Ankle-brachial Index Research Articles

Does PAD and microcirculation status impact the tissue availability of intravenously administered antibiotics in patients with infected diabetic foot? Results of the DFIATIM substudy.

The aim of this substudy (Eudra CT No:2019-001997-27)was to assess ATB availability in patients with infected diabetic foot ulcers(IDFUs)in the context of microcirculation and macrocirculation status. For this substudy, we enrolled 23 patients with IDFU. Patients were treated with boluses of amoxicillin/clavulanic acid(AMC)(12patients) or ceftazidime(CTZ)(11patients). After induction of a steady ATB state, microdialysis was performed near the IDFU. Tissue fluid samples from the foot and blood samples from peripheral blood were taken within 6 hours. ATB potential efficacy was assessed by evaluating the maximum serum and tissue ATB concentrations(Cmax and Cmax-tissue)and the percentage of time the unbound drug tissue concentration exceeds the minimum inhibitory concentration (MIC)(≥100% tissue and ≥50%/60% tissue fT>MIC). Vascular status was assessed by triplex ultrasound, ankle-brachial and toe-brachial index tests, occlusive plethysmography comprising two arterial flow phases, and transcutaneous oxygen pressure(TcPO2). Following bolus administration, the Cmax of AMC was 91.8 ± 52.5 μgmL-1 and the Cmax-tissue of AMC was 7.25 ± 4.5 μgmL-1(P<0.001). The Cmax for CTZ was 186.8 ± 44.1 μgmL-1 and the Cmax-tissue of CTZ was 18.6 ± 7.4 μgmL-1(P<0.0001). Additionally, 67% of patients treated with AMC and 55% of those treated with CTZ achieved tissue fT>MIC levels exceeding 50% and 60%, respectively. We observed positive correlations between both Cmax-tissue and AUCtissue and arterial flow. Specifically, the correlation coefficient for the first phase was r=0.42; (P=0.045), and for the second phase, it was r=0.55(P=0.01)and r=0.5(P=0.021). Bactericidal activity proved satisfactory in only half to two-thirds of patients with IDFUs, an outcome that appears to correlate primarily with arterial flow.

Exploring the influence of dietary habits on foot risk in type 2 diabetes patients: An observational study

Background & AimTo date, there are no studies demonstrating the impact of the Mediterranean diet on the risk of diabetic foot ulcer. The aim of this research was to examine the connection between adherence to the Mediterranean diet and the level of risk of diabetic foot ulcers in individuals with type 2 diabetes. MethodsObservational pilot study collecting sociodemographic, anthropometric, lifestyle, and type 2 diabetes-related data. Loss of protective sensation was assessed using the Semmes Weinstein 5.07-10g monofilament, considered altered when not perceived in four points. Vascular status was assessed by palpating pulses and ankle-brachial index, indicating peripheral arterial disease if ankle-brachial index was less than 0.9 or if both pulses were absent. Foot deformities were recorded. The risk of diabetic foot ulcers was stratified into two categories: no risk and risk of diabetic foot ulcers. Adherence to the Mediterranean diet was evaluated using the Mediterranean Diet Adherence Screener-14 questionnaire (good adherence with score > 7). ResultsOf the 174 patients with type 2 diabetes mellitus who participated (61.5% men and 38.5% women) with a mean age of 69.56 ± 8.86 years and a mean duration of type 2 diabetes of 15.34 ± 9.83 years. Non-adherent patients to the Mediterranean diet exhibited a higher association of diabetic foot ulcers (p=0.030) and a lower average score on the Mediterranean Diet Adherence Screener-14 (p=0.011). Additionally, a lower incidence of diabetic foot ulcers was observed in those who consumed nuts three or more times a week (p=0.003) and sautéed foods two or more times a week (p=0.003). Multivariate analysis highlighted the importance of physical activity (OR=0.25, 95% CI 0.11-0.54; p<0.001), podiatric treatment (OR=2.59, 95% CI 1.21-5.56; p=0.014), and duration of type 2 diabetes (OR=3.25, 95% CI 1.76-5.99; p<0.001) as significantly associated factors related to the risk of diabetic foot ulcers. ConclusionsAdhering to the Mediterranean diet correlates with a lower incidence of diabetic foot ulcers in individuals diagnosed with type 2 diabetes mellitus. Furthermore, factors such as regular physical activity, podiatric treatment, and the duration of type 2 diabetes mellitus emerge as pivotal in preventing diabetic foot ulcers.

