Evaluation of Varenicline (Champix) in Smoking Cessation for Patients Post-Acute Coronary Syndrome (EVITA) Trial

Objectives: 1. The primary objective of the Evaluation of Varenicline (Champix™) in SmokIng Cessation for PaTients Post-Acute Coronary Syndrome (EVITA) Trial is to evaluate the impact of varenicline on smoking cessation rates at 24 weeks following an enzyme-positive acute coronary syndrome (ACS).

2. The secondary objectives are to examine the efficacy of varenicline on smoking cessation rates and daily cigarette reduction at 52 weeks, and to determine the safety of varenicline in patients following an ACS.

Rationale: Patients who continue smoking after an acute coronary syndrome (ACS) have a 35% increased risk of reinfarction or death compared with those who quit. Many patients attempt to stop smoking after an ACS, but relapse rates approach 66%. A variety of smoking cessation aids have been shown to be effective for the general population. However, physicians are reluctant to use a nicotine-based therapy because of its hemodynamic effects. Varenicline has been recently shown to improve abstinence rates in healthy young smokers compared to bupropion (Zyban™) and placebo. Although varenicline has successfully been shown to reduce smoking rates in healthy young populations, its efficacy in the setting of patients recovering from an ACS is unknown.

Methods: The EVITA Trial will directly compare the efficacy of varenicline versus placebo as a means of reducing smoking rates in patients following an ACS. The trial will be a multi-center effort, coordinated from the Jewish General Hospital/McGill University (Montreal, Quebec). A total of 300 patients will be randomized following an ACS but before hospital discharge. While in-hospital, patients will quit smoking and they will be instructed to not restart smoking following discharged. Half the patients will receive varenicline for 12 weeks and the other half will receive placebo pills for 12 weeks. Patients receiving varenicline will be given 1.0 mg twice a day during the 12-week treatment period. Study nurses will perform telephone follow-ups with the patients at weeks 1, 2 and 8, and patients will return for clinic visits at weeks 4, 12, 24, and 52. Smoking abstinence will be assessed at follow-up clinic visits.

The primary endpoint will be smoking abstinence at 24 weeks. Smoking abstinence will be defined as complete abstinence in the week prior to the clinic visits and levels of exhaled carbon monoxide ≤ 10 ppm. The secondary endpoints (smoking abstinence at 52 weeks, side effects of varenicline in patients following an ACS, percent of patients attaining a ≥ 50% reduction in daily consumption of cigarettes at 52 weeks, and clinical events following initiation of treatment) will be measured at 1, 2, 4, 8, 12, 24, and 52 weeks. The occurrence of clinical events will be based on the observed frequency of composite events including death, myocardial infarction, and hospitalization for unstable angina. Withdrawal symptoms and number of cigarettes smoked will also be assessed by the use of questionnaires. The EVITA trial will require 36 months for completion: 3 months for preparation, 18 months for patient enrollment, 12 months for follow-up, and 3 months for data analysis and manuscript preparation.

Significance: The EVITA trial will be the first to examine the efficacy of varenicline in a group of patients who have suffered an ACS. These patients, if they continue to smoke, are at exceptionally high risk for recurrent cardiac events. If varenicline is effective in this population, it will have a major impact on secondary prevention of recurrent clinical events in patients who suffer an ACS.