Corrigendum to ‘Global Vascular Guidelines on the Management of Chronic Limb-Threatening Ischemia’ [European Journal of Vascular & Endovascular Surgery 58/1S (2019) 1–109]

Comparison of direct oral anticoagulants and warfarin in chronic limb-threatening ischemia

OBJECTIVE

The role of direct oral anticoagulants (DOACs) in chronic limb-threatening ischemia after revascularization is unknown. Current evidence-based guidelines do not provide clear guidance on the role of anticoagulation or the selection of anticoagulant. Current practice is highly varied and based on provider and patient preference. The purpose of this study was to measure the impact of different anticoagulants on the incidence of major adverse limb events (MALEs) after revascularization for chronic limb-threatening ischemia, major adverse cardiovascular events (MACEs), all-cause mortality, and hospitalization for major bleeding events.

METHODS

This was a single-center, observational, retrospective cohort study. Subjects were eligible if they were 18 years or older; underwent endovascular or open revascularization for chronic limb-threatening ischemia, rest pain, or tissue loss; and were subsequently prescribed apixaban, rivaroxaban, or warfarin. The primary end point was the incidence of MALEs, including above-ankle amputation or major index-limb reintervention, within 1 year of index event. Secondary end points included the rate of all-cause mortality, MACEs, and incidence of International Society on Thrombosis and Haemostasis (ISTH) major bleeding.

RESULTS

From January 1, 2017, to September 20, 2022, 141 patients met the inclusion and exclusion criteria and were reviewed. The median age was 67 years, with 92 patients prescribed apixaban or rivaroxaban and 49 patients prescribed warfarin. Of these, 42 patients were prescribed triple antithrombotic therapy, 88 dual antithrombotic therapy, and 13 anticoagulant monotherapy. The primary outcome of 1-year MALEs occurred in 36.7% of the warfarin group and 33.7% of the DOAC group (relative risk [RR], 1.09; 95% CI, 0.53-2.25; P = .72). Secondary outcomes of 1-year MACEs (10.2% vs 4.3%; RR, 2.35; 95% CI, 0.60-9.18; P = .18) and 1-year all-cause mortality (26.5% vs 16.3%; RR, 1.63; 95% CI, 0.70-3.78; P = .15) did not differ between the groups. The secondary safety outcome of 1-year ISTH major bleeding occurred in 16.3% of the warfarin group and 4.3% of the DOAC group (RR, 3.76; 95% CI, 1.07-13.19; P = .015).

CONCLUSIONS

In patients with chronic limb-threatening ischemia who were revascularized and prescribed anticoagulation with apixaban, rivaroxaban, or warfarin on discharge, no difference in MALEs, MACEs, or all-cause mortality was found. However, 1-year admissions for ISTH major bleeding were significantly higher among patients prescribed warfarin. A randomized trial may confirm these findings.

Association of Preoperative Frailty with Inferior Outcomes for Patients Undergoing Lower Extremity Bypass for Chronic Limb Threatening Ischemia: A Systematic Review

BACKGROUND

Frailty is a risk factor associated with adverse postoperative outcomes following lower extremity bypass (LEB) surgery in patients with peripheral arterial disease (PAD). Chronic limb threatening ischemia (CLTI) represents the worst form of PAD, and frailty is common among patients presenting with CLTI. Multiple frailty assessment scores have been developed for the past 2 decades; however, a universal clinical assessment tool for measuring frailty has not yet been established due to the complexity of the concept. This systematic review aimed to evaluate the use of a frailty index as a predictor of postoperative outcomes in patients undergoing LEB.

METHODS

The review protocol was registered in the international prospective register of systematic reviews (PROSPERO) database (CRD42022358888). A systematic literature search was conducted using the PubMed and Scopus databases. The review followed the preferred reporting items for systematic reviews and metaanalyses (PRISMA) guidelines. The risk of bias was evaluated using the Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool. A total of 3,929 studies were initially selected originally and were eventually left with 6 studies that met the inclusion criteria of this systematic review.

