March 3, 2015
European Heart Journal
TAKE-HOME MESSAGE
- In this trial of patients undergoing coronary CTA, patients were grouped by smoking status and followed for major adverse cardiovascular events. Patients with a history of smoking were significantly more likely to have a higher plaque burden than never smokers. There was no difference between never smokers and former smokers in terms of major adverse cardiac events.
- The reduction of major adverse events in former smokers to never-smoker levels, despite having a higher plaque burden, emphasizes the importance of smoking cessation.
– Samer Ajam, MD
AbstractAIMS
We evaluated coronary artery disease (CAD) extent, severity, and major adverse cardiac events (MACEs) in never, past, and current smokers undergoing coronary CT angiography (CCTA).
METHODS AND RESULTS
We evaluated 9456 patients (57.1 ± 12.3 years, 55.5% male) without known CAD (1588 current smokers; 2183 past smokers who quit ≥3 months before CCTA; and 5685 never smokers). By risk-adjusted Cox proportional-hazards models, we related smoking status to MACE (all-cause death or non-fatal myocardial infarction). We further performed 1:1:1 propensity matching for 1000 in each group evaluate event risk among individuals with similar age, gender, CAD risk factors, and symptom presentation. During a mean follow-up of 2.8 ± 1.9 years, 297 MACE occurred. Compared with never smokers, current and past smokers had greater atherosclerotic burden including extent of plaque defined as segments with any plaque (2.1 ± 2.8 vs. 2.6 ± 3.2 vs. 3.1 ± 3.3, P < 0.0001) and prevalence of obstructive CAD [1-vessel disease (VD): 10.6% vs. 14.9% vs. 15.2%, P < 0.001; 2-VD: 4.4% vs. 6.1% vs. 6.2%, P= 0.001; 3-VD: 3.1% vs. 5.2% vs. 4.3%, P < 0.001]. Compared with never smokers, current smokers experienced higher MACE risk [hazard ratio (HR) 1.9, 95% confidence interval (CI) 1.4–2.6, P < 0.001], while past smokers did not (HR 1.2, 95% CI 0.8–1.6, P= 0.35). Among matched individuals, current smokers had higher MACE risk (HR 2.6, 95% CI 1.6–4.2, P < 0.001), while past smokers did not (HR 1.3, 95% CI 0.7–2.4, P = 0.39). Similar findings were observed for risk of all-cause death.
CONCLUSION
Among patients without known CAD undergoing CCTA, current and past smokers had increased burden of atherosclerosis compared with never smokers; however, risk of MACE was heightened only in current smokers.