the leg up to the heart. Then they use a balloon to inflate the valve, and the hardened tissue of the old valve holds it tightly in place.
The new valves, first used in 2002, have been approved for use in Europe, and more than 2,000 patients worldwide have received them. The valves are used only in the sickest patients, those who have a greater than 1 in 10 chance of dying within a month of open-heart surgery. They might be available in the U.S. around 2011, says Larry Wood, Edwards vice president for transcatheter valve replacement.
Edwards' collapsible valves are only appropriate for stenosis, not a leaky valve, because they require the calcified tissue of a stenotic valve to hold them in place. Although Wood ultimately expects the valves to be offered to lower-risk patients, he notes that there are not yet scientific data to justify widespread use.
"Surgery remains the gold standard," he says. "You're much better going with surgery that we have 50 years of experience with."