A deep dive into Transcatheter Aortic Valve Implantation (TAVI)

Transcatheter Aortic Valve Implantation (TAVI) is a groundbreaking alternative to traditional open-heart surgery.

Busamed Cardiologist Dr Andrew Asherson sheds light on the intricacies of this life-changing procedure and its profound impact on patients facing aortic valve issues. He explains that TAVI is a minimally invasive procedure used to replace a narrowed or blocked aortic valve in the heart.

Instead of traditional open-heart surgery, TAVI involves inserting a replacement valve through a catheter, usually via the femoral artery in the groin, and guiding it to the heart, he says.

This procedure is mostly performed on patients who are considered high-risk or ineligible for traditional surgery due to advanced age or other health conditions. “TAVI is a medical procedure designed to replace a blocked or narrowed aortic valve—the crucial gateway between the heart and the rest of the body. As people age, this valve can narrow, leading to severe health complications.”

The traditional approach to treating a blocked aortic valve involves open-heart surgery, but TAVI offers a minimally invasive alternative, revolutionising the landscape of cardiovascular interventions. “When you are born, the aortic valve usually has three thin, membranous leaflets. Over the passage of time, those leaflets can become thickened and heavily calcified, and restricted in their movement, which means that the blood can no longer exit the heart freely. This leads to a tremendous pressure build-up inside the heart, and a very high pressure gradient between the heart and the rest of the body or the main blood vessel in the body, the aorta. ‘Aortic valve stenosis’ is diagnosed when the valve becomes significantly narrowed.”

Left untreated, aortic stenosis (AS) is a dangerous condition, and from the time a person develops symptoms, their prognosis might be less than two years (or shorter). “It’s an important condition to recognise and diagnose, and it’s an important condition to treat because it is life shortening or life threatening.” According to Dr Asherson, who started the Gateway Hospital TAVI program in 2019, the key to successful TAVI lies in rigorous patient selection, careful procedural planning, and teamwork. He emphasised the importance of meticulous workup for the procedure, including a separate hospital admission for a coronary angiogram and a CT scan. The CT scan data is then analysed by the valve manufacturer (Edwards Lifesciences) to determine the correct valve size, and assess any potential TAVI risks.

According to Dr Asherson, TAVI was traditionally reserved for older patients deemed unfit for open-heart surgery due to advanced age, frailty and other complex medical problems. “However, evolving research suggests that TAVI is at least as good, if not better than conventional surgery. As a result, the age criterion has become less stringent, with well, low surgical risk patients in their 70s now commonly undergoing the procedure.”

TAVI involves replacing the aortic valve without open-heart surgery, and is less invasive, if equally intricate. Dr Asherson describes the process as a “keyhole” procedure, performed through a small incision in the groin using catheters. A TAVI procedure is often completed in under an hour, under local anaesthetic, and the recovery time for TAVI is remarkably shorter than that of traditional open-heart surgery, Dr Asherson explains. “Patients usually spend two nights in the hospital if they have a TAVI with us, but it is likely in time that it will become an overnight stay. In contrast, open-heart surgery may require 7 to 10 days in the hospital, and an extended postoperative recovery period running into weeks.”

While TAVI offers a transformative solution for many, not everyone can have a TAVI. According to Dr Asherson, the main contraindication to TAVI is if a patient’s life expectancy is thought to be less than a year. Patients with disseminated malignancy don’t do well in the South African ‘SHARE-TAVI’ registry, a mandatory data collection tool run out of Stellenbosch University to ensure that the outcomes of all patients who have a TAVI in South Africa are carefully followed. “There are also technical challenges, such as large calcium deposits in critical areas, or stenosis in a two-leaflet (bicuspid) aortic valve, in which case patients might be directed towards alternative treatments, including in some cases, medical therapy (no operation of any sort).”

Dr Asherson stressed the importance of collaborative decision-making, and relies heavily on a vastly experienced team of a cardiothoracic surgeon Dr Del Winter and cardiac anaesthetist and ICU specialist, Dr Colin Padoa. This ensures a comprehensive evaluation of the patient’s suitability for TAVI, minimising risks, and maximising positive outcomes.

As the field of cardiology continues to evolve, TAVI is emerging as the dominant method for aortic valve replacement. With ongoing trials and advancements, TAVI’s reach is expanding, offering hope to a broader range of patients.

TAVI stands as a beacon of innovation in cardiovascular medicine, transforming the lives of individuals facing aortic valve disease. Dr Asherson’s insights provide a glimpse into the future of heart procedures, where minimally invasive techniques are redefining what’s possible in the cardiac care space.

Read Mr Mike Cameron’s story following his TAVI procedure here