Newer implants help heart-failure patients live near-normal lives longer
Singapore — About half of advanced heart-failure patients do not survive beyond a year if they rely only on medication, said Dr C Sivathasan, director of the Heart Transplant and Mechanical Assist Device Programme at National Heart Centre Singapore (NHCS).
In such cases, heart transplantation is considered the “gold standard” treatment, but donor hearts are notoriously hard to come by. Each year, NHCS — the only healthcare institution here that performs heart transplants — receives about 20 referrals for the procedure, but only an average of three will receive them.
Enter the implantable mechanical heart pump. Known as left ventricular assist devices (LVADs), the newer-generation devices are giving patients a new lease on life while they wait for a suitable donor heart.
The newer LVADs are expected to last about 10 years, about the average length of survival for a heart transplant patient, said heart failure specialist Dr Kenneth Ng of Novena Heart Centre at Mount Elizabeth Novena Hospital. The one-year survival rate for both procedures is also similar, about 90 per cent, he added. NHCS’ longest surviving heart transplant patient survived 25 years post-transplant.
“Practically speaking, for some patients, these devices can even replace a heart transplant at the moment due to a worldwide shortage of donor hearts,” said Dr Ng.
The life-saving technology has come a long way since 2001, when NHCS introduced its first implantable pump, a bulky device that was only suitable for patients above 70kg. “Even then, they were designed only to support the patient for about 12 to 18 months while they waited for a heart transplant,” said Dr Sivathasan.
Fast forward to 2016, and everything from technology to size has undergone an upgrade.
In 2009, NHCS introduced the second-generation heart assist devices. Significantly smaller, the newer pumps could be entirely implanted in the body, making them more suitable for people with a smaller build. Recently, the centre implanted its newest version, known as the HeartMate 3, which runs on magnetic levitation technology that allows the device’s rotor to be suspended so that it does not make contact with other parts of the system. This reduces damage to blood cells and the risk of blood-clotting, which can lead to complications, such as stroke.
Since 2009, 67 NHCS patients have been implanted with the newer generation LVADs, of whom a fifth have undergone a heart transplant and half are still waiting on a donor heart.
According to Dr Sivathasan, the first patient who underwent the second-generation device implantation at NHCS in May 2009 is still surviving on the heart pump. So is Mount Elizabeth Novena’s first LVAD patient, who was implanted four years ago, said Dr Ng.
But these devices do not suit some patients, including those who require dialysis or cannot take blood thinners. There are also risks such as infection of the wound site, gastrointestinal bleeding and stroke, said Dr Sivathasan.
Heart failure is the fifth-most-common diagnosis at emergency departments, the most common cause being coronary artery disease, said Assistant Professor Raymond Wong, senior consultant and programme director of the heart failure programme at National University Heart Centre, Singapore. Each year, public hospitals see an estimated 6,000 heart failure admissions. Numbers are rising with factors such as better post-heart-attack survival and an ageing population, he said. EVELINE GAN
