Medical breakthroughs in cardiology
By Dr Dinesh Nair
Photo above: CT pictures of Medtronic CoreValve valve prosthesis after a successful implantation.
Many of us are probably familiar with the often used term "heart blockages". These can be within the arteries or the valves of the heart. Although blockages of the arteries are more common, blockages of the valves are also very important. Aortic Stenosis, which refers to the narrowing of the heart's main valve, the aortic valve, interferes with regular blood flow out of the heart, and causes a strain on that vital organ of yours.
Know that it is not a small matter if you start experiencing one or more of the following symptoms:
• Chest pain
• Shortness of breath
• Loss of consciousness
Symptomatic Severe Aortic Stenosis claims the lives of more than 50 per cent of patients within a two-year period when nothing is done. No need to panic, there are ways to treat it.
At present, Aortic Stenosis is treated via surgical valve replacement, also known as open heart surgery.
That said, more than 30 per cent of patients are not able to undergo this life-saving therapy because of high-risk factors.
You are likely to be considered a high-risk patient if you have other heart conditions, have previously undergone a heart operation, been diagnosed with cirrhosis of the liver, or have Cachexia (Wasting Syndrome) - a condition characterised by unintentional weight loss.
What is TAVI?
Transcatheter Aortic Valve Implantation (TAVI) is a new, minimally invasive option suitable for high-risk patients unable to undergo open heart surgery.
It involves the use of a Corevalve Device that makes its way to the affected aortic valve via the bloodstream. Once at the narrowed valve, a balloon is used to open up a bigger pathway for blood to pass through.
Once done, a metal stent made of Nitinol (special metal alloy) is put in place to secure that opening permanently together with man-made valve leaflets to direct the flow of blood. (This is a concept similar to that of cardiac ballooning and stenting.)
The Corevalve Device can be inserted through a small cut in the skin through four different approaches:
• Transfemoral - groin area
• Transapical - left nipple region between the ribs
• Transaortic - sternum area at the chest centre
• Subclavian - left shoulder area
Patients who undergo this treatment can expect to be (varies between patients):
Fully alert and talking within hours Fully mobile within five days Discharged within a week
In the future
Although relatively new at this point, TAVI has been approved to help high-risk heart patients to tackle Aortic Stenosis.
As more experience is gained in this area, it will eventually be opened up to more groups of patients in the future.
This article was contributed by Dr Dinesh Nair, Senior Consultant of Cardiology at the Parkway Heart and Vascular Centre.