HK firm's new heart stent speeds up healing

PUBLISHED : Sunday, 13 May, 2012, 12:00am
UPDATED : Sunday, 13 May, 2012, 12:00am


A Hong Kong-based medical device manufacturer has developed a breakthrough stent for heart patients that speeds up healing and lowers the chance of a relapse.

The new generation 'combo stent' - coated with both drugs and antibodies - has been designed for coronary angioplasty to treat heart blood-vessel obstruction, said Professor Michael Haude, chairman of the Working Group on Interventional Cardiology of the German Society of Cardiology.

'It puts together the best of both worlds - the drug technology and antibody technology,' said Haude, the principal investigator in research to prove its safety and quality.

The manufacturer, OrbusNeich, expects that the cost of combo stents to be similar to drug-eluting stents, at around HK$20,000 each and to become available before the end of this year. OrbusNeich, based in Hong Kong, specialises in interventional medical devices that are sold around the world.

The earlier generations were either drug-coated or antibody-coated. Patients either suffered from their blood vessels re-narrowing or obstructions by clot formation. Both may result in relapse and the surgery would have to be repeated, said Dr Chris Wong Kwok-yiu, president of Hong Kong College of Cardiology.

The first generation, a bare metal stent, typically made of stainless steel or cobalt-chromium alloy, was introduced in angioplasty surgeries because around half of the patients suffered relapses six months to a year after surgery, he said.

The stent is inserted and remained in the vessel to keep it open, but it could cause injury to the inner vessel wall, causing cell proliferation and re-narrowing of the vessel in the repairing process. Its relapse rate is around 25 per cent.

The second generation drug-eluting stent was introduced in Hong Kong in 2002 and is coated with drugs to inhibit cell proliferation. The relapse rate with this stent was reduced to around 9.5 per cent.

Following the development of the combo stent, Haude led a study in 2010 with 183 patients (including 31 from Hong Kong's Queen Mary Hospital) from eight countries, comparing the results of the combo stent and drug-eluting stent.

Study results showed that patients using the combo stent had more new tissue layers covering it after nine months, and a similar cell proliferation inhibiting effect as the drug-eluting stent. The relapse rate among patients with combo stents was 5.2 per cent. None of the patients suffered blood clots and the new stent was proven safe, said Haude.