Medical News Today -- Pfizer Inc announced the results of a study that found that 47 percent of smokers with a history of cardiovascular disease who took CHANTIX/CHAMPIX® (varenicline) were able to quit smoking and remain abstinent during the last four weeks of treatment (weeks 9-12) compared with just 13.9 percent of those given placebo. These findings were presented at the American College of Cardiology 58th Annual Scientific Session in Orlando, Fla.