Background: Smoking has conflicting results on outcomes following acute myocardial infarction (AMI). We evaluated the independent influence of smoking status on patient outcomes.

Methods: We included patients with AMI undergoing invasive coronary angiography with available self-reported smoking status. The incidence of death of any cause was evaluated during a median follow-up of 1.14 years (range 0.36–3.40 years). Association between smoking status and long-term mortality was evaluated using multivariable adjusted Cox regression analysis.

Results: From 1612 AMI patients (aged 65.7 ± 13.3 years, 72.1 % male), 378 patients (23.4 %) were current-smokers, 311 (19.3 %) ex-smokers, and 923 (57.3 %) non-smokers. Compared with non-smokers, current-smokers were younger (68.5 ± 13.0 vs. 58.6 ± 12.5, p < 0.0001) and more frequently presented with STEMI (21.6 % vs. 35,4 %, p < 0.0001), while ex-smokers with similar frequency of STEMI-manifestation as non-smokers (22.5 %, p = 0.79) constituted an intermediate-group in terms of age (65.8 ± 11,6 years). Although smoking status was not significantly associated with long-term survival in unadjusted-analysis, active-smokers had 56 % higher long-term mortality than non-smokers when adjusting for age, gender, medications and other traditional risk factors, whereas ex-smokers possessed comparable survival probability (current-smokers: 1.56[1.14–2.14], p = 0.006, ex-smokers 1.16[0.84–1.59], p = 0.37). Current-smokers had unadjusted lower NT-proBNP and modestly higher absolute in-hospital left ventricular global longitudinal strain (LV GLS) values that did not differ among groups after the same adjustments (NT-proBNP: −0.08[-0.31; 0.15], p = 0.5, LV GLS: 0.65[-0.26; 1.55], p = 0.16).

Conclusion:Active smoking is associated with increased adjusted long-term mortality, earlier onset and more frequent manifestation as STEMI, compared to non-smoking. Comparable adjusted results for LV GLS and NT-proBNP between groups support the presence of the pseudoparadox.