Lower Extremity Peripheral Artery Disease: Contemporary Epidemiology, Management Gaps, and Future Directions: A Scientific Statement From the American Heart Association

Enhancing walking performance in patients with peripheral arterial disease: An intervention with ankle-foot orthosis

Lower extremity peripheral artery disease (PAD) is a cardiovascular condition manifesting from narrowed or blocked arteries supplying the legs. Gait is impaired in patients with PAD. Recent evidence suggests that walking with carbon fiber ankle foot orthoses (AFOs) can improve patient mobility and delay claudication time. This study aimed to employ advanced biomechanical gait analysis to evaluate the impact of AFO intervention on gait performance among patients with PAD. Patients with claudication had hip, knee, and ankle joint kinetics and kinematics assessed using a cross-over intervention design. Participants walked over the force platforms with and without AFOs while kinematic data was recorded with motion analysis cameras. Kinetics and kinematics were combined to quantify torques and powers during the stance period of the gait cycle. The AFOs effectively reduced the excessive ankle plantar flexion and knee extension angles, bringing the patients' joint motions closer to those observed in healthy individuals. After 3 months of the AFO intervention, the hip range of motion decreased, likely due to changes occurring within the ankle chain. With the assistance of the AFOs, the biological power generation required from the ankle and hip during the push-off phase of walking decreased. Wearing AFOs resulted in increased knee flexor torque during the loading response phase of the gait. Based on this study, AFOs may allow patients with PAD to maintain or improve gait performance. More investigation is needed to fully understand and improve the potential benefits of ankle assistive devices.

Impact of hyperuricemia on 5-year clinical outcomes following percutaneous transluminal angioplasty

BACKGROUND

Although the correlation between hyperuricemia and cardiovascular disease (CVD) is well known, there have been limited data regarding the impact of hyperuricemia on long-term clinical outcomes in patients with peripheral arterial disease (PAD) after percutaneous transluminal angioplasty (PTA).

METHODS

A total of 718 patients who underwent PTA for PAD were enrolled. The patients were divided into the hyperuricemia group (N = 168) and the normal group (N = 550). Hyperuricemia was defined as a uric acid level ≥ 7.0 mg/dL in men, and ≥ 6.5 mg/dL in women. The primary endpoint was major adverse cerebral and cardiovascular event (MACCE), including death, myocardial infarction (MI), any coronary revascularization, and stroke, up to 5 years. The secondary endpoint was major adverse limb event (MALE), including any repeated PTA, and target extremity surgery (TES). Inverse probability weighting (IPTW) analysis, derived from the logistic regression model, was performed to adjust potential confounders.

RESULTS

After IPTW matching analysis, compared to the normal group, the hyperuricemia group was not associated with increased MACCE but was associated with an increased incidence of MI (2.6 % vs. 0.5 %, p = 0.001), and coronary revascularization (6.7 % vs. 3.9 %, p = 0.018). Also, the hyperuricemia group was associated with a higher incidence of MALE (45.3 % vs. 28.9 %, p < 0.001), including target extremity revascularization (TER; 25.1 % vs. 15.9 %, p < 0.001), non-TER (11.5 % vs. 5.6 %, p < 0.001), and TES (22.8 % vs. 16.2 %, p = 0.002).

CONCLUSIONS

In the present study, hyperuricemia was associated with worse clinical outcomes in PAD patients following PTA during 5-year clinical follow-up. Further investigations should be made regarding the clinical benefit of controlling hyperuricemia on clinical outcomes.

Tomographic 3D ultrasound for grading stenosis of superficial femoral artery

INTRODUCTION

Treatment decision of lower extremity peripheral arterial disease (PAD) is governed by the severity of stenosis. Tomographic 3D ultrasound (t3DUS) is a reliable imaging technique for measuring vessel stenosis. In this study we attempted to provide a precise measurement of superficial femoral artery (SFA) stenosis using t3DUS in patients with PAD.

METHODS

t3DUS was used to measure maximum stenosis percentage in SFA from 50 patients with lower extremity PAD. The maximum stenosed segment in SFA was defined using Duplex 2DUS aliasing was noted. The peak systolic velocity (PSV) was measured at the maximum stenotic site and proximal to aliasing for calculating the velocity ratio. The association between blood flow velocity ratio and the degree of stenosis measured using Duplex 2DUS and t3DUS, respectively, was assessed using Spearman rank correlation.

RESULTS

There was a strong positive correlation between velocity ratio and degree of stenosis in SFA measured using t3DUS (correlation value (r) = 0.99, p < 0.001). The correlation between Stenosis percentage and velocity ratio in SFA are as followed: <50:<2; 50-54:2-2.4; 55-59:2.5-2.9; 60-64:3-3.4; 65-69:3.5-3.9; 70-74:4-4.4; 75-79:4.5-4.9; >80:>5.

t3DUS can be used to provide precise measurement of the severity of SFA stenosis in patients with lower extremities arterial disease. The established criteria for grading SFA stenosis in this study can be applied to the current practice alongside Duplex 2DUS as it showed a strong positive correlation with velocity ratio. Further studies investigating the sensitivity and specificity of t3DUS in the assessment of stenosis in lower limbs arteries are required.

Cardiovascular Outcomes in Hypertension-Treated Patients With Peripheral Artery Disease: The VALUE Trial

BACKGROUND

Systolic blood pressure (BP) is a key predictor of cardiovascular events, but patients with peripheral artery disease (PAD) are rarely included in hypertension trials. The VALUE trial (Valsartan Antihypertensive Long-Term Use Evaluation) investigated the long-term effects of valsartan- or amlodipine-based treatments on cardiovascular outcomes in patients with hypertension with a high cardiovascular risk. The aim of this subanalysis was to clarify the relationship between achieved BP on treatment and cardiovascular outcomes in patients with hypertension with PAD.

METHODS

Patients were followed for 4 to 6 years, and BP was measured regularly. The primary end point was time to the first major adverse cardiovascular event, including myocardial infarction, stroke, cardiovascular death, and heart failure requiring hospitalization. Statistical analyses were performed using Cox regression, adjusting for various baseline covariates.

RESULTS

Of the 13 803 participants, 1898 (13.8%) had PAD. During a median follow-up of 4.5 years, patients with PAD had a 23% increased risk of major adverse cardiovascular events compared with patients without PAD. Patients with an achieved systolic BP <130 mm Hg and 130 to 139 mm Hg, compared with those with systolic BP ≥140 mm Hg, were associated with a decreased risk of a major adverse cardiovascular event (hazard ratio, 0.65 [95% CI, 0.43-0.97]; P=0.037; 0.85 [95% CI, 0.74-0.97]; P=0.016, respectively). Additionally, systolic BP <130 mm Hg was associated with a decreased risk of cardiovascular death (hazard ratio, 0.33 [95% CI, 0.12-0.92]; P=0.034). The incidence of the primary outcome did not differ between antihypertensive treatment regimens (P=0.365).

CONCLUSIONS

Our results indicate that more intensive BP control is associated with a reduction in cardiovascular morbidity and mortality in patients with hypertensive PAD.

Challenges and opportunities in the management of type 2 diabetes in patients with lower extremity peripheral artery disease: a tailored diagnosis and treatment review

Lower extremity peripheral artery disease (PAD) often results from atherosclerosis, and is highly prevalent in patients with type 2 diabetes mellitus (T2DM). Individuals with T2DM exhibit a more severe manifestation and a more distal distribution of PAD compared to those without diabetes, adding complexity to the therapeutic management of PAD in this particular patient population. Indeed, the management of PAD in patients with T2DM requires a multidisciplinary and individualized approach that addresses both the systemic effects of diabetes and the specific vascular complications of PAD. Hence, cardiovascular prevention is of the utmost importance in patients with T2DM and PAD, and encompasses smoking cessation, a healthy diet, structured exercise, careful foot monitoring, and adherence to routine preventive treatments such as statins, antiplatelet agents, and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. It is also recommended to incorporate glucagon-like peptide-1 receptor agonists (GLP-1RA) and sodium-glucose cotransporter-2 inhibitors (SGLT2i) in the medical management of patients with T2DM and PAD, due to their demonstrated cardiovascular benefits. However, the specific impact of these novel glucose-lowering agents for individuals with PAD remains obscured within the background of cardiovascular outcome trials (CVOTs). In this review article, we distil evidence, through a comprehensive literature search of CVOTs and clinical guidelines, to offer key directions for the optimal medical management of individuals with T2DM and lower extremity PAD in the era of GLP-1RA and SGLT2i.

LncRNA H19/miR-107 regulates endothelial progenitor cell pyroptosis and promotes flow recovery of lower extremity ischemia through targeting FADD

BACKGROUND

Peripheral artery disease (PAD) is an ischemic disease with a rising incidence worldwide. The lncRNA H19 (H19) is enriched in endothelial progenitor cells (EPCs), and transplantation of pyroptosis-resistant H19-overexpressed EPCs (oe-H19-EPCs) may promote vasculogenesis and blood flow recovery in PAD, especially with critical limb ischemia (CLI).

