Association between smoking and recurrence of venous thromboembolism and bleeding in elderly patients with past acute venous thromboembolism

- Prospective study including a population aged more than 65 years with VTE
- Analysing VTE recurrence in smokers, non-smokers and former smokers
- First study on smoking and VTE recurrence in that age range
- No difference in VTE recurrence in smokers compared to non- or former-smokers

BackgroundWhile the association between smoking and arterial cardiovascular events has been well established, the association between smoking and venous thromboembolism (VTE) remains controversial.ObjectivesTo assess the association between smoking and the risk of recurrent VTE and bleeding in patients who have experienced acute VTE.Patients/methodsThis study is part of a prospective Swiss multicenter cohort that included patients aged ≥ 65 years with acute VTE. Three groups were defined according to smoking status: never, former and current smokers. The primary outcome was the time to a first symptomatic, objectively confirmed VTE recurrence. Secondary outcomes were the time to a first major and clinically relevant non-major bleeding. Associations between smoking status and outcomes were analysed using proportional hazard models for the subdistribution of a competing risk of death.ResultsAmong 988 analysed patients, 509 (52%) had never smoked, 403 (41%) were former smokers, and 76 (8%) current smokers. After a median follow-up of 29.6 months, we observed a VTE recurrence rate of 4.9 (95% confidence interval [CI] 3.7-6.4) per 100 patient-years for never smokers, 6.6 (95% CI 5.1-8.6) for former smokers, and 5.2 (95% CI 2.6-10.5) for current smokers. Compared to never smokers, we found no association between current smoking and VTE recurrence (adjusted sub-hazard ratio [SHR] 1.05, 95% CI 0.49-2.28), major bleeding (adjusted SHR 0.59, 95% CI 0.25-1.39), and clinically relevant non-major bleeding (adjusted SHR 1.21, 95% CI 0.73-2.02).ConclusionsIn this multicentre prospective cohort study, we found no association between smoking status and VTE recurrence or bleeding in elderly patients with VTE.