Evaluation of short-term mortality in patients with Medicare undergoing endovascular interventions for chronic limb-threatening ischemia.

INTRODUCTION: Patients with chronic limb-threatening ischemia (CLTI) have high mortality rates after revascularization. Risk stratification for short-term outcomes is challenging. We aimed to develop machine-learning models to rank predictive variables for 30-day and 90-day all-cause mortality after peripheral vascular intervention (PVI). METHODS: Patients undergoing PVI for CLTI in the Medicare-linked Vascular Quality Initiative were included. Sixty-six preprocedural variables were included. Random survival forest (RSF) models were constructed for 30-day and 90-day all-cause mortality in the training sample and evaluated in the testing sample. Predictive variables were ranked based on the frequency that they caused branch splitting nearest the root node by importance-weighted relative importance plots. Model performance was assessed by the Brier score, continuous ranked probability score, out-of-bag error rate, and Harrell's C-index. RESULTS: A total of 10,114 patients were included. The crude mortality rate was 4.4% at 30 days and 10.6% at 90 days. RSF models commonly identified stage 5 chronic kidney disease (CKD), dementia, congestive heart failure (CHF), age, urgent procedures, and need for assisted care as the most predictive variables. For both models, eight of the top 10 variables were either medical comorbidities or functional status variables. Models showed good discrimination (C-statistic 0.72 and 0.73) and calibration (Brier score 0.03 and 0.10). CONCLUSION: RSF models for 30-day and 90-day all-cause mortality commonly identified CKD, dementia, CHF, need for assisted care at home, urgent procedures, and age as the most predictive variables as critical factors in CLTI. Results may help guide individualized risk-benefit treatment conversations regarding PVI.

Correlation between physiological assessment and imaging findings during drug-coated balloon treatment for femoropopliteal diseases.

BACKGROUND: This prospective cross-sectional study evaluated the correlation between physiological assessment (PA) and minimum lumen area (MLA) by intravascular ultrasound (IVUS) during drug-coated balloon (DCB) treatment for femoropopliteal (FP) diseases. METHODS: A total of 51 limbs of 44 patients undergoing endovascular treatment with DCB for de novo FP disease were examined from April 2022 to February 2023. PA was conducted at baseline, after balloon dilatation, and after DCB treatment. PA was measured before (pressure ratio; PR) and after vasodilation (peripheral flow fractional flow reserve; pFFR) with the administration of 30 mg papaverine through a guiding catheter. The correlation of PA with percent diameter stenosis (%DS) and MLA was examined, and factors correlated with higher pFFR after balloon dilatation were evaluated in a multivariate analysis. RESULTS: At baseline, there were correlations between pressure ratio (PR) and %DS (coefficients: 0.641 [p < 0.001]) and between pFFR and %DS (0.666 [p < 0.001]). After balloon dilatation, there was no correlation between PR and %DS (coefficients: 0.33 [p = 0.27]) or between pFFR and %DS (0.41 [p = 0.71]). At baseline, PR and MLA were correlated (coefficients: 0.757 [p < 0.001]) as were pFFR and MLA (0.762 [p < 0.001]). After balloon dilatation, PR and MLA were correlated (coefficients: 0.524 [p < 0.001]) as were pFFR and MLA (0.601 [p < 0.001]). Balloon/EEM ratio, calcification >270°, and chronic total occlusion were associated with pFFR after balloon dilatation. CONCLUSION: After balloon dilatation, PA was correlated with MLA by IVUS but not with %DS based on angiography.

An exercise stress test for contrast-enhanced duplex ultrasound assessment of lower limb muscle perfusion in patients with peripheral arterial disease.

OBJECTIVE: The aim of the present study was to develop a standardized contrast-enhanced duplex ultrasound (CE-DUS) protocol to assess lower-extremity muscle perfusion before and after exercise and determine relationships of perfusion with clinical and functional measures. METHODS: CE-DUS (EPIQ 5G, Philips) was used before and immediately after a 10-minute, standardized bout of treadmill walking to compare microvascular perfusion of the gastrocnemius muscle in older (55-82 years) patients with peripheral arterial disease (PAD) (n = 15, mean ankle-brachial index, 0.78 ± 0.04) and controls (n = 13). Microvascular blood volume (MBV) and microvascular flow velocity (MFV) were measured at rest and immediately following treadmill exercise, and the Modified Physical Performance Test (MPPT) was used to assess mobility function. RESULTS: In the resting state (pre-exercise), MBV in patients with PAD was not significantly different than normal controls (5.17 ± 0.71 vs 6.20 ± 0.83 arbitrary units (AU) respectively; P = .36); however, after exercise, MBV was ∼40% lower in patients with PAD compared with normal controls (5.85 ± 1.13 vs 9.53 ± 1.31 AU, respectively; P = .04). Conversely, MFV was ∼60% higher in patients with PAD compared with normal controls after exercise (0.180 ± 0.016 vs 0.113 ± 0.018 AU, respectively; P = .01). There was a significant between-group difference in the exercise-induced changes in both MBV and MFV (P ≤ .05). Both basal and exercise MBV directly correlated with MPPT score in the patients with PAD (r = 0.56-0.62; P < .05). CONCLUSIONS: This standardized protocol for exercise stress testing of the lower extremities quantifies calf muscle perfusion and elicits perfusion deficits in patients with PAD. This technique objectively quantifies microvascular perfusion deficits that are related to reduced mobility function and could be used to assess therapeutic efficacy in patients with PAD.