RESULTS

Six studies were examined that assessed the relationship between frailty index and long-term mortality following LEB for CLTI were screened. All analyses were published between 2017 and 2020 and included a broad spectrum of patients who underwent LEB. The results of these studies showed inconsistencies in the reporting of postoperative outcomes and the time endpoint of these events. However, all correlated with higher frailty index and increased mortality rate.

CONCLUSIONS

Higher frailty index preoperatively is associated with an increased likelihood of postoperative comorbidities after undergoing LEB. Identifying and addressing the preoperative frailty index of these patients may be a practical approach to reducing postoperative adverse outcomes. A thorough review of the frailty spectrum and standardized reporting of outcomes in the context of frailty could be helpful to have a more comprehensive understanding of this subject.

A Meta-Analysis of Randomized Controlled Trials on Therapeutic Efficacy and Safety of Autologous Cell Therapy for Atherosclerosis Obliterans

BACKGROUND

Atherosclerosis obliterans (ASO) is a chronic occlusive arterial disease and the most common type of peripheral arterial disease. Current treatment options like medication and vascularization have limited effects for "no-option" patients, and stem cell therapy is considered a viable option although its application and efficacy have not been standardized. The objective of this review was to assess the safety and efficacy of autologous stem cell therapy in patients with ASO.

METHODS

We performed a literature search of published RCTs for ASO patients receiving stem cell therapy without a revascularization option. PubMed, Embase, and the Cochrane Library were searched. This study was conducted by a pair of authors independently and audited by a third author. Data were synthesized with a random-effect model.

RESULTS

630 patients in 12 RCTs were included. The results showed that cell therapy significantly improved total amputation (RR: 0.64, p = 0.004, 95% CI: [0.47, 0.87]), major amputation (RR: 0.69, p = 0.02, 95% CI: [0.50, 0.94]), ankle-brachial index (ABI) (MD = 0.08, p = 0.004, 95% CI: [0.02, 0.13]), transcutaneous oxygen tension (TcO₂) (MD = 11.52, p = 0.004, 95% CI: [3.60, 19.43]) and rest pain score (MD = -0.64, p = 0.007, 95% CI: [-1.10, -0.17]) compared to placebo or standard care. However, current studies showed cell therapy was not superior to placebo or standard care in all-cause death (RR: 0.75, p = 0.34, 95% CI: [0.41, 1.36]) and ulcer size (MD = -8.85, p = 0.39, CI: [-29.05,11.36]).

LIMITATION

The number of trials included was limited. Moreover, most trials were designed for "no-option" patients and thus the results should be applied with caution to other PAD patients.

CONCLUSION

ASO patients can benefit from autologous cell therapy in limb salvage, limb blood perfusion, and rest pain alleviation.

The Development and Usability of the AMPREDICT Decision Support Tool: A Mixed Methods Study

OBJECTIVE

Amputation level decision making in patients with chronic limb threatening ischaemia is challenging. Currently, evidence relies on published average population risks rather than individual patient risks. The result is significant variation in the distribution of amputation levels across health systems, geographical regions, and time. Clinical decision support has been shown to enhance decision making, especially complex decision making. The goal of this study was to translate the previously validated AMPREDICT prediction models by developing and testing the usability of the AMPREDICT Decision Support Tool (DST), a novel, web based, clinical DST that calculates individual one year post-operative risk of death, re-amputation, and probability of achieving independent mobility by amputation level.

METHODS

A mixed methods approach was used. Previously validated prediction models were translated into a web based DST with additional content and format developed by an expert panel. Tool usability was assessed using the Post-Study System Usability Questionnaire (PSSUQ; a 16 item scale with scores ranging from 1 to 7, where lower scores indicate greater usability) by 10 clinician end users from diverse specialties, sex, geography, and clinical experience. Think aloud, semi-structured, qualitative interviews evaluated the AMPREDICT DST's look and feel, user friendliness, readability, functionality, and potential implementation challenges.

RESULTS

The PSSUQ overall and subscale scores were favourable, with a mean overall total score of 1.57 (standard deviation [SD] 0.69) and a range from 1.00 to 3.21. The potential clinical utility of the DST included (1) assistance in counselling patients on amputation level decisions, (2) setting outcome expectations, and (3) use as a tool in the academic environment to facilitate understanding of factors that contribute to various outcome risks.

