March 26 (UPI) -- The drug varenicline, marketed as Chantix, significantly reduced smoking among patients who had suffered a heart attack one year earlier, according to a controlled trial.
Researchers from Canada examined the efficacy of varenicline in patients with acute coronary syndrome, publishing their findings Monday in the Canadian Medical Association Journal.
After acute coronary syndrome, including a heart attack or reduced blood flow to the heart, patients are at increased risk for another attack and death if they do not quit smoking, experts say.
In past studies, varenicline has been shown to help stop smoking in patients with heart attack within the first six months, but its longer-term success was not known.
Researchers recruited 302 patients with a median age of 55 in Canada and the United States who had been admitted to hospital for acute coronary syndrome, smoked at least 10 cigarettes a day for the previous year and wanted to quit smoking. Most of them had moderate to severe nicotine dependency.
They received smoking cessation counseling, as well as varenicline or a placebo control, for 12 weeks.
Among those who received varenicline, 39.9 percent were not smoking at one year, compared with 29.1 percent in the placebo group.
Also, daily cigarette smoking was reduced in 57.8 percent taking varenicline group compared with 49.7 for the placebo group.
Rates of continuous abstinence at week 52 were 31.1 percent in the varenicline group vs. 21.2 percent in the placebo group
In both groups, rates of adverse events were similar.
"This suggests that varenicline is safe for use in these patients," Dr. Mark Eisenberg, of Jewish General Hospital and McGill University in Montreal, said in a press release. "However, new strategies for smoking cessation are still needed, given that 60 percent of smokers who received treatment with varenicline returned to smoking by one year after their acute coronary syndrome."
If varenicline were used as routine treatment in smokers after heart attack, smoking would be reduced by 10 percent, the researchers estimate.
On Friday, Pfizer announced results from a Phase 4 study evaluating the efficacy and safety of varenicline for smoking cessation in nicotine dependent adolescents 12-19 years of age. The study did not meet its primary endpoint of the four-week continuous abstinence rate at weeks nine through 12 for the drug compared with a placebo.