Prediction Models for Two Year Overall Survival and Amputation Free Survival After Revascularisation for Chronic Limb Threatening Ischaemia.

OBJECTIVE

The aim of this study was to create prediction models for two year overall survival (OS) and amputation free survival (AFS) after revascularisation in patients with chronic limb threatening ischaemia (CLTI).

METHODS

This was a retrospective analysis of prospectively collected multicentre registry data (JAPAN Critical Limb Ischaemia Database; JCLIMB). Data from 3 505 unique patients with CLTI who had undergone revascularisation from 2013 to 2017 were extracted from the JCLIMB for the analysis. The cohort was randomly divided into development (2 861 patients) and validation cohorts (644 patients). In the development cohort, multivariable risk models were constructed to predict two year OS and AFS using Cox proportional hazard regression analysis. These models were applied to the validation cohort and their performances were evaluated using Harrell's C index and calibration plots.

RESULTS

Kaplan-Meier estimates of two year OS and AFS post-revascularisation in the whole cohort were 69% and 62%, respectively. Strong predictors for OS consisted of age, activity, malignant neoplasm, chronic kidney disease (CKD), congestive heart failure (CHF), geriatric nutritional risk index (GNRI), and sex. Strong predictors for AFS included age, activity, malignant neoplasm, CKD, CHF, GNRI, body temperature, white blood cells, urgent revascularisation procedure, and sex. Prediction models for two year OS and AFS showed good discrimination with Harrell's C indexes of 0.73 (95% confidence interval [CI] 0.69 - 0.77) and 0.72 (95% CI 0.68 - 0.76), respectively

CONCLUSION

Prediction models for two year OS and AFS post-revascularisation in patients with CLTI were created. They can assist in determining treatment strategies and serve as risk adjustment modalities for quality benchmarking for revascularisation in patients with CLTI at each facility.