METHODS

EPCs isolated from human peripheral blood was characterized using immunofluorescence and flow cytometry. Cell proliferation was determined with CCK8 and EdU assays. Cell migration was assessed by Transwell and wound healing assays. The angiogenic potential was evaluated using tube formation assay. The pyroptosis pathway-related protein in EPCs was detected by western blot. The binding sites of H19 and FADD on miR-107 were analyzed using Luciferase assays. In vivo, oe-H19-EPCs were transplanted into a mouse ischemic limb model, and blood flow was detected by laser Doppler imaging. The transcriptional landscape behind the therapeutic effects of oe-H19-EPCs on ischemic limbs were examined with whole transcriptome sequencing.

RESULTS

Overexpression of H19 in EPCs led to an increase in proliferation, migration, and tube formation abilities. These effects were mediated through pyroptosis pathway, which is regulated by the H19/miR-107/FADD axis. Transplantation of oe-H19-EPCs in a mouse ischemic limb model promoted vasculogenesis and blood flow recovery. Whole transcriptome sequencing indicated significant activation of vasculogenesis pathway in the ischemic limbs following treatment with oe-H19-EPCs.

CONCLUSIONS

Overexpression of H19 increases FADD level by competitively binding to miR-107, leading to enhanced proliferation, migration, vasculogenesis, and inhibition of pyroptosis in EPCs. These effects ultimately promote the recovery of blood flow in CLI.

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

Leveraging the Cardiovascular Team in Peripheral Artery Disease Diagnosis: A Call to Action

Lower extremity peripheral artery disease (PAD) is a common atherosclerotic cardiovascular disease (ASCVD) involving the aortoiliac, femoropopliteal, and infrapopliteal arterial segments. PAD remains a largely underdiagnosed and undertreated condition. The ankle-brachial index (ABI) is a simple and widely available test that is key detection tool in the diagnosis of PAD and is prognostic for mortality and morbidity. The cardiovascular (CV) team is a diverse array of health care clinicians (eg, nurses, nurse practitioners, physician assistants/associates, pharmacists, podiatrists) who have the qualifications and skills to be able to recognize when patients are at risk for PAD and perform an ABI. It is critical that the healthcare community recognize the critical role the CV team could play in improving outcomes and reducing disparities for patients with PAD.

Intravascular Ultrasound during Endovascular Intervention for Peripheral Artery Disease, by Severity, Location, Device, and Procedure

There is limited evidence for the role of intravascular ultrasound (IVUS) in patients who underwent peripheral vascular intervention (PVI). We conducted retrospective cohort study utilizing the Healthcare Cost and Utilization Project-Agency for Healthcare Research and Quality National Readmission database to delineate outcomes in IVUS-guided PVI versus non-IVUS-guided PVI. The present study utilized National Readmission database between January 1, 2016, and December 31, 2019. We identified patients who underwent endovascular intervention for peripheral artery disease using relevant International Classification of Diseases, Tenth Revision, Procedural Coding System. The cohort was divided based on the use of IVUS during the procedure. The primary outcome was major amputation at 6 months after index hospitalization. Measured confounders were matched using propensity score inverse probability of treatment weighing method. We further performed a subgroup analysis based on disease severity, location of intervention, device, and procedure. A total of 434,901 hospitalizations were included in the present analysis. PVI with IVUS compared with no IVUS had similar risk of amputation at 6 months (195 of 8,939 [2.17%] vs 10,404 of 384,003 [2.71%]), hazard ratio 0.98, CI 0.77 to 1.25. Further, there was no difference in the rates of secondary outcomes. On subgroup analysis, amputation rates were significantly lower in patients with rest pain, in iliac intervention, or patients who underwent drug-eluting stent implantation with the use of IVUS compared with no IVUS. This nationwide observational study showed that there was no difference in major amputation rates with the use of IVUS in patients who underwent PVI. However, in subgroup of patients with rest pain, iliac intervention or drug-eluting stent implantation IVUS use was associated with significantly lower major amputation rates.

2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS Guideline for the Management of Lower Extremity Peripheral Artery Disease" provides recommendations to guide clinicians in the treatment of patients with lower extremity peripheral artery disease across its multiple clinical presentation subsets (ie, asymptomatic, chronic symptomatic, chronic limb-threatening ischemia, and acute limb ischemia).

METHODS

A comprehensive literature search was conducted from October 2020 to June 2022, encompassing studies, reviews, and other evidence conducted on human subjects that was published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through May 2023 during the peer review process, were also considered by the writing committee and added to the evidence tables where appropriate.

STRUCTURE

Recommendations from the "2016 AHA/ACC Guideline on the Management of Patients With Lower Extremity Peripheral Artery Disease" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with peripheral artery disease have been developed.

The resistive and pulsatility indices of the dorsal metatarsal artery for the screening of peripheral lower artery disease in patients with and without diabetes

BACKGROUND

In lower extremity peripheral artery disease (PAD), the ankle-brachial index (ABI) is an easily reproducible diagnostic tool for PAD, but it loses reliability when > 1.4 due to calcification of the vessel wall. Patients with diabetes are at higher risk for wall calcification. In order to overcome the limitation and reliability of ABI, particularly in patients with diabetes, we decided to assess resistive (RI) and pulsatility index (PI) by ultrasound doppler of the dorsal metatarsal artery (DMA).

RESULTS

We therefore analyzed 51 legs (32 patients), evaluating the correlation between PI, RI, and ABI. Patients with diabetes were 21 (65.6 %), accounting for 33 legs (64.7 %). Out of 51 legs assessed, 37 (72.5 %) cases had compressible arteries, whereas in 14 legs (27.5 %) ABI was not calculable due to wall calcification. PAD was significantly associated with lower both RI and PI of the DMA (both p < 0.000). RI, but not PI, showed a significant correlation (r = 0.535) with ABI, when ABI was less than 1.4, but not when ABI > 1.4. When analyzed separately, patients with diabetes showed a similar figure in comparison with those without diabetes (r = 0.600), RI, but not PI, showed a significant correlation with ABI.

CONCLUSION

Dorsal metatarsal artery resistive index (MARI) showed a significant inverse correlation with PAD, similarly to ABI, irrespective of the presence of diabetes. MARI seems to be an effective screening tool for PAD even in patients with wall calcification. Further studies are needed for confirming the results of the present pilot study.

Undiagnosed and Untreated Peripheral Complications of Diabetes: Findings from a Pilot Study on Diabetes-Related Foot Diseases (DFD) in Patients with Glycemic Disorders

BACKGROUND Diabetes-related foot disease (DFD) is a serious complication of diabetes, increasing the risk of amputation. Coimplications are preventable, but most diabetics do not receive proper screening and treatment, despite indications. This study was a pilot screening of diabetes-related foot disease in a group of people with glycemic disorders. MATERIAL AND METHODS We recruited 143 volunteers over 40 years of age. In the final analysis, we included 85 people diagnosed with glycemic disorders (diabetes or prediabetes), for whom we performed a total of 170 foot measurements. We screened for peripheral artery disease using: foot pulse, ankle-brachial index (manual and automatic), toe-brachial index, and transcutaneous oxygen pressure (TcPO2). To screen for diabetic peripheral neuropathy, we used indicators of loss of protective sensation: pressure perception and temperature perception, and plantar pressure distribution. RESULTS A history of diabetes was reported by 26 (30.6%) of the subjects. Disorders of at least 1 foot occurred in 20 (66.7%) subjects with diagnosed diabetes and in 10 (17%) subjects declaring no diabetes. Higher risk and DFD category were correlated with duration of diabetes (r=0.68, p=0.007), glycemic levels (r=0.56, p=0.001), age (r=0.57, p=0.007), and the presence of other diabetes complications. The best predictor of risk in DFD was manual ABI, p=0.001; followed by automatic ABI, p=0.006. CONCLUSIONS Our results showed that peripheral complications of diabetes, such as DFD, often remain undiagnosed and untreated despite the high risk of developing ulcers. There is a need for multi-center screening studies.

Multi-modality imaging for assessment of the microcirculation in peripheral artery disease: Bench to clinical practice

Peripheral artery disease (PAD) is a highly prevalent disorder with a high risk of mortality and amputation despite the introduction of novel medical and procedural treatments. Microvascular disease (MVD) is common among patients with PAD, and despite the established role as a predictor of amputations and mortality, MVD is not routinely assessed as part of current standard practice. Recent pre-clinical and clinical perfusion and molecular imaging studies have confirmed the important role of MVD in the pathogenesis and outcomes of PAD. The recent advancements in the imaging of the peripheral microcirculation could lead to a better understanding of the pathophysiology of PAD, and result in improved risk stratification, and our evaluation of response to therapies. In this review, we will discuss the current understanding of the anatomy and physiology of peripheral microcirculation, and the role of imaging for assessment of perfusion in PAD, and the latest advancements in molecular imaging. By highlighting the latest advancements in multi-modality imaging of the peripheral microcirculation, we aim to underscore the most promising imaging approaches and highlight potential research opportunities, with the goal of translating these approaches for improved and personalized management of PAD in the future.