Arterial stiffness and endothelial function in the long-term period after a coronavirus disease 2019

Aim. To assess endothelial function and arterial stiffness over time in patients after hospitalization with coronavirus disease 2019 (COVID-19) and compare them with a control group.Material and methods. A total of 53 patients over 18 years of age were hospitalized for COVID-19 in June — August 2021 was examined at two visits: the first — 10-16 months, the second — 14-23 months after discharge from the hospital. Control group included 53 patients from the ESSE-RF epidemiological study of a St. Petersburg population who did not have COVID-19, selected by sex, status of smoking, hypertension and type 2 diabetes. Endothelial function was assessed by the levels of vascular cell adhesion molecule 1 (VCAM-1) and von Willebrand factor (vWF) in plasma and the reactive hyperemia index (lnRHI) on the EndoPAT 2000 system. Carotid-femoral pulse wave velocity (cfPWV) was determined using the SphygmoCor device, while cardio-ankle vascular index (CAVI) and ankle-brachial index (ABI) — using the VaSera device.Results. The prevalence of endothelial vasomotor function disorders at the first and second visits in the active group did not differ significantly as follows: lnRHI £0,51 — 21% and 21%, cfPWV &gt;10 m/s — 17% and 14%, and SLSI &gt;9 — 28% and 34%, respectively. Plasma VCAM-1 levels were significantly higher during hospitalization than at the first and second visits — no differences were found between visits. The levels of lnRHI, vWF, cfPWV, CAVI, ABI at the first and second visits did not differ significantly. Post-COVID-19 patients differed from the control group only by a significantly higher ABI level at the second visit. According to the analysis of covariance, COVID-19 is associated with a CAVI increase at the first visit, as well as with an increase in ABI at both visits.Conclusion. The 1,5-2-year follow-up of patients after COVID-19, which required hospitalization, showed a decrease in the plasma endothelial dysfunction parameter VCAM-1. There is no changes in endothelial function and arterial stiffness over a period of time from 10-16 months to 14-23 months after hospitalization with COVID-19.

Effects of additional exercise therapy after a successful vascular intervention for people with symptomatic peripheral arterial disease.

Effects of additional exercise therapy after a successful vascular intervention for people with symptomatic peripheral arterial disease.

ANKLE-BRACHIAL INDEX AS SHORT TERM AND LONG-TERM PREDICTOR OF CARDIOVASCULAR EVENTS AFTER MYOCARDIAL INFARCTION: A 3-YEAR FOLLOW-UP STUDY

Objective: The ankle-brachial index (ABI) is a non-invasive index originally proposed for the diagnosis of lower-extremity peripheral artery disease. It is also a marker of atherosclerosis in other vascular sites and may serve as a prognostic marker for cardiovascular events even in the absence of PAD symptoms. However, data on the prognostic value of this index in the setting of acute myocardial infarction (MI) are scarce. Design and method: We prospectively evaluated 441 patients [79.4% male; average age 62 years, 67.6% hypertensive, 29.7% diabetes mellitus (DM); 54.9% STEMI] hospitalized for acute MI. Basic demographic, echocardiographic, peri- and postoperative details were recorded and analyzed. The ABI threshold used to define abnormal levels was less than or equal to 0.90 and recorded according to established guidelines using a certified automated device (ABPI MD, MESI®). The primary endpoint was a composite of all-cause and cardiovascular death, as well as major cardiovascular events including decompensated heart failure, new ACS, cerebrovascular event, malignant arrhythmia, PAD event and new onset renal dysfunction. All events were assessed both in-hospital and within 3 years of follow-up. Results: The mean ABI of our study population was estimated to be 1.1 (IQR: 1.00 to 1.18). In reduced multivariate regression models ABI was a prognostic indicator for the in-hospital composite endpoint. Particularly, patients with abnormal ABI showed a threefold risk of in-hospital events [HR 2.93, 95% CI: 1.48-5.81, p=0.002]. Regarding all-cause mortality, after multivariate analysis, ABI [HR 2.88, 95% CI: 1.53 – 5.42, p=0.001] maintained its predictive power regardless of hypertension, DM, LDL levels and smoking status of the study population in 3 years follow-up. Conclusions: In the setting of an acute MI, lower ABI values expose these patients to a higher risk of in-hospital events and are independently associated with long-term all-cause mortality. Consequently, ABI monitoring in patients with MI may identify patients with a higher risk profile and contribute to early clinical decision making.

