Is it true: Vioxx cardiovascular risk and Merck's disclosure (1999-2004)?

Partly — it's more complicated than the claim suggests.

Partly true. Documented: Vioxx raised cardiovascular risk (APPROVe, placebo-controlled, relative risk 1.92); Merck had a heart-attack signal from VIGOR by 2000 and attributed it to a possible protective effect of naproxen; the FDA's September 2001 warning letter, a regulator's finding about Merck's promotion rather than a court finding, said the promotion minimizes the potentially serious cardiovascular findings from VIGOR; the New England Journal of Medicine said three heart attacks, all on Vioxx, were left out of the published VIGOR paper and questioned the integrity of its cardiovascular data (the concern was about the paper's authors, who disputed it); the cardiovascular label change came in April 2002. Not established: that Merck intended to conceal or to play down the risk. The VIGOR imbalance was released in March 2000, given to the FDA in June 2000 and published in November 2000. Merck stressed that its $4.85 billion settlement (2007) was not an admission of fault, and the 2011 guilty plea was a misdemeanour for promoting Vioxx for rheumatoid arthritis before approval. A parallel $628 million civil settlement resolved allegations about misleading cardiovascular safety statements; Merck said it was not an admission of liability.