His widow had won a $253 million verdict against New Jersey-based Merck in 2005, but Texas punitive damage caps later cut that to about $26 million.
Also Thursday, a New Jersey appeals court voided $9 million of the $13.9 million awarded to John McDarby in 2006 by a jury in Atlantic City.
The panel found that New Jersey's Product Liability Act was pre-empted by the federal Food Drug and Cosmetic Act. McDarby survived his 2004 heart attack.
Thursday's rulings give Merck 11 victories and three losses stemming from the trials that reached verdicts, with the damages now reduced in one of those losses. Retrials are pending in a few cases.
Merck pulled Vioxx in September 2004 after its own study showed Vioxx doubles risk of heart attack or stroke.
In a statement, Merck general counsel Bruce Kuhlik said it was gratified that the Texas 14th Court of Appeals found Vioxx did not cause Ernst's death.
"In addition, the New Jersey court correctly reversed the awards of punitive damage and consumer fraud," Kuhlik said. "We intend to seek further review of the portion of the award that remains standing after the New Jersey decision. We continue to believe Merck acted responsibly."
McDarby lawyer Ellen Relkin said that while they were delighted "with the robust affirmance" of the $4.5 million compensatory verdict, they will consider appealing the reversal of the $9 million in punitive damages.
"I think the most important legal finding is they recognized that under New Jersey law a person such as John McDarby who has underlying cardiac risk factors, such as diabetes, elevated cholesterol and advanced age ... it is proper under New Jersey law a jury can find an additional risk such as Vioxx can contribute to the heart attack," Relkin said.
The New Jersey ruling also upheld a verdict in favor of Merck in the case of Thomas Cona, who survived a June 2003 heart attack. His case was heard simultaneously in Atlantic City with McDarby's case.
Cona lawyer W. Mark Lanier called the ruling "unfortunate," but said the New Jersey panel's 126-page decision on Cona and McDarby was well-reasoned.
Lanier, who also represented Ernst, complained that the Texas appellate panel's ruling failed to interpret the evidence in the light most favorable to the jury verdict.
"It's a sad day that they can write a 10-page opinion and wipe out a widow's verdict with a new judicial activism that reinterprets the evidence to support corporate executives," Lanier said.
He also said the ruling demonstrates that Texas should not have elected judges, asserting it was "outrageous" that all three judges on the appellate panel took campaign contributions from law firms involved in defending Merck.
Lanier said he would appeal to the Texas Supreme Court if the appellate panel declines to reconsider the ruling.
All three cases -- Ernst, McDarby and Cona -- were excluded from the settlement Merck reached in November in which it agreed to pay $4.85 billion to end thousands of other Vioxx lawsuits.
In November, Merck announced the proposed $4.85 billion settlement for U.S. personal injury cases involving a heart attack, stroke or death. According to the company, some 45,000 eligible claimants had initiated enrollment as of March 31.
Merck shares rose 64 cents, or 1.7 percent, to $39.30 in midday trading Thursday.