CHF valve repair may supplant replacement
New technique may avoid downward spiral of CHF
A new surgical procedure focuses on the role of the mitral valve in treating patients with congestive heart failure (CHF).
The technique uses a ring to reinforce the valve so it can keep blood from flowing backward into the left atrium. Instead of the traditional method of replacing the mitral valve, the procedure involves "scrunching it down;" reinforcing it so the heart won’t pull it open when it should stay closed. Better flow is restored without loss in power.
With more efficient blood flow through the heart, patients may be able to regain cardiac performance over time. For now, the procedure may help some patients in advanced heart failure live longer even if they are not candidates for a transplant. Eventually, researchers hope that, as they learn more about who is right for the procedure, they can use it to help their patients avoid the downward spiral of CHF.
Viable alternative
"We think this is a viable alternative," says University of Michigan (Ann Arbor) cardiothoracic surgeon Steven Bolling, MD.
Bolling says when the heart enlarges during failure, its inner walls pull at the mitral valve. The pressure causes a problem, not in the organic makeup of the valve, but in the way it functions. Because it can’t stay closed when it should, regur-gitation develops. Half of the blood that should be exiting the heart goes back into the atrium. This reverse flow becomes yet another obstacle to circulation that the heart has to overcome.
Going in to replace the valve has meant robbing the heart of some pumping power, and surgeons leave the valve alone when the ejection fraction is low — less than 40%. But if patients are already compromised by heart failure, Bolling says, they "have nothing more to give. . . . We are taking no function away from the heart." That could make the procedure available to a broader spectrum of CHF patients.
Changing our way of thinking
"We have to change our thinking about these patients," says Bolling. The perspective change begins with understanding the relationship between valve and ventricle. The elements work together and should not be seen as separate parts. "We are not treating a ventricular problem with a valve solution. We are treating a ventricular prob-lem with a ventricular solution."
Another conceptual change is that perhaps damaged heart muscle, like other tissue, can heal if it can be rested. Finding a way to give the myocytes some down time is tough, however, because surrounding tissue continues to be worked on and has to keep pumping. Bolling says helping flow efficiency can make tasks easier on the heart. Also, it is possible the surgery can be used in combination with other techniques such as the left-ventricular assist devices.
In the first phase of his study, Bolling operated on nearly 100 patients and found 70% to 80% were alive two years after surgery, compared to about 10% if the patient didn’t have the surgery. He reported his findings at the American Heart Association conference in Dallas last November.
"He is getting some marvelous results," says Mehmet C. Oz, MD, a cardiothoracic surgeon at Columbia-Presbyterian Medical Center in New York City. Oz says his hospital performed a dozen mitral valve procedures with similar findings.
First, is surgery feasible?
Bolling notes the first stage of the study was to determine the feasibility of the surgery and if it should be studied against traditional drug ther-apy. Randomizing patients to medication and surgery is the next step.
"We need to identify patients who would do well," he notes. Being able to get to them for a quick surgical intervention may keep many from going on to develop serious disease requiring extensive and expensive treatment like transplantation.
If we could go upstream and head them off at the pass, Bolling notes, "the patient would then never go down the inevitable cascade of CHF."
A patient who had an ejection fraction of 5% came into the surgical program after living with CHF for years. Bolling operated on her and notes that he wishes now that he could have performed the operation on her 10 years ago, before her quality of life declined to a point where she had to spend most of her day sitting in a chair.
Right after surgery, her ejection fraction probably was the same as before. Without the regurgitation, her heart has a better chance of regaining some lost ground. It will take about two years to be more certain of the long-term benefits, he says.
In the first study, patients were at advanced stages of the disease. The second part of the study, dubbed the PREMIUM trial, will include patients in NYHA Class III disease. Because patients are not as sick with heart failure, it take longer to determine the benefit of the surgery because, unlike the first study, most patients would be expected to survive longer than a year without the surgery. The PREMIUM trial also could hint at which patients may be at a stage of failure that cannot be reversed.
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