Cost-effectiveness analysis of intravascular ultrasound-guided peripheral vascular interventions in patients with femoropopliteal peripheral artery disease.

Background: Intravascular ultrasound (IVUS)-guided percutaneous transluminal angioplasty (PTA) might offer clinical benefits compared to angiography-guided PTA in patients with peripheral artery disease (PAD). A cost-effectiveness model was developed to examine the benefits and costs of IVUS-guided PTA versus angiography-guided PTA in PAD patients with femoropopliteal (FP) occlusive disease. Methods: A two-step model (a one-year decision tree followed by a lifetime semi-Markov model) was developed from a German healthcare payer perspective to estimate the costs and outcomes over a one-year and lifetime horizon. Clinical events included target lesion revascularization (TLR), amputation, and death. Transition probabilities and utility values were derived from published literature. Healthcare costs were based on German Diagnosis Related Groups (DRG) codes. Costs and outcomes were discounted at a rate of 3% per year. The incremental cost-effectiveness ratio (ICER) was calculated, and sensitivity analyses were performed to assess the robustness of the results. Results: In the one-year horizon, IVUS-guided PTA resulted in incremental quality-adjusted life-years (QALY) and costs of 0.02 and €919 per patient respectively, with a corresponding ICER of €45,195/QALY gained versus angiography-guided PTA. In the lifetime horizon, IVUS-guided PTA outperforms angiography-guided PTA; it was associated with a cost saving of €46 per patient and incremental QALY of 0.22. Utility value for post-TLR, as well as probabilities of death and TLR had the greatest impact on the one-year ICER, while cost of TLR and probabilities of TLR and amputation influenced the lifetime ICER most. The probability of IVUS-guided PTA being cost-effective at a willingness-to-pay (WTP) threshold of €50,000/QALY was 50.4% in the one-year horizon and increased to 85.9% in the lifetime horizon. Conclusions: In this analysis IVUS-guided PTA among patients with symptomatic FP atherosclerosis was cost-saving in a lifetime horizon from the German healthcare payer perspective.

Racial Differences in Presentation and Outcomes After Peripheral Arterial Interventions: Insights From the NCDR-PVI Registry.

BACKGROUND: We assess the rates of device use and outcomes by race among patients undergoing lower extremity peripheral arterial intervention using the American College of Cardiology National Cardiovascular Data Registry-Peripheral Vascular Intervention (PVI) registry. METHODS: Patients who underwent PVI between April 2014 and March 2019 were included. Socioeconomic status was evaluated using the Distressed Community Index score for patients' zip codes. Multivariable logistic regression was used to assess factors associated with utilization of drug-eluting technologies, intravascular imaging, and atherectomy. Among patients with Centers for Medicare and Medicaid Services data, we compared 1-year mortality, rates of amputation, and repeat revascularizations. RESULTS: Of 63 150 study cases, 55 719 (88.2%) were performed in White patients and 7431 (11.8%) in Black patients. Black patients were younger (67.9 versus 70.0 years), had higher rates of hypertension (94.4% versus 89.5%), diabetes (63.0% versus 46.2%), less likely to be able to walk 200 m (29.1% versus 24.8%), and higher Distressed Community Index scores (65.1 versus 50.6). Black patients were provided drug-eluting technologies at a higher rate (adjusted odds ratio, 1.14 [95% CI, 1.06-1.23]) with no difference in atherectomy (adjusted odds ratio, 0.98 [95% CI, 0.91-1.05]) or intravascular imaging (adjusted odds ratio, 1.03 [95% CI, 0.88-1.22]) use. Black patients experienced a lower rate of acute kidney injury (adjusted odds ratio, 0.79 [95% CI, 0.72-0.88]). In Centers for Medicare and Medicaid Services-linked analyses of 7429 cases (11.8%), Black patients were significantly less likely to have surgical (adjusted hazard ratio, 0.40 [95% CI, 0.17-0.96]) or repeat PVI revascularization (adjusted hazard ratio, 0.42 [95% CI, 0.30-0.59]) at 1 year compared with White patients. There was no difference in mortality (adjusted hazard ratio [0.8-1.4]) or major amputation (adjusted hazard ratio, 2.5 [95% CI, 0.8-7.6]) between Black and White patients. CONCLUSIONS: Black patients presenting for PVI were younger, had higher prevalence of comorbidities and lower socioeconomic status. After adjustment, Black patients were less likely to have surgical or repeat PVI revascularization after the index PVI procedure.

