The OAC3-PAD Risk Score Predicts Major Bleeding Events one Year after Hospitalisation for Peripheral Artery Disease

Antithrombotic treatment following revascularization for chronic limb-threatening ischaemia: a scientific statement of the European Society of Cardiology Working Group on Aorta and Peripheral Vascular Diseases and the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy

Chronic limb-threatening ischaemia (CLTI) is defined as ischaemic rest pain, or non-healing ulceration, requiring endovascular or surgical lower limb revascularization (LLR). Lower limb revascularization in CLTI entails a high risk of major adverse limb events (MALE) and major adverse cardiovascular events (MACE). This scientific statement addresses this risk based on a systematic review. A structured literature search was performed, and articles were independently evaluated by two investigators. In total, 1678 articles were identified, of which 34 were included in the final analysis. Only three randomized controlled trials (RCTs) addressed antithrombotic therapy in CLTI following LLR. None of these demonstrated superiority of any antithrombotic regimen over the other. Eight RCTs investigated antithrombotic therapy following LLR in populations with peripheral arterial disease including CLTI subgroups and suggest a benefit of dual antiplatelet therapy on limb events. One large RCT demonstrated that dual pathway inhibition with aspirin and vascular-dose rivaroxaban reduced the risk of MALE, MACE, and unplanned target limb revascularization. Data from 22 observational studies suggest a benefit of dual antiplatelet therapy on overall survival and amputation-free survival after LLR as compared with single antiplatelet therapy. Intensified antithrombotic treatment should be proposed in patients with CLTI following LLR to reduce the risk of MALE and MACE. Randomized controlled trials on antithrombotic therapy in patients with CLTI following LLR are scarce. Dual pathway inhibition is the only regimen for which an RCT demonstrated a reduction of MALE and MACE following LLR. Dual antiplatelet therapy appears to be associated with a reduced risk of MALE in CLTI following LLR.

Antithrombotic therapy impact on patency and bleeding complications of arteriovenous graft placement in dialysis patients

Background: Arteriovenous grafts (AVG) can be the only bailout solution for patients who require kidney replacement therapy but are unsuitable for arteriovenous fistula (AVF) creation. Currently, high-level evidence on the effectiveness and safety of antithrombotic therapy in AVG patients is scarce. Materials and methods: Following the PICO (patient; intervention; comparator; outcome) model and the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, a data search of the English literature in PubMed, SCOPUS, Central Cochrane was conducted, until March 1st, 2023 (PROSPERO Protocol Number: CRD42023401785). Studies on humans with an AVG receiving any kind of antithrombotic medication, reporting on primary and secondary patency rates, and bleeding complications were included. Due to data heterogeneity, a descriptive report of the outcomes was undertaken. Results: Twelve studies, including 22,436 patients with end-stage renal disease (ESRD) and AVG were included, with patient recruitment spanning over a 41-year time-period (1982-2023). Antithrombotic factors included acetylsalicylic acid (ASA), clopidogrel, dipyridamole, warfarin, unfractioned heparin (UFH), and direct oral anticoagulants (DOACs). Ten studies reported on primary patency rates, and two on secondary patency rates. Primary and secondary patency rates (PPR, SPR) were reported better in four studies, similar in three and worse in one study, regarding patients receiving any kind of antiplatelet therapy. Anticoagulation therapy was not associated with increased PPR or SPR, except for one study on apixaban. Patients receiving single or combined antiplatelets versus patients receiving no treatment presented higher bleeding risk in two studies and similar bleeding risk in three studies. Anticoagulation therapy, excluding apixaban, was associated with higher bleeding risk in three studies, when compared to no anticoagulation. Conclusions: Data derived from the current literature were equivocal regarding the use of antiplatelet treatment in patients with AVG. Studies on anticoagulation therapy are confined. Randomized trials with confounder stratification remain crucial for robust long-term data.

The incidence and significance of delayed bleeding events after lower extremity revascularization in patients with advanced peripheral arterial disease

OBJECTIVE

As novel medications are used in various combinations to prevent thrombosis, few studies have focused on bleeding events after lower extremity revascularization (LER) in patients with peripheral artery disease (PAD). Moreover, the impact of bleeding events on long-term outcomes and the prescription of antithrombotic therapy is not well-reported. This study examines the incidence of bleeding events after LER and their significance in patients with advanced PAD.

