Cessation treatment adherence and smoking abstinence in patients after acute myocardial infarction

Background Previous trials examining the use of bupropion for smoking cessation therapy after myocardial infarction (MI) have been inconclusive. To understand better the observed lack of effectiveness of bupropion in this population, we examined abstinence rates by level of adherence across treatment groups. Methods We used data from a randomized, double-blind, placebo-controlled trial of bupropion in smokers (n = 388) hospitalized with MI to study the association of interest. Patients were classified as being fully adherent if they reported taking 2 pills/d; partially adherent if they reported 0, 1, and/or 2 pills/d; and nonadherent if they reported 0 and/or 1 pill/d throughout the 9-week treatment period. Abstinence was assessed by 7-day biochemically validated self-report at 4 and 9 weeks and 6 and 12 months. Results A total of 156 patients were fully adherent to the study medication (66 bupropion and 90 placebo), 149 were partially adherent (76 and 73, respectively), and 83 were nonadherent (46 and 37, respectively). Regardless of treatment group, patients who were fully or partially adherent reported greater abstinence than did nonadherent patients. Among partially adherent patients, bupropion conferred an important benefit at 12 months (% difference 13.3, 95% CI 1.3-25.3). At 12 months, patients who were fully adherent were more likely to be abstinent compared with those who were nonadherent (adjusted odds ratio 7.6, 95% CI 3.2-17.6). Conclusions Adherence to study medication, regardless of assigned treatment, is associated with a substantial increase in abstinence. Patients who are motivated to quit smoking should be targeted for smoking cessation treatment after MI.