WY-14643, a novel antiplatelet and antithrombotic agent targeting the GPIbα receptor

BACKGROUND AND PURPOSE

Hypolipidemia and platelet activation play key roles in atherosclerotic diseases. Pirinixic acid (WY-14643) was originally developed as a lipid-lowering drug. Here we focused on its antiplatelet and antithrombotic abilities and the underlying mechanism.

EXPERIMENTAL APPROACH

The effects of WY-14643 on platelet aggregation was measured using a lumi-aggregometer. Clot retraction and spreading on fibrinogen were also assayed. PPARα-/- platelets were used to identify the target of WY-14643. The interaction between WY-14643 and glycoprotein Ibα (GPIbα) was detected using cellular thermal shift assay (CETSA), surface plasmon resonance (SPR) spectroscopy and molecular docking. GPIbα downstream signaling was examined by Western blot. The antithrombotic effect was investigated using mouse mesenteric arteriole thrombosis model. Mouse tail bleeding model was used to study its effect on bleeding side effects.

KEY RESULTS

WY-14643 concentration-dependently inhibits human washed platelet aggregation, clot retraction, and spreading. Significantly, WY-14643 inhibits thrombin-induced activation of human washed platelets with an IC50 of 7.026 μM. The antiplatelet effect of WY-14643 is mainly dependent of GPIbα. CESTA, SPR and molecular docking results indicate that WY-14643 directly interacts with GPIbα and acts as a GPIbα antagonist. WY-14643 also inhibits phosphorylation of PLCγ2, Akt, p38, and Erk1/2 induced by thrombin. Noteworthily, 20 mg/kg oral administration of WY-14643 inhibits FeCl3-induced thrombosis of mesenteric arteries in mice similarly to clopidogrel without increasing bleeding.

CONCLUSION AND IMPLICATIONS

WY-14643 is not only a PPARα agonist with lipid-lowering effect, but also an antiplatelet agent as a GPIbα antagonist. It may have more significant therapeutic advantages than current antiplatelet agents for the treatment of atherosclerotic thrombosis, which have lipid-lowering effects without bleeding side effects.

The Role of Lipoprotein(a) in Peripheral Artery Disease

Lipoprotein(a) is a low-density-lipoprotein-like particle that consists of apolipoprotein(a) bound to apolipoprotein(b). It has emerged as an established causal risk factor for atherosclerotic cardiovascular disease, stroke, and aortic valve stenosis through multifactorial pathogenic mechanisms that include inflammation, atherogenesis, and thrombosis. Despite an estimated 20% of the global population having elevated lipoprotein(a) levels, testing remains underutilized due to poor awareness and a historical lack of effective and safe therapies. Although lipoprotein(a) has a strong association with coronary artery disease and cerebrovascular disease, its relationship with peripheral artery disease is less well established. In this article, we review the epidemiology, biology, and pathogenesis of lipoprotein(a) as it relates to peripheral artery disease. We also discuss emerging treatment options to help mitigate major adverse cardiac and limb events in this population.

Efficacy of comprehensive structured exercise program on claudication pain and quality of life in type 2 diabetes mellitus with peripheral arterial disease

Background

Peripheral arterial disease is one of the leading complications of type 2 diabetes mellitus. The primary symptom of peripheral arterial disease is claudication pain. Exercise is known to improve the claudication pain, thereby improving the quality of life.

Methods

A total of 74 participants were recruited in each group and a detailed demographic assessment was done for all the participants. The study group received a comprehensive structured exercise program and standard care whereas the control group received only the standard care. Progression of the exercise was made at the 6th week of the protocol. All the outcome measures were reassessed after the 12th weeks for both study and control group.

Results

The mean age of participants was 60.78 ± 11.29 (years) and 59.98 ± 11.42 (years) for the study and control group, respectively. There was a statistically significant difference in toe brachial index (p < 0.001), ankle brachial index (p < 0.001), 6-minute walk distance (p < 0.001), WHO-BREF quality of life questionnaire (p < 0.001), and walking ability ((p < 0.001) in the study group in comparison to the control group.

Conclusion

In the present study we found that comprehensive structured exercise program improves the arterial indices, quality of life, walking ability and reduces claudication pain in type 2 diabetes mellitus with peripheral arterial disease.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-024-01426-2.

Adherence and Persistence to Antiplatelet Therapy in Lower Extremity Peripheral Arterial Disease: A Danish Population Based Cohort Study

OBJECTIVE

Adherence to antiplatelet therapy is recommended but unexplored in patients with symptomatic lower extremity peripheral arterial disease (PAD). Therefore, this study aimed to determine adherence and persistence to antiplatelet therapy in patients with PAD, defined as intermittent claudication and chronic limb threatening ischaemia.

DESIGN

Population based nationwide cohort study.

METHODS

This study included all Danish citizens aged ≥ 40 years with a first inpatient or outpatient diagnosis of symptomatic PAD between 2010 - 2017, and who had at least one prescription claim for aspirin and/or clopidogrel within 90 days after diagnosis. Adherence was determined by the proportion of days covered (PDC) during the first year after diagnosis. Persistence was defined as no treatment gap ≥ 30 days between prescription renewals over three year follow up.

RESULTS

A total of 39 687 patients were eligible for inclusion, of whom 23 279 (58.7%) claimed a prescription for aspirin and/or clopidogrel within 90 days of diagnosis. Among these, 12 898 (55.4%) were prevalent users, while the remainder comprised new users who initiated the therapy after the index PAD diagnosis. The mean PDC was 74.5% (SD 35.0%) for prevalent users and 60.5% (SD 30.5%) for new users. Adherence increased with age and number of concomitant drugs. The overall one year cumulative incidence treatment discontinuation was 13.0% (95% CI 12.5 - 13.4%) overall, 17.2% (CI 16.6 - 17.9%) for prevalent users, and 7.9% (CI 7.4 - 8.4%) for new users. At three year follow up, the cumulative incidence of discontinuation was 31.5% (CI 30.9 - 32.2%) overall, 44.6% (CI 43.7 - 45.4%) for prevalent users, and 14.6% (CI 13.9 - 15.3) for new users.

CONCLUSION

Less than 60% of patients with newly diagnosed symptomatic PAD claimed a prescription for antiplatelet therapy within 90 days of diagnosis, and both adherence and persistence were moderate during the first year after diagnosis. These findings underscore the importance of efforts to improve the initiation and continuation of antiplatelet therapy in patients with PAD.

Epidemiology of Non-Traumatic Lower Extremities Amputations in West Africa: Nationwide Data from Togo

OBJECTIVE

Non-traumatic lower limb amputation (NT-LLA) has consequences at individual and public health levels. Population based studies in sub-Saharan Africa are scarce and often related to single centre series. This study aimed to estimate the incidence of NT-LLA (minor and major) and to describe epidemiological, clinical, and prognostic aspects in Togo.

METHODS

This was a population based observational study conducted among all patients who underwent NT-LLA. Traumatic amputations were excluded. Sociodemographic, clinical, and work up data were collected from clinical files in any Togolese health centre from 1 January 2016 to 31 December 2021. Incidence rates were adjusted for age.

RESULTS

Over the six year period, 352 patients (59% males) underwent NT-LLA (mean ± standard deviation age 60 ± 15.7 years). The average age adjusted incidence rate of NT-LLA was 8.5 per million/year (95% confidence interval [CI] 7.6 - 9.4). Men were 1.7 times more likely to undergo a NT-LLA than women. The relative risk of NT-LLA was 48 times higher in patients with diabetes than in patients without diabetes. Around 61.0% of the NT-LLAs occurred within the 50 - 74 age group and 54.3% had diabetes mellitus. Among amputees, 54.5% had a diagnosis of peripheral artery disease (PAD) and 52.8% had diabetic ulcers, with co-existence of several factors. Less than 5% of participants had a history of smoking tobacco. Average length of hospital stay was 12 days. The in hospital mortality rate was 8.8% (9.0% for major, 6.7% for minor amputations). Only 18.2% had duplex ultrasound performed and 1.7% angiography prior to amputation. No patient underwent vascular intervention prior to amputation.

CONCLUSION

This is the first study to report nationwide and contemporary epidemiological data on NT-LLAs in West Africa, highlighting several specificities. Large scale interventions are needed to ameliorate the care of diabetes and PAD and improve facilities for optimal management of patients at risk of amputation in Africa.

