Background: Peak oxygen uptake (VO_2peak), obtained from cardiopulmonary exercise testing is a marker of functional capacity and a modifiable risk factor. VO_2peak is a strong predictor of all-cause mortality in the general population. The utility of VO_2peak in end-stage renal disease (ESRD) patients is not explored.

Aim: Determine the predictive and discriminatory power of VO_2peak and all-cause mortality among ESRD patients being evaluated for kidney transplant (TX).

Methods: In 2012 Mayo Clinic, AZ incorporated VO_2peak into the cardiac screening algorithm among high-risk patients being evaluated for kidney TX. High-risk patients included: >50 years, ± history of diabetes, ± history of cardiovascular disease (CVD). VO_2peak was transformed to standardized scores. We studied 410 consecutive patients who underwent VO_2peak testing to determine its association with all-cause mortality. The significance of this association was tested using logistic regression models, and likelihood ratio statistics with adjustment for confounding covariates in multivariate analyses.

Results: The study cohort included 410 patients with mean age of 57.4±12 years, 251 (61.2 %) female, 195 (47.6%) had preTX diabetes and 76 (18.5%) had preTx CVD. Average follow-up was 54.9 months during which 201 (49%) received a kidney transplant. We observed 55 all-cause deaths of whom 42 were male and 13 were female.

Association of VO_2peak and all-cause mortality

*Adjusted for age, gender, pre-TX history of diabetes, pre-TX history of CVD, recipient of TX

Concordance analysis in the multivariate model revealed a strong discriminatory capacity of VO_2peak on all-cause mortality with C-statistic = 0.79

Conclusion: VO_2peak has moderately high discriminatory power and is a strong predictor of all-cause mortality in our high-risk cohort of ESRD patients being evaluated for kidney transplant. Validation studies need to be performed to confirm these findings. These results suggest that VO_2peak, a modifiable risk factor, may be a potential intervention target to reduce mortality in this high-risk population.

CITATION INFORMATION: Chakkera H, Temkit M, Kaplan B, Gaesser G, Heilman R, Khamash H, Reddy K, Steidley E, Mathur A, Nair S, Mour G, Huskey J, Moss A, Singer A, Hewitt W, Qaqish I, Behmen S, Angadi S. VO_2peak: A Significant Marker of All-Cause Mortality Among Patients with End-Stage Renal Disease Being Evaluated for Kidney Transplant. Am J Transplant. 2017;17 (suppl 3).

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