The FDA is informing the public about results of a meta-analysis that compared patients who received the smoking cessation drug varenicline (Chantix, Pfizer) with patients who received a placebo. The meta-analysis found a higher occurrence of major adverse cardiovascular (CV) events (a combined outcome of CV-related death, nonfatal heart attack and nonfatal stroke) in patients using Chantix.

These events were "uncommon" in both the Chantix and placebo groups, according to the FDA, and "the increased risk was not statistically significant, which means it is uncertain whether the excess risk for the Chantix group was due to the drug or due to chance." However, the data were analyzed many different ways and consistently showed a higher occurrence of events in patients using Chantix, which makes it seem more likely that it is related to the drug and not purely a chance finding, the agency added.

The agency required the manufacturer of Chantix to conduct the meta-analysis to further evaluate the cardiovascular safety of the drug. The FDA first notified the public about a possible increased risk of CV adverse events with Chantix in June 2011, and noted that these findings of CV risk are similar to the findings in the smoking cessation clinical trial of patients with stable CV disease.

Also, researchers from Johns Hopkins University School of Medicine in Baltimore, the University of East Anglia in Norwich, England, and Wake Forest Baptist Medical Center in Winston-Salem, N.C., conducted an independent analysis examining 14 trials with 8,216 patients. They found that the use of varenicline is associated with a 72 percent increased risk of a serious adverse cardiovascular event.