Background: Lung transplant (LTx) has the potential to effectively extend the life expectancy for patients with end-stage lung disease. Both high and low body mass indices (BMI) have been associated with poor post-transport outcomes, and obesity (BMI ≥30 kg/m²) is considered a relative contraindication for LTx. We sought to investigate the relationship between BMI and LTx outcomes at a single center.

Methods: A single site database was reviewed to identify patients undergoing LTx from Feb-2012 to Dec-2014. Patients were divided into 6 groups based on the clinical guidelines on obesity by the National Institutes of Health (NIH): underweight (BMI <18.5 kg/m²), normal (BMI = 18.5-24.9 kg/m²), overweight (BMI = 25.0-29.9 kg/m²), obesity class I (BMI = 30.0-34.9 kg/m²), obesity class II (BMI = 35.0-39.9 kg/m²), and extreme obesity/obesity class III (BMI ≥ 40 kg/m²). We examined the relationship between length of stay (LOS), lung allocation score (LAS), post-Ltx tracheostomy and ECMO usage on survival for the six BMI groups using SAS Stats. The observed/expected mortality ratio (O/E) was compared to the national transplant SRTR data for survival outcome.

Results: Of the 99 LTx recipients, 6% had an underweight BMI (<18.5), 22% had a normal BMI (18.5-24.9), 41% had an overweight BMI (25.0-29.9), 29% had an obesity class I BMI (30.0-34.9), 2% had an obesity class II BMI (35.0-39.9), and 0% had an obesity class III BMI ( ≥ 40 kg/m²). 70% of the patients undergoing LTx had interstitial pulmonary fibrosis, 20% had COPD, and 10% were of other etiologies. There were no significant differences in 50-days survival outcome (p=0.0968) in any BMI group. LOS (p=0.5998), LAS (p=0.3442), post-LTx tracheostomy (p=0.846), and post-LTx ECMO usage (p=0.355) did not have any effect in any BMI group survival. One year survival data was comparable with SRTR data (HR=0.69; Pearson Chi² ; p=0.42). Our O/E ratio was lower but not significant (p=0.83) compared to SRTR data.

Conclusion: Our results show LTx can be safely performed in carefully selected high and low BMI patients with similar outcomes and short-time survival. Overall, BMI was not a significant predictor of survival in LTx. LOS, LAS, post transplant tracheostomy and ECMO usage also did not show any effect on survival in each of the BMI classes.

CITATION INFORMATION: Kashem M, Shiose A, Abraham J, Dean N, Breves S, Cordova F, Patel N, Yoshizumi T, Criner G, Toyoda Y. The Effect of Body Mass Index on Lung Transplant Outcomes. Am J Transplant. 2016;16 (suppl 3).

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