ZILVERPASS Study: ZILVER PTX Stent vs. Bypass Surgery in Femoropopliteal Lesions, 3 year results and economic analysis.

BACKGROUND: To report the 3-year safety and effectiveness results of a multicenter, prospective, randomized controlled trial comparing the ZILVER PTX paclitaxel-eluting stent to surgical bypass and to conduct a health economic analysis up to 3-year follow-up of the two treatment modalities. METHODS: This is a study in symptomatic TransAtlantic Inter-Society Consensus (TASC) C and D femoropopliteal lesions comparing endovascular ZILVER PTX stenting vs. surgical bypass surgery using a prosthetic graft (ClinicalTrials.gov identifier NCT01952457). Between October 2013 and July 2017, 220 patients (mean age 68.6±10.5 years; 159 men) were enrolled and randomized to the ZILVER PTX treatment group (113, 51.40%) or the bypass treatment group (107, 48.60%). One of the secondary outcomes was primary patency at 3-year, defined as no evidence of binary restenosis or occlusion within the target lesion or bypass graft based on a duplex ultrasound peak systolic velocity ratio <2.4 and no clinically-driven target lesion revascularization (TLR) in endovascular cases or reintervention to restore flow in the bypass. An economic analysis was conducted to analyze the cost differences between ZILVER PTX and bypass, which shows the perspective of the public authority/organization that pays for healthcare in the two countries (payor), Germany and USA. RESULTS: The 3-year primary patency rate was 53.30% (95% CI 61.40% to 45.20%) for the ZILVER PTX group vs. 58.20% (95% CI 67.10% to 49.30%) for the bypass arm (P=0.9721). Freedom from TLR at 3-year was 62.80% (95% CI 72.60% to 53%) for the ZILVER PTX group vs. 65.30% (95% CI 75.40% to 55.20%) for the bypass group (P=0.635). There was also no significant difference (P=0.358) in survival rate at 3-year between the ZILVER PTX group 78.50%, (95% CI to 87.70% to 69.30%) and the bypass group 87.40% (95% CI 97.6% to 77.2%). None of the deaths was categorized as related to the procedure or device. The economic analysis, taking into account procedural-, hospitalization- and reintervention costs, showed a clear cost-benefit for Zilver PTX in both investigated countries up to 3-year follow-up: Germany (Bypass €9446 per patient versus ZILVER PTX €5755) and USA (Bypass $26,373 per patient versus ZILVER PTX $19,186). CONCLUSIONS: The non-inferior safety and effectiveness results of the ZILVER PTX stent were associated with lower costs for the payer and confirmed that ZILVER PTX stent treatment can be considered as a valid alternative for bypass surgery in long and complex femoropopliteal lesions.

Impact of calcification on clinical outcomes after drug-coated balloon angioplasty for superficial femoral artery disease: Assessment using the peripheral artery calcification scoring system.

PURPOSE: To investigate whether the severity of calcification assessed by the peripheral artery calcification scoring system (PACSS) was associated with clinical outcomes of drug-coated balloon (DCB) angioplasty for femoropopliteal lesions. MATERIALS AND METHODS: We retrospectively analyzed 733 limbs with intermittent claudication of 626 patients, who underwent DCB angioplasty for de novo femoropopliteal lesions between January 2017 and February 2021 at seven cardiovascular centers in Japan. The patients were categorized using the PACSS classification (grades 0-4: no visible calcification of the target lesion, unilateral wall calcification < 5 cm, unilateral calcification ≥ 5 cm, bilateral wall calcification < 5 cm, and bilateral calcification ≥ 5 cm, respectively). The main outcome was primary patency at 1 year. The Cox proportional hazards analysis was used to explore whether the PACSS classification was an independent predictor of clinical outcomes. RESULTS: The distribution of PACSS was grade 0 in 38%, grade 1 in 17%, grade 2 in 7%, grade 3 in 16%, and grade 4 in 23%. The 1-year primary patency rates in these grades, respectively, were 88.2%, 89.3%, 71.9%, 96.5%, and 82.6%, respectively (p < 0.001). Multivariate analysis disclosed that PACSS grade 4 (hazard ratio: 1.82, 95% confidence interval 1.15-2.87, p = 0.010) was associated with restenosis. CONCLUSION: The PACSS grade 4 calcification was independently associated with poor clinical outcomes after DCB angioplasty for de novo femoropopliteal lesions.

Technical success and associated economic implications of conventional re-entry devices in subintimal recanalization of femoro-popliteal chronic total occlusions.

