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Survival rates up as more patients have defective valves repaired instead of replaced
COMMON defects to a heart valve used to be fixed by replacing the valve.
But now, with better techniques available, two-thirds of the cases can be repaired instead.
This has improved survival rates for patients, both on the operating table as well as in the long term, said the National Heart Centre (NHC) yesterday.
The defects occur in the mitral valve, which separates the two left chambers of the heart.
Oxygen-poor blood from the body flows into the heart’s right chambers, which pump it into the lungs to receive oxygen.
Oxygen-rich blood then flows from the lungs into the heart’s top left chamber. The accumulation of blood exerts pressure that opens the mitral valve so that the blood flows into the bottom left chamber, and is pumped to the body.
The mitral valve can become torn or leaky because of ageing, heart failure and congenital defects.
This can lead to a backflow of blood into the top left chamber, which can result in symptoms such as breathlessness and, over time, even heart failure.
Two out of three heart valve cases involve the mitral valve, said Associate Professor Chua Yeow Leng, senior consultant of the NHC’s cardiothoracic surgery department.
About 15 years ago, practically all damaged mitral valves were replaced, but now, they are replaced in about a third of cases and usually when they have become hardened, he said.
At the NHC, 66 per cent of patients who underwent mitral valve procedures had it repaired last year, up from 46 per cent in 2005.
Altogether, the centre carried out 139 mitral valve procedures last year, from 112 in 2005. Some seven out of 10 heart valve operations in public hospitals are done there.
Prof Chua said: “Repairing disturbs the heart less, so the general outcome and heart function are better.”
In Singapore, about five in 100 will die while having a heart valve replaced, compared with fewer than two in 100 while having it repaired.
Studies in the United States have shown that 87 per cent of those whose valves were repaired lived beyond 10 years, compared with 60 per cent who received a replacement.
Furthermore, those who have a replacement valve must take blood-thinning medication for life.
This carries a risk of causing complications such as stroke.
The method of repair has also become less invasive over the years, with robot-assisted surgery becoming an alternative to open-heart surgery.
Since January 2007, 13 patients at the NHC have undergone a procedure in which doctors mended the valve by using robotic arms holding the surgical equipment. These arms enter the body via a 4cm hole and three other 9mm ones, and the patient’s breastbone does not have to be broken.
Bank executive Bryan Cheah, 32, had such a procedure in June last year to repair his mitral valve, which had been leaky due to a congenital defect.
Explaining his decision on the type of operation to choose, he said: “Getting a replacement meant going on long-term medication, which isn’t good for health.
“A repair keeps what is already part of your body, so that’s definitely better. And the robot-assisted operation
is less traumatic than open-heart surgery.”
All the mitral valve treatments will be covered in a three-day symposium on heart valve therapy, SingValve, held for the first time from yesterday to tomorrow by the NHC. About 100 doctors from Singapore and other countries are attending the event.
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