Influence of the Donor History of Tobacco and Marijuana Smoking on Early and Intermediate Lung Transplant Outcomes

J Heart Lung Transplant, June 5, 2020 (online ahead of print). Mark McDonald, David V Pilcher, MBBS, MRCP, FRACP

Published: June 05, 2020DOI:https://doi.org/10.1016/j.healun.2020.05.019

Background:
Donor smoking histories are common in the lung donor pool, with known to adversely affect post lung transplant (LTx) outcomes. However, no evidence is available about smoking status (current/former), cumulative dose effect or the combined effect of tobacco with marijuana.

Methods:
We retrospectively reviewed our local state-based donation organization records and subsequent LTx recipient outcomes. The primary outcome was 3-year graft survival, with cause of death as secondary outcomes. Univariate and multivariate Cox regression analyses were used to explore smoking status or cumulative dose effect.

Results:
Between 2014-2018, 304 LTx were performed; 133 LTx (44%) were from never-smoker donors; 68 (22%) from former-smoker donors; 103 (34%) from current-smoker donors. Of the current-smoker donors, 48% had marijuana-use history. There was no significant difference in early mortality, although recipients received from current-smoker donors had a lower 3-year graft survival compared to those from never-smokers. Multivariate modeling showed current tobacco smoking (hazard ratio [HR] 2.13 [95% CI: 1.13-3.99]) and a more than 5-year weekly marijuana-use (HR 2.97 [95%CI: 1.29-6.87]) were independent donor factors affecting graft survival. Chronic lung allograft dysfunction (CLAD) accounted for a higher proportion of the causes of death within 3 years post-LTx where lungs from current/former-smokers were utilized compared to those from never-smokers (CLAD-cause mortality: 11%, 7%, 0%, respectively).

Conclusion:
More than half of LTx donors had smoking histories. Current tobacco, or more than 5-year weekly marijuana smoking history adversely affected 3-year graft survival. Our findings support the importance of obtaining a detailed donor tobacco and marijuana smoking history.