Development of a Tetherless Bioimpedance Device That Uses Morphologic Changes to Predict Blood Flow Restrictions Mimicking Peripheral Artery Disease Progression

A tetherless multi-targeted bioimpedance device was designed, modeled, built, and tested for measuring arterial pulse and, using morphological analysis, its potential for monitoring blood flow restrictions that mimic Peripheral Artery Disease (PAD) was assessed across multiple peripheral arteries. Specifically, we first developed a small form factor, tetherless, bioimpedance device, based on high-frequency structure simulator (HFSS) simulations. After designing and building the device we then tested it in vivo on human subjects on multiple arteries and found that we did not need to modify the gain on the device compared to the bench top system. Further, it was found that changes in the morphology of the bioimpedance signal over time, depicted through the ratio of the first and second harmonic in the signal frequency, could be used to predict blood flow restrictions that mimic peripheral artery disease (PAD). The HFSS simulations helped guide the modulation frequency selection and the placement of the bioimpedance electrodes. We built the device and compared it to two commercially available bioimpedance devices and it was shown to demonstrate a distinct advantage in its multi-target capability, enabling more accurate pulse measurements from different arteries without the need for tuning the circuit for each artery. Comparing the ratio of the 1st and 2nd harmonics as a function of the blood flow restriction, the two commercial devices showed a maximum error across arteries of between 22% and 27% depending on the measurement location, whereas our system consistently displayed a stable value of just below 4%. With this system, there is the potential for comprehensive and personalized medical examinations for PAD at the point of care (POC).

Polymer-based drug-eluting stent treatment extends the time to reintervention for patients with symptomatic femoropopliteal artery disease: clinical evidence and potential economic value

Aim: Use long-term follow-up data from the IMPERIAL study to determine whether drug-eluting polymer-based nitinol stent treatment can delay the time to repeat intervention for femoropopliteal artery disease and how such a delay may result in cost savings in a value-based episode of care. Patients & methods: The IMPERIAL randomized controlled trial was an international study of a paclitaxel-eluting polymer-coated stent (Eluvia, Boston Scientific, MA, USA) versus a polymer-free paclitaxel-coated stent (Zilver PTX, Cook Corporation, IN, USA) for treating lesions of the femoropopliteal arterial segment. Study patients (n = 465) had symptomatic lower limb ischemia. Safety and efficacy assessments were performed through 5 years. Mean time to first reintervention was calculated in post-hoc analysis for patients who underwent a clinically driven target lesion revascularization (CD-TLR) through 3 or 5 years following the index procedure. To simulate potential cost savings associated with differential CD-TLR burden over time, a cost-avoidance analysis using input parameters from IMPERIAL and US 100% Medicare standard analytical files was developed. Results: Among patients with a first CD-TLR through 3 years of follow-up, mean time to reintervention was 5.5 months longer (difference 166 days, 95% CI: 51, 282 days; p = 0.0058) for patients treated with Eluvia (n = 56) than for those treated with Zilver PTX (n = 30). Through the 5-year study follow-up period, CD-TLR rates were 29.3% (68/232) for Eluvia and 34.2% (39/114) for Zilver PTX (p = 0.3540) and mean time to first reintervention exceeded 2 years for patients treated with Eluvia at 737 days versus 645 days for the Zilver PTX group (difference 92 days, 95% CI: -85, 269 days; p = 0.3099). Simulated savings considering reinterventions occurring over 1 and 5 years following initial use of Eluvia over Zilver PTX were US $1,395,635 and US $1,531,795, respectively, when IMPERIAL CD-TLR rates were extrapolated to 1000 patients. Conclusion: IMPERIAL data suggest initial treatment with Eluvia extends the time patients spend without undergoing reintervention. This extension may be associated with cost savings in relevant time frames.

Higher Levels of Cytokines in Patients with Chronic Limb-Threatening Ischemia

BACKGROUND

Inflammation is a key element in the initiation and progression of peripheral arterial disease (PAD). Understanding the impact of inflammatory molecules, as cytokines in PAD could help us to improve the prognosis of these patients. The main goal of this study was to compare the serum level of cytokines between patients with claudication to those with chronic limb-threatening ischemia (CLTI). The second objective was to evaluate the relationship between the levels of cytokines and death or amputation rate.

METHODS

An observational, single-center, and prospective study was conducted from January 2018 to July 2022. The study was approved by the ethical commission of the Local Hospital (75/2017). Patients with PAD, suggested by the clinical history and objective examination and confirmed with ankle-brachial index, attending vascular surgery consultations of the first author were included. The following exclusion criteria were applied: i) bedridden individuals or subjects who refused to participate in the protocol; ii) diseases responsible for body composition changes or proinflammatory state; iii) recent diet change, iv) active malignancy, v) autoimmune disease, vi) active infection, vii) chronic renal failure (glomerular filtration rate <30 mL/min/1.73 m2), or viii) heart failure in the past 3 months. This cohort was observed at admission, 3, 6, and 12 months. A panel of 27 cytokines was determined with ELISA, at baseline.

RESULTS

We included 119 subjects (mean age: 67.58 ± 9.60 years old; 79.80% males), 65 patients with claudication and 54 with CLTI. From the 27 cytokines analyzed, patients with CLTI, when compared to those with claudication, had a higher serum level of 11 cytokines: IL1ra, IL-6, IL-8, IL12 p70, G-CSF, IP-10, MCP-1, MIP-1α, PDGF-β, RANTES, and TNF-α. From the group of patients with CLTI those who underwent a major amputation had a higher serum level of FGF-basic [median = 49.04; interquartile range = 37.03-52.49; versus median = 33.04; interquartile range = 28.60-38.98; P = 0.001].

CONCLUSIONS

Patients with CLTI have higher serum level of inflammatory cytokines, which may have role in the prognosis of these patients.

Prognostic Factors and Models to Predict Mortality Outcomes in Patients with Peripheral Arterial Disease: A Systematic Review

OBJECTIVE

Predicting adverse outcomes in patients with peripheral arterial disease (PAD) is a complex task owing to the heterogeneity in patient and disease characteristics. This systematic review aimed to identify prognostic factors and prognostic models to predict mortality outcomes in patients with PAD Fontaine stage I - III or Rutherford category 0 - 4.

DATA SOURCES

PubMed, Embase, and Cochrane Database of Systematic Reviews were searched to identify studies examining individual prognostic factors or studies aiming to develop or validate a prognostic model for mortality outcomes in patients with PAD.

REVIEW METHODS

Information on study design, patient population, prognostic factors, and prognostic model characteristics was extracted, and risk of bias was evaluated.

RESULTS

Sixty nine studies investigated prognostic factors for mortality outcomes in PAD. Over 80 single prognostic factors were identified, with age as a predictor of death in most of the studies. Other common factors included sex, diabetes, and smoking status. Six studies had low risk of bias in all domains, and the remainder had an unclear or high risk of bias in at least one domain. Eight studies developed or validated a prognostic model. All models included age in their primary model, but not sex. All studies had similar discrimination levels of > 70%. Five of the studies on prognostic models had an overall high risk of bias, whereas two studies had an overall unclear risk of bias.

CONCLUSION

This systematic review shows that a large number of prognostic studies have been published, with heterogeneity in patient populations, outcomes, and risk of bias. Factors such as sex, age, diabetes, hypertension, and smoking are significant in predicting mortality risk among patients with PAD Fontaine stage I - III or Rutherford category 0 - 4.

Arm and ankle blood pressure indices, and peripheral artery disease, and mortality: a cohort study

BACKGROUND AND AIMS

Few studies have compared arm and ankle blood pressures (BPs) with regard to peripheral artery disease (PAD) and mortality. These relationships were assessed using data from three large prospective clinical trials.

METHODS

Baseline BP indices included arm systolic BP (SBP), diastolic BP (DBP), pulse pressure (arm SBP minus DBP), ankle SBP, ankle-brachial index (ABI, ankle SBP divided by arm SBP), and ankle-pulse pressure difference (APPD, ankle SBP minus arm pulse pressure). These measurements were categorized into four groups using quartiles. The outcomes were PAD (the first occurrence of either peripheral revascularization or lower-limb amputation for vascular disease), the composite of PAD or death, and all-cause death.

RESULTS

Among 40 747 participants without baseline PAD (age 65.6 years, men 68.3%, diabetes 50.2%) from 53 countries, 1071 (2.6%) developed PAD, and 4955 (12.2%) died during 5 years of follow-up. Incident PAD progressively rose with higher arm BP indices and fell with ankle BP indices. The strongest relationships were noted for ankle BP indices. Compared with people whose ankle BP indices were in the highest fourth, adjusted hazard ratios (95% confidence interval) for each lower fourth were 1.64 (1.31-2.04), 2.59 (2.10-3.20), and 4.23 (3.44-5.21) for ankle SBP; 1.19 (0.95-1.50), 1.66 (1.34-2.05), and 3.34 (2.75-4.06) for ABI; and 1.41 (1.11-1.78), 2.04 (1.64-2.54), and 3.63 (2.96-4.45) for APPD. Similar patterns were observed for mortality. Ankle BP indices provided the highest c-statistics and classification indices in predicting future PAD beyond established risk factors.

CONCLUSIONS

Ankle BP indices including the ankle SBP and the APPD best predicted PAD and mortality.

