A multicentric registry-based score for identifying patients with critical limb ischemia who might benefit from the use of an heparin-bonded ePTFE graft

BACKGROUND: Starting from the dataset of the Italian Registry on Propaten® graft (W.L. GORE, Flagstaff, Az) we aimed to create a predictive score in order to identify patients with critical limb ischemia (CLI) who may benefit from the use of heparin-bonded expanded polytetrafluorethilene (ePTFE) bypass graft (Hb-ePTFE) as first graft choice for distal revascularization. METHODS: Over a 13-year period, 683 patients were treated with below-knee revascularization using an HbePTFE for CLI in a multicentric registry involving seven Italian hospitals. Primary endpoint was amputation-free survival (AFS): univariate and multivariable analyses with Kaplan Meier estimates were used to identify potential significant predictors of the primary endpoint at 5-years, and then a predictive risk score was constructed. A qualitative assessment of the Kaplan-Meier survival estimates for each integer score was performed and subgroups of risk were stratified on the basis of the primary endpoint. RESULTS: Overall, estimated 5-year survival rate was 63% (SE 0.025), while AFS was 48% (SE 0.024). Older age, coronary artery disease, end-stage renal disease, tissue loss and poor run-off score were statistical significantly predictors of AFS. The integer score ranged from 0 to 8; Kaplan-Meier analysis for AFS in each score group identified three subgroups with significant differences at 5 years: low-risk subgroup (scores from 0 to 3, 61.6%), medium-risk subgroup (score 4, 36.4%, p<0.001 in comparison with low-risk subgroup) and high risk subgroup (scores from 5 to 8, 20.7%, p<0.001 in comparison with low-risk subgroup and p=0.002 in comparison with medium-risk subgroup). When comparing 5-year AFS rate in the low risk category with that obtained in patients operated on with autologous saphenous vein (ASV) of our registry dataset (508 interventions in the same centres in the same period of time), no significant difference was found (61.6% and 58.5%, respectively, p=0.4, log rank 0.9). CONCLUSIONS: In this retrospective analysis of our multicentric registry, we created a dedicated predictive score for patients who underwent Hb-ePTFE. Using this score we identified a low risk category of patients who had 5-year amputation-free survival comparable to those obtained with the ASV, thus suggesting a primary role for Hb-ePTFE even in the presence of good quality vein. As well, in those with intermediate and high-risk scores, the use of Hb-ePTFE should be reserved only in the lack of adequate ASV.

BACKGROUND: Starting from the dataset of the Italian Registry on Propaten® graft (W.L. GORE, Flagstaff, AZ, USA), we aimed to create a predictive score in order to identify patients with critical limb ischemia (CLI) who may benefit from the use of heparin-bonded expanded polytetrafluorethilene (ePTFE) bypass graft (Hb-ePTFE) as first graft choice for distal revascularization. METHODS: Over a 13-year period, 683 patients were treated with below-knee revascularization using an Hb-ePTFE for CLI in a multicentric registry involving seven Italian hospitals. Primary endpoint was amputation-free survival (AFS): univariate and multivariable analyses with Kaplan Meier estimates were used to identify potential significant predictors of the primary endpoint at 5-years, and then a predictive risk score was constructed. A qualitative assessment of the Kaplan-Meier survival estimates for each integer score was performed and subgroups of risk were stratified on the basis of the primary endpoint. RESULTS: Overall, estimated 5-year survival rate was 63% (SE 0.025), while AFS was 48% (SE 0.024). Older age, coronary artery disease, end-stage renal disease, tissue loss and poor run-off score were statistical significantly predictors of AFS. The integer score ranged from 0 to 8; Kaplan-Meier analysis for AFS in each score group identified three subgroups with significant differences at 5 years: low-risk subgroup (scores from 0 to 3, 61.6%), medium-risk subgroup (score 4, 36.4%, P<0.001 in comparison with low-risk subgroup) and high risk subgroup (scores from 5 to 8, 20.7%, P<0.001 in comparison with low-risk subgroup and P=0.002 in comparison with medium-risk subgroup). When comparing 5-year AFS rate in the low risk category with that obtained in patients operated on with autologous saphenous vein (ASV) of our registry dataset (508 interventions in the same centers in the same period of time), no significant difference was found (61.6% and 58.5%, respectively, P=0.4, log rank 0.9). CONCLUSIONS: In this retrospective analysis of our multicentric registry, we created a dedicated predictive score for patients who underwent Hb-ePTFE. Using this score we identified a low risk category of patients who had 5-year amputation-free survival comparable to those obtained with the ASV, thus suggesting a primary role for Hb-ePTFE even in the presence of good quality vein. As well, in those with intermediate and high-risk scores, the use of Hb-ePTFE should be reserved only in the lack of adequate ASV.