Author + information
- Received March 26, 2019
- Revision received September 26, 2019
- Accepted September 30, 2019
- Published online December 9, 2019.
- Sadeer G. Al-Kindi, MDa@Sadeer_AlKindi,
- Anuja Sarode, MPHb,
- Melissa Zullo, MPH, PhDb,
- Jeff Brook, PhDc,
- Rick Burnett, PhDd,
- Guilherme H. Oliveira, MDa,
- Wei Huang, ScDe,
- Robert Brook, MDf and
- Sanjay Rajagopalan, MDa,g,∗ ( )(, )@UHhospitals
- aHarrington Heart and Vascular Institute, University Hospitals, Cleveland, Ohio
- bCollege of Public Health, Kent State University, Kent, Ohio
- cSchool of Public Health, University of Toronto, Ontario, Canada
- dHealth Canada, Ontario, Canada
- eSchool of Public Health, Peking University, Beijing, China
- fDepartment of Medicine, University of Michigan, Ann Arbor, Michigan
- gCase Cardiovascular Research Institute, Case Western Reserve University, Cleveland, Ohio
- ↵∗Address for correspondence:
Dr. Sanjay Rajagopalan, Case Cardiovascular Research Institute, Case Western Reserve University School of Medicine, University Hospitals, Harrington Heart and Vascular Institute, 11100 Euclid Avenue, Cleveland, Ohio 44106.
Background Heart transplant recipients are at high risk for mortality, with traditional risk scores performing modestly in predicting post-transplant survival, underscoring the importance of as yet unidentified factors in determining prognosis. In this analysis, the association between PM2.5 exposure levels and survival after heart transplantation were investigated.
Objectives This study sought to study the association between PM2.5 exposure and mortality following heart transplantation.
Methods On the basis of the zip code of residence, mortality data in patients who underwent heart transplantation (2004 to 2015) in the United Network for Organ Sharing (UNOS) database were linked with validated estimates of fine particulate matter concentrations (particles with diameter <2.5 μm [PM2.5]; 1 × 1-km grids) for each calendar year during which a UNOS cardiac transplant recipient was at risk for death. Cox proportional hazard models were used to estimate the relationship between exposure and overall mortality adjusting for recipient, donor, and neighborhood variables.
Results A total of 21,800 patients with 86,713 patient-years of follow-up was included. Mean age at transplantation was 52.6 ± 12.6 years, 75% were male, 69% were white, and 39% had ischemic etiology of heart failure. Mean annual exposure to PM2.5 was 10.6 ± 2.3 μg/m3. At a median follow-up of 4.8 (95% confidence interval: 2.0 to 7.8) years, 5,208 patients (23.9%) had died. The estimated mortality hazard ratio, per 10 μg/m3 increment increase in annual PM2.5 exposure was 1.43 (95% confidence interval: 1.21 to 1.49). After adjusting for 30 recipient, donor, and neighborhood variables, the estimated mortality hazard ratio per 10 μg/m3 increment in annual exposure to PM2.5 was 1.26 (95% confidence interval: 1.11 to 1.43) relative increase in hazard of mortality. This association was consistent across subgroups.
Conclusions This study provides evidence linking air pollution with mortality after heart transplantation. These results suggest an important influence of a key environmental factor in outcomes following heart transplantation, and supports the need for further studies in this population.
This work was supported in part by National Institutes of Health grants 5R01ES019616-07 (to Drs. Brook and Rajagopalan) and 1R01ES026291 (to Dr. Rajagopalan), and the Health Resources and Services Administration contract 234-2005-37011C. The content is the responsibility of the authors alone and does not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government. The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received March 26, 2019.
- Revision received September 26, 2019.
- Accepted September 30, 2019.
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