LONG-TERM CHANGES IN ARTERIAL STIFFNESS AFTER COVID-19

Objective: To assess if COVID-19 is associated with increase in arterial stiffness using a long-term follow-up study. Design and method: 53 patients hospitalized for COVID-19 in 2021 and 53 age and sex-matched subjects from a proportional cohort were examined. COVID-19 convalescents were evaluated twice; the first visit was 10-16 months after hospitalization, followed by a second visit 6 months after (n=44). The VaSera device (Fukuda Denshi, Japan) was used to measure vascular age, cardio-ankle vascular index (CAVI) and ankle brachial index (ABI). Results: Groups did not differ by gender, smoking status, presence of hypertension or diabetes, but the control group and the second visit group differ by age (Table 1). There was no difference between the control group and COVID-19 group in vascular age and CAVI, however, there was a difference between the control group and the second visit in ABI (p=0.002). To assess the effect of COVID-19 on arterial stiffness; age, arterial hypertension, diabetes, smoking status, and systolic blood pressure were considered during analysis of covariance (ANCOVA) (Table 2). Patients in the control group and COVID-19 group did not differ in vascular age and CAVI after adjustment, but there was a trend toward increasing statistical significance at different visits. Patients in the control group and COVID-19 group differed in ABI, with statistical significance increasing at the later visit. Conclusions: There is an elevation in ABI in patients hospitalized with COVID-19 compared to those not affected by COVID-19. This effect becomes more pronounced over time. No statistical significance was observed for vascular age and CAVI, although an upward trend was noted. Longer follow-up is needed to provide accurate conclusions as to whether these parameters may increase after COVID-19.

Abstract 1153: Adipose-derived Mesenchymal Stem-cell Therapy Improves Arteriogenesis, Hemodynamics, And Walking Performance In A Porcine Model Of Peripheral Artery Disease

Background: There are few effective alternatives to revascularization for peripheral artery disease (PAD). We used our porcine model of PAD to test the hypothesis that adipose derived mesenchymal stem cells (ADMSC) injected around the aortic trifurcation in the pelvis improve ischemic limb hemodynamics and walking performance (WP). Methods: In Ossabaw miniswine (N=13, Age=6 mo) with metabolic syndrome, right (R) hindlimb ischemia was induced with R External Iliac and Superficial Femoral artery coil occlusion (T0) via carotid artery access. All swine had weekly testing of WP on a treadmill. At weeks 0 (T0), 4 (T4), and 8 (T8), ankle brachial indices (ABI) and muscle tissue oximetry (STO 2 ) were measured. At T4 and T8 all swine underwent angiography. At T4, in treatment (Tx) swine (N=4) ADMSC were isolated using stromal vascular fractionation of autologous abdominal wall fat. Using jugular vein access, a catheter with a retractable side-deploying needle was inserted in the R iliac vein and stabilized by a juxtaposed angioplasty balloon. The needle was deployed to access the retroperitoneum and ADMSC were infused around the aortic trifurcation. Results: Ischemic controls (IC) had no differences between T4 and T8 in ABIs, and mean STO 2 differences between R and L in calves and thighs. Tx improved both ABI and mean STO 2 measurements (table 1). IC had no changes in WP between T4 and T8, while Tx showed improvements (table1). On angiography, IC had growth of R Internal iliac artery (RIIA, the main inflow to the ischemic R hindlimb) and shorter appearance time (AT) of RIIA compared to L with no difference between T4 and T8. Tx showed increased growth of RIIA and shorter AT at T8 compared to T4 (table 1). Conclusion: In a clinically-relevant (similar to humans in size, anatomy, physiology and comorbidities) porcine model of PAD we found that ADMSC injection around the aortic trifurcation in the pelvis induces arteriogenesis and improves ischemic limb hemodynamics and walking performance.

Abstract 1154: Length And Proximal Extent Of Occlusion Dictates Severity Of Disease In A Mini-swine Model Of PAD

Background: There is ongoing need for large animal models of peripheral artery disease (PAD) that replicate human disease. We present mild (MI), moderate (MD) and Severe (S) phenotypes of PAD in an Ossabaw mini-swine platform. Methods: Metabolic syndrome was induced in swine (N=16; age= 4 mo) with a high fat/fructose/sodium diet for 8 weeks. Ischemia induction (T0) consisted of: (1) open ligation and resection of R Superficial Femoral Artery (SFA) for MI(N=4); (2) endovascular coil occlusion of R External Iliac Artery (REIA), RSFA and popliteal artery for MD (N=9); and (3) coil occlusion of REIA, RSFA, and right internal iliac artery (RIIA) for S (N=4). At 4 weeks (T4) and 8 (T8), all swine underwent angiography via carotid access, and bilateral gastrocnemius biopsy. All swine had measurements of ankle brachial indices (ABIs), and calf muscle tissue oximetry (STO 2 ) measurements at T0, T4 and T8, along with weekly measurement of walking performance on a treadmill (WP). Results: At T4 and T8 R ABI were increasingly decreased from MI to MD to S (table 1). Mean STO 2 difference between R and L calf at T4 and T8 had no changes in MI, while the differences were larger in S compared to MD (table 1). WP was increasingly decreased from MI to MD to S (table 1). The artery that grew the most on angiography at T4 and T8 were R profunda artery (RPFA) in MI; RIIA in MD; and LIIA in S (table 1). In MI, R PFA had faster flow at T4 and T8 compared to L PFA. At T4, MD and S had similar delays of RPFA reconstitution, this improved at T8 in MD but did not in S (table 1). On histology, MI had no obvious myopathy, MD and S had moderate and severe myopathy respectively. All S subjects developed poorly-healing ischemic ulcers. Conclusion: Length and proximal extent of occlusion dictated the characteristics and severity of phenotypes in our Ossabaw swine model of PAD. This mirrors PAD in humans and can be used to develop therapies for different disease severities.

