Varenicline Helps ACS Patients Quit Smoking, But Effect Wanes

ORLANDO, FL—When started in the hospital, varenicline increases smoking abstinence in ACS patients for up to 6 months when accompanied by low-intensity counseling, the EVITA trial shows, although the effect gets progressively smaller over time.

“The numbers that I’m presenting today are probably much better than they are in real life because many patients are not motivated to quit and not even willing to take medication for smoking cessation,” said presenter Mark Eisenberg, MD, MPH, of Jewish General Hospital/McGill University (Montreal, Canada), at the American Heart Association 2015 Scientific Sessions.

Commenting on the findings, Donald Lloyd-Jones, MD, ScM, of Northwestern University Feinberg School of Medicine (Chicago, IL), said “this is a very good early result,” adding that follow-up is required to sustain the effect of treatment, which lasted 12 weeks.

The findings were published simultaneously online on November 9 in Circulation.

EVITA, performed at 40 Canadian and US centers, included 302 smokers (mean age 55; 75% men) who were hospitalized for ACS and were motivated to quit. Patients had been smoking for an average of 36 years and were going through about a pack a day at baseline. They were randomized to 12 weeks of treatment with varenicline (Chantix; Pfizer) or placebo, with at least 1 dose administered during the initial hospital stay. Patients received telephone follow-up at weeks 1, 2, and 8 and attended clinic visits at weeks 4, 12, and 24. Low-intensity counseling was provided at baseline and at all follow-up contacts.

Smoking abstinence—assessed using self-reported abstinence in the past week plus biochemical validation using exhaled carbon monoxide ≤ 10 ppm—was more frequent in the varenicline group at weeks 4, 12, and 24, but the effect appeared to wear off over time. Abstinence at 24 weeks was the primary endpoint of the trial (table 1).

Among the secondary endpoints, continuous abstinence—meeting criteria for abstinence at all follow-up visits—was higher in the varenicline group at weeks 4 and 12, but the difference was no longer significant at week 24 (35.8% vs 25.8%; P =.081). The proportion of patients smoking at least 50% fewer cigarettes daily compared with baseline was higher in the varenicline arm at each time point.

Safety Requires Further Study

At 30 days, there was no difference between the varenicline and placebo groups in the rate of overall serious adverse events (11.9% vs 11.3%) or MACE (4.0% vs 4.6%; P > .99 for both). Only 1 varenicline-treated patient had a neuropsychiatric event (it was neuropsychiatric events that prompted European regulators, followed by the FDA, to add a warning to the medication insert in 2008 and 2009, respectively). This single incident involved hospitalization for depression 25 days after receipt of a single dose of the drug.

The most common side effects were insomnia (17.9% vs 12.6%; P = .26), nausea (13.9% vs 8.6%; P = .20), and abnormal dreams (15.2% vs 4.6%; P < .01).

Three patients—all in the varenicline arm—died, including 2 cardiovascular-related deaths in the first 30 days and 1 death related to a perforated gastric ulcer at a later time point.

Because the study was not powered for safety endpoints, Eisenberg said, “future studies are needed to definitively establish the safety of varenicline in this patient population.”

Source:
Eisenberg MJ, Windle SB, Roy N, et al. Varenicline for smoking cessation in hospitalized patients with acute coronary syndrome. Circulation. 2015;Epub ahead of print.

Disclosures:

• Pfizer provided funding and varenicline/placebo for the trial.
• Eisenberg reports receiving honoraria from Pfizer for providing continuing medical education on smoking cessation.
• Lloyd-Jones reports no relevant conflicts of interest.

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