Non-surgical alternative to replace faulty heart valve

According to cardiologists Transcatheter Aortic Valve Replacement has changed the way heart valve replacements are done and has saved the lives of high-risk patients.
Non-surgical alternative to replace faulty heart valve

Rajan Thomas, a 70-year-old resident of Alappuzha, was often experiencing increased fatigue, shortness of breath, chest pain, and occasional dizziness. Initially, he thought his condition had something to do with the impact of Covid-19 infection he had two years ago. However, when he met his physician, the true cause was revealed when the doctor placed a stethoscope on Rajan’s chest—there was an unmistakable heart murmur indicative of an underlying heart valve condition. If all four of his heart valves had been functioning properly, there would have been no murmur, only the clear sound of a healthy heartbeat.

Rajan was subsequently referred to a cardiologist who recommended further tests (echocardiogram, electrocardiogram, chest X-ray, CT scan), confirming that Rajan’s problematic heart valve was the root cause of his symptoms. Specifically, his aortic valve, positioned between the left lower heart chamber and the body’s main artery, had narrowed and was not opening fully, thus affecting blood flow through the heart.

A malfunctioning valve places additional strain on the heart which has to pump harder to adequately supply blood to the rest of the body, particularly the brain. If left untreated, this condition can lead to serious complications such as blood clots, heart failure, stroke, cardiac arrest, or even death.

Upon learning of his condition, Rajan, classified as an intermediate-risk patient, was presented with two treatment options for replacing his aortic valve: Surgical aortic valve replacement (SAVR), which involves open-heart surgery, and transcatheter aortic valve replacement (TAVR), a less invasive non-surgical procedure. SAVR, although cheaper, carries higher risks compared to TAVR. After discussions with his family members, Rajan opted for TAVR.

Less chances of complications

According to cardiologists TAVR has changed the way heart valve replacements are done and has saved lives of high risk patients. “Clinical trials and real-world data have shown that TAVR has been associated with lower rates of complications such as stroke and bleeding with significant improvements in symptoms and overall quality of life,” said Dr G Sengottuvelu, clinical lead, structural heart programme, Apollo Group of Hospitals.

In TAVR a replacement valve is inserted via a catheter into the heart, typically through an artery in the groin or chest. A collapsible replacement valve (biological valve made from animal tissue) is placed into position within the diseased aortic valve. Once expanded, the new valve takes over the function of the old, damaged valve. The defective valve gets crushed against the wall of the aorta. It takes 3-4 hours to complete the procedure. Patients in the high risk category are put on a ventilator before the procedure, while it can be managed with general anaesthesia for those in the less risk category.

“Earlier, a risky open chest surgery was the only option for patients with calcified aortic valves. It cannot be performed on people who are in the high risk category and they used to die of complications. People with lung diseases, renal failures and aged above 80 are at high risk of complications from open-heart surgery. The procedure is helpful even in intermediate risk groups as well,” said Dr Harikrishnan S, professor and interventional cardiologist at Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram.

Degenerative aortic stenosis, characterised by gradual narrowing of valves, is commonly observed in elderly individuals like Rajan. Dr Harikrishnan pointed out that the procedure is common in metros and a state-like metro where the longevity is high. Cholesterol deposition is also a factor. People born with two flaps instead of the normal three have a greater chance of developing aortic valve problems, he added.

400-500 TAVRs performed every month

“Degenerative aortic stenosis (AS) is now becoming common. It has the same risk factors as of coronary heart disease (like heart attack). The treatment for severe AS is aortic valve replacement,” said Dr Mathew Iype, professor of cardiology, Government Medical College, Thiruvananthapuram. “TAVR can be done in high risk patients. That is the beauty of TAVR. Patients can be mobilised on the second day of the procedure which again is good for the patient. The longer the patient is in the hospital, the higher the risks of venous thrombosis of legs and hospital acquired infections, etc,” he added.

One size does not fit all

TAVR still comes with challenges. As it cannot be performed on all patients, cardiologists need to perform more tests such as angiogram to assess the suitability for TAVR. “One main problem of TAVR is the requirement for a good sized leg artery through which the device has to be taken to the heart. If there is such a problem, an alternative now available is the carotid artery (in the neck),” said Dr Iype.

Doctors use two types of valves - one is biological (made from animal tissue or from human donor tissue) and the other is mechanical (made of metal or plastic). The tissue valve is used for patients above the age of 65. These valves tend to wear out after 10-15 years. The mechanical valve offers longer protection, but has higher chances for heart infection and blood clots, which need to be addressed through medication.

The valve usually comes in 20-30 mm sizes. A series of tests are performed to determine the size required. The tests can also reveal if the patient requires a pacemaker to ensure proper conduction of electricity in the heart. According to Dr Harikrishnan, around 7% of patients require a pacemaker.

Improvements in valve design

Advancements in TAVR technology continue to offer hope to patients with smaller-sized leg arteries, as manufacturers are developing smaller valves capable of passing through narrower blood vessels. Additionally, valve-in-valve procedures are available to address calcification of previously replaced valves, thereby avoiding riskier repeat surgeries.

According to Dr Sengottuvelu, who is one of the pioneers of TAVR programme in the country, newer advancements including better valve designs, delivery systems, and imaging techniques have enhanced the safety and efficacy of the procedure. “When we started TAVR in 2015, only one (type of) valve was available and we had to get an import licence and import the valve which takes weeks to arrive. Today we have 7-8 types of TAVR valves available on our shelves and can plan TAVR within hours. We were involved from early trials of indigenously developed India-made MyVal which has now shown to have excellent results compared to available western transcatheter valves.”

MyVal has also helped to reduce the cost of the procedure which usually ranges from Rs 15 lakh - Rs 25 lakh depending on the valve. Although TAVR can be expensive, the overall cost may be offset by reduced hospital stays and quicker recovery times, leading to lower long-term healthcare costs. Studies have shown that TAVR can be a cost-effective treatment option, especially when considering the quality of life improvements.

(With inputs from Sinduja Jane @ Chennai)

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