Factors Determining Risk of Contralateral Lower Limb Amputations in Unilateral Dysvascular Transfemoral and Transtibial Amputees

Abstract Background: This study deals with the factors influencing contralateral lower limb amputations among unilateral dysvascular transfemoral and transtibial amputees. Aim: (1) Early identification of risk factors responsible for amputations in contralateral lower limb. (2) To determine the preventive measures of the concerned risk factors. (3) The aim of this study was to determine the risk factors associated with, contralateral amputation in patients with chronic limb threatening ischaemia (CLTI). Study Design: Cross-sectional study, 45 patients with unilateral transfemoral and transtibial amputees due to diabetes and peripheral arterial disease (PAD) were recruited for this study. Materials and Methods: Analysis of risk factors by ankle-brachial index (ABI), Claudication Pain Scale. Results: Unilateral transfemoral and transtibial amputees due to diabetic foot syndrome and PAD are at 2–4 times increased risk for contralateral lower-limb amputations. Conclusions: Risk of anticipated contralateral limb amputation is high based on ABI and Claudication Pain Scale. All patients, but particularly those at increased risk, should undergo close surveillance and counselling to help prevent subsequent amputations in their contralateral lower extremity.

PHENOTYPIC CHARACTERISTICS OF PATIENTS WITH INCREASED ARTERIAL STIFFNESS IN A HYPERTENSION UNIT

Objective: Arterial stiffness is related to the increase in morbidity and mortality of patients with arterial hypertension (HTN). The characteristics of a sample of patients where PWV was performed. Our goal was to look for differential characteristics among those with increased PVW. Design and method: Retrospective study of patients assessed in the hypertension unit of a tertiary hospital during 2019. Patients were assessed through ABPM by Space labs(R), Ankle brachial index by ABI Huntleigh (R) and PWV measured by Sphygmocor®. Characteristics of patients with High PWV are presented. Results: A total of 22 patients were included, mean age was 60 (± 18.1), average abdominal circumference was 99.3 cm (± 18) and average BMI was 28.55 kg/m2 (± 6.4). Office Blood pressure (BP): Mean systolic BP of 156mmHg (± 22), a mean diastolic BP of 76.58mmHg (± 10.89), a mean heart rate (HR) of 69bpm (± 10), mean central systolic BP of 135.66mmHg (± 10.76) and mean central diastolic BP of 81mmHg (± 12.4). An ankle-brachial index (ABI) was performed on 9 patients, with a mean right ABI of 120 (± 11.87) with a mean intima media thickness (IMG) of 626 (± 206.1) and a mean left ABI of 118 (± 14.61) with an IMT of 631.7 (± 143.83). Ambulatory blood pressure monitoring (ABPM) was performed in 11 of the patients, which showed a mean systolic BP of 138mmHg (± 17.57), mean diastolic BP of 75mmHg (± 11.65), and mean HR of 68bpm (± 11.94). Regarding the correlation with the laboratory findings, a mean glucose value of 108 g/dL (± 29.9), mean triglycerides of 146.9mg/dL (± 54), mean cholesterol of 191.27mg/dL (± 40.94), mean LDL of 114mg/dL (± 36.57) and mean HDL of 48.7mg/dL (± 11.37), and a mean glomerular filtration rate of 64ml/min (± 14.25). This sample was compared with patients with non-pathological PWV, with no significant differences between the groups. Conclusions: We did not find statistically significant associations, in our data, that would allow us to differentiate patients who had pathological OPV during the first visit. More studies are needed

