QUIT Forum -

In this week’s CMAJ, there is a meta-analysis of the risks of serious cardiovascular events associated with the use of varenicline (see article at: http://www.cmaj.ca/content/early/2011/07/04/cmaj.110218). It is a known fact that smoking raises the risk of cardiovascular disease immensely; the relative risk of mortality from coronary heart disease among women who smoke is about 4-5 times the risk of seen among women who have never smoked; so, one must weight the cardiovascular risks of smoking versus the potential cardiovascular risks of using varenicline for smoking cessation.

A commentary on the meta-analysis was published in the CMAJ, asserting that one must critically appraise literature such as this, before making any clinical decisions. There were several issues raised about the research article. Firstly, the meta-analysis was based on a 72% increased risk of adverse cardiovascular events, however, this was rare in both treatment groups (1.06% in those given varenicline and 0.82% in those given a placebo). Secondly, the rate of participants lost to follow up was greater in the placebo arm of the studies analyzed than in the treatment arm, which could translate into bias.

The commentary recommends that more rigorous studies be conducted among smokers with known CV disease. It cautions healthcare providers against abandoning the use of varenicline based on this research article alone, since it has been proven to be among the most efficacious smoking cessation tool available. Also, it states that the small absolute risk of cardiovascular events associated with taking varenicline is outweighed by the enormous benefit of reducing cardiovascular morbidity and mortality that can be achieved through smoking cessation.