Endovascular Transvenous versus Open Femoropopliteal Bypass

Background and Objectives: Lower extremity arterial disease is one of the most prevalent manifestations of atherosclerosis. The results from numerous studies regarding the best revascularization method of an occluded superficial femoral artery have been conflicting. The aim of this study was to compare the patency of transvenous endovascular with open femoropopliteal bypass, both with vein and prosthetic grafts. To our knowledge, a direct patency comparison between transvenous endovascular and open femoropopliteal bypass has not been published. This could help elucidate which method is preferable and in which cases. Materials and Methods: Patients with complex TASC-C and D SFA lesions were offered endovascular transvenous or open bypass. A total of 384 consecutive patients with PAD requiring surgical treatment were evaluated for inclusion in this study. Three-year follow-up data were collected for 52 endovascular procedures, 80 prosthetic grafts, and 44 venous bypass surgeries. Bypass patency was investigated by Duplex US every 6 months. Kaplan-Meier plots were used to analyze primary, primary-assisted, and secondary patency for endovascular transvenous, autovenous, and prosthetic bypasses. Results: Primary, primary-assisted, and secondary patency in venous group at 3 years was 70.5%, 77.3%, and 77.3%, respectively. In the endovascular transvenous group, primary, primary-assisted, and secondary patency at 3 years was 46.2%, 69.2%, and 76.9%, respectively. The lowest patency rates at 3 years were noted in the prosthetic graft group with 22.5% primary, 26.6% primary-assisted, and 28.2% secondary patency. Conclusions: The saphenous vein is the best graft to perform in above-the-knee femoropopliteal bypass. Transvenous endovascular bypass is a viable option with comparable primary-assisted and secondary patency. Primary patency is substantially lower for endovascular transvenous compared to venous bypass. Patients treated with endovascular transvenous bypass will require a significant number of secondary procedures to provide optimal patency. Prosthetic grafts should only be used if no other option for bypass is available.

Assessment of causal associations between obesity and peripheral artery disease: a bidirectional Mendelian randomization study

Background

Several observational studies have documented a potential link between obesity and peripheral artery disease (PAD), although conflicting findings exist. The causal relationship between obesity and PAD continues to be a subject of ongoing debate in the medical community.

Objectives

In this study, we employed a bidirectional Mendelian randomization (MR) analysis to explore the potential causal relationship between obesity and the risk of PAD.

Methods

To investigate these causal relationships, we conducted bidirectional MR analysis using publicly available genome-wide association study (GWAS) data. Effect estimates were calculated using the random-effects inverse variance-weighted (IVW) method.

Results

We identified eight independent single nucleotide polymorphisms (SNPs) associated with obesity in 218,735 samples involving 16,380,465 SNPs, all of which met the genome-wide significance threshold (p < 5 × 10-⁸). The IVW analysis indicates a significant positive association between genetic obesity and multiple datasets with PAD as the outcome: Queue-1 (GWAS ID: finn-b-I9_PAD) (OR = 1.138, 95% CI: 1.027-1.261, p = 0.013), Queue-2 (GWAS ID: bbj-a-144) (OR = 1.190, 95% CI: 1.019-1.390, p = 0.028), Queue-3 (GWAS ID: ebi-a-GCST90018670) (OR = 1.174, 95% CI: 1.014-1.360, p = 0.032), and Queue-4 (GWAS ID: ebi-a-GCST90018890) (OR = 1.194, 95% CI: 1.099-1.296, p < 0.001). However, we did not observe a significant genetic-level association between obesity and PAD for Queue-5 (GWAS ID: ukb-d-I9_PAD) (OR = 1.001, 95% CI: 1.000-1.002, p = 0.071). Furthermore, we conducted a reverse causal MR analysis to explore the potential reverse causal relationship between obesity and PAD. This comprehensive analysis did not provide evidence of a reverse causal association between these two factors.

Conclusions

In summary, our study offers genetic evidence suggesting a possible causal link between obesity and PAD. While we did not find evidence supporting the "obesity paradox", prudent weight management remains crucial, as lower weight does not necessarily guarantee better outcomes. As with any study, caution is required in interpreting the findings. Further research is essential to assess the clinical relevance of weight in preventing PAD, which could inform the development of more precise intervention strategies.

Impact of Tissue Damage and Hemodynamics on Restenosis Following Percutaneous Transluminal Angioplasty: A Patient-Specific Multiscale Model

Multiscale agent-based modeling frameworks have recently emerged as promising mechanobiological models to capture the interplay between biomechanical forces, cellular behavior, and molecular pathways underlying restenosis following percutaneous transluminal angioplasty (PTA). However, their applications are mainly limited to idealized scenarios. Herein, a multiscale agent-based modeling framework for investigating restenosis following PTA in a patient-specific superficial femoral artery (SFA) is proposed. The framework replicates the 2-month arterial wall remodeling in response to the PTA-induced injury and altered hemodynamics, by combining three modules: (i) the PTA module, consisting in a finite element structural mechanics simulation of PTA, featuring anisotropic hyperelastic material models coupled with a damage formulation for fibrous soft tissue and the element deletion strategy, providing the arterial wall damage and post-intervention configuration, (ii) the hemodynamics module, quantifying the post-intervention hemodynamics through computational fluid dynamics simulations, and (iii) the tissue remodeling module, based on an agent-based model of cellular dynamics. Two scenarios were explored, considering balloon expansion diameters of 5.2 and 6.2 mm. The framework captured PTA-induced arterial tissue lacerations and the post-PTA arterial wall remodeling. This remodeling process involved rapid cellular migration to the PTA-damaged regions, exacerbated cell proliferation and extracellular matrix production, resulting in lumen area reduction up to 1-month follow-up. After this initial reduction, the growth stabilized, due to the resolution of the inflammatory state and changes in hemodynamics. The similarity of the obtained results to clinical observations in treated SFAs suggests the potential of the framework for capturing patient-specific mechanobiological events occurring after PTA intervention.

Solid state, pulsed-wave 355 nm UV laser atherectomy debulking in the treatment of infrainguinal peripheral arterial disease: The Pathfinder Registry

BACKGROUND

Atherectomy is an important option for debulking atherosclerotic plaque from diseased arteries in patients with infrainguinal arterial disease. Laser atherectomy uses a high-powered laser to remove the plaque from the arteries to restore blood flow.

AIMS

The Pathfinder multicenter registry was initiated to evaluate the safety and efficacy of the 355 nm laser atherectomy system in a real-world setting for the treatment of de novo, re-stenotic and in-stent restenosis (ISR) lesions in infrainguinal arteries of patients with peripheral artery disease (PAD).

METHODS

The study was a prospective, single-arm, multicenter, open-label registry study for patients treated with the 355 nm laser system. Clinical and lesion characteristics, procedural safety and efficacy data, and baseline, 6-, and 12-month outcomes data, including Ankle Brachial Index (ABI), Rutherford class, and Walking Impairment Questionnaires (WIQ), were collected. The primary efficacy endpoint was the achievement of ≤30% final residual stenosis at the index lesion postatherectomy and adjunctive therapy evaluated by an angiographic Core Lab. The primary safety endpoint was the percentage of subjects who did not experience periprocedural major adverse events (PPMAEs) before discharge.

RESULTS

One hundred and two subjects with 121 lesions treated with the 355 nm laser device at 10 centers were included in the analysis. Mean age was 68.4 ± 10.21 years, 61.8% of subjects were male, 44.6% had critical limb ischemia (CLI), and 47.3% had tibial lesions. The mean residual stenosis at the end of the procedure was 24.4 ± 15.5 with 69 lesions (69.0%) achieving technical procedural success (<30% stenosis); similar rates were observed for subjects with ISR (25.5 ± 14.9), chronic total occlusion (CTO) (28.1 ± 17.0), and severe calcification (36.5 ± 21.6) lesions. Mean ABI, Rutherford, and WIQ scores were improved at both 6 and 12 months. Ninety-seven of 102 subjects (95.1%) met the primary safety endpoint of not experiencing a PPMAE before discharge.

CONCLUSIONS

The initial data from the Pathfinder Registry demonstrates the 355 nm laser system is safe and effective in a real-world setting for performing atherectomy in patients with infrainguinal PAD.

Evaluation of Plasma Biomarkers for Causal Association With Peripheral Artery Disease

BACKGROUND

Hundreds of biomarkers for peripheral artery disease (PAD) have been reported in the literature; however, the observational nature of these studies limits causal inference due to the potential of reverse causality and residual confounding. We sought to evaluate the potential causal impact of putative PAD biomarkers identified in human observational studies through genetic causal inference methods.

METHODS

Putative circulating PAD biomarkers were identified from human observational studies through a comprehensive literature search based on terms related to PAD using PubMed, Cochrane, and Embase. Genetic instruments were generated from publicly available genome-wide association studies of circulating biomarkers. Two-sample Mendelian randomization was used to test the association of genetically determined biomarker levels with PAD using summary statistics from a genome-wide association study of 31 307 individuals with and 211 753 individuals without PAD in the Veterans Affairs Million Veteran Program and replicated in data from FinnGen comprised of 11 924 individuals with and 288 638 individuals without PAD.