METHODS

A retrospective review of patients undergoing LER for PAD in a tertiary care center was performed. Bleeding was classified into major and minor based on the International Society of Thrombosis definitions and captured outside the 30-day perioperative period of LER. Characteristics and outcomes of patients who experienced bleeding events more than 30 days after initial LER were compared with patients who did not.

RESULTS

A total of 1932 patients underwent LER, and 529 (27.4%) experienced a bleeding event (53% major, 47% minor) over 4.3 years. Patients who experienced a bleeding event were more likely to have hypertension (93% vs 89%; P = .005), coronary artery disease (58% vs 53%; P = .047), chronic renal insufficiency (25% vs 16%; P < .001), end-stage renal disease (12% vs 6.8%; P < .001), a history of smoking (84% vs 79%; P = .007), and be on dual antiplatelet therapy (31% vs 25%; P = .029) at baseline. Patients who experienced a bleeding event after 30 days were also more likely to have developed perioperative bleeding (7.6% vs 5.2%; P = .049) after the first LER. On follow-up, patients with bleeding were more likely to have reinterventions (51% vs 43%; P = .002), major amputation (14% vs 7.1%; P < .001), myocardial infarction (33% vs 17%; P < .001), stroke (9.5% vs 5.1%; P < .001), and mortality (48% vs 38%; P < .001). The most common type of bleeding was gastrointestinal (47%), followed by surgical site unrelated to LER (13%), and intracranial. Blood transfusion was used in 48% of patients. Moreover, 40% of patients with an initial bleeding episode had at least one recurrent bleeding episode, with a mean of 2.9 bleeding episodes per patient. After the first bleeding episode, 15% of patients were discharged without any antithrombotic therapy and 13%, 16%, and 11% had discontinuation of ASA, P2Y12 inhibitors, and anticoagulation respectively.

CONCLUSIONS

Bleeding events are common after LER for advanced PAD and are associated with worse overall outcomes. Recurrent bleeding events are likely and significantly affect antithrombotic medication prescriptions.

Artificial Intelligence Techniques for Prognostic and Diagnostic Assessments in Peripheral Artery Disease: A Scoping Review

Peripheral artery disease (PAD) is a major public health concern worldwide, associated with high risk of mortality and morbidity related to cardiovascular and adverse limb events. Despite significant advances in both medical and interventional therapies, PAD often remains under-diagnosed, and the prognosis of patients can be difficult to predict. Artificial intelligence (AI) has brought a wide range of opportunities to improve the management of cardiovascular diseases, from advanced imaging analysis to machine-learning (ML)-based predictive models, and medical data management using natural language processing (NLP). The aim of this review is to summarize and discuss current techniques based on AI that have been proposed for the diagnosis and the evaluation of the prognosis in patients with PAD. The review focused on clinical studies that proposed AI-methods for the detection and the classification of PAD as well as studies that used AI-models to predict outcomes of patients. Through evaluation of study design, we discuss model choices including variability in dataset inputs, model complexity, interpretability, and challenges linked to performance metrics used. In the light of the results, we discuss potential interest for clinical decision support and highlight future directions for research and clinical practice.

External validation of the OAC3-PAD risk score after endovascular revascularisation

Background: The OAC3-PAD bleeding risk score was developed to assess the bleeding risk in patients with peripheral arterial disease (PAD), however its performance in patients treated exclusively with endovascular revascularisation has not yet been tested. We aimed to externally validate the bleeding risk score for this patient cohort. Patients and methods: A retrospective observational study, analysing the data of all PAD patients successfully treated with endovascular revascularisation in a single centre within a five-year period. The performance of the Cox proportional hazards (CPH) model, upon which the OAC3-PAD bleeding risk score is based, was tested using calibration methods, discrimination, and a scaled Brier score for overall performance. The OAC3-PAD bleeding risk score was calculated for all patients, classifying them into the four respective risk groups. Kaplan-Meier curves were plotted for all risk groups and discrimination was tested using log-rank tests. Results: While discrimination of the CPH model was adequate, calibration of the model was poor and the scaled Brier score was 3.27% (95% CI 0.65%-4.40%). Of the 1,434 patients, 33 (2.3%) experienced a major bleeding event. The frequency of bleeding was 0.4% in the low risk group (3/736 patients), 0.8% in the low-to-moderate risk group (2/243 patients), 5.8% in the moderate-to-high risk group (15/258 patients), and 6.6% in the high risk group (13/197 patients). The OAC3-PAD score successfully discriminated each of the two lower bleeding risk groups from one of the two higher risk groups, but failed to discriminate among the two lower risk groups and the two higher risk groups, respectively. Conclusions: Although the OAC3-PAD score did not stratify patients into the four respective risk groups, it allowed discrimination between the low risk patients and the high risk patients. It could therefore become a useful tool for predicting major bleeding events in patients with PAD after endovascular revascularisation.

