Bharat SainiLast Updated on April 26, 2019 by Bharat Saini
Trans-catheter Aortic Valve Replacement (TAVR), the replacement of aortic valve with a minimally invasive procedure, in which the only incision is a small hole in the groin where a catheter is inserted, is found, in a large clinical trial, to perform better than open-heart surgery even in low-risk patients with severe aortic stenosis. The results of related study, “Trans-catheter Aortic Valve Replacement with a Balloon-Expandable Valve in Low-Risk Patients”, presented during the late-breaking clinical trials session at the American College of Cardiology Conference in New Orleans and simultaneously published online in the New England Journal of Medicine, widely circulated on 17 March 2019, found that one year after the procedure, the rate of death, stroke, or rehospitalisation was significantly lower with TAVR than with surgery.
Aortic valve is a delicate but strong structure between the heart and the rest of the circulatory system that serves to keep blood flowing forward and preventing backflow.
- It opens with each heart beat and closes as the heart refills to pump again.
- At least 37 million times a year, the three leaflets of the valve open and close.
- Sometimes, especially as we age, the leaflets, normally as tough as your ear but as thin as a blister, thicken, harden and stick together in a way that narrows the opening through which blood flows.
- This forces the heart muscle to work extra hard to push blood through a hole of a pencil’s size instead of the normal opening, about the diameter of a quarter.
- This narrowing prevents the valve from opening fully, which obstructs blood flow from the heart into the aorta and onward to the rest of the body.
- We call this disease process Aortic Stenosis or Aortic Valve Stenosis.
- Aortic stenosis restricts the blood flow from the left ventricle to the aorta and may also affect the pressure in the left atrium.
Aortic Valve Stenosis: a build-up of calcium in the aortic valve that can lead to heart failure – the narrowed aortic valves, replacement with artificial valves made of either man-made or natural materials, is one of the triumphs of modern medicine.
The severe aortic valve stenosis usually needs surgery to replace the valve. Left untreated, aortic valve stenosis can lead to serious heart problem.
Traditional surgery, the Open-Heart Surgery, involves cracking open the ribs and stopping the heart to insert the new valve. These open heart operations are miraculously effective in relieving the heart of the worrisome extra workload from squeezing blood through openings much too narrow. But the price we pay for this relief is the stress of anaesthesia, an operation to open the breast bone and expose the heart, and the use of a heart-lung machine to temporarily take over the heart’s work as the valve is replaced. Although still the standard way of dealing with aortic stenosis for most patients, some are too sick to tolerate the stresses involved without having the risks outweigh the benefits. Many patients who most needed valve replacement were too sick or frail to undergo surgery.
With TAVR, the operation is a daring one, to replace a failing heart valve cardiologists insert a replacement through a patient’s groin and thread it all the way to the heart, manoeuvring it into the site of the old valve.
“When TAVR was introduced, it was regarded as an alternative for patients who were too sick to undergo open-heart surgery. Today’s findings suggest that TAVR may be superior to surgery, even for patients with low operative risk,” said the principal investigator of the trial Martin B. Leon, MD, Director of the Centre for Interventional Vascular Therapy at New York-Presbyterian/Columbia University Irving Medical Centre.
For nearly a decade, TAVR has provided a less invasive option for these patients. In TAVR, doctors thread a catheter through an artery in the groin and into the heart so that a new aortic valve can be fitted inside the diseased valve without surgically opening the chest.
In U.S. an estimated 5 million adults have Aortic Stenosis.
In India The prevalence of any valve disease is 2.8%. Of those with valve disease about 0.4% have Aortic Stenosis. The prevalence of moderate or severe aortic stenosis in patients more than 75 years old is 3.0%. It is the most common valvular heart disease of the elderly and increases with age. The prevalence is 4.5% at age 75 years and 9.1% at 85 years
As many as 400000 patients around the world have had TAVR since it was first introduced in the mid-2000s.