RESULTS

We identified 204 unique circulating biomarkers for PAD from the observational literature, of which 173 were genetically instrumented using genome-wide association study results. After accounting for multiple testing (false discovery rate, <0.05), 10 of 173 (5.8%) biomarkers had significant associations with PAD. These 10 biomarkers represented categories including plasma lipoprotein regulation, lipid homeostasis, and protein-lipid complex remodeling. Observational literature highlighted different pathways including inflammatory response, negative regulation of multicellular organismal processes, and regulation of response to external stimuli.

CONCLUSIONS

Integrating human observational studies and genetic causal inference highlights several key pathways in PAD pathophysiology. This work demonstrates that a substantial portion of biomarkers identified in observational studies are not well supported by human genetic evidence and emphasizes the importance of triangulating evidence to understand PAD pathophysiology. Although the identified biomarkers offer insights into atherosclerotic development in the lower limb, their specificity to PAD compared with more widespread atherosclerosis requires further study.

Clinical physiology: the crucial role of MRI in evaluation of peripheral artery disease

Peripheral artery disease (PAD) is a common vascular disease that primarily affects the lower limbs and is defined by the constriction or blockage of peripheral arteries and may involve microvascular dysfunction and tissue injury. Patients with diabetes have more prominent disease of microcirculation and develop peripheral neuropathy, autonomic dysfunction, and medial vascular calcification. Early and accurate diagnosis of PAD and disease characterization are essential for personalized management and therapy planning. Magnetic resonance imaging (MRI) provides excellent soft tissue contrast and multiplanar imaging capabilities and is useful as a noninvasive imaging tool in the comprehensive physiological assessment of PAD. This review provides an overview of the current state of the art of MRI in the evaluation and characterization of PAD, including an analysis of the many applicable MR imaging techniques, describing the advantages and disadvantages of each approach. We also present recent developments, future clinical applications, and future MRI directions in assessing PAD. The development of new MR imaging technologies and applications in preclinical models with translation to clinical research holds considerable potential for improving the understanding of the pathophysiology of PAD and clinical applications for improving diagnostic precision, risk stratification, and treatment outcomes in patients with PAD.

Impact of hyperuricemia on 5-year clinical outcomes in patients with critical limb ischemia following percutaneous transluminal angioplasty

BACKGROUND

A growing evidence on the correlation between hyperuricemia and cardiovascular disease (CVD) has been previously reported. However, there have been limited data on the impact of hyperuricemia on long-term clinical outcomes in patients with critical limb ischemia (CLI) who underwent percutaneous transluminal angioplasty (PTA).

METHODS

A total of 425 peripheral artery disease patients who underwent PTA for CLI were enrolled. The patients were divided into the hyperuricemia group (n = 101) and the normal group (n = 324). The primary endpoint was major adverse cerebral and cardiovascular event (MACCE), including death, myocardial infarction, any coronary revascularization, and stroke, up to 5 years. The secondary endpoint was a major adverse limb event (MALE), including any repeated PTA, and target extremity surgery. Inverse probability weighting (IPTW) analysis, derived from the logistic regression model, was performed to adjust for potential confounders.

RESULTS

After IPTW matching analysis, compared to the normal group, the hyperuricemia group was associated with a higher incidence of MACCE (20.7% vs. 13.6%, hazard ratio [HR], 1.65; 95% confidence interval [CI], 1.15-2.38, P  = 0.006) including non-cardiac death (11.7% vs. 6.3%, HR: 1.95, 95% CI: 1.19-3.19, P  = 0.006) and MALE (47.7% vs. 36.0%, HR: 1.62, 95% CI: 1.23-2.13, P  = 0.001) including non-target extremity revascularization (15.0% vs. 6.8%, HR: 2.42, 95% CI: 1.52-3.84, P  < 0.001).

CONCLUSION

In the present study, hyperuricemia was associated with worse clinical outcomes in patients with CLI following PTA during 5-year clinical follow-up. Efficacy of controlling hyperuricemia in improving clinical outcomes should be evaluated in further studies.

Sex Differences in Mortality Risk after the First Hospitalisation with Lower Extremity Peripheral Arterial Disease

OBJECTIVE

Lower extremity peripheral arterial disease (PAD) is a severe condition that increases the risk of major adverse cardiovascular events, major adverse limb events, and all cause mortality. This study aimed to investigate the mortality risk among females and males hospitalised for the first time with lower extremity PAD.

METHODS

Three cohorts of patients who were admitted for the first time with lower extremity PAD in 2007 - 2010, 2011 - 2014, and 2015 - 2018 were constructed. For the 2007 - 2010 and 2011 - 2014 cohorts, the 28 day, one year, and five year mortality rates were calculated, assessing survival time from date of hospital admission until date of death, end of study period, or censoring. For the 2015 - 2018 cohort, only 28 day and one year mortality were investigated due to lack of follow up data. Mortality rates of these cohorts were compared with the general population using standardised mortality rates (SMRs), and the risk of death between sexes was evaluated using Cox proportional hazards models. Cox models were adjusted for age, cardiovascular disease, and diabetes mellitus to account for potential confounding factors.

RESULTS

In total, 7 950, 9 670, and 13 522 patients were included in the 2007 - 2010, 2011 - 2014, and 2015 - 2018 cohorts, respectively. Over 60% of individuals in each cohort were males. Mortality rates at 28 day and one year remained stable across all cohorts, while the five year mortality rate increased for both males and females in the 2011 - 2014 cohort. The SMRs both of females and males with PAD were significantly higher than in the general population. Multivariable regression analyses found no significant differences in mortality risk between sexes at 28 day and one year. However, the five year mortality risk was lower in females, with a hazard ratio of 0.89 (95% confidence interval [CI] 0.83 - 0.97) in the 2007 - 2010 cohort and 0.88 (95% CI 0.82 - 0.94) in the 2011 - 2014 cohort.

CONCLUSION

The five year mortality risk has increased, and females face a lower mortality risk than males. Lower extremity PAD still carries unfavourable long term consequences compared with the general population.

Smoking as a risk factor for lower extremity peripheral artery disease in women compared to men: A systematic review and meta-analysis

BACKGROUND

To investigate whether the relationship between smoking and peripheral artery disease (PAD) differs by sex (PROSPERO CRD42022352318).

METHODS

PubMed, EMBASE, and CINAHL were searched (3 March 2024) for studies reporting associations between smoking and PAD in both sexes, at least adjusted for age. Data were pooled using random effects. Between-study heterogeneity was examined using I2 statistic and Cochran's Q test. Newcastle-Ottowa Scale was adopted for quality assessment.

RESULTS

Four cohort studies (n = 2,117,860, 54.4% women) and thirteen cross-sectional studies (n = 230,436, 59.9% women) were included. In cohort studies, former and current smokers had higher risk of PAD than never smokers. Compared to those who never or previously smoked, women current smokers (relative risk (RR) 5.30 (95% confidence interval 3.17, 8.87)) had higher excess risk of PAD than men (RR 3.30 (2.46, 4.42)), women-to-men ratio of RR 1.45 (1.30, 1.62)(I2 = 0%, p = 0.328). In cross-sectional studies, risk of PAD was higher among former and current compared to never smokers, more so in men, women-to-men ratios of odds ratio: 0.64 (0.46, 0.90)(I2 = 30%, p = 0.192), 0.63 (0.50, 0.79)(I2 = 0%, p = 0.594), respectively. For both sexes, risk of PAD was higher among current smokers compared to those who were not currently smoking. Cohort studies and five cross-sectional studies were of good quality, scoring 6 to 8 of a possible maximum 9 points. Eight cross-sectional studies scored 2 to 5.

DISCUSSIONS

Further research is required to elucidate sex differences in the relationships between smoking and PAD, as the current evidence is limited and mixed. Tobacco-control programs should consider both sexes.

Enabling Non-invasive Tracking of Vascular Endothelial Cells Derived from Induced Pluripotent Stem Cells Using Nuclear Imaging

PURPOSE

The absence of clinically applicable imaging techniques for continuous monitoring of transplanted cells poses a significant obstacle to the clinical translation of stem cell-based therapies for vascular regeneration. This study aims to optimize a clinically applicable, non-invasive imaging technique to longitudinally monitor vascular endothelial cells (ECs) for vascular regeneration in peripheral artery disease (PAD).

METHODS

Human induced pluripotent stem cells (HiPSCs) were employed to generate ECs (HiPSC-ECs). Lentiviral vectors encoding human sodium iodide symporter (hNIS) and enhanced green fluorescent protein (eGFP) genes were introduced to HiPSCs and HiPSC-ECs at varying multiplicities of infection (MOI). Through a combination of fluorescence microscopy and flow cytometry, an optimized transduction technique for introducing hNIS-eGFP into HiPSC-ECs was established. Subsequently, single-photon emission computed tomography (SPECT) was utilized for imaging of the transduced cells in vitro and in vivo after transplantation into the gastrocnemius muscle of nude mice.