PURPOSE: Re-entry devices contribute to the high success rate of subintimal recanalization of chronic total occlusions (CTO). However, to date, there are no studies comparing the available conventional re-entry devices concerning the impact of their technical success on economic aspects, as these devices differ greatly in their acquisition costs. This prospective observational study intends to contribute to this question. METHODS: Prior to the start of the prospective study, all previous applications of the Outback® in femoro-popliteal CTO since its introduction to our hospital were analyzed retrospectively (n = 31). From June 2018 until January 2020, all patients with femoro-popliteal CTO treated with clear subintimal recanalization were included (n = 109). In the case of failed spontaneous re-entry, either the OffRoad® (study arm I, n = 20) or the Enteer® catheter (study arm II, n = 20) was used. If assisted re-entry failed, the Outback® device was used as a bailout. Baseline demographic and clinical data, morphologic characteristics, and technical success were documented. Additional per-patient costs due to the use of re-entry devices were analyzed. RESULTS: A retrospective evaluation of all Outback® applications revealed a technical success rate of 97% (30/31). In the prospective study, 63% (68/109) were successfully treated without using re-entry devices. The overall procedural success was 95% (103/109). In study arm I, the OffRoad® achieved a success rate of 45% (9/20), with a subsequent successful application of the Outback® in 80% (8/10) of the failed cases. In study arm II, the Enteer® was successfully employed in 60% (12/20) of cases, and the Outback® was then used successfully in a further 62% (5/8) of cases. Too large a distance between the device and the target lumen was a knockout criterion for all tested devices, leading to a subgroup analysis with the exclusion of three cases, resulting in a success rate of 47% for the OffRoad® and 67% for the Enteer® device. Furthermore, in severe calcification, only the Outback® reliably enabled revascularization. Significant savings of almost €600 were only achieved in study arm II according to German prices. CONCLUSION: With proper patient selection, a gradual approach with the Enteer® as the primarily used device, with the Outback® used additionally in case of failure, leads to significant savings and can be recommended. In severe calcification, the Outback® should be used as the primary device.

Association between sex and long-term outcomes of endovascular treatment for peripheral artery disease.

BACKGROUND: Endovascular peripheral vascular intervention (PVI) has become the primary revascularization technique used for peripheral artery disease (PAD). Yet, there is limited understanding of long-term outcomes of PVI among women versus men. In this study, our objective was to investigate sex differences in the long-term outcomes of patients undergoing PVI. METHODS: We performed a cohort study of patients undergoing PVI for PAD from January 1, 2010 to September 30, 2015 using data in the Vascular Quality Initiative (VQI) registry. Patients were linked to fee-for-service Medicare claims to identify late outcomes including major amputation, reintervention, major adverse limb event (major amputation or reintervention [MALE]), and mortality. Sex differences in outcomes were evaluated using cumulative incidence curves, Gray's test, and mixed effects Cox proportional hazards regression accounting for patient and lesion characteristics using inverse probability weighted estimates. RESULTS: In this cohort of 15,437 patients, 44% (n = 6731) were women. Women were less likely to present with claudication than men (45% vs. 49%, p < 0.001, absolute standardized difference, d = 0.08) or be able to ambulate independently (ambulatory: 70% vs. 76%, p < 0.001, d = 0.14). There were no major sex differences in lesion characteristics, except for an increased frequency of tibial artery treatment in men (23% vs. 18% in women, p < 0.001, d = 0.12). Among patients with claudication, women had a higher risk-adjusted rate of major amputation (hazard ratio [HR] = 1.72, 95% confidence interval [CI]: 1.18-2.49), but a lower risk of mortality (HR = 0.86, 95% CI: 0.75-0.99). There were no sex differences in reintervention or MALE for patients with claudication. However, among patients with chronic limb-threatening ischemia, women had a lower risk-adjusted hazard of major amputation (HR = 0.79, 95% CI: 0.67-0.93), MALE (HR = 0.86, 95% CI: 0.78-0.96), and mortality (HR = 0.86, 95% CI: 0.79-0.94). CONCLUSION: There is significant heterogeneity in PVI outcomes among men and women, especially after stratifying by symptom severity. A lower overall mortality in women with claudication was accompanied by a higher risk of major amputation. Men with chronic limb-threatening ischemia had a higher risk of major amputation, MALE, and mortality. Developing sex-specific approaches to PVI that prioritizes limb outcomes in women can improve the quality of vascular care for men and women.

Assessment of 3-Year Patency after Endoluminal versus Surgical Bypass Therapy for Complex Femoropopliteal Artery Disease.