Ice cooling challenge as a means to probe skin microvascular function

Skin microvasculature provides a window to study both systemic and local physiology. In vascular medicine, various challengers such reactive hyperemia, hypoxia or hyperoxia, and heat, have been used to study function and search for potential clinical biomarkers. A positive relationship between increased skin temperature and skin perfusion has been suggested, but skin cooling as a challenger has not been well explored. In the present study, the adaptive cardiovascular and hemodynamic impacts of single hand cooling were examined in a group of ten healthy women, 27.3±7.9 years old, of normal body mass index and ankle-brachial index, normotensive, non-smoking, and free from any medication and supplements. The study followed all principles of good clinical practice and ethics commission approval. After complete stabilization, a participant’s palm, randomly chosen, was placed in contact with a frozen surface covered by a plasticized cotton cloth. Blood perfusion was measured using a laser Doppler flowmetry (LDF) instrument, and temperature were continuously registered in both hands, before, during, and after (early and late recovery) the ice cooling challenge. Nominal values for blood perfusion and temperature were considered, as well as their wavelet transform (WT) components, translating endothelial [0.0095; 0.021] Hz, autonomic [0.021; 0.052] Hz, myogenic [0.052; 0.015] Hz, respiratory [0.15; 0.6] Hz, and cardiac [0.6; 2] Hz activities. No significant differences were observed between limbs regarding nominal LDF values for each experimental phase. Nonetheless, significant differences were observed for nominal temperature signals between limbs during the challenge (Wilcoxon’s signed rank test; p=0.047), and for early (p=0.028) and late (p=0.028) recovery phases. Significant differences were observed for ipsi- and contralateral LDF signals (Friedmann’s test, p&lt;0.001, and p=0.012, respectively), and also for ipsi- and contralateral temperature signals (Friedmann’s test, p&lt;0.001, and p=0.004, respectively). These contralateral responses have been previously described with other challengers applied only in the ipsilateral limb, whilst it is known that local cooling stimulates cutaneous thermoreceptors, sympathetic nerve activity and cutaneous vascular resistance. However, our findings also show that temperature may be more sensitive than LDF for studying the ice cooling challenge, and that the WT analysis approach can provide potential physiological interpretations. Nonetheless, a strong positive correlation (Spearman’s rs = 0.820, p&lt;0.001) was observed between temperature and LDF signals overall for both limbs. In conclusion, this preliminary study suggests that this cooling challenger is effective to elicit vascular physiological changes in both limbs, indicating a putative centrally-mediated adaptive process that might be quantified by changes in cardiac and respiratory activities, as shown from WT analysis. Additionally, temperature signals and the use of WT analysis seem to provide more sensitive and explanatory insights than the use of LDF signals and nominal values alone. Suported by COFAC/ALIES. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Abstract 3027: Home-based, High-pressure Intermittent Limb Compression Following Lower Extremity Revascularization In Patients With Severe Peripheral Artery Disease: A Pilot Trial

Objective: Many patients who undergo lower extremity revascularization (LER) for peripheral artery disease (PAD) continue to experience mobility impairment despite adequate revascularization. High-pressure intermittent limb compression (HPILC) has been shown to augment leg blood flow and improve walking endurance in symptomatic PAD patients. This pilot trial aimed to examine the feasibility of home-based HPILC for 2 hours daily over 3 consecutive months in patients who underwent LER for PAD. The primary outcome was the change in 6-minute walk distance from baseline to 3-month follow-up. Methods: Three months following LER, 9 participants were randomly assigned to either HPILC (n=5) or a sham (n=4) group. Participants were provided with a portable pneumatic air pump and inflatable cuffs that were wrapped around the feet, ankles, and calves (ArtAssist, ACI Medical). The inflation pressures were 120 mmHg and 30 mmHg in the HPILC and sham devices, respectively. A built-in timer, inaccessible to participants, provided one estimate of treatment compliance. Outcomes were assessed before and after the completion of the 3-month interventions. Results: Among the 9 randomized participants, one individual required reintervention and was withdrawn from the study. Adherence to treatment was 74% for HPILC and 92% for sham. As shown in Figure 1, the change in 6-minute walk distance from baseline tended to be higher in the HPILC group compared to the sham-treated group (HPILC: 35.2±38.7 m vs. Sham: -14.7±25 m, p=0.07). There were no group differences in the secondary outcomes, including the changes in the ankle-brachial index, the toe-brachial index, and the Vascular Quality of Life questionnaire scores. Conclusions: Home-based HPILC following LER for PAD is feasible, well-tolerated, and appears to improve walking performance. These preliminary findings indicate that HPILC may be a useful adjunct therapy to enhance lower extremity functioning in patients recovering from LER.

Patient Reported Barriers for Participation in Supervised Exercise Therapy for Symptomatic Peripheral Artery Disease

