Effectiveness of a smoking cessation intervention in a cardiac rehabilitation program after myocardial infarction

Background Smoking cessation is the most effective preventive measure in post-myocardial infarction patients (MI), yet many patients continue smoking after MI. Cardiac Rehabilitation Programs (CRP) provide the ideal framework for smoking cessation intervention. Purpose To analyse the effectiveness of a smoking cessation strategy during CRP in post-MI patients and the factors associated with smoking habit and persistent smoking. Methods 209 MI sufferers between November 2021 and September 2024 submitted to our local CRP were included in a prospective registry. We analysed secondary prevention goals before and after Phase 2 CRP, such as low-density lipoprotein cholesterol (LDL-C) <55mg/dL and quality of life in the 36-Item Short Form Survey Instrument (SF-36), among others. Smoking cessation intervention by cardiologists and nurses was provided to all previous smokers during CRP: 1. Brief advice to quitters without significant craving, 2. Motivational interview to quitters with craving symptoms, and 3. Pharmacological therapy in persistent smokers or quitters with severe craving and high risk of relapse. Comparisons were made between previous non-smokers and smokers, and quitters vs. persistent smokers after CRP. Results 101 (48.3%) patients were smokers before MI (mean 17.85±10.5 cigarettes per day and mean 37.73±24.34 pack-years). Previous smokers were younger (57.99±7.86 vs. 66.92±11.6 years, p<0.001). After Phase 2 CRP, they demonstrated worse weight (body mass index <30 in 72.3% vs. 85.2%, p=0.02) and lipid (LDL-C <55mg/dL in 80.2% vs. 88.9%, p=0.04) control, more emotional limitations (75.33±24.86 vs. 81.87±25.83 points, p=0.04), less emotional well-being (67.03±21.09 vs. 73.98±21.31 points, p=0.02), and more anxiety symptoms (1.65±1.6 vs. 1.18±1.5 points in GAD-2, p=0.03). Prescription and adherence rates were 34.7% and 57.1% for short-acting nicotine replacement therapy (NRT), 34.7% and 48.6% for long-acting NRT, 28.7% and 79.3% for bupropion, and 17.8% and 94.4% for cytisine. After a median of 7.78 [6.31-10.1] months of Phase 2 CRP follow-up, 91 (90.1%) previous smokers maintained smoking abstinence. Persistent smokers had a trend towards higher accumulated exposure (51.01±28.8 vs. 36.26±23.52 pack-years, p=0.07) and were more frequently treated with NRT and bupropion, with similar adherence to quitters. However, they showed worse lipid control (LDL-C <55mg/dL in 50% vs. 83.5%, p=0.01). No association was found with infarct severity variables such as GRACE score, Killip class during admission, or left ventricular ejection fraction at discharge. Conclusion A specific smoking cessation intervention during Phase 2 CRP can achieve excellent abstinence rates more than 6 months after MI. Previous smokers demonstrate worse weight and lipid control outcomes and more impaired mental health well-being. Moreover, half of persistent smokers did not reach target LDL-C control, further increasing their cardiovascular risk.Smoking cessation during CRP after MI