PURPOSE: To compare the 3-year clinical outcomes of endoluminal bypass with those of surgical bypass for complex femoropopliteal (FP) arterial lesions. MATERIALS AND METHODS: In this retrospective multicenter study, 530 patients with symptomatic peripheral artery disease (Rutherford classification 1-3, 66.0%; 4-6, 34.0%) who underwent either endoluminal bypass with Viabahn stent grafts (n = 276) or surgical bypass (n = 254) (with saphenous vein grafts, 74.4%; prosthetic grafts, 25.6%) for FP arterial lesions between 2010 and 2018 were analyzed. The propensity score-matched analysis was performed to compare the 3-year clinical outcomes of endoluminal bypass with those of surgical bypass. The primary end point was primary patency (freedom from restenosis). The secondary end points were secondary patency, freedom from target lesion revascularization (TLR), limb salvage, and overall survival. The interaction effect of baseline characteristics on the association of the revascularization strategy with the risk of restenosis was analyzed using the Poisson mixed-effect model. RESULTS: The propensity score-matched analysis extracted 107 pairs. After propensity score matching, the primary patency rate at 1, 2, and 3 years was 84.5%, 75.1%, and 70.9%, respectively, for the endoluminal bypass group versus 78.6%, 73.3%, and 72.0%, respectively, for the surgical bypass group (P = .65). There was no significant difference in secondary patency, freedom from TLR, limb salvage, and overall survival (all P > .05). The subsequent interaction analysis revealed that the involvement of popliteal lesions, small distal reference vessel diameters, and long lesions favored surgical bypass over endoluminal bypass because of improved primary patency (all P for interaction < .05). CONCLUSIONS: The 3-year clinical outcomes after endoluminal bypass or surgical bypass for FP arterial lesions were similar.

Assessment of chronic limb threatening ischemia using thermal imaging.

OBJECTIVES: Current chronic limb threatening ischemia (CLTI) diagnostics require expensive equipment, using ionizing radiation or contrast agents, or summative surrogate methods lacking in spatial information. Our aim is to develop and improve contactless, non-ionizing and cost-effective diagnostic methods for CLTI assessment with high spatial accuracy by utilizing dynamic thermal imaging and the angiosome concept. APPROACH: Dynamic thermal imaging test protocol was suggested and implemented with a number of computational parameters. Pilot data was measured from 3 healthy young subjects, 4 peripheral artery disease (PAD) patients and 4 CLTI patients. The protocol consists of clinical reference measurements, including ankle- and toe-brachial indices (ABI, TBI), and a modified patient bed for hydrostatic and thermal modulation tests. The data was analyzed using bivariate correlation. RESULTS: The thermal recovery time constant was on average higher for the PAD (88%) and CLTI (83%) groups with respect to the healthy young subjects. The contralateral symmetry was high for the healthy young group and low for the CLTI group. The recovery time constants showed high negative correlation to TBI (ρ = -0.73) and ABI (ρ = -0.60). The relation of these clinical parameters to the hydrostatic response and absolute temperatures (|ρ|<0.3) remained unclear. CONCLUSION: The lack of correlation for absolute temperatures or their contralateral differences with the clinical status, ABI and TBI disputes their use in CLTI diagnostics. Thermal modulation tests tend to augment the signs of thermoregulation deficiencies and accordingly high correlations were found with all reference metrics. The method is promising for establishing the connection between impaired perfusion and thermography. The hydrostatic modulation test requires more research with stricter test conditions.

Variations in Practice Patterns for Peripheral Vascular Interventions Across Clinical Settings.

BACKGROUND: Peripheral vascular interventions (PVIs) for lower extremity peripheral artery disease have been increasing, particularly in the office-based setting. Our goal was to evaluate practice patterns for PVI by site of service using a contemporary real-world dataset. METHODS: The Vascular Quality Initiative PVI registry was queried from 2010-2021. Site of service was classified as hospital/inpatient, hospital/outpatient, and ambulatory/office-based center. Patient demographics, comorbidities, procedural details, and periprocedural outcomes were analyzed. RESULTS: There were 54,897 hospital/inpatient (43.2%), 64,105 hospital/outpatient (50.4%), and 8,179 ambulatory/office-based center (6.4%) PVI. When comparing the 2 outpatient settings, ambulatory/office-based center patients were older than hospital/outpatient (mean age 70.7 vs. 68.7 years), more often female sex (41.4% vs. 39.1%), never smokers (27.5% vs. 18.5%), primary Medicare (61.6% vs. 55.9%), nonambulatory (6.5% vs. 4.7%), less often with coronary artery disease (30.2% vs. 34.1%), chronic obstructive pulmonary disease (18.1% vs. 26.9%), congestive heart failure (13% vs. 17.2%), obesity (30.9% vs. 33.6%), and less often on a statin (71.4% vs. 76.1%) (P < 0.001). Ambulatory/office-based center procedures were more likely for claudication (60.1% vs. 55.8%), more often involved femoro-popliteal (73.1% vs. 64.6%) and infrapopliteal (36.7% vs. 24.3%), and less often iliac interventions (24.1% vs. 33.6%) (P < 0.001).Overall, atherectomy was used in 14.2% of hospital/inpatient, 19.4% of hospital/outpatient, and 63.4% of ambulatory/office-based center procedures. Stents were used in 41.8% of hospital/inpatient, 45.1% of hospital/outpatient, and 48.8% of ambulatory/office-based center procedures. However, stent grafts were used in 12.5% of hospital/inpatient, 8.8% of hospital/outpatient, and only 1.3% of ambulatory/office-based center procedures. On multivariable analysis, compared with hospital/inpatient, atherectomy use was associated with ambulatory/office-based center setting (Odds ratio 10.9, 95% confidence interval 10.3-11.5, P < 0.001) and hospital/outpatient setting (Odds ratio 1.57, 95% confidence interval 1.51-1.62, P < 0.001). Periprocedure complications including hematoma requiring intervention (0.3%), any stenosis/occlusion (0.2%), and distal embolization (0.6%) were quite low across all settings. CONCLUSIONS: There are substantial variations in patient populations, procedural indications, and types of interventions undertaken during PVI across different locations. Ambulatory/office-based procedures more commonly treat claudicants, use atherectomy, and less often use stent grafts. Further research is warranted to investigate long-term trends in practice patterns and long-term outcomes, for PVI in the ever-expanding ambulatory/office-based setting.

