The Society for Vascular Surgery Wound, Ischemia, and foot Infection (WIfI) classification system predicts wound healing better than direct angiosome perfusion in diabetic foot wounds.

OBJECTIVE: Previous studies show conflicting results in wound healing outcomes based on angiosome direct perfusion (DP), but few have adjusted for wound characteristics in their analyses. We have previously shown that the Society for Vascular Surgery Wound, Ischemia, and foot Infection (WIfI) classification correlates with wound healing in diabetic foot ulcers (DFUs) treated by a multidisciplinary team. The aim of this study was to compare WIfI classification vs DP and pedal arch patency as predictors of wound healing in patients presenting with DFU and peripheral arterial disease. METHODS: We performed a retrospective review of a prospectively maintained database of all patients with peripheral arterial disease presenting to our multidisciplinary DFU clinic who underwent angiography. An angiosome was considered directly perfused if the artery feeding the angiosome was revascularized or was completely patent. Wound healing time at 1 year was compared on the basis of DP vs indirect perfusion, Rutherford pedal arch grade, and WIfI classification using univariable statistics and Cox proportional hazards models. RESULTS: Angiography was performed on 225 wounds in 99 patients (mean age, 63.3 ± 1.2 years; 62.6% male; 53.5% black) during the entire study period. There were 33 WIfI stage 1, 33 stage 2, 51 stage 3, and 108 stage 4 wounds. DP was achieved in 154 wounds (68.4%) and indirect perfusion in 71 wounds (31.6%). On univariable analysis, WIfI classification was significantly associated with improved wound healing (57.2% for WIfI 3/4 vs 77.3% for WIfI 1/2; P = .02), whereas DP and pedal arch patency were not (both, P ≥ .08). After adjusting for baseline patient and wound characteristics, WIfI stage remained independently predictive of wound healing (WIfI 3/4: hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.67-0.88), whereas DP (HR, 0.82; 95% CI, 0.55-1.21) and pedal arch grade (HR, 0.85; 95% CI, 0.70-1.03) were not. CONCLUSIONS: In our population of patients treated by a multidisciplinary diabetic foot service, the Society for Vascular Surgery WIfI classification system was a stronger predictor of diabetic foot wound healing than DP or pedal arch patency. Our results suggest that a measure of wound severity should be included in all future studies assessing wound healing as an outcome, as differences in patients' wound characteristics may be a strong contributor to the variation of angiosome-directed perfusion results previously observed.

Association of Hemoglobin A1c and Wound Healing in Diabetic Foot Ulcers.

OBJECTIVE: This study evaluated the association between hemoglobin A1c (A1C) and wound outcomes in patients with diabetic foot ulcers (DFUs). RESEARCH DESIGN AND METHODS: We conducted a retrospective analysis of an ongoing prospective, clinic-based study of patients with DFUs treated at an academic institution during a 4.7-year period. Data from 270 participants and 584 wounds were included in the analysis. Cox proportional hazards regression was used to assess the incidence of wound healing at any follow-up time in relation to categories of baseline A1C and the incidence of long-term (≥90 days) wound healing in relation to tertiles of nadir A1C change and mean A1C change from baseline, adjusted for potential confounders. RESULTS: Baseline A1C was not associated with wound healing in univariate or fully adjusted models. Compared with a nadir A1C change from baseline of -0.29 to 0.0 (tertile 2), a nadir A1C change of 0.09 to 2.4 (tertile 3) was positively associated with long-term wound healing in the subset of participants with baseline A1C <7.5% (hazard ratio [HR] 2.07; 95% CI 1.08-4.00), but no association with wound healing was seen with the mean A1C change from baseline in this group. Neither nadir A1C change nor mean A1C change were associated with long-term wound healing in participants with baseline A1C ≥7.5%. CONCLUSIONS: There does not appear to be a clinically meaningful association between baseline or prospective A1C and wound healing in patients with DFUs. The paradoxical finding of accelerated wound healing and increase in A1C in participants with better baseline glycemic control requires confirmation in further studies.

The Society for Vascular Surgery Wound, Ischemia, and foot Infection (WIfI) classification system predicts wound healing but not major amputation in patients with diabetic foot ulcers treated in a multidisciplinary setting.

