TAVI has ushered in a new age in treating aortic valve diseases: how it works and who it is for

By the time Mr. Saravanan turned 87, he had a severely narrowed aortic valve that was impacting his daily activities to an extent where he required oxygen support for about a month. Post the successful completion of a Transcatheter Aortic Valve Implantation (TAVI) procedure, however, he recovered at an impressive pace. In just four days, he regained the strength to venture outdoors and cast his vote for the municipal elections. He lived an independent lifestyle till he crossed the milestone of 93 years old and finally breathed his last due to a fall while playing with his grandchildren. Mr. Saravanan’s journey tells us the story of how far medical advancement in treating aortic valve disease has progressed. For those who qualify, TAVI offers a unique technique to replace the faulty aortic valve without undergoing the traditional open-heart surgery.Understanding the aortic valveThe aortic valve forms one of the four valves within the human heart structure. It lies between the largest artery called the aorta and the main ventricle of the heart that pumps oxygen-rich blood across the entire body system. Each beat allows the leaflets of the valve, also known as cusps, to open for the outflow of blood and shut to stop any back flow.With increasing years, calcium deposits on these valves make them thickened and rigid. The term for this is ‘aortic stenosis’. This condition is most prevalent as age advances over 70 years, when the calcification of the valve becomes prominent due to wear and tear. In many cases, patients present with aortic stenosis at an earlier stage of life due to a birth defect in the aortic valve. Being born with only two cusps of the valve instead of three, makes such valves prone to wear out sooner.Why the narrowed valve is a problemWith a narrowing of the aortic valve, the heart needs to exert additional pressure to ensure flow of the blood through the restricted space. Early signs could be subtle: a task which had been manageable might now need an extra halt in between; routine tasks could suddenly drain energy like never before.As symptoms intensify with time, the patient might encounter shortness of breath, discomfort in the chest area, dizziness or even fainting spells. These indicate worsening of the condition and must be addressed without further delay. A test known as an echocardiography is a painless diagnostic procedure using ultrasonic waves to assess the extent of narrowing of the valve, besides assessing cardiac function.Commencement of symptomatic severe aortic stenosis marks an ominous milestone. It heralds rapid progression towards end-stage illness. Untreated, aortic stenosis inevitably results in heart failure and can lead to sudden cardiac death.When the valve needs replacingFor several decades, severe aortic valve diseases were treated only with open heart surgery. TAVI has revolutionised the entire process for eligible patients. In TAVI, a biological valve, usually bovine or porcine tissue stitched within a metallic frame, is placed at the tip of a catheter. The catheter is then typically inserted through the leg artery and moved all the way into the heart. At the site of the damaged valve, the new valve is deployed and it starts operating instantly.Unlike traditional surgical procedures for valve replacement, TAVI doesn’t involve cutting through the chest bone. It is often performed under local anaesthesia with mild sedation depending on individual patient circumstances.Its main benefit lies in quick mobilisation and most patients can be discharged within a few days after the procedure.There can be no denying the fact that TAVI is evolving rapidly as an interventional cardiovascular technique. Its origins lay in its development for patients who were deemed too risky for any kind of surgical intervention. Over time, it has become the procedure of choice in most patients with aortic stenosis over 65 years.Matching patients to treatmentsIt is important to understand that TAVI is not an option for everyone with aortic stenosis. It should be considered carefully in younger patients and in people with certain types of bicuspid aortic valve, an enlarged aorta or a need for additional bypass surgery.Many factors come into play when determining what would work best for a given patient. Among the factors to consider are: age, general health status, longevity prospects, valve robustness, anatomical considerations, and potential need for further procedures down the line.Advanced imaging technologies enable the medical team to analyse the anatomy of the patient, select the most appropriate path of intervention and decide on the correct valve and its size. There cannot be any one-size-fits-all strategy here. The treatment must focus on the unique circumstances of each person.It is important to keep future treatment options open as each tissue valve can only last upto 10-12 years. This is why the heart team plays a significant role. Cardiologists, cardiac surgeons, and imaging experts work together to plan the most suitable treatment option for that individual. What patients should knowFor patients diagnosed with aortic stenosis and found suitable for TAVI, the procedure can improve quality of life and help them live longer. By easing symptoms such as breathlessness, tiredness and chest discomfort, it may make everyday activities easier again. The decision should also be part of a lifelong heart valve plan that considers how long the replacement valve may last and what treatment options might be needed in the future.(Dr. G. Sengottuvelu is senior consultant – interventional cardiology, Apollo Hospitals, Greams Road, Chennai. drgseng@gmail.com)