ObjectivesSupervised exercise therapy (SET) provides clinical benefit for patients suffering from intermittent claudication due to peripheral artery disease (PAD). However, enrollment in programs when offered remains low. We sought to identify patient-reported barriers to enrollment in SET as part of a prospective quality improvement program. MethodsPatients who presented to clinic and were diagnosed with claudication were offered enrollment in a prospective quality improvement protocol, offered at nine regional offices throughout our health system. Both patients who enrolled and declined enrollment were offered a 12-question questionnaire to identify potential barriers to enrollment. Additional data including gender, smoking status, ankle-brachial index (ABI), proximity to the nearest regional office, and disadvantage levels of neighborhoods (low: 1-3, medium: 4-7, and high: 8-10 area deprivation index [ADI]) was collected and compared by program participation using univariate analysis. ResultsPatients enrolled in the SET program (n=66 patients) versus those who declined (n=84 patients) were of similar age (medium age: 71.4 vs. 69.7 years, p=0.694), baseline ABI (0.6 vs. 0.6, p=0.944), smoking status (former 56.1% vs. 53.6%, p=0.668), distance away from outpatient center (8.2 mi vs. 8.4 mi, p=0.249), and had similar Connecticut state ADIs (2021 high-disadvantage: 35.4% vs 33.3%, p=0.549). Patients participating in the SET program were more likely to be male (78.8% vs. 56.0%, p=0.003). Top self-reported barriers for patients who declined participation included transportation/distance (39.3%), preference for independent walking (56.0%), inability to commit to three sessions per week (52.4%), and lack of interest (20.2%). In addition, a higher proportion of patients who declined participation identified severe barriers of preference for independent walking (39.3% vs. 1.5%, p<0.001), inability to commit to three sessions per week (26.2% vs. 3.0% p<0.001), transportation/distance issues (23.8% vs. 7.6% p=0.008), and cost (27.4% vs. 9.1%, p=0.005) as significant barriers for participation in SET. ConclusionsPatients who declined participation in SET for PAD had similar disease status and access to care than participating counterparts. Top reported barriers to enrollment include a preference for independent walking, transportation/distance, commitment to 3x/week program, and cost, which highlight areas of focus for equitable access to these limb-saving services.

Endothelial function cannot be assessed by the reactive hyperemia following occlusion

Reactive hyperemia (RH) and the post occlusive reactive hyperemia (PORH) are known to assess vascular function in vivo and referred as useful prognostic tools in vascular medicine. However, its translation to clinical practice is poor due to important unsolved inconsistencies. Our group has been studying the adaptive responses following RH. Here we clarify the involved mechanism, its impact on general hemodynamics and the significance of these responses. A convenience sample of fourteen healthy women (48.0 ± 8.0 y.o.) was selected, all being normotensive non-menopausal, with no signs of vascular impairment (normal ankle-brachial index and mean arterial pressure MAP), and with (self-reported) equivalent levels of physical activity. The study followed all principles of good clinical practice established for human research and was previously approved by the institutional Ethics Committee. The protocol included three phases—a baseline register (Phase I) during rest, giving place to the occlusion as part of the PORH maneuver challenge period (Phase II) with one minute, followed by a ten-minute recovery period (Phase III). PORH was performed on one randomly chosen upper limb, using the cuff of the TASK FORCE® platform for the continuous monitoring of blood pressure and hemodynamics. After baseline acquisition, the cuff was rapidly inflated with 200 mmHg to occlude the brachial artery for one minute. Then the cuff was rapidly deflated, and signals registered for recovery recordings. Perfusion was measured in both hands by laser Doppler flowmetry (3rd finger) with a Perimed5000 system. To confirm previous evidence regarding the mechanism(s) involved, we also accessed the RH impact(s) on the contralateral forearm skin circulation by functional imaging using a multi-scan photoptoacoustic tomography (PAT) (MSOT iThera system). The tissue hypoxia related to RH-PORH is referred to evoke a local vasodilation, such that hyperemia occurs following the cessation of occlusion. Thus, any reduction of this response has been associated to endothelial impairment. However, our studies have shown suffcient evidence of a centrally mediated reflex rather than a local response mediated by local vasodilators. In fact, LDF clearly detected significant perfusion reductions in both hands during and following occlusion, more pronounced in the challenged limb, while PAT confirmed similar changes in the superficial plexus on the contralateral forearm. Additionally of interest, no significant hemodynamical changes were found with PORH apart from MAP when comparing recovery with baseline periods. Our results clearly show that the physiological significance of RH or POHR reduction can no longer be regarded to solely represent “endothelial disfunction” but rather an expression of a global adaptive hemodynamical response, centrally mediated, that might originate essential endpoints also measurable in the contralateral limb, with clinical utility. This research was financed by national funds through FCT - Foundation for Science and Technology, I.P. (Portugal), under the [UIDB/04567/2020] and [UIDP/ 04567/2020] projects, and by COFAC/ALIES for the use of the photoacoustic instrument. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Light physical activity improves lower limb perfusion asymmetries in older sedentary adults — an exploratory study