Assessment of microcirculatory changes in local tissue oxygenation after revascularization for peripheral arterial disease with the Hyperview®, a portable hyperspectral imaging device.

OBJECTIVES: The Hyperview® is a hyperspectral camera, which can be used to assess the microcirculation of patients with peripheral arterial disease (PAD) and/or diabetes mellitus (DM). It measures local tissue oxygenation in concentrations of oxyhemoblobin (OXY), deoxyhemoglobin (DEOXY), and O2-saturation (O2-SAT) in arbitrary units. The aim of this validation study is to assess whether the Hyperview® is able to monitor microcirculatory changes after revascularization in patients with PAD. METHODS: In this prospective observational cohort study, 50 patients with PAD were included who were scheduled for endovascular, hybrid, or open revascularization. The ankle-brachial index (ABI), systolic toe pressure (TP) (in case of DM), and a set of Hyperview® measurements of the plantar region were recorded before and after treatment. Changes in pre- and postoperative measurements were assessed with the paired t-test. RESULTS: Some 38 patients underwent endovascular revascularization and eight patients underwent hybrid or open vascular surgical revascularization. After revascularization, the ABI improved from 0.58 to 0.80 (p < 0.001). OXY increased from 72.6 to 77.8 (p = 0.134). DEOXY decreased from 69.1 to 55.0 (p < 0.001). O2-SAT increased from 51.3 to 58.1 (p < 0.001). TP improved from 50.6 to 61.9 mmHg (p = 0.065) but was measured in only 16 patients. CONCLUSION: The Hyperview® is able to observe changes in the microcirculation after revascularization in terms of DEOXY and O2-SAT. The results of this study are a promising step into the validation of the Hyperview®.

The Influence of the Socioeconomic Status and the Density of the Population on the Outcome After Peripheral Artery Disease.

BACKGROUND: Low socioeconomic status (SES) and living in a rural environment are associated with poorer health and a higher number of amputations among the population at large. The purpose of this study is to determine the influence of low SES and of the degree of urbanization on the short-term and long-term results of patients after revascularization for peripheral artery disease. METHODS: An observational retrospective follow-up study of 770 patients operated on for peripheral artery disease at three university centers in north-western Spain from January 2015 to December 2016. The events studied were Rutherford classification of severity upon admission, direct amputation, amputations in the follow-up period, new revascularization procedures, major adverse cardiovascular events (MACE), and overall mortality. Mean personal income and income of the household associated with the street in which each patient lived and the degree of urbanization in three areas as per Eurostat criteria: densely populated areas, intermediate density areas, and thinly populated areas. Comorbidity, surgical, and follow-up variables were also collected. Descriptive analysis and Cox regression were used. Approval was obtained from the regional ethics committee. RESULTS: Median follow-up was 47.5 months. MACE occurred in 21.5% of the series and overall mortality was 47.0%. Living in a thinly populated area is associated with a lower risk of MACE (adjusted subhazard ratio = 0.60; 95% confidence interval [CI]: 0.39-0.91). Overall survival is lower in intermediate density area patients (adjusted Hazard Ratio = 1.46; 95% CI: 1.07-2.00). The third quartile of mean personal and household income is associated with a higher risk of major amputation at follow-up (adjusted Odds Ratio 1.92, 95% CI: 1.05-3.52 and adjusted Odds Ratio 1.93, 95% CI: 1.0.3-3.61, respectively). CONCLUSIONS: Patients who live in a densely populated area run a higher risk of MACE. SES is neither associated with worse outcomes after surgery nor with MACE in long-term follow-up.

ACR Appropriateness Criteria® Lower Extremity Arterial Claudication-Imaging Assessment for Revascularization: 2022 Update.

Arterial claudication is a common manifestation of peripheral artery disease. This document focuses on necessary imaging before revascularization for claudication. Appropriate use of ultrasound, invasive arteriography, MR angiography, and CT angiography are discussed. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Temporal Trends, Practice Variation, and Associated Outcomes With IVUS Use During Peripheral Arterial Intervention.

