Smoking cessation after acute myocardial infarction: a Swiss-wide cohort study

Abstract Background Smoking is a major cardiovascular risk factor and of great importance in terms of both primary and secondary prevention. The present study aims to identify patient characteristics associated with smoking cessation within 1 year after acute myocardial infarction (AMI) to inform physician-patient interactions, secondary prevention measures, and public health planning. Methods ST-elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) patients enrolled between 2012 and 2022 in the AMIS Plus registry who were active smokers at the time of the index event were included. At the 1-year follow-up, patients were questioned about their smoking behaviour via telephone interview and were further classified into those who had quit (stoppers) or continued (continuers) smoking. Patient characteristics were collected at the time of the index event and at follow-up and then compared using descriptive statistics. Results From a total of 4523 patients with AMI, 4242 (93.8%) provided information regarding their smoking status at a median follow-up of 395 days (interquartile range 370 to 469) after the index event. Of 1691 (39.9%) active smokers at the time of AMI, 861 (50.9%) reported quitting whereas 830 (49.1%) were still smoking at the 1-year follow-up. Stoppers were younger (57 vs. 58 years, p<0.001), more likely to be male (82.8% vs. 77.7%, p=0.008) and have presented with STEMI (77.0% vs. 71.0%, p=0.005), and less likely to have had a previous AMI (6.6% vs. 13.3%, p<0.001) than continuers. Smoking cessation was more common in patients with a more severe AMI characterised by a greater extent of myocardial injury (in-hospital median peak creatine kinase level 1291 IU/L vs. 1101 IU/L, p=0.012), at least one in-hospital complication (13.9% vs. 9.9%, p=0.01), and participation in a rehabilitation programme (83.7% vs. 68.8%, p<0.001). Stoppers more frequently implemented other favourable lifestyle changes, such as dietary changes (56.2% vs. 45.2%, p<0.001) and increased physical activity (54.6% vs. 37.7%, p<0.001) than continuers. Self-reported weight gain was more prevalent among those who quit smoking (44.0% vs. 19.7%, p<0.001). Conclusions In Switzerland, half of the patients with AMI who were active smokers at the time of AMI, reported to have stopped smoking 1 year after the index event. Smoking cessation was associated with participation in a rehabilitation programme and occurred more often in patients with larger AMI sizes, higher in-hospital complication rates and more frequent implementation of other favourable lifestyle changes after AMI. The significant weight gain after smoking cessation seems to represent a major issue that should specifically be addressed.