Preoperative smoking status and long-term survival after coronary artery bypass grafting: a competing risk analysis

Data de publicação: 01/01/2024

Autores da FMUP

• Joaquim Adelino Correia Ferreira Leite Moreira

  Autor

Participantes de fora da FMUP

• Abreu A.
• Máximo J.D.

Unidades de investigação

• Cirurgia e Fisiologia

• Laboratório Associado RISE- Rede de Investigação em Saúde

  

  Investigador

  Fernando Carlos De Landér Schmitt

• RISE-Health

  

  Investigador

  Fernando Carlos De Landér Schmitt

Abstract

OBJECTIVES: Patients with severe coronary artery disease who undergo coronary artery bypass grafting consistently demonstrate that continued smoking after surgery increases late mortality rates. Smoking may exert its harmful effects through the ongoing chronic process of atherosclerotic progression both in the grafts and the native system. However, it is not clear whether cardiac mortality is primary and solely responsible for the inferior late survival of current smokers. METHODS: In this retrospective analysis, we included all consecutive patients undergoing primary isolated coronary artery bypass surgery from 1 January 2000 to 30 September 2015 in an Academic Hospital in Northern Portugal. The predictive or independent variable was the patients' smoking history status, a categorical variable with 3 levels: non-smoker (the comparator), ex-smoker for >1 year (exposure 1) and current smoker (exposure 2). The primary end point was long-term all-cause mortality. Secondary outcomes were long-term cause-specific mortality (cardiovascular and noncardiovascular). We fitted overall and Fine and Gray subdistribution hazard models. RESULTS: We identified 5242 eligible patients. Follow-up was 99.7% complete (with 17 patients lost to follow-up). The median follow-up time was 12.79years (interquartile range, 9.51-16.60). Throughout the study, there were 2049 deaths (39.1%): 877 from cardiovascular causes (16.7%), 727 from noncardiovascular causes (13.9%) and 445 from unknown causes (8.5%). Ex-smokers had an identical long-term survival than non-smokers [hazard ratio (HR) 0.99; 95% confidence interval (CI) 0.88, 1.12; P¼0.899]. Conversely, current smokers had a 24% increase in late mortality risk (HR 1.24; 95% CI 1.07, 1.44; P¼0.004) as compared to non-smokers. While the current smoker status increased the relative incidence of noncardiac death by 61% (HR 1.61; 95% CI 1.27, 2.05, P<0.001), it did confer a 25% reduction in the relative incidence of cardiac death (HR 0.75; 95% CI 0.59, 0.97; P¼0.025). CONCLUSIONS: Whereas ex-smokers have an identical long-term survival to non-smokers, current smokers exhibit an increase in late all-cause mortality risk at the expense of an increased relative incidence of noncardiac death. By subtracting the inciting risk factor, smoking cessation reduces the relative incidence of cardiac death. © The Author(s) 2024.

© The Author(s) 2024. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery.

Keywords

• Aged; Coronary Artery Bypass; Coronary Artery Disease; Female; Humans; Male; Middle Aged; Portugal; Preoperative Period; Retrospective Studies; Risk Assessment; Risk Factors; Smoking; acute heart infarction; adult; aged; all cause mortality; analysis of variance; anemia; aortic atherosclerosis; Article; body mass; cardiopulmonary bypass; cardiovascular disease; cardiovascular mortality; cerebrovascular accident; Charlson Comorbidity Index; chronic kidney failure; chronic obstructive lung disease; Cochran Armitage trend test; competing risk analysis; controlled study; coronary artery bypass graft; coronary artery disease; creatinine clearance; diabetes mellitus; female; Fine and Gray subdistribution hazard model; follow up; hazard ratio; health care planning; homoscedasticity; hospitalization; human; hyperlipidemia; hypertension; ICD-10; ICD-9-CM; incidence; independent variable; Kaplan Meier method; long term survival; longitudinal study; major clinical study; male; middle aged; mort