BACKGROUND: Intravascular ultrasound (IVUS) has been shown in limited prospective studies to improve procedural outcomes for patients undergoing lower extremity peripheral arterial intervention (PVI). OBJECTIVES: The authors aimed to study temporal trends, practice variation, and associated outcomes with the use of IVUS during PVI among Medicare beneficiaries. METHODS: All PVIs performed from 2016 to 2019 among Medicare beneficiaries aged >65 years were included. Temporal trends in IVUS use were stratified by procedural location (inpatient, outpatient, or ambulatory surgery center [ASC]/office-based laboratory [OBL]) and physician specialty. The primary outcome was major adverse limb events (MALE). Inverse probability weighting was used to account for differences in baseline characteristics. Cox regression with competing risks was used to estimate weighted hazard ratios. RESULTS: During the study period, 543,488 PVIs were included, of which 63,372 (11.7%) used IVUS. A substantial growth in IVUS use was observed, which was driven by procedures performed in ASCs/OBLs (23.6% increase from quarter 1 of 2016 through quarter 4 of 2019). Among operators who used IVUS, there was also notable variation in use (median operator use 5.4% of cases; IQR: 2.2%-15.0%; range, <1%-100%). In weighted analysis, IVUS use during PVI was associated with a lower risk of MALE through a median of 514 days (adjusted hazard ratio: 0.73; 95% CI: 0.70-0.75; P < 0.0001). CONCLUSIONS: In contemporary nationwide data, IVUS use during PVI has increased since 2016, driven by growth in the ASC/OBL setting. However, there remains substantial variation in operator practice. When used during PVI, IVUS was associated with a lower risk of short- and long-term MALE.

Femoropopliteal Arterial Dissections Following FLEX VP and Balloon Angioplasty Versus Balloon Angioplasty Alone: Intravascular Ultrasound Assessment and Correlation With Angiographic Findings.

BACKGROUND: The Flex VP is a longitudinal micro-incision catheter approved for vessel prepping of femoropopliteal arteries and arteriovenous fistulas. In this study, we evaluated the presence of deep dissections (adventitia) using IVUS in patients undergoing Flex VP followed by angioplasty (PTA) versus PTA alone. METHODS: 17 patients (20 limbs) with femoropopliteal artery (FP) disease were prospectively and consecutively included (10 limbs received PTA followed by 10 limbs that received FLEX VP microincision catheter treatment followed by adjunctive PTA). Dissections post PTA, FLEX VP and FLEX VP+ PTA were evaluated using intravascular ultrasound (iDissection classification) and angiographically (NHLBI classification) by core laboratory. The evaluated segment of the vessel was prespecified at 10 cm at the most severe lesion location. Statistical differences were analyzed between the 2 groups at each appropriate procedural point for dissections, minimal luminal diameter (MLD), minimal luminal area (MLA), and residual stenosis. Statistical significance was determined by a p-value <0.05. RESULTS: Baseline demographics and angiographic variables were similar between the PTA vs FLEX VP + PTA groups with the exception of more males (87.5 % vs 33.3 %, p = 0.0274) and longer treated length (median 300 mm vs 150 mm, p = 0.0240) in the FLEX VP + PTA group. Lesion length, chronic total occlusions, angiographic and IVUS evaluated segment length for dissections, calcium severity and final balloon pressures and inflation duration were all similar between the 2 groups. Angiographic dissections were similar between the 2 groups but the increase in severe dissections from index to post POBA on IVUS (involving the adventitia) were significantly more for PTA when compared to FLEX VP + PTA (0 to 12 and 0 to 1 respectively, p = 0.0353). Bailout stenting was statistically similar for PTA as compared to FLEX VP + PTA per core lab evaluation (50 % vs 20 %, p = 0.3498). Minimal luminal area (MLA) gain by IVUS was similar between the 2 groups following FLEX VP + PTA vs PTA (7.4 mm2 vs 6.5 mm2, p = 0.7250). No serious major adverse events occurred in either group. CONCLUSION: Vessel prepping with the FLEX VP + PTA vs PTA yielded lower rates of adventitial dissections as seen on IVUS. The long-term outcomes of these findings remain unclear.

Patient-level and external factors in the use of drug-coated balloons and drug-eluting stents in femoropopliteal endovascular interventions.

