Transcatheter aortic valve implantation (TAVI) has revolutionised the treatment of aortic stenosis by providing a safer and less invasive alternative to traditional open-heart surgery. With its expanding applications and high success rates, TAVI has transformed cardiac care and significantly improved outcomes for patients worldwide.
In an interview with The Week, Dr. Anjan Siotia, Director of the Cardiology Department at the BM Birla Heart Research Centre in Kolkata, discussed the significant impact of TAVI on the field of cardiology.
What is aortic stenosis, and why is it more commonly observed in elderly patients?
Aortic stenosis is a condition when one of the heart valves called the aortic valve becomes tight and does not open properly. It is usually seen in elderly patients for as we grow old the valve degenerates and calcium is deposited on it. This causes the valve not to open fully. There is no medical treatment for this condition and if the valve becomes tight enough to cause symptoms, the only treatment available is to replace the valve. The valve replacement has traditionally been done surgically, which means with an open-heart surgery when the surgeon cuts open the chest, opens the heart and takes the diseased valve out, and puts a new artificial valve in.
What are the challenges associated with the traditional approach for treating aortic stenosis?
Open heart surgery has been the standard treatment for patients with aortic stenosis over the course of time. Unfortunately, as I said earlier, this condition is more prevalent in elderly patients who have a lot of comorbidities. As a result of these comorbidities sometimes these patients are not suitable for surgery, and they are rejected by surgeons on account of their high risk. In the Western world, many patients were denied aortic valve surgery because of high risk and hence this idea of replacing the aortic valve without opening the chest came about. Further, the procedure called TAVI (transcatheter aortic valve implantation) was invented whereby cardiologists started replacing the aortic valve from the leg just like an angioplasty.
Could you explain how transcatheter aortic valve implantation (TAVI) revolutionized the treatment of aortic stenosis, and what makes it an attractive alternative to open heart surgery?
This procedure has now expanded is performed on lakhs of patients all over the world, every year. Patients who are not fit for open heart surgery have benefitted. But even in those who are fit for surgery, this procedure is found to be safer than open heart surgery. It is a much simpler procedure whereby we put a tube in the right leg and through that tube pass catheters all the way to the heart and that catheter contains an artificial valve which is implanted in place. At BM Birla, we have done multiple such procedures with very high success rates during the last five years.
How has the adoption of TAVI evolved over the years, and what types of patients benefit from this procedure?
The adoption of TAVI has evolved significantly over the years. Initially, TAVI was primarily reserved for patients deemed high-risk or inoperable for traditional open-heart surgery. However, as technology improved and experience grew, its application expanded to include intermediate and even low-risk patients. The evolution of TAVI has led to a more inclusive approach, making this procedure accessible to a wider range of patients with aortic valve disease. However, patient selection remains crucial, and decisions are typically made through a multidisciplinary heart team approach considering individual patient characteristics and preferences.
Can you share a specific case study or success story involving a TAVI procedure, highlighting the patient's condition, the procedure's outcome, and any notable improvements?
One such case was done earlier this year in January on a 58-year-old patient who had severe aortic stenosis. He wasn't very old, but the ejection fraction (the amount of blood the heart pumps every time it beats) of the heart was only 18%. He was considered extremely high risk for any open-heart surgery and so he underwent TAVI. The procedure was done by my team and me. Immediately in the postoperative period, the patient had some complications with the electrical rhythm of the heart, but he was discharged three or four days after the TAVI procedure, and I have been following up with the patient since then. When he was last seen for his regular check-up, his echocardiogram showed that his heart function had improved from 18% to completely normal, which is quite exceptional and rare. TAVI has led to a significant improvement in his left ventricular (LV) function. (a failure of the LV can impact all other organs of the body)
How does TAVI work, what its shortcomings and is it unsuitable for some patients?
TAVI is a way to fix a heart valve without open-heart surgery.
How it works: Doctors use a thin tube to put a new valve inside your old one. The new valve starts working right away. It helps blood flow better, which is good for your heart.
Shortcomings: TAVI is great for many people, but it's not perfect. Sometimes, the new valve can leak, or it might not fit well. Also, it might not last as long as a valve from open-heart surgery.
Unsuitable for some patients: TAVI might not be the best choice for everyone. It depends on your health and the condition of your heart. Doctors will decide if it’s right for you. If you have questions, don't hesitate to ask your doctor.
It is also a less expensive way to treat heart valve problems.
What is the difference between TAVI and stenting?
TAVI and stenting are both procedures done through thin tubes (catheters), but they're used for different reasons in the heart.
TAVI is mainly for fixing a damaged aortic valve, which controls blood flow out of the heart. In TAVI, a new valve is placed inside the old one to make it work better. It's often used in older people who can't have open-heart surgery.
Stenting is used to clear blocked blood vessels. A stent is a tiny metal tube that's placed in a blocked artery to keep it open. It's used when there's a problem with the blood vessels themselves, not the heart valves.
So, the key difference is what they're used for: TAVI is for heart valve problems, while stenting is for blocked blood vessels.