CONCLUSION

After extensive iterative development and testing, the AMPREDICT DST was found to demonstrate strong usability characteristics and clinical relevance. Further evaluation will benefit from integration into an electronic health record with assessment of its impact on physician and patient shared amputation level decision making.

Long-term outcomes following endovascular and surgical revascularization for peripheral artery disease: a propensity score-matched analysis

AIMS

Peripheral artery disease (PAD) revascularization can be performed by either endovascular or open surgical approach. Despite increasing use of endovascular revascularization, it is still uncertain which strategy yields better long-term outcomes.

METHODS AND RESULTS

This retrospective cohort study evaluated patients hospitalized with PAD in Australia and New Zealand who underwent either endovascular or surgical revascularization between 2008 and 2015, and compared procedures using a propensity score-matched analysis. Hybrid interventions were excluded. The primary endpoint was mortality or major adverse limb events (MALE), defined as a composite endpoint of acute limb ischaemia, urgent surgical or endovascular reintervention, or major amputation, up to 8 years post-hospitalization using time-to-event analyses 75 189 patients fulfilled eligibility (15 239 surgery and 59 950 endovascular), from whom 14 339 matched pairs (mean ± SD age 71 ± 12 years, 73% male) with good covariate balance were identified. Endovascular revascularization was associated with an increase in combined MALE or mortality [hazard ratio (HR) 1.13, 95% confidence interval (CI): 1.09-1.17, P < 0.001]. There was a similar risk of MALE (HR 1.04, 95% CI: 0.99-1.10, P = 0.15), and all-cause urgent rehospitalizations (HR 1.01, 95% CI: 0.98-1.04, P = 0.57), but higher mortality (HR 1.16, 95% CI: 1.11-1.21, P < 0.001) when endovascular repair was compared to surgery. In subgroup analysis, these findings were consistent for both claudication and chronic limb-threatening ischaemia presentations.

CONCLUSION

Although the long-term risk of MALE was comparable for both approaches, enduring advantages of surgical revascularization included lower long-term mortality. This is at odds with some prior PAD studies and highlights contention in this space.

Evaluation of Clinical Outcomes After Revascularization in Patients With Chronic Limb-Threatening Ischemia: Results From a Prospective National Cohort Study (RIVALUTANDO)

We evaluated the outcomes of revascularization in patients with chronic limb-threatening ischemia (CLTI) treated in real-world settings. This is a prospective multicenter cohort study with 12-month follow-up enrolling patients (n = 287) with CLTI undergoing open, endovascular, or hybrid lower extremity revascularization. The primary end point was amputation-free survival (AFS) at 12 months. Cox proportional analysis was used to determine independent predictors of amputation and restenosis. At 30 days, major adverse cardiovascular and major adverse limb events (MALE) rates were 3.1% and 2.1%, respectively. At 1 year, the overall survival rate was 88.8%, the AFS was 86.6%, and the primary patency was 70.5%. Freedom from MALE was 62.5%. After multivariate analysis, smoking (hazard ratio [HR] = 2.2, P = 0.04), renal failure (HR = 2.3, P = 0.03), Rutherford class (≥5) (HR = 3.2, P = 0.01), and below-the-knee disease (HR = 2.0, P = 0.05) were significant predictors of amputation; iloprost infusion (>10 vials) (HR = 0.64, P = 0.05) was a significant protective factor. Cilostazol administration (HR = 0.77, P = 0.05) was a significant protective factor for restenosis. Results from this prospective multicenter registry offer a consistent overview of clinical outcomes of CLTI patients at 1 year when adequately revascularized. Medical treatment, including statins, cilostazol and iloprost, were associated with improved 1-year freedom from restenosis and amputation.

Risk Stratification for 2-Year Mortality in Patients with Chronic Limb-Threatening Ischemia Undergoing Endovascular Therapy

AIM

The latest Global Vascular Guidelines (GVG) recommend assessing the 2-year mortality risk in patients with chronic limb-threatening ischemia (CLTI) before revascularization. This study aimed to reveal whether the Wound, Ischemia and foot Infection (WIfI) classification, developed originally as a risk assessment tool for limb prognosis, would be useful in predicting the 2-year mortality risk in patients with CLTI in the era of GVG and WIfI.

