1Universitätsklinikum Essen Klinik für Kardiologie und Angiologie Essen, Deutschland
Background: Smoking, one of the leading causes of preventable death, has conflicting results in the literature on short-term outcomes following acute myocardial infarction (AMI), potentially due to differences in global cardiovascular risk profile in smokers and non-smokers. We aimed to evaluate the independent influence of smoking status on procedural outcomes, echocardiographic measures, and long-term mortality in a large AMI cohort.
Methods: We included patients with AMI undergoing invasive coronary angiography between 2004 and 2019 at our center. The incidence of death due to any cause was evaluated during a mean follow-up of 2.5±3.0 years. Association between smoking status and long-term mortality was evaluated using multivariable adjusted Cox regression analysis.
Results: From 1612 AMI patients (mean age 65.7±13.3 years, 72.1% male), 403 patients with ST-elevation myocardial infarction (STEMI) and 1208 patients with non-ST-elevation myocardial infarction (NSTEMI) were included. Of these, 378 patients (23.4%) were current smokers, 311 patients (19.3%) were ex-smokers, and the remaining 923 patients (57.3%) were non-smokers. Compared with non-smokers, current smokers were younger (68.5±13 vs 58.6±12.5, p<0.0001) and more frequently presented with STEMI (35.4% vs 21.6%, p<0.0001). Although smoking status didn’t affect unadjusted long-term survival, 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 to non-smokers (current smokers: 1.56 [1.14-2.14], p=0.006, ex-smokers (1.16 [0.84-1.59], p=0.37). Likewise, in multivariable regression analysis, current smokers had comparable NT-proBNP, left ventricular global longitudinal strain (LV GLS) and left atrial (LA) strain values (NT-proBNP: -0.08[-0.31-0.15],p=0.5, LV GLS: 0.65[-0.26-1.55], p=0.16, LA strain: -0.36[-1.91-1.20], p=0.65).
Conclusion: Active smoking is associated with increased adjusted long-term mortality, younger onset and more frequent manifestation as STEMI, compared to non-smoking. Comparable adjusted results for LV GLS, LA strain and NT-proBNP between groups support the hypothesis of the short-
term pseudoparadox of smoking in AMI.
Keywords: Myocardial infarction; NSTEMI; Smoker's paradox; Smoking; STEMI; TIMI flow