Risk of Cardiovascular Series of Adverse Events Associated With Varenicline Use for Tobacco Cessation: Systematic Review and Meta-Analysis

A popular smoking cessation medication has been under a cloud of suspicion ever since the Canadian Medical Association Journal (CMAJ) published a study July 2011, reporting “risk of serious adverse cardiovascular events associated with varenicline.  ” Varenicline, also known as Chantix, blocks the pleasant effects of nicotine on the smoker’s brain and lessens nicotine withdrawal symptoms.

UCSF researchers, however, question the way the previous study was conducted, and their new analysis, published May 2012, in British Medical Journal (BMJ), reached a very different conclusion.  “We found no clinically or statistically significant increase in serious adverse cardiovascular events associated with using varenicline,” said lead author Judith J. Prochaska PhD, MPH, an associate professor in UCSF’s Department of Psychiatry and researcher with the Center for Tobacco Control Research and Education.

Prochaska and Joan F. Hilton, ScD, MPH, a professor in UCSF’s Department of Epidemiology & Biostatistics, conducted the new study, which, like the prior one, used meta-analytic statistical techniques to combine results from different trials of varenicline with tobacco users. The UCSF and prior analysis, however, differed in several fundamental ways.

The previous study, led by Sonal Singh, MD, MPH, assistant professor of medicine at Johns Hopkins University, looked at a sample size of 8,216 patients in 14 trials and ­­­reported a 72 percent (relative) increase in risk of heart attack or other serious heart problems.  The UCSF study found a 0.27 percent (absolute) risk difference, which it determined was neither clinically nor statistically significant. 

“One of the most important things you can do for your heart is to quit smoking,” Prochaska said. “Clinical practice guidelines recommend the use of FDA medications to quit smoking. All medications carry some risk; however, we hope the FDA and other experts compare the Singh analysis to ours to determine what action, if any, should be taken with regard to varenicline and cardiovascular risk. Tobacco is a deadly addiction, and patients need effective treatments.”  To read full article, click here