Utility of Six-Minute-Walk Distance in Predicting Lung Transplant Benefit in the Lung Allocation Score Era.

S. Shah,¹ D. Tumin,³ B. Whitson,² A. Pope-Harman,¹ S. Kirkby,¹ A. Kilic,² P. Lee,² D. Hayes.^1,3

¹Pulmonary and Critical Care, Ohio State University Wexner Medical Center, Columbus, OH
²Division of Cardiac Surgery, Ohio State University Wexner Medical Center, Columbus, OH
³Pediatrics, Ohio State University, Columbus, OH.

Meeting: 2016 American Transplant Congress

Abstract number: 151

Keywords: Allocation, Lung transplantation, Outcome, Prediction models

Session Information

Session Name: Concurrent Session: Lung Transplant: Moving the Field Forward

Session Type: Concurrent Session

Date: Sunday, June 12, 2016

Session Time: 4:30pm-6:00pm

Presentation Time: 5:30pm-5:42pm

Location: Room 313

Transplant physicians evaluate patients for lung transplant (LTx) who are on ventilators and ECMO with high lung allocation scores (LAS). Six-minute walk distance (6MWD) predicts post-transplant survival. In patients with rapid decline in function, illness severity is reflected with a high LAS but inability to obtain 6MWD leaving the LTX physicians with the challenge to determine which patient may benefit from LTx. We analyzed the United Network for Organ Sharing (UNOS) database to assess for LTx benefit in this specific population.

Methods: Adults listed for LTx from 05/2005-06/2015 in UNOS database were included. 6MWD was categorized into 9 groups: 0ft and 8 others in increments of 200ft. In multivariable Cox regression, a time-varying covariate representing LTx effects was interacted with 6MWD to identify variation in LTx survival benefit controlling for age, gender, race, ethnicity, diagnosis, LAS, Karnofsky score, ECMO and ventilator at the time of listing. We performed nearest-neighbor propensity score matching of 6MWD of 0ft (cases) to nonzero 6MWD ≤600ft (controls) using all covariates to compare waitlist and post-transplant survival within matched pairs by stratified Cox regression.

Results: 19,948 patients were evaluated. 948 (5%) patients had 6MWD 0ft and 5,359 (27%) had nonzero 6MWD ≤600ft. 545 patients with 6MWD 0ft were transplanted. The mean LAS of the 0ft subgroup was 64.4 (range:60-90). LTx was protective at 6MWD 0ft (HR=0.20; 95% CI=0.16, 0.24; p<0.001) and 1-200ft (HR=0.50; 95% CI=0.41, 0.61; p<0.001), but not at higher 6MWD, despite optimal post-LTx survival among patients with 6MWD>1400 ft. Propensity score matching demonstrated worse waitlist survival among patients with 6MWD 0ft relative to nonzero 6MWD ≤600ft (HR=2.02; 95% CI=1.44, 2.83; p<0.001) but similar post-transplant survival between these two groups. Propensity matched patients with 6 MWD 0ft benefited from LTx.

Conclusions: In propensity score matched analysis of UNOS LTx patients, a high LAS has an elevated waitlist mortality. However, the subgroup of 6MWD 0ft did benefit from LTx. Carefully selected patients who have rapid decompensation and high LAS can prove to have significant survival benefit from LTx despite 6MWD 0ft.

CITATION INFORMATION: Shah S, Tumin D, Whitson B, Pope-Harman A, Kirkby S, Kilic A, Lee P, Hayes D. Utility of Six-Minute-Walk Distance in Predicting Lung Transplant Benefit in the Lung Allocation Score Era. Am J Transplant. 2016;16 (suppl 3).

To cite this abstract in AMA style:

Shah S, Tumin D, Whitson B, Pope-Harman A, Kirkby S, Kilic A, Lee P, Hayes D. Utility of Six-Minute-Walk Distance in Predicting Lung Transplant Benefit in the Lung Allocation Score Era. [abstract]. Am J Transplant. 2016; 16 (suppl 3). https://atcmeetingabstracts.com/abstract/utility-of-six-minute-walk-distance-in-predicting-lung-transplant-benefit-in-the-lung-allocation-score-era/. Accessed May 21, 2025.

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