Perfusion asymmetries between lower limbs are common even in healthy young individuals, although their physiological significance is unknown. Even in the absence of vascular disease, ageing is among the determinants that seem to accentuate those differences. While it is known that physical activity affects vascular hemodynamics, its specific impact on perfusion asymmetries in healthy elderly individuals is still unclear. This study aimed to identify vascular asymmetries and their variations after a regular program of light exercise in older individuals with age-related comorbidities in the absence of peripheral vascular disease (PVD). Ten participants, mean age 62.4 ± 5.6 years old, were selected following specific criteria. Participants were mostly sedentary, combining one or more common morbidities for this age group — in particular hypertension, overweight and / or diabetes (T2D). Exclusion criteria were an abnormal Ankle-Brachial Index assessed in a standing position at rest and evidence of compromised mobility. All procedures respected the principles of good clinical practice, being previously submitted and approved by the institutional Ethical Commission. Lower limb perfusion was assessed in both feet (anteromedial region) at two time points — day zero (D0) and thirty days later (D30) — using two optical-based technologies — Laser Doppler Flowmetry (LDF) and Polarized Spectroscopy (PSp). These two technologies measure at different depths, with LDF providing deeper tissue readings. During this evaluation period, participants underwent a daily structured program of light exercises based on the FITT principles (F, frequency; I, intensity; T, time and T, type of activity/activity performance) centred in the lower limb perfusion. The group revealed significant asymmetries at D0, where the right foot consistently showed higher values with both technologies correlating positively. At D30, LDF values increased by 57.5% in both feet, meaning that asymmetries disappeared. No significant changes were observed with PSp. Basic cardiovascular functions such as blood pressure and mean arterial pressure were also evaluated, showing significant decreases in systolic pressure and mean arterial pressure. These encouraging results suggest that regular physical activity, even if light in intensity and duration, improves overall hemodynamics and specifically raises perfusion in the lower limbs. These findings should be further explored with the aimof prevention and treatment of PVD. This research was financed by national funds through FCT - Foundation for Science and Technology, I.P. (Portugal), under the [UIDB/04567/2020] and [UIDP/ 04567/2020] programs. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Impact of regional differences and neighborhood socioeconomic deprivation on the outcomes of patients with lower extremity wounds evaluated by a limb-preservation service

ObjectiveManagement of lower extremity (LE) wounds has evolved with the establishment of specialized limb preservation services. Although clinical factors contribute to limb outcomes, socioeconomic status and community factors also influence the risk for limb loss. The Distressed Community Index (DCI) score is a validated index of social deprivation created to provide an objective measure of economic well-being in United States communities. Few studies have examined the influence of geographic deprivation on outcomes in patients with LE wounds. We examined relationships between socioeconomic deprivation and outcomes of inpatients evaluated by a dedicated limb preservation service (Functional Limb Extremity Service [FLEX]). MethodsInpatients referred to FLEX over a 5-year period were included. Wound, Ischemia, foot Infection (WIfI) staging was collected. DCI scores were determined using seven indices based on ZIP Code. Outcomes included any minor or major amputations, any endovascular or open LE revascularization, or wound care procedures. Disease etiology, demographic, and anthropometric data were collected. Associations between neighborhood deprivation and limb-specific outcomes were evaluated in models for the DCI and each of its components separately. ResultsA total of 677 patients were included. Thirty-eight percent were female, with a mean age of 64 years. Sixty percent had WIfI stage 3 or 4 risk of amputation, and 43% had WIfI stage 3 or 4 risk of revascularization. Mean ankle-brachial index and toe pressure were 0.96 (standard deviation [SD], 0.43) and 80 (SD, 57) mmHg. Thirty-five percent were non-White. Amputation was performed in 31% of patients, whereas 17% underwent revascularization. The mean distress score was 64 (SD, 24). Mean DCI scores did not differ across WIfI scores. Likewise, overall DCI distress score was not related to any of the outcomes in univariable or multivariable linear regression models. In univariable linear regression models for amputation, higher poverty rate (odds ratio for SD increase 1.20; 95% confidence interval, 1.02-1.42; P = .025) was significantly associated with the outcome. In multivariable models, neither DCI distress score nor any of its components remained significantly associated with the outcome. ConclusionsDespite known racial disparities in limb-specific outcomes, an aggregate measure of community level distress was not found to be related to outcomes. Although the poverty rate demonstrated a significant relationship with amputation in univariable analysis, this association was not found in multivariable models. Notably, non-White race emerged as a predictor of amputation, underscoring the importance of addressing racial disparities in LE outcomes. Further investigation of potential determinants of LE outcomes is needed, particularly the interaction of such factors with race.

Ankle Brachial Index (ABI) Versus Point-of-Care Arterial Duplex Ultrasound (DUS) in Early Detection and Diagnosis of Diabetic Foot Ischemia in Hemodialysis Unit

Background: Diabetes is a widespread noncommunicable disease affecting an estimated 463 million adults worldwide in 2019 and will affect 700 million by 2045. Diabetic foot lesions remain a major cause of morbidity in patients with renal failure, especially those on dialysis. Ankle Brachial Index (ABI) may inaccurately assess lower extremity perfusion in patients with highly calcified, no compressible tibial arteries. focused Arterial duplex ultrasound (DUS) of the distal anterior and posterior tibial arteries at the ankle can be readily learnt by novices (nurse/physician) and performed rapidly and accurately for early diagnosis and referral.

Association between Atherosclerosis and High-Risk Colorectal Adenomas based on Cardio-Ankle Vascular Index and Ankle-Brachial Index.

