CABG Surgery in Smokers: Candidacy, Risks, and the Imperative to Quit

Coronary Artery Bypass Grafting and Tobacco Use

Smoking is the single most modifiable risk factor for coronary artery disease (CAD) and a major predictor of perioperative complications. However, active smoking is not an absolute contraindication to CABG. Candidacy is individualized.

Risk Amplification in Smokers

Complication	Relative Risk (vs. Never-Smoker)
Sternal wound infection / dehiscence	2–4×
Pulmonary complications (pneumonia, prolonged vent)	2–3×
Graft occlusion (early & late)	1.5–2× (vein grafts)
Myocardial infarction / death (30-day)	1.3–1.8×
Long-term mortality	Significantly higher if continued smoking

Preoperative Optimization

• Minimum 4–8 weeks cessation: Restores ciliary function, improves immune response, reduces carboxyhemoglobin. Even 48 hours lowers CO/Hb.
• Pharmacotherapy: Varenicline, bupropion, NRT—start pre-op.
• Behavioral Support: Counseling, quitlines, text programs.
• Objective Verification: Exhaled CO <10 ppm or cotinine testing.

If Unable to Quit Preoperatively

• Surgery may proceed if CAD severity (left main, 3-vessel, low EF) outweighs smoking risk.
• Intensive postoperative monitoring: ICU, aggressive pulmonary toilet, early extubation protocol, strict glycemic control, infectious disease vigilance.
• Mandatory inpatient cessation program; follow-up linkage.

Shared Decision-Making

The heart team (surgeon, cardiologist, anesthesiologist, patient) weighs: SYNTAX score, frailty, comorbidities, psychosocial support, and patient values. Quitting is the single most impactful "medication" a surgical candidate can take.