Increased anti-thrombotic therapy is associated with decreased major adverse limb events in patients with low wound and foot infection scores

INTRODUCTION

The optimal anti-thrombotic management of patients after lower extremity bypass has yet to be fully elucidated, in part due to significant heterogeneity in patient presentation and practice patterns. The Wound, Ischemia, and foot Infection (WIfI) score is a validated scoring system to assist in the management of patients with chronic limb threatening ischemia (CLTI). We hypothesized that performing a restriction analysis based on WIFI scores would assist in the postoperative anti-thrombotic management of patients undergoing infrainguinal bypass.

METHODS

A retrospective cohort of infrainguinal bypass procedures completed at a single hospital system between January 2018 and January 2021 was selected, and preoperative WIfI scores were extracted for each patient. Patients with either Wound scores of 2 and 3, or Ischemia Scores of 0 and 1, or Foot Infection Scores of 3 were excluded. Based on the type of anti-thrombotic regimen on discharge, demographics, comorbidities, type of bypass, 30-day rates of graft occlusion, major amputation, mortality, and major adverse limb events (MALE) were analyzed. Statistical analysis included t-tests, chi square tests, and time-to-event survival analysis.

RESULTS

230 procedures were included in the study. 69 (30.0%) patients were discharged on single antiplatelet therapy (SAPT), compared to 161 (70.0%) who were discharged on either dual antiplatelet therapy or anticoagulation (DAPT/AC). There was a higher prevalence of bypasses using prosthetic conduit in the DAPT/AC group (45.9 vs 31.8%, p = .047); no other demographic or procedural variable analyzed had any significant differences. At 30-days postoperatively, there was no significant difference in postoperative reintervention rates, however, the DAPT/AC group had significantly lower rates of mortality (1.2 vs 7.2%, p = .01), major amputation (1.2% vs 5.8%, p = .04), and MALE (3.7 vs 13.0%, p < .01). There were no significant differences in bleeding complications. Survival analysis demonstrated that MALE-free survival was higher in the DAPT/AC group compared to the SAPT group (p < .01). On Cox regression analysis, DAPT/AC was associated with significantly decreased rates of MALE + mortality (Hazard Ratio (HR) 0.20 [0.06 - 0.66]).

CONCLUSION

Lower extremity bypasses patients with low Wound and low foot Infection scores who are discharged on DAPT/AC postoperatively have a significantly higher 30-day MALE-free survival rate compared to patients discharged on SAPT; consideration could be made to preferentially discharge such post-bypass patients on DAPT/AC.

Antithrombotic Therapy in High Bleeding Risk, Part II: Noncardiac Percutaneous Interventions

Over the past decades, there have been great advancements in the antithrombotic management of patients undergoing percutaneous interventions, but most of the available evidence derives from studies conducted in the setting of cardiac interventions. Antithrombotic treatment regimens used in patients undergoing percutaneous cardiac interventions, in particular coronary, are frequently extrapolated to patients undergoing noncardiac interventions. However, the differences in risk profile of the population treated and the types of interventions performed may translate into differences is the safety and efficacy associated with antithrombotic therapy. Noncardiac percutaneous interventions are commonly performed in patients at high bleeding risk, which may indeed impact outcomes, hence underscoring the importance of risk stratification to guide clinical decision-making processes. In this review, we appraise the available evidence on antithrombotic therapy in high-bleeding-risk patients undergoing noncardiac percutaneous interventions.

