Effect of Smoking Status on Mortality and Morbidity Following Coronary Artery Bypass Surgery[*]

Abstract

Background: We aimed to examine the effect of smoking on outcomes following coronary artery bypass grafting (CABG). Methods: We retrospectively analysed 6 367 consecutive patients who underwent CABG between April 1997 and March 2003. Logistic regression was used to risk adjust in-hospital outcomes, while Cox proportional hazards analysis was used to risk adjust Kaplan-Meier survival curves. Outcomes were adjusted for variables suggested by the American Heart Association and American College of Cardiology. Results: 947 (14.9 %) patients were current smokers (smoking within 1 month of surgery), while 3857 (60.6 %) were ex-smokers and 1 563 (24.5 %) were non-smokers. After adjusting for differences in case-mix, current smokers were more likely to develop chest infections (p < 0.001), atelectasis (p < 0.001), and require ventilation longer than 48 hours (p = 0.003). Current smokers were also more likely to stay in intensive care for more than 3 days (p < 0.001). Ex-smokers were not associated with excess mortality (p = 0.11), while current smokers had significantly increased mortality during follow-up (p = 0.029). Conclusions: Patients should be encouraged to stop smoking to maximise the long-term benefits of CABG.

Key words

Smoking - coronary artery bypass grafting - mortality - morbidity - risk adjustment

1 Presented at the 4th joint meeting of the German, Austrian, and Swiss Society of Thoracic and Cardiovascular Surgery, Hamburg, February 2004

References

• 1 Ferguson Jr T B, Hammill B G, Peterson E D, DeLong E R, Grover F L. STS National Database Committee. A decade of change - risk profiles and outcomes for isolated coronary artery bypass grafting procedures, 1990 - 1999.  Ann Thorac Surg. 2002;  73 480-490
• 2 Ngaage D L, Martins E, Orkell E. et al . The impact of the duration of mechanical ventilation on the respiratory outcome in smokers undergoing cardiac surgery.  Cardiovasc Surg. 2002;  10 345-350
• 3 Moller A M, Maaloe R, Pedersen T. Postoperative intensive care admittance: the role of tobacco smoking.  Acta Anaesthesiol Scand. 2001;  45 345-348
• 4 Spivack S D, Shinozaki T, Albertini J J, Deane R. Preoperative prediction of postoperative respiratory outcome: coronary artery bypass grafting.  Chest. 1996;  109 1222-1230
• 5 Hulzebos E HJ, Van Meeteren N LU, De Bie R A, Dagnelie P C, Helders P JM. Prediction of postoperative pulmonary complications on the basis of preoperative risk factors in patients who had undergone coronary artery bypass graft surgery.  Phys Ther. 2003;  83 8-16
• 6 Hosmer D, Lemeshow S. Applied Logistic Regression. New York, NY; John Wiley & Sons Inc 1989
• 7 Kaplan E L, Meier P. Nonparametric estimation from incomplete observations.  J Am Stat Assoc. 1958;  53 547-581
• 8 Cox D R. Regression models and life tables.  J R Stat Soc. 1972;  34 187-220
• 9 Eagle K A, Guyton R A, Davidoff R. et al . ACC/AHA guidelines for coronary artery bypass graft surgery. A report of the American College of Cardiology/American Heart Association task force on practice guidelines (committee to revise the 1991 guidelines for coronary artery bypass graft surgery).  Circulation. 1999;  100 1464-1480
• 10 Ball K, Turner R. Smoking and the heart.  Lancet. 1974;  2 822-826
• 11 Pearce A C, Jones R M. Smoking and anesthesia: preoperative abstinence and perioperative morbidity.  Anesthesiology. 1984;  61 576-584
• 12 Djaiani G N, Phillips-Bute B, Blumenthal J A, Newman M F. Neurological Outcome Research Group; CARE Investigators of the Duke Heart Centre. Chronic exposure to nicotine does not prevent neurocognitive decline after cardiac surgery.  J Cardiothorac Vasc Anesth. 2003;  17 341-345
• 13 John R, Choudhri A F, Weinberg A D. et al . Multicentre review of preoperative risk factors for stroke after coronary artery bypass grafting.  Ann Thorac Surg. 2000;  69 30-36
• 14 Van Domburg R T, Meeter K, van Berkel D F, Veldkamp R F, van Herwerden L A, Bogers A J. Smoking cessation reduces mortality after coronary artery bypass surgery: a 20-year follow-up study.  J Am Coll Cardiol. 2001;  37 2009-2010
• 15 Silberg A. Biorheological matching: mucociliary interaction and epithelial clearance.  Biorheology. 1983;  20 215-222
• 16 Kensler C J, Battista S P. Chemical and physical factors affecting mammalian ciliary activity.  Am Rev Respir Dis. 1966;  93 93-102
• 17 Chodoff P, Margand P MS, Knowles C L. Short term abstinence from smoking: its place in preoperative preparation.  Crit Care Med. 1975;  3 131-133
• 18 Ingersoll G L, Grippi M A. Preoperative pulmonary status and postoperative extubation outcome of patients undergoing elective cardiac surgery.  Heart Lung. 1991;  20 137-143
• 19 Branca P, McGaw P, Light R. Factors associated with prolonged mechanical ventilation following coronary artery bypass surgery.  Chest. 2001;  119 537-546
• 20 Warner M A, Offord K P, Warner M E, Lennon R L, Conover M A, Jansson-Schumacher U. Role of preoperative cessation of smoking and other factors in postoperative pulmonary complications: a blinded prospective study of coronary artery bypass patients.  Mayo Clin Proc. 1989;  64 609-616

1 Presented at the 4th joint meeting of the German, Austrian, and Swiss Society of Thoracic and Cardiovascular Surgery, Hamburg, February 2004