Here's what the NEJM thinks about COX-2's and heart attack:
Solomon et al. Cardiovascular Risk Associated with Celecoxib in a Clinical Trial for Colorectal Adenoma Prevention. Volume 352:1071-1080 March 17, 2005 Number 11:
A composite cardiovascular end point of death from cardiovascular causes, myocardial infarction, stroke, or heart failure was reached in 7 of 679 patients in the placebo group (1.0 percent), as compared with 16 of 685 patients receiving 200 mg of celecoxib twice daily (2.3 percent; hazard ratio, 2.3; 95 percent confidence interval, 0.9 to 5.5) and with 23 of 671 patients receiving 400 mg of celecoxib twice daily (3.4 percent; hazard ratio, 3.4; 95 percent confidence interval, 1.4 to 7.

. Similar trends were observed for other composite end points. On the basis of these observations, the data and safety monitoring board recommended early discontinuation of the study drug.
Conclusions Celecoxib use was associated with a dose-related increase in the composite end point of death from cardiovascular causes, myocardial infarction, stroke, or heart failure. In light of recent reports of cardiovascular harm associated with treatment with other agents in this class, these data provide further evidence that the use of COX-2 inhibitors may increase the risk of serious cardiovascular events.
Bresalier et al. Cardiovascular Events Associated with Rofecoxib in a Colorectal Adenoma Chemoprevention Trial. Volume 352:1092-1102 March 17, 2005 Number 11
A total of 46 patients in the rofecoxib group had a confirmed thrombotic event during 3059 patient-years of follow-up (1.50 events per 100 patient-years), as compared with 26 patients in the placebo group during 3327 patient-years of follow-up (0.78 event per 100 patient-years); the corresponding relative risk was 1.92 (95 percent confidence interval, 1.19 to 3.11; P=0.008). The increased relative risk became apparent after 18 months of treatment; during the first 18 months, the event rates were similar in the two groups. The results primarily reflect a greater number of myocardial infarctions and ischemic cerebrovascular events in the rofecoxib group. There was earlier separation (at approximately five months) between groups in the incidence of nonadjudicated investigator-reported congestive heart failure, pulmonary edema, or cardiac failure (hazard ratio for the comparison of the rofecoxib group with the placebo group, 4.61; 95 percent confidence interval, 1.50 to 18.83). Overall and cardiovascular mortality was similar in the two groups. Correction issued later: "In a post hoc assessment, visual inspection of Figure 2 suggested that the Kaplan–Meier curves separated 18 months after randomization. However, the results of an overall test of the proportional-hazards assumption for the entire 36-month observation period did not reach statistical significance (P=0.07)."
Nissen (letter): Volume 355:203-205 July 13, 2006 Number 2
The original article included a post hoc hypothesis that curves for confirmed thrombotic events would not begin to diverge until after 18 months of exposure to rofecoxib. However, all intention-to-treat analyses in the newly released report show that the event curves begin to diverge much earlier, generally within four to six months. The most useful Kaplan–Meier curves, involving intention-to-treat analysis of the APTC end point, show divergence after only three months of exposure to rofecoxib (Figure 1). Figure 2 shows the intention-to-treat analysis for confirmed thrombotic cardiovascular events. The Adenoma Prevention with Celecoxib (APC) study, a trial otherwise similar in design, reported data in which the intention-to-treat approach was used, with no censoring of delayed events.3
Free full text of letter exchanges from Merck and editorialists:
http://content.nejm.org/cgi/content/ful ... type=HWCIT
Note section on thrombogenicity of vioxx and theory that naproxen was protective.
Okie, S. What Ails the FDA? Volume 352:1063-1066 March 17, 2005 Number 11
"Testifying before a spellbound audience in a Senate hearing room this past November, scientist and whistle-blower David J. Graham charged that his employer, the Food and Drug Administration (FDA), is incapable of protecting the public from dangerous prescription drugs. Graham, an epidemiologist who monitors drug safety, conducted a study that confirmed an increase in the risk of myocardial infarction among users of rofecoxib (Vioxx), Merck's blockbuster antiinflammatory medicine. When he informed his supervisors about his findings last summer, he said, they pressured him to change his conclusions because they were inconsistent with the FDA's position on the drug's safety. A few weeks later, Merck withdrew Vioxx from the market in the face of studies suggesting that it had contributed to tens of thousands of heart attacks.
"Vioxx is a terrible tragedy and a profound regulatory failure," Graham told the Senate Finance Committee.
Coxibs and Cardiovascular Disease
FitzGerald G. A. N Engl J Med 2004; 351:1709-1711, Oct 21, 2004; published at
www.nejm.org on Oct 6, 2004
http://content.nejm.org/cgi/content/ful ... type=HWCIT
Note: "Coincident with the approval of rofecoxib and celecoxib in 1999, my colleagues and I reported that both drugs suppressed the formation of prostaglandin I2 in healthy volunteers.2 Prostaglandin I2 had previously been shown to be the predominant cyclooxygenase product in endothelium, inhibiting platelet aggregation, causing vasodilatation, and preventing the proliferation of vascular smooth-muscle cells in vitro. However, it was assumed that prostaglandin I2 was derived mainly from COX-1, the only cyclooxygenase species expressed constitutively in endothelial cells. This assumption later proved incorrect, since studies in mice and humans showed that COX-2 was the dominant source. The individual cardiovascular effects of prostaglandin I2 in vitro contrast with those of thromboxane A2, the major COX-1 product of platelets, which causes platelet aggregation, vasoconstriction, and vascular proliferation.
Whereas aspirin and traditional NSAIDs inhibit both thromboxane A2 and prostaglandin I2, the coxibs leave thromboxane A2 generation unaffected, reflecting the absence of COX-2 in platelets. Increasing laminar shear stress in vitro increases the expression of the gene for COX-2, leading our group to suggest that COX-2 might be hemodynamically induced in endothelial cells in vivo. If so, suppression of the COX-2–dependent formation of prostaglandin I2 by the coxibs might predispose patients to myocardial infarction or thrombotic stroke.
Thus, a single mechanism, depression of prostaglandin I2 formation, might be expected to elevate blood pressure, accelerate atherogenesis, and predispose patients receiving coxibs to an exaggerated thrombotic response to the rupture of an atherosclerotic plaque. The higher a patient's intrinsic risk of cardiovascular disease, the more likely it would be that such a hazard would manifest itself rapidly in the form of a clinical event. "
Oberholzer; Merck's REcall of Rofecoxib
When Merck announced the voluntary withdrawal of its acute-pain medication, rofecoxib (Vioxx), on September 30, 2004, its stock price collapsed, wiping out more than a quarter of the company's market value in a single day. A second blow came on November 1, when an article in the Wall Street Journal suggested that Merck had known about elevated risks of heart attack and stroke for years and had tried to intimidate scientists who questioned the safety of rofecoxib. On that day, Merck's stock price fell by another 10 percent. The recall came as a shock not only to patients and their physicians; the debacle was also terrible news for those awaiting new medical therapies, because the dramatic financial consequences of withdrawing rofecoxib might well hamper the ability of a major pharmaceutical company to invest in new drugs that could help patients in the future.
And here's the conclusion, of a sort:
Expression of Concern Reaffirmed
Gregory D. Curfman, M.D., Stephen Morrissey, Ph.D., and Jeffrey M. Drazen, M.D. "The information we have indicates that the VIGOR article, because it did not contain relevant safety data available to the authors more than four months before publication, did not accurately reflect the potential for serious cardiovascular toxicity with rofecoxib. We therefore reaffirm our expression of concern. "
http://content.nejm.org/cgi/content/ful ... type=HWCIT