Smoking Cessation Before Coronary Artery Bypass Grafting Improves Operative Outcomes

Study Questions:

Does smoking cessation improve postoperative outcomes among patients after coronary artery bypass grafting (CABG)?

Methods:

A retrospective analysis on a large cohort of patients who underwent CABG at a single institution was performed. Patients were queried about their smoking habits at admission. Patients were grouped based on smoking habits: 1) never smoked, defined as patients who had never smoked cigarettes regularly; 2) ex-smokers, defined as those who had quit smoking at least 4 weeks before the index procedure; and 3) current smokers, defined as those who smoked within 4 weeks before the index procedure. Smoking cessation services were provided for all prospective surgical candidates and brief intervention counseling was offered during surgical preadmission checks. All smokers and ex-smokers (within 5 years) had preoperative pulmonary function testing and bronchodilators were started before surgery, if indicated. Outcomes were assessed postoperatively including major lung complications such as full tracheostomy; reintubation; lung infection/consolidation; low cardiac output syndrome, defined as the need for inotropes and/or an intra-aortic balloon pump after surgery; need for renal replacement therapy; a postoperative cerebrovascular accident, both transient or permanent; re-exploration for bleeding; sternal rewiring for instability; sternal wound infection, either superficial or deep; postoperative atrial fibrillation; pleural effusion requiring drainage; prolonged postoperative hospital stay (defined as length of stay ≥75th percentile of postoperative stay length distribution); and in-hospital mortality.

Results:

A total of 6,113 patients who underwent isolated CABG for the first time were included. At baseline, there were 640 (10.4%) current smokers, 3,309 (54.1%) ex-smokers, and 2,164 (35.3%) nonsmokers. Eight of 16 variables examined were different among smoking status groups including age, female gender, previous myocardial infarction, chronic obstructive pulmonary disease, reduced left ventricular ejection fraction, peripheral vascular disease, nonelective indication, and the use of cardiopulmonary bypass. Median postoperative length of stay was 7 days (interquartile range, 6-10). Prolonged hospital stay (>10 days) occurred in 1,604 patients (26.2%). The rate of lung infection/consolidation was slightly increased among current smokers (p = 0.047), but not the incidence of reintubation (p = 0.25), full tracheostomy (p = 0.1), and overall incidence of major lung complication (p = 0.1). Multilevel propensity score weighted analysis showed a beneficial effect of smoking cessation compared with current smoking, which increased the risk for all major pulmonary complications (odds ratio [OR], 1.54; 95% confidence interval [CI], 1.13-2.10; p = 0.006), including reintubation (OR, 1.95; 95% CI, 1.17-3.25; p = 0.01), full tracheostomy (OR, 3.04; 95% CI, 1.49-6.18; p = 0.002), and lung infection/consolidation (OR, 1.44; 95% CI, 1.02-2.02; p = 0.03). Although smoking cessation did not significantly improve other outcomes, it was associated with a nonsignificant trend toward a decreased risk for in-hospital mortality (OR, 1.83; 95% CI, 0.85-3.91; p = 0.1).

Conclusions:

The investigators concluded that this study showed that smoking cessation before CABG reduced the risk of serious pulmonary complications. The present findings indicate that embarking on a smoking cessation program should not be deferred until after surgery.

Perspective:

These data suggest that smoking cessation, even 1 month prior to surgery, reduces the risk for postoperative complications following bypass surgery. Further research, including prospective data collection and efforts to assist patients in quitting prior to surgery, is recommended.

Clinical Topics: Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Atherosclerotic Disease (CAD/PAD), Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Odds Ratio, Risk, Postoperative Complications, Myocardial Infarction, Stroke, Hospital Mortality, Pleural Effusion, Tracheostomy, Counseling, Wound Infection, Peripheral Vascular Diseases, Bronchodilator Agents, Cardiac Output, Low, Length of Stay, Pulmonary Disease, Chronic Obstructive, Drainage, Stroke Volume, Atrial Fibrillation, Cardiopulmonary Bypass, Smoking Cessation, Renal Replacement Therapy


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