RESULTS

Lentiviral transduction resulted in sustained co-expression of hNIS and eGFP in HiPSC-ECs when transduced post-endothelial differentiation. An optimal MOI of five yielded over 90% hNIS-eGFP expression efficiency without compromising cell viability. hNIS-eGFP+ HiPSC-ECs exhibited 99mTc uptake and were detectable through SPECT in vitro. Additionally, intramuscular injection of hNIS-eGFP+ HiPSC-ECs with MatrigelTM into the hindlimbs of nude mice enabled real-time SPECT/CT tracking, from which a reduction in signal exceeding 80% was observed within 7 days.

CONCLUSIONS

This study establishes an optimized cell modification and imaging protocol for tracking transplanted cells. Future efforts will focus on enhancing cell survival and integration via improved delivery systems, thereby advancing the potential of cell-based therapies for PAD.

Retrospective Evaluation of the Effect of Lumbar Sympathetic Blockade on Pain Scores, Fontaine Classification, and Collateral Perfusion Status in Patients with Lower Extremity Peripheral Arterial Disease

Background and Objectives: The aim of this retrospective study was to evaluate the effect of lumbar sympathetic block (LSB) on pain scores, Fontaine Classification, and collateral perfusion status in patients with lower extremity peripheral artery disease (PAD), in whom revascularization is impossible. Material and Methods: Medical records of 21 patients with PAD who underwent LSB with a combination of local anesthetics, steroids, and patient follow-up forms containing six-month follow-ups between January 2020 and March 2021 were retrospectively reviewed. Numeric Rating Scale (NRS), Pain Detect Questionnaire (PDQ) scores, Fontaine Classification Stages, and collateral perfusion status (collateral diameter and/or development of neovascularization) evaluated by arterial color Doppler Ultrasound (US) from the medical records and follow-up forms of the patients were reviewed. Results: NRS and PDQ scores were significantly lower, and regression of the Fontaine Classification Stages was significantly better after the procedure at the first, third, and sixth month than at the baseline values (p < 0.001). Only four patients (19%) had collaterals before the procedure. An increase in the collateral diameter after LSB was noted in three out of four patients. Before the procedure, 17 patients had no prominent collateral. However, in thirteen of these patients, after LSB, neovascularization was detected during the six-month follow-up period (three patients in the first month, seven patients in the third month, and thirteen patients in the sixth month). The number of patients evolving neovascularization after LSB was found to be statistically significant at the third and sixth months compared to the initial examination (p < 0.001). Conclusions: LSB with the use of local anesthetic and steroids in patients with lower extremity PAD not only led to lower NRS and PDQ scores, but also resulted in regressed Fontaine Classification Stages and better collateral perfusion status.

Chronological vs Biological Age in Interventional Cardiology: A Comprehensive Approach to Care for Older Adults: JACC Family Series

Aging is the gradual decline in physical and physiological functioning leading to increased susceptibility to stressors and chronic illnesses, including cardiovascular disease. With an aging global population, in which 1 in 6 individuals will be older than 60 years by 2030, interventional cardiologists are increasingly involved in providing complex care for older individuals. Although procedural aspects remain their main clinical focus, interventionalists frequently encounter age-associated risks that influence eligibility for invasive care, decision making during the intervention, procedural adverse events, and long-term management decisions. The unprecedented growth in transcatheter interventions, especially for structural heart diseases at extremes of age, have pushed age-related risks and implications for cardiovascular care to the forefront. In this JACC state-of-the-art review, the authors provide a comprehensive overview of the aging process as it relates to cardiovascular interventions, with special emphasis on the difference between chronological and biological aging. The authors also address key considerations to improve health outcomes for older patients during and after their invasive cardiovascular care. The role of "gerotherapeutics" in interventional cardiology, technological innovation in measuring biological aging, and the integration of patient-centered outcomes in the older adult population are also discussed.

Short-duration aerobic high-intensity intervals versus moderate exercise training intensity in patients with peripheral artery disease: study protocol for a randomised controlled trial (the Angiof-HIIT Study)

INTRODUCTION

Supervised exercise training is among the first-line therapies for patients with peripheral artery disease (PAD). Current recommendations for exercise include guidance focusing on claudication pain, programme and session duration, and frequency. However, no guidance is offered regarding exercise training intensity. This study aims to compare the effects of 12-week-long supervised walking exercise training (high-intensity interval training (HIIT) vs moderate-intensity exercise (MOD)) in patients with chronic symptomatic PAD.

METHODS AND ANALYSIS

This study is a monocentric, interventional, non-blinded randomised controlled trial. 60 patients (30 in each group) will be randomly allocated (by using the random permuted blocks) to 12 weeks (three times a week) of HIIT or MOD. For HIIT, exercise sessions will consist of alternating brief high-intensity (≥85% of the peak heart rate (HRpeak)) periods (≤60 s) of work with periods of passive rest. Patients will be asked to complete 1 and then 2 sets of 5-7 (progressing to 10-15×60 s) walking intervals. For the MOD group, exercise training sessions will consist of an alternation of periods of work performed at moderate intensity (≤76% HRpeak) and periods of passive rest. Interventions will be matched by training load. The primary outcome will be the maximal walking distance. Secondary outcomes will include functional performance, functional capacity, heath-related quality of life, self-perceived walking abilities, physical activity and haemodynamic parameters.

ETHICS AND DISSEMINATION

The Angiof-HIIT Study was approved by the Human Research Ethics Committee of the Canton de Vaud (study number: 2022-01752). Written consent is mandatory prior to enrolment and randomisation. The results will be disseminated via national and international scientific meetings, scientific peer-reviewed journals and social media.

TRIAL REGISTRATION NUMBER

NCT05612945.

Reversion of the Inflammatory Markers in Patients With Chronic Limb-Threatening Ischemia

BACKGROUND

Peripheral artery disease is characterized by an intense inflammatory process that can be associated with a higher mortality rate, particularly in chronic limb-threatening ischemia (CLTI). This study aims to compare the evolution of inflammatory markers between patients with claudication with those with CLTI at 3, 6, and 12 months.

METHODS AND RESULTS

An observational, single-center, and prospective study was conducted. A total of 119 patients with peripheral artery disease (65 with claudication and 54 with CLTI) were observed and inflammatory markers collected at admission and 3, 6, and 12 months. At admission, patients with CLTI, when compared with patients with claudication, had significantly higher serum levels of C-reactive protein and fibrinogen (positive acute-phase proteins) and lower serum level of albumin, total cholesterol, and high-density lipoprotein (negative acute-phase proteins): C-reactive protein (g/dL), 2.90 (25th-75th percentile, 2.90-4.90) versus 6.80 (25th-75th percentile, 2.90-53.26) (P=0.000); fibrinogen (mg/dL), 293.00 (25th-75th percentile, 269.25-349.00) versus 415.50 (25th-75th percentile, 312.00-615.75) (P=0.000); total cholesterol (mg/dL), 161.79±95% [152.74-170.85] versus 146.42%±95% [135.30-157.53] (P=0.034); high-density lipoprotein (mg/dL), 50.00 (25th-75th percentile, 41.00-60.00) versus 37.00 (25th-75th percentile, 30.00-45.50) (P=0.000); albumin (g/dL): 4.00 (25th-75th percentile, 3.70-4.20) versus 3.60 (25th-75th percentile, 3.10-4.00) (P=0.003). The association between CLTI and total cholesterol was lost after adjusting for confounders. Three months after the resolution of the CLTI, there was an increase in the levels of negative acute-phase proteins and a decrease in positive acute-phase proteins. These inflammatory proteins did not register an evolution in patients with claudication. The differences in the inflammatory proteins between groups disappeared at 6 months.

CONCLUSIONS

CLTI has an inflammatory environment that can be partially reverted after resolution of the ischemic process, emphasizing the importance of timely intervention.

Sarcopenia in peripheral arterial disease: Establishing and validating a predictive nomogram based on clinical and computed tomography angiography indicators

Purpose

To establish, validate, and clinically evaluate a nomogram for predicting the risk of sarcopenia in patients with peripheral arterial disease (PAD) based on clinical and lower extremity computed tomography angiography (LE-CTA) imaging characteristics.

Methods

Clinical data and CTA imaging features from 281 PAD patients treated between January 1, 2019, and May 1, 2023, at two hospitals were retrospectively analyzed using binary logistic regression to identify the independent risk factors for sarcopenia. These identified risk factors were used to develop a predictive nomogram. The nomogram's effectiveness was assessed through various metrics, including the receiver operating characteristic (ROC) curve, area under the curve (AUC), concordance index (C-index), Hosmer-Lemeshow (HL) test, and calibration curve. Its clinical utility was demonstrated using decision curve analysis (DCA).

Results

Several key independent risk factors for sarcopenia in PAD patients were identified, namely age, body mass index (BMI), history of coronary heart disease (CHD), and white blood cell (WBC) count, as well as the severity of luminal stenosis (P < 0.05). The discriminative ability of the nomogram was supported by the C-index and an AUC of 0.810 (95% confidence interval: 0.757-0.862). A robust concordance between predicted and observed outcomes was reflected by the calibration curve. The HL test further affirmed the model's calibration with a P-value of 0.40. The DCA curve validated the nomogram's favorable clinical utility. Lastly, the model underwent internal validation.