Dual Antithrombotic Therapy versus Anticoagulant Monotherapy for Major Adverse Limb Events in Patients with Concomitant Lower Extremity Arterial Disease and Atrial Fibrillation: A Propensity Score Weighted Analysis

OBJECTIVE

Patients with symptomatic lower extremity arterial disease (LEAD) are recommended to receive antiplatelet therapy, while direct oral anticoagulants (DOACs) are standard for stroke prevention in patients with atrial fibrillation (AF). For patients with concomitant LEAD and AF, data comparing dual antithrombotic therapy (an antiplatelet agent used in conjunction with a DOAC) vs. DOAC monotherapy are scarce. This retrospective cohort study, based on data from the Taiwan National Health Insurance Research Database, aimed to compare the efficacy and safety of these antithrombotic strategies.

METHODS

Patients with AF who underwent revascularisation for LEAD between 2012 - 2020 and received any DOAC within 30 days of discharge were included. Patients were grouped by antiplatelet agent exposure into the dual antithrombotic therapy and DOAC monotherapy groups. Inverse probability of treatment weighting was used to mitigate selection bias. Major adverse limb events (MALEs), ischaemic stroke or systemic embolism, and bleeding outcomes were compared. Patients were followed until the occurrence of any study outcome, death, or up to two years.

RESULTS

A total of 1 470 patients were identified, with 736 in the dual antithrombotic therapy group and 734 in the DOAC monotherapy group. Among them, 1 346 patients received endovascular therapy as the index revascularisation procedure and 124 underwent bypass surgery. At two years, dual antithrombotic therapy was associated with a higher risk of MALEs than DOAC monotherapy (subdistribution hazard ratio [SHR] 1.34, 95% confidence interval [CI] 1.15 - 1.56), primarily driven by increased repeat revascularisation. Dual antithrombotic therapy was also associated with a higher risk of major bleeding (SHR 1.43, 95% CI 1.05 - 1.94) and gastrointestinal bleeding (SHR 2.17, 95% CI 1.42 - 3.33) than DOAC monotherapy.

CONCLUSION

In patients with concomitant LEAD and AF who underwent peripheral revascularisation, DOAC monotherapy was associated with a lower risk of MALEs and bleeding events than dual antithrombotic therapy.

Antithrombotic Therapy in Patients Undergoing Peripheral Artery Interventions

Patients with peripheral artery disease (PAD) who undergo lower extremity revascularization (LER) are at high risk for cardiovascular and limb-related ischemic events. The role of antithrombotic therapy is to prevent thrombotic complications, but this requires balancing increased risk of bleeding events. The dual pathway inhibition (DPI) strategy including aspirin and low-dose rivaroxaban after LER has been shown to reduce major adverse cardiovascular and limb-related events without significant differences in major bleeding. There is now a need to implement the broad adoption of DPI therapy in PAD patients who have undergone LER in routine practice.

Patient Factors Influencing Prescription of Antithrombotic Medication After Lower Limb Endovascular Intervention

OBJECTIVE

There is significant practice variation in the use of antithrombotic therapy after endovascular intervention for lower limb peripheral arterial disease, with differences in medication choice and duration. Prescriber decision making is complex, and patient factors have been shown to substantially contribute to prescribing variation. To determine the influence of patient factors on antithrombotic prescribing, a discrete choice experiment was distributed to vascular surgeons and trainees across Australia and Aotearoa New Zealand.

METHODS

After pilot testing, the discrete choice experiment questionnaire was distributed to 300 vascular surgeons and trainee members of the Australian and New Zealand Society for Vascular Surgery. Multinomial logistic regression models were used to analyse patient factors that had the most influence on decisions to prescribe a second antithrombotic agent, and the preferred choice of antithrombotic (clopidogrel 75 mg daily or rivaroxaban 2.5 mg twice daily) in addition to aspirin 100 mg daily. The odds ratio (OR) with 95% confidence interval (CI) reported preference strength.

RESULTS

A total of 44 questionnaires were completed between September and October 2023, reaching the 15% targeted response rate. Prescribing a second antithrombotic was more likely after femoropopliteal stenting compared with angioplasty (OR 1.89, 95% CI 1.20 - 2.13), and in chronic limb threatening ischaemia compared with intermittent claudication (OR 1.58, 95% CI 1.20 - 2.13). Most respondents preferred clopidogrel over rivaroxaban (62%), with over a third of respondents exclusively prescribing clopidogrel. Patients with stents (OR 1.77, 95% CI 1.32 - 2.37) or moderate bleeding risk (OR 1.38, 95% CI 0.97 - 1.84) were more likely to receive clopidogrel than rivaroxaban.

