In July of 2011, the FDA issued a warning linking Chantix to an increase in the rate of heart attacks in patients with stable cardiovascular disease. That same month a meta-analysis published in the Canadian Medical Association Journal by Doctor Sonal Singh and his colleagues revealed that in smokers without a history of cardiovascular disease, Chantix was associated with a 72% increase in the relative risk of serious cardiovascular events, including ischemia, arrhythmia, congestive heart failure, sudden death, and cardiovascular-related death. Cardiovascular disease is an important cause of morbidity and mortality among smokers, and quitting smoking is widely supposed to reduce this risk, but in this case the data were going the other way.
In fairness, it should be pointed out that the increase in risk was small -- on the order of one extra serious cardiovascular event per year for every 28 patients treated with Chantix -- but the benefits of Chantix also are small, and even those have been demonstrated only in highly artificial clinical situations unavailable to the average quitter.
