New Delhi: The Watchman implant devised by Boston Scientific is supposed to be a safe alternative to replace blood-thinning medicines among heart patients. But in India, which has the largest number of people suffering from cardiovascular diseases, the ‘filter-type, umbrella-like’ device has found few takers so far.
One in eight Indians suffers from high blood pressure, while heart disease is the biggest killer in this country. And yet, since 2017, when the Watchman was introduced in India, only about 30 devices have been implanted. There are three reasons for this: The procedure is expensive, studies on future complications arising out of the device have been contradictory, and most Indian surgeons don’t have the skill to correctly implant it.
Why Watchman is rarely used
The Watchman is the only device of its kind approved by America’s health regulator, the US Food and Drug Administration. It is used to close the left atrial appendage (LAA) — a small cavity located in the wall of the left atrium, one of the four chambers of the human heart. The device eliminates the necessity to take blood thinners by closing the LAA, the part of heart where around 90 per cent of blood clots are formed.
The Watchman was approved for use in India in 2016, and it became commercially available in 2017, Boston Scientific told ThePrint.
The device is prescribed for patients suffering from atrial fibrillation — a condition where an irregular heart rhythm leads to an increased risk of having a stroke — and is used in patients who cannot take blood-thinning medication like Warfarin.
Dr Rupesh Kaushik, head of cardiology at Aakash Healthcare Super Speciality Hospital in New Delhi’s Dwarka, explained: “In patients with atrial fibrillation, a pinhead-sized blood clot can travel the short distance from the heart’s left-side chamber to the brain, which could result in a life-threatening stroke. For these patients, blood thinners are life-saving.
“But there are some patients who are at high risk for bleeding, or who had bled in the past and are at high risk for re-bleeding with blood thinners. These patients should consider the device to reduce his risk of stroke.”
Dr Kaushik said the procedure costs Rs 8 to 10 lakh in private hospitals, adding he has implanted the device in less than 10 patients in the last two years.
Dr Balbir Singh, chairman of interventional cardiology and electrophysiology at Gurugram’s Medanta Heart Institute, added that the scale of the problem the Watchman tries to fix is huge in India.
“The number of patients suffering from atrial fibrillation is huge in India. Among people around 80 years of age, around 20 per cent will be suffering from it, while in the 60-year age group, at least 10 per cent will have it,” he said.
“However, the fitting procedure is complicated. Moreover, it falls under the ‘2B’ rating, which means it is not a ‘first-line’ treatment. Hence, the procedure is avoided by majority of doctors. For treating LAA, India has used around 30-40 Watchman implants in the last two years. I have used just 6 or 7.”
The Watchman is inserted by using general anaesthesia in a one-time procedure, more or less in a similar manner to inserting stents in angioplasty. A narrow tube is sent through a small cut in the thigh, guiding the implant into the patient’s heart.
“Reaching the spot is not easy. In India, less than 10 doctors have the expertise to run the procedure,” said Dr J.P.S. Sawhney, chairman of the department of cardiology at the Sir Ganga Ram Hospital, New Delhi.
“While the device is being run through the vein in the thigh to the heart, the wall between the right atrium and the left atrium needs to be punctured. Until then, the device is deflated. Under X-ray guidance, the implant is positioned carefully and inflated as it fits into the appendage.”
Boston Scientific claims that in clinical trials, “approximately 92 per cent of patients were able to stop taking Warfarin 45 days after implant, and over 99 per cent were able to stop taking Warfarin by one year following the implant procedure.”
When is the Watchman prescribed?
According to Dr Pradeep Kumar D, senior consultant, interventional cardiology, at Bengaluru’s Aster CMI Hospital, there are “scoring systems which give an individual’s risk of having a stroke, and oral anti-coagulation (blood thinner) is given only when the risk of stroke is more than 3 per cent annually”.
Common blood-thinners like Aspirin and Clopidogrel (commonly known by the brand-name Plavix) are not enough to reduce the risk of atrial fibrillation-related stroke. In these cases, new-age blood thinners like Dabigatran, Rivaroxaban and Apixaban are prescribed, which are expensive — around Rs 700 to Rs 800 for 10 tablets.
“These medicines come with their own set of risks. Several patients report bleeding after consuming blood thinners,” said Dr Sawhney. “A patient could suffer bleeding in the intestine, brain, urinary tract or stomach. In such cases, the blood thinner needs to be stopped immediately. In such cases, my suggestion would be to consider the Watchman device to reduce the risk of stroke.”
The device can also be useful for elderly patients with a history of intolerance to blood thinners, or patients with other complications such as hypertension, diabetes or a history of strokes.
Questions on efficacy and long-term usage
In the US, the Watchman has been used aggressively, with Boston Scientific claiming “a proven record of safety — with over 20,000 procedures performed worldwide and over 10 years of clinical studies in more than 2,000 patients”.
However, several questions have also been raised on its efficacy and cost for stroke prevention.
“The downside: Expense, potential complications, and spiralling use as the device begins to be implanted for questionable indications. There have already been well more than 50,000 placed worldwide,” wrote Dr David Becker of Temple Chestnut Hill Cardiology in Flourtown, Pennsylvania, part of the Temple University Heart & Vascular Institute.
In India too, medical experts advise that the Watchman should be used as a last resort.
“There are significant adverse events reported abroad, including bleeding, left atrial perforation, device embolisation and even death. Therefore, these devices should be used in patients with high risk of stroke with very high bleeding risk, and cannot be an alternative for blood thinners,” said Dr Pradeep Kumar.
Dr Samanjoy Mukherjee, senior interventional cardiologist at Manipal Hospital in Dwarka, agreed. “It is an invasive procedure and has inherent risk of various complications, including device dislodgement and cardiac perforation, which can be life threatening,” he said.