Little difference between cardiac stents: Lancet

There is no difference between one type of cardiac stent from another, according to the latest paper published in the international medical journal, The Lancet. It challenges the typical trend of showing the new thing to be shinier and the old thing dustier than it really is, as far as different categories of cardiac stents are concerned.

The National Pharmaceutical Pricing Authority (NPPA) in India recently cracked down on selling stents at an exhorbitant rate and capped ceiling prices for drug eluting stents (DES) and bioresorbable vascular scaffolds (BVS) at Rs 29, 600, whereas bare metal stents (BMS) will cost Rs 7,260.

Earlier, NPPA chairman Bhupendra Singh while capping prices had reiterated that there was no difference between DES and BVS. A DES releases a drug to prevent clotting as it clears blockage in an artery. A BVS also serves the same purpose, but is made up of organic material that dissolves in blood after clearing the artery, while a BMS is a mesh-like tube of thin wire, but does not release drugs, which were said to prevent clotting. The stent market has evolved since 1987, with industry claiming introduction of next-generation stents which are superior in quality each time to hike prices of stents.

Even after the prices in India have been capped, NPPA continues receiving complaints of stents being charged at two to four times the ceiling price in public and private hospitals.

The Lancet article, interestingly points out that there are various studies indicating that there is no difference between using DES and BVS stents. BVS stents were considered to be the most expensive, the price ranging upto Rs 2.5 lakhs, before capping. The article states that, "There is non-inferiority in terms of late luminal loss (restenosis) or superiority in vasomotor reactivity of the bioresorbable vascular scaffolds compared with the drug-eluting stents." Restenosis, means re-narrowing of arteries, that may occur over long term after the procedure, and upheaval in vasomotor reactivity means an artery going into spasm. Such adverse events pose a danger to the life of the patient. There was no difference between how DES or BVS stents affected the patient as far as these repercussions go.

Even though bare metal stents (BMS) are cheaper than DES and BVS, the article further states that, " There are no significant differences between participants receiving drug-eluting stents and those receiving bare-metal stents in the composite outcome of death from any cause and non-fatal myocardial infarctions."

Dr Suhas Parikh, cardiac surgeon at privately-run Wockhardt Hospital in Mumbai Central agrees. He said, "A study on 5000 patients published in New England Journal of Medicine (NEJM) claimed that there were no long term differences in patient outcomes of BMS and DES." Use any kind of stent, there is always a certain chance of re-narrrowing of artery or spasm. "A 100 per cent gold standard has not been achieved," said Dr Parikh. The articles states, "The results of these studies clearly show that the stent revolution, which started in 1987, has come full circle."

It further elaborates and says that even as newer technologies try to curb problems with more expensive technologies, problems continue occuring like thrombosis, stent recoil and require stronger medications for longer durations.

STENT EVOLUTION

The technology surrounding stents has been evolving since 1987. The cheapest variety, a bare metal stent (BMS) is a thin wire tube mesh. A drug eluting stent is a type which relases medication during the procedure to prevent a clot. the bioresorbable vascular scaffolds (BVS) serves a similar purpose, but is made or organic material. The Lancet study claims that there is barely any different between these.