Updated

The cardiologist for a man who sued Merck & Co. Inc. (MRK), blaming Vioxx (search) for his 2001 heart attack, testified Thursday that the withdrawn painkiller and not heart disease was likely responsible.

Dr. David Sim, an Idaho cardiologist who has treated plaintiff Frederick "Mike" Humeston since his heart attack, said he was able to eliminate many of the most common high risk factors for causing a heart attack.

"He had a paucity of risk factors for having an event," said Sim at the second Vioxx trial in testimony provided through video deposition.

Sim said Humeston was not a smoker.

"It appears that there was very likely something else going on in his case that caused him to have this event," Sim said.

Asked if there were any potential medication-related reasons that might have caused the heart attack, Sim said: "The drug that was potentially relevant for Mr. Humeston was Vioxx."

A spokesman for Merck was not immediately available to comment on Thursday's testimony.

Sim said tests performed on Humeston after what he called a "moderate" size heart attack indicated that the heart was not diseased.

"It did not look like he had generalized coronary atherosclerosis (search)," said Sim, who added that Humeston's heart has suffered diminished pumping efficiency since the attack.

Merck contends that Humeston only took the drug intermittently for two months and that his age, weight and other medical factors led to his heart attack — not Vioxx.

Humeston charges that Merck long hid the risks of Vioxx in an effort to preserve sales of its multibillion-dollar drug — a contention expected to resurface in thousands of pending Vioxx lawsuits.

The drugmaker has said it pulled the arthritis drug from the market last September as soon as it had definitive evidence that long-term use doubled heart attack and stroke risks.

The Atlantic City trial is being closely watched following Merck's defeat last month in Texas in the first Vioxx lawsuit to go to trial.

A Texas jury in August found Merck negligent in the death of a man who died of heart arrhythmia (search) after taking Vioxx and awarded $253 million to his widow — an award expected to be reduced and a verdict Merck has said it would appeal.

Roughly half of the 5,000 Vioxx cases Merck faces have been filed in New Jersey, home to many pharmaceutical companies, including Merck.