Tobacco smoking and the risk of aortic dissection in the UK Biobank and a meta-analysis of prospective studies.

Tobacco smoking is thought to increase risk of aortic dissection, however, few prospective studies have been published on the association to date and little is known about the effect of smoking cessation on risk of aortic dissection. To clarify these associations we investigated the association between different aspects of tobacco smoking and aortic dissection in the UK Biobank Study and we summarized the available data in a meta-analysis of cohort studies. Multivariable Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between smoking and risk of aortic dissection in the UK Biobank. PubMed and Embase were searched up to 19th of July 2024 to identify relevant cohort studies and random effects models were used to calculate summary relative risks (RRs) and 95% CIs in the meta-analysis. During a mean follow-up of 12.3 years a total of 376 incident cases of aortic dissection were identified among 499,078 participants. The multivariable adjusted hazard ratio for current and former smokers versus never smokers were 2.48 (1.87-3.29) and 1.03 (0.81-1.29), respectively. There was a dose-response between increasing number of cigarettes smoked per day and aortic dissection risk with HRs (95% CIs) of 2.31 (1.13-4.71), 2.94 (1.88-4.58), and 2.63 (1.65-4.37) for 1-9, 10-19, and ≥ 20 cigarettes/day among current smokers. Greater number of pack-years was positively associated with aortic dissection (1.66, 1.21-2.28 for ≥ 30 pack-years vs. never smokers). Former smokers who had quit for varying durations had a 48-75% reduction in aortic dissection risk when compared to current smokers. In the meta-analysis, the summary RR was 2.44 (1.65-3.60, I = 68%, n = 3) for current and 1.32 (0.72-2.40, I = 75%, n = 3) for former vs. never smokers, 1.52 (1.30-1.79, I = 31%, n = 3) per 10 cigarettes/day, 1.16 (1.06-1.28, I = 44%, n = 3) per 10 pack-years, and 0.78 (0.71-0.86, I = 0%, n = 2) per 10 years since quitting smoking. These results provide further support that tobacco smoking increases the risk of developing aortic dissection with some indication of a dose-response with increasing intensity and amount, while smoking cessation attenuated this risk. Although further studies are needed, these findings provide further support for policies to reduce the prevalence of smoking in the general population and to promote smoking cessation among smokers.