OBJECTIVE: Drug-coated balloons (DCB) and drug-eluting stents (DES) have been rapidly adopted for femoropopliteal endovascular interventions due to their favorable patency rates. It is unclear whether choice of using drug coated devices versus bare metal stents (BMS) or plain balloon angioplasty (POBA) as primary treatment in femoropopliteal disease is mostly associated with patient-level factors, safety concerns, or by operator preferences. This study sought to evaluate factors associated with their use in a contemporary dataset. METHODS: All femoropopliteal lesions treated with endovascular interventions between 2016 and 2019 from the Vascular Quality Initiative registry were included. For each procedure, a primary treatment was identified based on the following hierarchy: DES > DCB > BMS > POBA. A hierarchical logistic regression model predicting DCB or DES use included patient-level characteristics, key events (period after Centers for Medicare and Medicaid Services reimbursement change, January 2018 [vs before] and period after Katsanos meta-analysis December 2018 [vs before]), and random effects for site and operator. Operator-level variability for DCB and DES use was summarized with an adjusted median odds ratio (MOR). RESULTS: A total of 57,753 femoropopliteal endovascular procedures were included. Poor functional status (odds ratio [OR], 0.92; 95% confidence interval [CI], 0.90-0.94), prior anticoagulant use (OR, 0.92; 95% CI, 0.87-0.97), higher Rutherford classification (OR, 0.86; 95% CI, 0.84-0.88), chronic kidney disease stage 4 or 5 (OR, 0.92; 95% CI, 0.86-0.98), and the period after the Katsanos meta-analysis publication (OR, 0.3; 95% CI, 0.29-0.32) were associated with a lower odds of DCB or DES use; whereas female sex (OR, 1.12; 95% CI,1.08-1.17), prior lesion treatment (OR, 1.17; 95% CI, 1.11-1.22), diabetes (OR, 1.07; 95% CI, 1.02-1.12), Trans-Atlantic Inter-Society Consensus class B (OR, 1.16; 95% CI, 1.09-1.24) and C (OR, 1.2; 95% CI, 1.12-1.28), and the period after the Centers for Medicare and Medicaid Services reimbursement change (OR, 1.08; 95% CI, 1.03-1.14) were associated with a higher odds of DCB or DES use. Significant variability in use was found across operators (adjusted MOR, 2.70; 95% CI, 2.55-2.85) and centers (adjusted MOR, 2.89; 95% CI, 2.50-3.27). CONCLUSIONS: DCB or DES use in femoropopliteal disease demonstrates wide variability across operators and is linked strongly with external factors, followed by anatomic lesion characteristics and a history of previous interventions. Future work needs to focus on tailoring DCB or DES use to patient and lesion characteristics and to develop appropriate use guidelines integrating these factors.

COVID-19-related Peripheral Arterial Thrombosis Treated in a Large Health Maintenance Organization.

BACKGROUND: COVID-19 was initially identified as an acute respiratory disease, but it was quickly recognized that multiple organ systems could be affected. Venous thrombosis and pulmonary embolism have been well reported. However, there is a paucity of data on COVID-19-related arterial thrombosis. We examined the incidence, characteristics, treatment, and outcome in patients with acute COVID-19-related arterial thrombosis in a large health maintenance organization (HMO). METHODS: A retrospective multicenter case review was performed from March 2020 to March 2021. Cases were identified through a questionnaire sent to vascular surgeons. Patient characteristics, imaging, treatment, and outcome were reviewed. Successful revascularization was defined as restoration of blood flow with viability of the end organ and absence of death within 30 days. Limb salvage was defined as prevention of major amputation (transtibial or transfemoral) and absence of death in 30 days. RESULTS: There were 37,845 patients admitted with COVID-19 complications during this time. Among this group, 26 patients (0.07%) had COVID-19-related arterial thrombosis. The mean age was 61.7 years (range, 33-82 years) with 20 men (77%) and 6 women (23%). Ethnic minorities comprised 25 of 26 cases (96%). Peripheral arterial disease (PAD) was present in 4 of 26 (15%), active smoking in 1 of 26 (3.8%), and diabetes in 19 of 26 (73%) cases. Most patients developed acute arterial ischemia in the outpatient setting, 20 of 26 (77%). Of the outpatients, 6 of 20 (30%) had asymptomatic COVID-19 and 14 of 20 (70%) had only mild upper respiratory symptoms. Distribution of ischemia was as follows: 23 patients had at least one lower extremity ischemia, one patient had cerebral and lower extremity, one had mesenteric and lower extremity, and one had upper extremity ischemia. Revascularization was attempted in 21 patients, of which 12 of 21 (57%) were successful. Limb salvage was successful in 13 of 26 (50%) patients. The overall mortality was 31% (8/26). CONCLUSIONS: Our experience in a large HMO revealed that the incidence of COVID-19-related arterial thrombosis was low. The actual incidence is likely to be higher since our method of case collection was incomplete. The majority of arterial thrombosis occurred in the outpatient setting in patients with asymptomatic or mild/moderate COVID-19 respiratory disease. Acute ischemia was the inciting factor for hospitalization in these cases. Acute lower extremity ischemia was the most common presentation, and limb salvage rate was lower than that expected when compared to ischemia related to PAD. Arterial thrombosis associated with COVID-19 portends a significantly higher mortality. Education of primary care providers is paramount to prevent delayed diagnosis as most patients initially developed ischemia in the outpatient setting and did not have a high cardiovascular risk profile.