Naturally dissolving stents safe for simple heart blockages: Study

Bioresorbable stents (BRS) are safe and effective, the state-run Sri Jayadeva Institute of Cardiovascular Sciences and Research has found during a multi-centre pan-India study with 108 patients.

Once the vessel blockage is treated and healed, the BRS dissolves fully and leaves the artery in its natural state with no foreign residue. This offers physicians and patients room to explore future treatment intervention in the same blood vessel if needed.

In contrast, the drug-eluting stents (DES), currently in use, stay permanently in the heart’s blood vessels. They could hinder future procedures performed in the same artery. Patients are followed up for three years.

Hospital director Dr C N Manjunath said the first-generation BRS made by the multinational company Abbott called Absorb, which was withdrawn from Indian market, was 150 microns in thickness.

But the second-gen BRS, made by Meril Life Sciences, is a naturally dissolving stent known as MeRes100 and is 100 microns in size. While the BRS is priced at Rs 90,000 to Rs 1 lakh, a DES costs Rs 30,080. MeRes 100 has been exempted by the drug regulator from price controls till 2025.

Dr T R Raghu, former HOD of cardiology at Jayadeva, said that for BPL patients, Rs 65,000 was given by the government for two stents and since BRS cost more and was not covered in any government scheme, public hospitals might not use them.

“They have got the approval of the Drug Controller General of India and the European regulatory body’s CE approval. Around 300 patients have been implanted in the country with the stents now. We have not used the stents outside the clinical trial in which 25 patients were implanted with these. At this point, it is useful for simple, low-risk, less-complex and non-calcific lesions in stable patients,” Dr Manjunath said.

While the BRS cannot replace the DES which are stronger, this technology finds a good indication in patients on the DES if they develop a restenosis (when an artery opened with a stent or angioplasty becomes narrowed again). “If a second metallic stent is put in, there is too much metal in the artery. Here it finds an application,” he added.

Dr Girish B Navasundi, Interventional Cardiologist at Apollo Hospitals, said: “We’ve implanted 12 BR stents in 10 patients, one of the highest in the city outside a clinical trial. Unlike the DES, the second-generation BRS comes with tools to prepare the blockage before implantation. This gives greater chance of success with the technology. By the end of three years, it will be completely dissolved."