Conclusions

A simple nomogram based on five independent factors, namely age, BMI, history of CHD, WBC count, and the severity of luminal stenosis, was developed to assist clinicians in estimating sarcopenia risk among PAD patients. This tool boasts impressive predictive capabilities and broad utility, significantly aiding clinicians in identifying high-risk individuals and enhancing the prognosis of PAD patients.

Outcomes of endovascular intervention for atherosclerotic lesions confined to the popliteal artery

OBJECTIVE

Most surgeons employ an endovascular-first approach to the treatment of peripheral arterial disease (PAD), but controversy remains regarding the ideal interventions for the management of isolated popliteal artery disease (IPAD). Indeed, there are a paucity of data that compare outcomes of popliteal stents vs other peripheral vascular interventions (PVIs). The goal of this study was to evaluate outcomes of PVIs in IPAD.

METHODS

The Vascular Study Group of New England database was queried for all IPAD PVIs performed for atherosclerotic occlusive disease from 2010 to 2021. Those with at least 1 year of follow-up data available were included for analysis. The primary endpoint was 1-year freedom from a composite target lesion (TL) treatment failure that included restenosis >50% on duplex, reintervention, or ipsilateral major amputation.

RESULTS

We included 689 procedures performed on 634 patients. Of these, 250 (36.3%) were treated with plain balloons (POBA), 215 (31.2%) had stents, 170 (24.7%) had special balloons (drug-coated, cutting, or lithotripsy), and 54 (7.8%) atherectomies were performed. Stent placement was associated with lower freedom from TL treatment failure (72.6%) than special balloon (81.2%; P = .048) and atherectomy (88.9%; P = .012), but not POBA (76.8%; P = .293). On multivariable logistic regression, stents (odds ratio, 0.637; P = .021) and preoperative P2Y12 inhibitor therapy (odds ratio, 0.683; P = .048) were both associated with lower freedom from intervention failure.

CONCLUSIONS

Popliteal stent placement is associated with a higher rate of TL treatment failure at 1 year when compared with other PVIs including special balloon angioplasty and atherectomy, but not POBA, and should therefore be avoided in favor of special balloons or atherectomy whenever feasible.

Medical Optimization of Patients with Symptomatic Peripheral Arterial Disease

Peripheral artery disease (PAD) is a progressive disease associated with the occurrence of major adverse cardiovascular and limb events and elevated mortality rates. Symptoms of PAD, including claudication and chronic limb-threatening ischemia, impair functional capacity and lead to lower quality of life. The focus of current therapies is to minimize symptoms, improve quality of life, and reduce adverse cardiovascular and limb events. Among the medical therapies are antiplatelets, anticoagulants, antihypertensives, lipid lowering therapies, cilostazol and pentoxifylline, and novel blood sugar-lowering therapies, plus exercise therapy and smoking cessation. In this review, we discuss these evidence-based medical therapies that are available for patients with symptomatic PAD.

In the Loop: Endovascular Pedal Arch Revascularization

Advanced endovascular techniques are increasingly being utilized to treat patients with peripheral arterial disease and chronic limb-threatening ischemia to improve lower extremity arterial perfusion. In diabetic patients, pedal arch patency has been associated with improved wound healing, limb salvage, and overall survival. Pedal-plantar loop revascularization is a technique that can restore arterial inflow between the dorsal and plantar arteries of the foot. This article will describe the inframallelolar arterial anatomy and focus on imaging, percutaneous endovascular techniques, and clinical study outcomes of pedal artery interventions.

Depalmitoylation and cell physiology: APT1 as a mediator of metabolic signals

More than half of the global population is obese or overweight, especially in Western countries, and this excess adiposity disrupts normal physiology to cause chronic diseases. Diabetes, an adiposity-associated epidemic disease, affects >500 million people, and cases are projected to exceed 1 billion before 2050. Lipid excess can impact physiology through the posttranslational modification of proteins, including the reversible process of S-palmitoylation. Dynamic palmitoylation cycling requires the S-acylation of proteins by acyltransferases and the depalmitoylation of these proteins mediated in part by acyl-protein thioesterases (APTs) such as APT1. Emerging evidence points to tissue-specific roles for the depalmitoylase APT1 in maintaining homeostasis in the vasculature, pancreatic islets, and liver. These recent findings raise the possibility that APT1 substrates can be therapeutically targeted to treat the complications of metabolic diseases.

Readability of Spanish-Language Online Patient Educational Materials for Peripheral Artery Disease Do Not Meet Recommended Standards and Represent a Literacy Barrier to Care

BACKGROUND

Online resources are a valuable source of information for patients and have been reported to improve engagement and adherence to medical care. However, readability of online patient educational materials (OPEMs) is crucial for them to serve their intended purpose. The American Medical Association (AMA) recommends that OPEM be written at or below the sixth grade reading level. To avoid disparities in access to comprehensible health information on peripheral artery disease (PAD), it is imperative that the readability of PAD OPEM is appropriate for both English-speaking and Spanish-speaking patients. The aim of this study is to evaluate the readability of PAD OPEM in Spanish and compare to English-language OPEM.

METHODS

We conducted a Google search in English and Spanish using "peripheral arterial disease" and "enfermedad arterial periferica", respectively, and the top 25 patient-accessible articles were collected for each. Articles were categorized by source type: hospital, professional society, or other. Readability of English-language OPEM was measured using the Flesch Reading Ease Readability Formula, Automated Readability Index, Coleman-Liau Index, Flesch-Kincaid Grade Level, Gunning Fog, Linsear Write Formula, and the Simple Measure of Gobbledygook Index. Readability of Spanish OPEM was measured using the Fernández-Huerta Index and Índice Flesch-Szigriszt Scale. Readability of the articles was compared to the AMA recommendation, between English- and Spanish-language, and across sources using statistical tests appropriate to the data.

RESULTS

OPEM from professional societies represented the fewest number of English- (n = 7, 28%) and Spanish-language (n = 6, 24%) articles. Most English-speaking (n = 18, 72%) and Spanish-language (n = 20, 80%) OPEM were considered difficult as measured by the Flesch Reading Ease Readability Formula and Fernández-Huerta Index, respectively, but did not significantly differ between languages (P = 0.59). There were no significant differences in the average readability of all readability measurements across sources (hospital, professional society, or other). All the average readability grade levels for English-speaking and Spanish-language OPEM was significantly higher than the sixth grade reading level (P < 0.01). Only 3 (6%) OPEM met the AMA recommended reading level and there was no significant difference between English-language and Spanish-language OPEM (P = 1.0).

CONCLUSIONS

Nearly all Spanish-language and English-language PAD OPEM assessed were written at a reading grade level higher than recommended by the AMA. There was no significant difference in the readability of materials from hospitals or professional societies. To prevent further widening of health disparities related to literacy, health content creators, particularly hospitals and professional societies, should prioritize, develop, and ensure that English-language and Spanish-language patient education materials are written at a level appropriate for the public.

Editor's Choice -- Survival, Limb Salvage, and Management of Patients with Lower Limb Acute Ischaemia: A French National Retrospective Observational Study

OBJECTIVE

The aim was to describe the baseline characteristics of French patients referred with acute limb ischaemia (ALI), and their clinical management and outcome (death, amputation).

METHODS

This retrospective observational cohort study used the National Health Data System. All adults hospitalised for ALI who underwent revascularisation with an endovascular or open surgical approach between 1 January 2015 and 31 December 2020 were included and followed up until death or the end of the study (31 December 2021). A one year look back period was used to capture patients' medical history. The risks of death, and major and minor amputations were described using Kaplan-Meier and Aalen-Johansen estimators. A Cox model was used to report the adjusted association between groups and risk of death and Fine-Gray models for the risk of amputations considering the competing risk of death.

RESULTS

Overall, 51 390 patients (median age 70 years, 69% male) were included and had a median follow up of 2.7 years: 39 411 (76.7%) were treated with an open approach and 11 979 (23.3%) with a percutaneous endovascular approach. The preferred approach for the revascularisation varied between French regions. The one year overall survival was 78.0% and 85.2% in the surgery and endovascular groups, respectively. The surgery group had a higher risk of death (hazard ratio [HR] 1.17, 95% CI 1.12 - 1.21), a higher risk of major amputation (sub-distribution HR 1.20, 95% CI 1.10 - 1.30) and lower risk of minor amputation (sub-distribution HR 0.66, 95% CI 0.60 - 0.71) than the endovascular group. Diabetes and dialysis increased the risk of major amputation by 52% and 78%, respectively. Subsequent ALI was the third most common cause of hospital re-admission within one year.

CONCLUSION

ALI remains a condition at high risk of death and amputation. Individual risk factors and ALI severity need to be considered to choose between approaches. Continued prevention efforts, improved management, and access to the most suitable approach are necessary.