Vioxx played 'substantial role' in heart attack, says US cardiologist

A LEADING US cardiologist has testified that the anti-arthritis drug Vioxx played a "substantial contributing role" in the heart attack of a 58-year-old Australian former navy officer.

A LEADING US cardiologist has testified that the anti-arthritis drug Vioxx played a "substantial contributing role" in the heart attack of a 58-year-old Australian former navy officer.

Douglas Zipes, from Indiana University, told the Federal Court yesterday he "strongly believed" the drug was a substantial factor in the 2003 heart attack of Graeme Peterson. But the class action against the US manufacturer of Vioxx, Merck & Co and its Australian subsidiary Merck, Sharp and Dohme also heard from other experts that there was no physical "footprint" in the body to prove Vioxx caused the heart attack.

They told the court Mr Peterson had other risk factors that could have caused his heart attack, such as high cholesterol, being overweight and being an older male.

Four eminent cardiologists -- two representing the plaintiff, including Professor Zipes, and two representing Merck -- were involved in what lawyers dubbed a "hot tub" of medical evidence.

Rather than giving evidence individually, the four experts gave their testimony together, each providing judge Christopher Jessup with competing opinions on whether Vioxx contributed to Mr Peterson's heart attack.

The role of the blockbuster drug, which was voluntarily withdrawn from the market in 2004 after a study found it increased the risk of cardiovascular problems, in the 58-year-old's heart attack is the crux of his class action.

Mr Peterson is representing thousands of Australians who used Vioxx and had a heart attack or stroke. He blames Vioxx for his 2003 heart attack and claims Merck knew about the cardiovascular risks of the drug long before the voluntary withdrawal but played them down.

Professor Zipes told the court Mr Peterson did have other risk factors that could have caused a heart attack but it was Vioxx that contributed to his having it in December 2003.

"It is difficult to say Vioxx was the cause of that specific heart attack ... (but) Vioxx played a substantial role," he said. "Absent the Vioxx, he may have not had an infarction (heart attack) at that time."

Richard Harper, from Monash University in Melbourne and also for the plaintiff, told the court the drug exacerbated Mr Peterson's risk factors.

"I believed Vioxx doubled his risk of heart attack," Professor Harper said. "It increased the risk of someone who was already at a high risk."

The two cardiologists called by Merck disagreed. Douglas Vaughan, from Northwestern University in Chicago, told the court it was not possible to say Vioxx caused Mr Peterson's heart attack over any of his other risk factors.

"We don't think there is a signature abnormality potentially caused by Vioxx versus any other heart attack," Professor Vaughan said.

David Celermajer, from the University of Sydney, said he did not believe that Vioxx played a role in Mr Peterson's heart attack, given he already had a moderate to high risk of a heart attack.

"There is no way to say that Vioxx was the culprit," Professor Celermajer told the court.

The trial continues.