OBJECTIVE: The Society for Vascular Surgery Wound, Ischemia, and foot Infection (WIfI) threatened limb classification has been shown to correlate well with risk of major amputation and time to wound healing in heterogeneous diabetic and nondiabetic populations. Major amputation continues to plague the most severe stage 4 WIfI patients, with 1-year amputation rates of 20% to 64%. Our aim was to determine the association between WIfI stage and wound healing and major amputation among patients with diabetic foot ulcers (DFUs) treated in a multidisciplinary setting. METHODS: All patients presenting to our multidisciplinary DFU clinic from July 2012 to December 2015 were enrolled in a prospective database. Wound healing and major amputation were compared for patients stratified by WIfI classification. RESULTS: There were 217 DFU patients with 439 wounds (mean age, 58.3 ± 0.8 years; 58% male, 63% black) enrolled, including 28% WIfI stage 1, 11% stage 2, 33% stage 3, and 28% stage 4. Peripheral arterial disease and dialysis were more common in patients with advanced (stage 3 or 4) wounds (P ≤ .05). Demographics of the patients, socioeconomic status, and comorbidities were otherwise similar between groups. There was a significant increase in the number of active wounds per limb at presentation with increasing WIfI stage (stage 1, 1.1 ± 0.1; stage 4, 1.4 ± 0.1; P = .03). Mean wound area (stage 1, 2.6 ± 0.6 cm2; stage 4, 15.3 ± 2.8 cm2) and depth (stage 1, 0.2 ± 0.0 cm; stage 4, 0.8 ± 0.1 cm) also increased progressively with increasing wound stage (P < .001). Minor amputations (stage 1, 18%; stage 4, 56%) and revascularizations (stage 1, 6%; stage 4, 55%) were more common with increasing WIfI stage (P < .001). On Kaplan-Meier analysis, WIfI classification was predictive of wound healing (P < .001) but not of major amputation (P = .99). For stage 4 wounds, the mean wound healing time was 190 ± 17 days, and risk of major amputation at 1 year was 5.7% ± 3.2%. CONCLUSIONS: Among patients with DFU, the WIfI classification system correlated well with wound healing but was not associated with risk of major amputation at 1 year. Although further prospective research is warranted, our results suggest that use of a multidisciplinary approach for DFUs may augment healing time and reduce amputation risk compared with previously published historical controls of standard wound care among patients with advanced stage 4 disease.

Burden of Infected Diabetic Foot Ulcers on Hospital Admissions and Costs.

BACKGROUND: Costs related to diabetic foot ulcer (DFU) care are greater than $1 billion annually and rising. We sought to describe the impact of diabetes mellitus (DM) on foot ulcer admissions in the United States, and to investigate potential explanations for rising hospital costs. METHODS: The Nationwide Inpatient Sample (2005-2010) was queried using International Classification of Diseases, 9th Revision (ICD-9) codes for a primary diagnosis of foot ulceration. Multivariable analyses were used to compare outcomes and per-admission costs among patients with foot ulceration and DM versus non-DM. RESULTS: In total, 962,496 foot ulcer patients were admitted over the study period. The overall rate of admissions was relatively stable over time, but the ratio of DM versus non-DM admissions increased significantly (2005: 10.2 vs. 2010: 12.7; P < 0.001). Neuropathy and infection accounted for 90% of DFU admissions, while peripheral vascular disease accounted for most non-DM admissions. Admissions related to infection rose significantly among DM patients (2005: 39,682 vs. 2010: 51,660; P < 0.001), but remained stable among non-DM patients. Overall, DM accounted for 83% and 96% of all major and minor amputations related to foot ulcers, respectively, and significantly increased cost of care (DM: $1.38 vs. non-DM: $0.13 billion/year; P < 0.001). Hospital costs per DFU admission were significantly higher for patients with infection compared with all other causes ($11,290 vs. $8,145; P < 0.001). CONCLUSIONS: Diabetes increases the incidence of foot ulcer admissions by 11-fold, accounting for more than 80% of all amputations and increasing hospital costs more than 10-fold over the 5 years. The majority of these costs are related to the treatment of infected foot ulcers. Education initiatives and early prevention strategies through outpatient multidisciplinary care targeted at high-risk populations are essential to preventing further increases in what is already a substantial economic burden.