NEW ORLEANS, Feb. 17 (AP) — A federal jury handed the drug maker Merck a major victory on Friday, clearing it of any responsibility in the death of a 53-year-old Florida man who had a heart attack after taking its once-popular painkiller Vioxx for less than a month.

This was the second court victory for Merck, and the first in a federal court. The company had argued in this case that the plaintiff's lawyers never proved any link between Vioxx and the heart attack that Richard Irvin suffered in 2001. Merck's lawyers contended that Mr. Irvin's age, gender and diet all put him at risk for a heart attack.

It was the second time jurors had heard the case, which was brought by Mr. Irvin's family. In Houston, where the case was heard in November and December because of damage from Hurricane Katrina, jurors were unable to reach a verdict. Merck won a state case in New Jersey last year, and it lost one in Texas.

Mr. Irvin's widow, Evelyn Irvin Plunkett; the youngest of their three daughters, Ashley Irvin; and their son, Richard Irvin III, all testified that Mr. Irvin's health had been excellent up to his heart attack. Ms. Plunkett left the courtroom in tears without talking to reporters.

Andy Birchfield, a lawyer for Ms. Plunkett, said the biggest problem was a ruling by Judge Eldon Fallon, shortly before the trial, that two of the plaintiff's experts — a cardiologist and a pathologist — could not testify that Vioxx was to blame for Mr. Irvin's heart attack. They were experts in their fields, but not about Vioxx, the judge ruled.

Mr. Birchfield said he would be talking with Ms. Plunkett about whether to appeal.

Phil Beck, a lawyer for Merck, said he believed the verdict indicated that the jury found "that the Merck scientists lived up to their legal and ethical responsibilities when manufacturing and marketing Vioxx and making the decision to take Vioxx off the market."

Shares of Merck rose 90 cents, or 2.5 percent, in after-hours trading. They closed up 7 cents at $36.05 Thursday in regular trading on the New York Stock Exchange.

The jury deliberated for 3 hours and 40 minutes, the shortest period of any jury in the Vioxx cases.

Mr. Irvin, a resident of St. Augustine, Fla., took Vioxx for back pain, but never saw a doctor about it. Instead, he called his son-in-law, Dr. Richard Schirmer, a physician who lived in another city. Mr. Irvin had not been able to keep down the first two painkillers prescribed by Dr. Schirmer; after he tried a sample given to him by an acquaintance, he asked Dr. Schirmer for Vioxx.

Dr. Schirmer testified that if the label had included a warning about heart attack risk, he would not have prescribed Vioxx for Mr. Irvin.

Ms. Plunkett's lawyers focused on whether Merck should have added a warning to the label after it learned in early 2000 that patients taking Vioxx in a drug test had five times as many heart attacks as those on naproxen, another painkiller.