MELD-XI: a rational approach to "sickest first" liver transplantation in cirrhotic patients requiring anticoagulant therapy

Priority for "sickest first" liver transplantation (LT) in the United States is determined by the model for end-stage liver disease (MELD). MELD is a good predictor of short-term mortality in cirrhosis, but it can overestimate risk when international normalized ratio (INR) is artificially elevated by anticoagulation. An alternate prognostic index omitting INR is needed in this situation. We retrospectively analyzed survival data for 554 cirrhotic veterans referred for consideration of LT prior to December 1, 2003 (training group). Using logistic regression we derived a predictive formula for 90-day pretransplant mortality incorporating bilirubin and creatinine but omitting INR. We normalized this formula to the same scale as MELD using linear regression. This yielded MELD-XI (for MELD excluding INR) = 5.11 Ln(bilirubin) + 11.76 Ln(creatinine) + 9.44. Accuracy of MELD-XI was validated in a holdout group of 278 cirrhotic veterans referred after December 1, 2003, and in an independent validation dataset of 7,203 cirrhotic adults listed for LT in the United States between May 1, 2001, and October 31, 2001. MELD-XI and MELD correlated well in training, holdout, and independent validation cohorts (r = 0.930, 0.954, and 0.902, respectively). In the holdout cohort, c-statistics of MELD vs. MELD-XI for mortality were, respectively, 0.939 vs. 0.906 at 30 days;0.860 vs. 0.841 at 60 days; 0.842 vs. 0.829 at 90 days; and 0.795 vs. 0.797 at 180 days. In the independent validation dataset, c-statistics for MELD vs. MELD-XI as predictors of 90-day survival were, respectively, 0.857 vs. 0.843 in noncholestatic liver diseases and 0.905 vs. 0.894 in cholestatic liver diseases. Comparable MELD and MELD-XI scores were associated with comparable prognosis. In conclusion, MELD-XI, despite omission of INR, is nearly as accurate as MELD in predicting short-term survival in cirrhosis. In patients treated with oral anticoagulants, substitution of MELD-XI for MELD may permit more accurate assessment of risk and more rational assignment of "sickest first" priority for LT.