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

No Genetic Causality between Tobacco Smoking and Venous Thromboembolism: A Two-Sample Mendelian Randomization Study

BACKGROUND

 Given the current debate in clinical research about the relationship between tobacco smoking and the risk of venous thromboembolism (VTE), a Mendelian randomization (MR) study was conducted aimed at elucidating the causal associations of current and past tobacco smoking with the risk of VTE, from the perspective of genetics.

METHODS

 Two-sample univariate and multivariable MR analyses were designed, using summary-level data from large genome-wide association studies involving European individuals. Causality was primarily assessed using multiplicative fixed-effects or random-effects model and inverse variance weighting, supplemented by MR-Egger regression, MR-PRESSO, Cochran's Q test, and leave-one-out for sensitivity analysis to test the reliability of the results.

RESULTS

 In the univariate MR analysis, no significant causal effects were found between current tobacco smoking and the risk of VTE, deep vein thrombosis (DVT), and pulmonary embolism (PE). Similarly, no significant causal effects were found between past smoking and VTE, DVT, and PE. As for the multivariable MR analysis, results were consistent with univariate MR analysis, with no significant causal effect of either current or past tobacco smoking on the risk of VTE, DVT, and PE.

CONCLUSION

 Evidence from both univariate and multivariable MR analyses demonstrated no significant causal relationships between current and past tobacco smoking and VTE, DVT, and PE. This contradicts positive correlations reported in some previous observational studies, which may be explained by other confounding factors. This provided genetic evidence for the conclusion reported in other observational studies that smoking did not affect VTE risk.

Prognostic Impact of Active Cigarette Smoking on Mortality in Patients with Acute Venous Thromboembolic Events, Findings from Real World Data

Background and Objectives: The influence of smoking habits on mortality, VTE recurrence, and major bleeding in patients receiving anticoagulant therapy for venous thromboembolism (VTE) has not been consistently evaluated. Materials and Methods: We used data from the RIETE (Registro Enfermedad TromboEmbólica) registry to compare mortality, VTE recurrence, and major bleeding risk in smoking versus non-smoking patients with acute VTE. Results: 50,881 patients (43,426 non-smoking and 7455 smoking patients) were included. After a median follow-up of 8.8 months, 7110 patients died (fatal PE 292 and fatal bleeding 281), 3243 presented VTE recurrence, and 1579 had major bleeding. At multivariate analysis, smoking behavior was associated with a higher hazard of death, (HR: 1.28; 95% CI: 1.19–1.40). The risk of VTE recurrence was marginally increased in smoking patients compared to non-smoking patients (1.14; 95% CI: 1.02–1.27). Major bleeding did not differ in smoking and non-smoking patients (1.15; 95% CI: 0.96–1.38). The presence of cancer did not appear to influence the association between smoking habits and death (HR: 1.34; 95% CI: 1.22–1.47 in cancer patients and HR: 1.23; 95% CI: 1.04, 1.45 in non-cancer patients, respectively) Conclusions: the risk of death after an acute episode of VTE appeared to be higher in smoking than in non-smoking patients and this risk is higher between patients presenting PE at the onset of symptoms.

Risk factors for venous thromboembolism in individuals undergoing coronary artery bypass grafting

OBJECTIVE

Venous thromboembolism (VTE) can easily occur after coronary artery bypass grafting (CABG). We assessed the proportion of patients with a diagnosis of VTE after CABG and determined the associated risk factors and complications in these patients.

METHODS

We assessed all the patients included in the American College of Surgeons National Surgical Quality Improvement Program database from 2012 to 2015 who had undergone CABG. The demographic characteristics, surgical parameters, and complications were analyzed using single-factor and binary logistic regression analyses to identify the risk factors for VTE after CABG.

RESULTS

Overall, 8956 patients were identified. Postoperative VTE was found in 1.75% of these patients, with pulmonary embolism and deep vein thrombosis accounting for 0.61% and 1.28%, respectively; 0.15% of the patients had both conditions. The patients who had developed VTE had greater odds of being white and having an American Society of Anesthesiologists classification of ≥5. Multivariate analysis showed that a history of bleeding disorders, congestive heart failure, and operative time of ≥310 minutes were risk factors for the development of postoperative VTE. Patients with VTE had worse outcomes, including greater odds of returning to the operating room, hospitalization, unplanned reoperation, and readmission. The occurrence of VTE was associated with several postoperative complications, including emergency intubation, ventilator time >48 hours, pneumonia, urinary tract infection, peri- and postoperative transfusions, gradual kidney function reduction, acute kidney failure, cardiac arrest necessitating cardiopulmonary resuscitation, myocardial infarction, and septic shock.

CONCLUSIONS

The overall VTE rate after CABG has been low. However, the condition has been associated with worse 30-day postoperative outcomes and complications. The independent predictors of VTE development included a history of bleeding disorders, congestive heart failure in the 30 days before surgery, and operative time of ≥310 minutes. Understanding these risk factors should aid physicians in the decisions regarding prophylaxis and treatment.