A study conducted by Danish researchers found that the use of Johnson & Johnson's stent coated with Cypher resulted in relatively fewer heart attacks, deaths and need for repeat procedures than that of Medtronic Inc.’s Endeavor stent, which used a drug other than Cypher.

Stents are basically small tubes meant to support the open arteries from where the blockages have been removed. And the drug coating is done to avoid the reclogging of the diseased artery.

The study observed the effectiveness of the two stents in 2,332-patients, eighteen months after placing them in the patients’ bodies. It was found that the measure of occurrence of cardiac death, heart attacks or target vessel in patients with Endeavour stent was 9.7%, whereas it was 4.5% for those with Cypher stent.

The study was lead by Dr. Michael Maeng from Aarhus University Hospital in Denmark and it was offered at the American College of Cardiology scientific meeting in Atlanta.

"If you have to compare the two stents, the Cypher stent is a better stent", Maeng said.

Medtronic accused the researchers of being biased towards Cypher and said that the data describing the performance of Cypher has been wrongly evaluated by them.

Maeng claimed that his study was significant being carried out practically, involving a variety of patients with coronary artery disease.