New Delhi, July 26: Hundreds of heart patients in India have received implants of tiny metallic devices that have neither been adequately tested nor approved for human use in their countries of origin, doctors said.
The devices called drug-coated stents are implanted after angioplasty to hold open blocked arteries and allow blood flow to the heart. Europe and the US have so far approved only two drug-coated stents.
“Indian drug laws do not cover medical devices such as drug-coated stents. So even unapproved products can be sold,” said Dr T.S. Kler, director of the cardiac catheter laboratory at the Escorts Heart Institute and Research Centre.
Figures provided by the two manufacturers of the approved drug-coated stents indicate that one out of four drug-coated stents implanted last year was a product that has not yet been approved, Kler said.
Doctors estimate that at least a dozen manufacturers of unapproved drug-coated stents are promoting their products among patients and doctors. “None of these products has been approved even in their countries of origin,” said Dr U. Kaul, director and head of cardiology at the Fortis Hospital in Delhi. “India has emerged as a fertile ground for such operators.”
Implanted in the artery, a stent contains a metallic structure and a drug it releases constantly to prevent fresh blocking of the artery. “Every stent is a different product. Information about one stent cannot be extrapolated to promote another one. We need to have rigorous animal studies and human clinical trials to determine whether they are safe and effective,” Kaul said.
The doctors said there is no evidence to prove that the unapproved stents have harmed patients. “But mishaps may not be reported. Without studies, we just don’t know whether unevaluated stents are potentially harmful or whether they are safe but not effective enough,” Kaul said.
He cited the example of an Indian company that introduced a drug-coated stent after cursory trials on a small number of animals. “It appeared to be in a tearing hurry to get it into the market,” Kaul said. But after it was implanted in patients, doubts about its safety began to circulate in cardiology circles, he added.
When some doctors insisted on more experimental data, the company conducted rigorous animal tests and reduced the amount of drug coated on the stent, Kaul said.
“Humans being implanted with a stent before stringent animal tests is a mockery of medical research,” Kaul said.
Cardiologists estimate that in 2004, some 28,000 patients would have received stents. Data provided to doctors by companies that make the two approved drug-coated stents indicates that 25 per cent would have received unapproved stents.
“Several hundred to a few thousand patients getting unapproved stents would be a conservative estimate,” Kler said.
The doctors said the high cost of the two approved drug-coated stents ' Rs 100,000 ' may be a factor that prompts patients to opt for unapproved products available for Rs 40,000-70,000.