Colorectal adenomas are precancerous lesions that may lead to colorectal cancer. Recent studies have shown that colorectal adenomas are associated with atherosclerosis. The cardio-ankle vascular index (CAVI) and ankle-brachial index (ABI) are noninvasive methods for evaluating atherosclerosis. This study examined the association between atherosclerosis and high-risk colorectal adenomas based on the CAVI and ABI. The data of patients aged ≥50 years who had a colonoscopy and CAVI and ABI measurements from August 2015 to December 2021 at the Kangwon National University Hospital were analyzed retrospectively. After the colonoscopy, subjects were divided into no, overall, and high-risk (size ≥1 cm, high-grade dysplasia or villous adenoma, three or more adenomas) adenoma groups based on the pathology findings. The data were subjected to univariate and multivariate logistic regression analyses. Among the 1,164 subjects, adenomas and high-risk adenomas were found in 613 (52.6%) and 118 (10.1%) patients, respectively. The rate of positive ABI (<0.9) and positive CAVI (≥9.0) were significantly higher in the high-risk adenoma group (22.0% and 55.9%) than in the no adenoma (12.3% and 39.6%) and the overall adenoma group (15.7% and 44.0%) (p=0.008 and p=0.006, respectively). Multivariate analysis revealed a positive CAVI and smoking status to be significantly associated with high-risk adenoma with an odds ratio of 1.595 (95% confidence interval 1.055-2.410, p=0.027) and 1.579 (1.072-2.324, p=0.021), respectively. In this study, a significant correlation between positive CAVI and high-risk adenomas was observed. Therefore, CAVI may be a significant predictor for high-risk colorectal adenoma.

Assessment of Frailty Among Older Adults in the Physical Activity Daily Trial.

Frailty is common among cardiac patients; however, frailty assessment data from patients with peripheral arterial disease (PAD) are limited. The purpose of this observational study was to identify the prevalence and factors related to frailty in addition to unique frailty marker groupings in a cohort of sedentary adults with PAD. We grouped three PAD-relevant frailty characteristics using Fried's frailty phenotype -1) exhaustion, (2) weakness, and (3) slowness-and observed the prevalence of pre-frailty (1-2 characteristics) and frailty (3 characteristics) in the PAD cohort. Of the 106 participants, 34.9% were robust/non-frail, 53.8% were pre-frail, and 2.8% were frail. Exhaustion (33.3%) was the most occurring characteristic followed by weakness (20.0%) and slowness (5.0%). The grouping of weakness + slowness (10.0%) was the most prevalent followed by exhaustion + weakness (8.3%) and exhaustion + slowness (5.0%). Among pre-frail participants, ankle brachial index was correlated with a reduction in gait speed.

The effect of the different waves of COVID-19 pandemic on the outcome of diabetic foot ulcers.

COVID-19 pandemic has massively impacted human health. We studied the effect of COVID-19 on outcome of Diabetic foot ulcers (DFUs). We recruited 483 people with DFUs from June 2020 to April 2022 (pandemic) together with a matched group of 226 people with DFU from March 2019 to March 2020 (pre-pandemic). Primary endpoint was outcome of ulcers-healed or amputation (major/minor). It was sub-analysed into 3 waves of COVID-19. Secondary endpoint was healing of individual types of DFUs. Basic anthropometric data included site and type of ulcer (ischemic or neuropathic), duration, presence or absence of infection and Wagner's grading of DFUs was collected for all patients. Diagnosis of peripheral neuropathy was done by monofilament testing and peripheral arterial disease by handheld Doppler and ankle brachial index (ABI). Standardized treatment protocol was provided. All patients were monitored for 6 months. In the pandemic group 323 (66.9%) patients in whom ulcers healed, 70 (14.5%) underwent minor amputation, 11 (2.2%) major amputation, 29 (6%) were lost to follow up, 22 (4.6%) were not healed. Rate of healing of DFU was higher (66.9% vs 53.5%) and rate of amputation was lower (16.7% vs 23.4%) in the pandemic group than in the pre-pandemic group (P = 0.001 and 0.037 respectively). Rate of healing in first, second and third wave was 65.4%, 75.2%, 58.3% respectively (P = 0.001). Neuropathic ulcers though less prevalent (49.8% vs 57.8%) in the first two waves than in the third wave, healing was better (79.3% vs 75.6%) in the first two waves than in the third wave (P = 0.085 and 0.488 respectively). Similarly, amputation rates in ischemic and neuro-ischemic ulcers were greater in the third wave than first two waves (46.7% vs 15.7%, P = 0.049). During the COVID-19 pandemic, healing of neuropathic ulcers was better, especially in the first and second waves and travel restriction may have accounted for this. However, worsening of ischemic and neuro-ischemic ulcers was observed with more amputation in these two groups. Conversely, in the third wave withdrawal of lockdown led to worsening of DFUs resulting in less healing and more amputation.