Smoking Cessation Drug Linked to Increased Risk of Cardiovascular Events

The researchers analyzed the medical records of 56,851 new users of varenicline.

The smoking cessation treatment, varenicline, was associated with a higher risk of cardiovascular events, according to a study published in American Journal of Respiratory and Critical Care Medicine

A team of researchers from the University of Toronto conducted a population-based, self-controlled risk interval study to evaluate the risk of cardiovascular and neuropsychiatric events after receiving varenicline in a real-world setting. Using universal health data from Ontario, Canada, new patients starting varenicline between September 1, 2011 and February 5, 2014 were observed from 1 year before to 1 year after receiving varenicline. Study authors calculated the relative incidences of cardiovascular and neuropsychiatric hospitalizations as well as emergency department (ED) visits in the 12 weeks after starting varenicline (risk interval) and compared them with the remaining observation period (control interval). 

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Of the total new patients started on varenicline (n=56,851), there were 10,041 neuropsychiatric and 6,317 cardiovascular events that led to hospitalizations or ED visits from 1 year before to 1 year after varenicline receipt. The occurrence of cardiovascular events was 34% higher in the risk interval vs the control interval (relative incidence [RI] 1.34, 95% CI: 1.25–1.44). 

Although the RI of neuropsychiatric events was marginally significant in the primary (RI 1.06, 95% CI: 1.00–1.13) analysis, it was not across all sensitivity analyses. 

The study authors were able to conclude that varenicline appeared to be associated with a greater risk of cardiovascular but not neuropsychiatric events. “Our findings should not be used to suggest people not take varenicline. The findings should be used to help people make an informed decision about whether they should take varenicline based on accurate information about its risks as well as its benefits,” said lead author Andrea S. Gershon, MD. 

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