Smoking is associated with adverse clinical outcomes in patients undergoing revascularization with PCI or CABG: the SYNTAX trial at 5-year follow-up.
Zhang YJ., Iqbal J., van Klaveren D., Campos CM., Holmes DR., Kappetein AP., Morice MC., Banning AP., Grech ED., Bourantas CV., Onuma Y., Garcia-Garcia HM., Mack MJ., Colombo A., Mohr FW., Steyerberg EW., Serruys PW.
BACKGROUND: Cigarette smoking is a well-known risk factor for development of coronary artery disease (CAD). However, some studies have suggested a "smoker's paradox," meaning neutral or favorable outcomes in smokers who have developed CAD, especially myocardial infarction (MI). OBJECTIVES: The study aimed to examine the association of smoking status with clinical outcomes in the randomized controlled SYNTAX (SYNergy Between PCI With TAXUS and Cardiac Surgery) trial at 5-year follow-up. METHODS: Detailed smoking history was collected at baseline, 6-month, 1-year, 3-year, and 5-year follow-up. The composite endpoints included death/MI/stroke (primary endpoint) plus major adverse cardiac and cerebrovascular events (MACCE) (combination of death/MI/stroke and target lesion revascularization) according to patient smoking status. The comparison of 5-year clinical outcomes between the groups according to smoking status was performed with Cox regression using smoking status at baseline or smoking as a time-dependent covariate. RESULTS: A sizeable proportion (n = 322, 17.9%) of patients had changing smoking status during 5-year follow-up. One in 5 patients with complex CAD was smoking at baseline. However, 60% stopped after revascularization while others continued to smoke. Smokers had worse clinical outcomes due to a higher incidence of recurrent MI in both revascularization arms. Smoking was an independent predictor of the composite endpoint of death/MI/stroke (hazard ratio [HR]: 1.8; 95% confidence interval [CI]: 1.3 to 2.5; p = 0.001) and MACCE (HR: 1.4; 95% CI: 1.1 to 1.7; p = 0.02). CONCLUSIONS: Smoking is associated with poor clinical outcomes after revascularization in patients with complex CAD. This places further emphasis on efforts at smoking cessation to improve revascularization benefits. (SYNTAX Study: TAXUS Drug-Eluting Stent Versus Coronary Artery Bypass Surgery for the Treatment of Narrowed Arteries; NCT00114972).