CONCLUSION

This study demonstrates that vascular surgeons primarily prioritise antithrombotic prescribing decisions by procedure type. Clopidogrel is more likely to be prescribed than rivaroxaban as a second agent in combination with aspirin, especially after stenting. Knowing these clinician preferences can target implementation strategies towards supporting decision making in subgroups of patients according to individual risk profiles.

Editor's Choice - Revascularisation for Peripheral Artery Disease in France: Implications for the Implementation of VOYAGER-PAD

OBJECTIVE

The VOYAGER-PAD trial demonstrated the interest in dual pathway inhibition (DPI) (low dose rivaroxaban plus aspirin) to reduce limb and cardiovascular events after revascularisation for peripheral artery disease (PAD), but its applicability in clinical practice has not yet been assessed. This study aimed to assess the number of patients revascularised in France for PAD and to estimate the proportion of those matching the VOYAGER-PAD trial selection criteria. A secondary objective was to examine the prognosis of revascularised patients in a real world setting.

METHODS

This observational retrospective study was conducted on the national hospital discharge database and included all patients with PAD who underwent lower extremity revascularisation for PAD (without lower extremity revascularisation in the two years prior to inclusion) from 1 January 2016 to 31 December 2019. Available VOYAGER-PAD selection criteria were then applied to the study population.

RESULTS

In total, 180 870 patients were included (mean age 72.0 ± 12.2 years, 30.9% female), with approximately 45 000 patients revascularised annually. Among them, 90 379 (50.0%) matched the VOYAGER-PAD trial criteria (VOYAGER-PAD eligible subgroup; mean age 69.8 ± 12.1 years, 29.5% female). In the study population and the VOYAGER-PAD eligible subgroup, 33.9% and 26.6% of patients had diabetes, 28.1% and 19.9% had chronic coronary artery disease, and 14.6% and 5.7% had renal failure, respectively. Overall, 73.1% of study patients were treated by an endovascular approach (75.5% in the VOYAGER-PAD eligible subgroup). In patients with more than one year of follow up, 45.4% of study patients and 36.0% of the VOYAGER-PAD eligible subgroup experienced a limb or cardiovascular event. The median time until the first event and in hospital death was 4.8 months and 7.8 months, respectively (6.7 months and 12.9 months in the VOYAGER-PAD eligible subgroup).

CONCLUSION

The burden of PAD for revascularisation and secondary events is considerable. One half of revascularised patients in France are eligible for DPI therapy. Those patients are younger, with fewer comorbidities, and better outcomes.

Growth Differentiation Factor-15 and Clinical Outcomes in Lower Extremity Artery Disease

AIM

Lower extremity artery disease (LEAD) is an increasingly common health problem that is associated with high mortality due to thrombotic and bleeding events. Growth differentiation factor-15 (GDF15), a stress-response cytokine belonging to the transforming growth factor-beta superfamily, is associated with cardiovascular disease and its outcomes. The aim of the present study was to examine the effect of serum GDF15 levels on clinical outcomes in patients with LEAD.

METHODS

We measured serum GDF15 levels in 200 patients with LEAD before their initial endovascular therapy. The primary endpoint was the all-cause mortality rate. The secondary endpoints, on the other hand, were thrombotic and bleeding events, such as cerebral infarction, acute coronary syndrome, acute limb ischemia, and Bleeding Academic Research Consortium types 3 and 5.

RESULTS

The serum GDF15 levels increased with advancing Fontaine class. Kaplan-Meier analysis revealed that the high-GDF15 group (≥ 2,275 pg/mL) had higher rates of all-cause deaths and thrombotic and bleeding events than the low-GDF15 group (＜2,275 pg/mL). Multivariate Cox proportional-hazards regression analysis revealed that GDF15 was an independent predictor of all-cause mortality and thrombotic and bleeding events after adjusting for confounding risk factors. When the ABC-AF-bleeding score was substituted for GDF15, similar results were obtained.

CONCLUSION

Serum GDF15 levels were associated with all-cause mortality and thrombotic and bleeding events in patients with LEAD. Serum GDF15 is a potentially useful marker of clinical outcomes, specifically for tracking thrombotic and bleeding events in patients with LEAD.

