Dr Simon Kennon MB ChB, FRCP, MD Consultant Cardiologist

Transcatheter Aortic Valve Implantation

The aortic valve is the main outlet valve of the heart, opening and closing around 100,000 times each day. Degeneration of the valve occurs in 2% of people over the age of 65, resulting in either narrowing of the valve orifice (‘aortic stenosis’) or incompetence of the valve leading to leak back (‘aortic regurgitation’). This places a strain on the heart causing symptoms (usually breathlessness, sometimes chest pain or lightheadedness) and ultimately heart failure.

Aortic stenosis and regurgitation when severe require aortic valve replacement with either TAVI (transcatheter aortic valve implantation) or aortic valve replacement surgery.

TAVI is safer than surgery, is less invasive and recovery is quicker. It has, however, only been routinely available for the last decade and performed in large numbers over the last 5-6 years. As such, we know that TAVI valves, made from animal tissue, last for at least 6-7 years but at present we do not have longer follow up data.

Aortic valve replacement has been undertaken for over 50 years. Surgical biological valves (made from animal tissue) generally last 10-15 years and mechanical (‘metal’) valves last for many decades. Mechanical valves require lifelong warfarin treatment.

Coronary artery disease can be treated with a bypass operation at the same time as aortic valve replacement surgery or with balloon and stent procedures either before or after a TAVI.

Failing tissue valves, both TAVI valves and surgical valves can be treated bya ‘valve-in-valve’ TAVI procedure.

Dr Kennon will discuss with you in detail the relative merits of TAVI and aortic valve surgery for you specifically to ensure that you get the form of treatment that is best for you.

The procedure

The procedure is performed under local anaesthetic in a cardiac catheter lab and generally takes about an hour. A cartoon of the procedure can be found here. A sheath is placed in the artery at the top of the right leg (the ‘femoral’ artery) and a wire passed through it, up the aorta, across the aortic valve and into the main pumping chamber of the heart, the ‘left ventricle’. The new TAVI valve is then passed over this wire, positioned across the aortic valve and deployed – pushing the aortic valve aside leaving a new functioning valve in place. The mechanism of valve deployment varies between devices. The Edwards Lifesciences Sapien device is deployed by inflating a balloon that it has been ‘crimped’ onto. The Boston Scientific Accuratevalve is a self expanding valve made of nitinol

TAVI procedures generally take about 1 hour.

Most people are discharged home 24 or 48 hours after the procedure.

Recovery

TAVI has been the subject of multiple research studies including large randomised controlled trials The largest series of trials is the PARTNER trials – all published in the New England Journal of Medicine These have demonstrated that for people with severe aortic stenosis, TAVI with a Sapien valve prolongs life, reduces symptoms and improves quality of life. They have also demonstrated that the risks of complications during TAVI are lower than during aortic valve replacement surgery – although both procedures are generally very safe.

Complications and risk

As with all cardiac procedures / operations, there are a number of potential complications. These include: death, stroke, heart attack, vascular trauma. For most people the combined risk of death or stroke will be less than 5%.Dr Kennonwill discuss with you what the risk of complications will be for you specifically.