METHODS

We retrospectively analyzed 849 patients with CLTI who were primarily treated with endovascular therapy (EVT) between April 2010 and December 2016. The impact of baseline characteristics, including the WIfI classification on mortality risk, was investigated using the Cox proportional hazards regression model.

RESULTS

During a mean follow-up of 19.3 months, 243 deaths were observed. The 2-year mortality rate was 32.3%. Multivariate analysis demonstrated that WIfI classification stages (p=0.037), in addition to male sex (p=0.010), age (p＜0.001), non-ambulatory status (p＜0.001), body mass index (p=0.002), and hemodialysis (p＜0.001), were independent predictors for an increased risk of mortality, while the Rutherford classification was not.

CONCLUSIONS

WIfI classification stages were independently associated with mortality risk in patients with CLTI undergoing EVT, while the Rutherford classification was not. The WIfI classification would be a practical tool for planning the revascularization strategy in CLTI treatment.

In Situ Vein Bypass Is Superior to Endovascular Treatment of Femoropopliteal Lesions in Chronic Limb-Threatening Ischemia

BACKGROUND

The objective of the study was to compare bypass surgery and endovascular revascularization of the femoropopliteal segment in patients with peripheral arterial disease and critical limb-threatening ischemia (CLTI).

METHODS

This is a single-center study including patients undergoing first-time lower extremity intervention with peripheral bypass surgery or percutaneous transluminal angioplasty with or without stenting (PTA/S) of the femoropopliteal segment because of CLTI from 2011 to 2015. Based on prospective entered data from the Danish Vascular Registry, the primary end points were amputation-free survival, overall mortality, and reinterventions.

RESULTS

A total of 679 patients with CLTI were included of which 35% (n = 239) were treated with PTA/S, 54% (n = 363) with vein bypass, and 11% (n = 77) with synthetic bypass. After 3 years, amputation-free survival was significantly better with a vein bypass (41.8% [95% CI: 35-48.4]) than both PTA/S (29.7% (95% CI: 22.7-37)) and synthetic bypass (31.7% [95% CI: 19-45.1]). Overall, the endovascular-treated patients faced more than 50% increased risk of major amputation or death than that of a vein bypass, after adjusting for comorbidity and Trans-Atlantic Inter-Society Consensus (TASC) classification (HR: 1.56 [95% CI: 1.21-2.05]). As expected, postoperative complications, length of hospital stay, and reinterventions were more frequent in the bypass groups.

CONCLUSIONS

In this nonrandomized study, autologous vein bypass was superior to both PTA/S and synthetic bypass in regard to amputation-free survival and overall mortality. Despite the increased frequency of surgical complications, a vein bypass appears justified in both shorter (TASC B-C) and longer (TASC D) femoropopliteal lesions.

Macrophage modulation by polymerized hemoglobins: Potential as a wound-healing therapy

Chronic skin wounds are hypoxic and are stalled in a pro-inflammatory state. Hemoglobin (Hb)-based oxygen carriers have shown potential in increasing oxygen delivery to aid wound healing. Macrophages also take up Hb, thus altering their phenotype and the regulation of inflammation. Herein, we compared the effect of Hb and polymerized Hbs (PolyHbs) on the phenotype of human macrophages. Macrophages were incubated with Hb or different forms of PolyHbs, and the inflammatory secretion profile was analyzed. PolyHbs were produced by polymerizing Hb in the relaxed (R) or tense (T) quaternary state and by varying the molar ratio of the glutaraldehyde crosslinking agent to Hb. Hb decreased the secretion of most measured factors. PolyHb treatment led to generally similar secretion profiles; however, Hb had more similar trends to R-state PolyHb. Ingenuity pathway analysis predicted positive outcomes in wound healing and angiogenesis for T-state PolyHb prepared with a 30:1 (glutaraldehyde:Hb) polymerization ratio. When tested in diabetic mouse wounds, T-state PolyHb resulted in the greatest epidermal thickness and vascular endothelial CD31 staining. Thus, the effects of PolyHb on macrophages are affected by the polymerization ratio and the quaternary state, and T-state PolyHb yields secretion profiles that are most beneficial in wound healing.