External Validation of the OAC3-PAD Bleeding Score in a Nationwide Population of Patients Undergoing Invasive Treatment for Peripheral Arterial Disease

OBJECTIVE

The OAC3-PAD score was developed to predict bleeding risk in patients with lower extremity peripheral arterial disease (PAD), but its performance in concomitant international cohorts is largely unknown. This study aimed to validate the OAC3-PAD score in an unselected nationwide population of patients undergoing invasive treatment for symptomatic PAD.

METHODS

This was a nationwide cohort study including all patients who underwent a first revascularisation procedure or major amputation for symptomatic PAD in Denmark from 2000 - 2021. The study population was stratified based on OAC3-PAD score, and the one year risk of major bleeding was assessed, accounting for the competing risk of death. The score performance was evaluated using calibration plots, C statistic, Brier score, and the index of prediction accuracy (IPA).

RESULTS

A total of 52 016 patients were included (mean age 71 years, 43.8% female). The one year risk of major bleeding increased with higher OAC3-PAD score, ranging from 1.6% (95% confidence interval [CI] 1.4 - 1.8%) to 2.3% (95% CI 2.0 - 2.5%), 3.5% (95% CI 3.2 - 3.8%), and 5.2% (95% CI 4.8 - 5.6%) for patients with low, low moderate, moderate high, and high score, respectively. Using patients with low risk as reference, the OAC3-PAD score effectively categorised patients, demonstrating statistically significant differences in bleeding risk across strata. However, the score showed modest discriminative performance, with a C statistic of 65% (95% CI 63 - 66%) and a Brier score of 2.6% (95% CI 2.5 - 2.7%). Nevertheless, it performed significantly better than the null model, as indicated by an IPA of 3.1%.

CONCLUSION

Among patients who underwent invasive treatment for symptomatic PAD in routine care, the OAC3-PAD score was associated with greater risk of major bleeding with increasing score level. However, its discriminatory ability was modest, and the clinical utility remains to be determined.

The Additional Value of Activated Clotting Time-Guided Heparinization During Interventions for Peripheral Arterial Disease

PURPOSE

Unfractionated heparin is widely used to lower the risk of arterial thromboembolic complications (ATECs) during interventions for peripheral arterial disease (PAD), but it is still unknown which heparin dose is the safest in terms of preventing ATECs and bleeding complications. This study aims to evaluate the incidence of complications during interventions for PAD and the relation between this incidence and different heparinization protocols.

MATERIALS AND METHODS

A retrospective analysis of a prospective multicenter cohort study was performed. Between June 2015 and September 2022, 355 patients who underwent peripheral interventions for PAD were included. All patients who were included before July 2018 received 5000 international units (IU) of heparin (group 1). Starting from July 2018, all included patients received an initial dose of 100 IU/kg, with potential additional heparin doses based on activated clotting time (ACT) values (group 2). Data on ACT values and complications within 30 days post-procedurally were collected.

RESULTS

In total, 24 ATECs and 48 bleeding complications occurred. In group 1, 8.7% (n=11) of patients suffered from ATEC, compared with 5.7% (n=13) in group 2. Thirteen percent of patients (n=17) in group 1 had a bleeding complication, compared with 14% (n=31) in group 2. Arterial thromboembolic complications were more often found in patients with peak ACT values of <200 seconds, compared with ACT values between 200 and 250 seconds, 15% (n=6) versus 5.9% (n=9), respectively, p=0.048. Patients with peak ACT values >250 seconds had a higher incidence of bleeding complications compared with an ACT between 200 and 250 seconds, 24% (n=21) versus 9.8% (n=15), respectively, p=0.003. Forty-four percent of patients (n=23) in group 1 reached a peak ACT of >200 seconds, compared with 95% (n=218) of patients in group 2 (p=0.001).

CONCLUSION

ATEC was found in 6.8% (n=24) and bleeding complications in 14% (n=48) of patients who underwent a procedure for PAD. There was a significantly higher incidence of ATECs in patients with a peak ACT value <200 seconds, and a higher incidence of bleeding complications in patients with a peak ACT value >250 seconds. The findings obtained from this study may serve as a basis for conducting future research on heparinization during procedures for PAD, with a larger sample size.

CLINICAL IMPACT

Heparin is administered during arterial interventions for peripheral arterial disease (PAD) to decrease the risk of arterial (thrombo)embolic complications (ATEC) during or shortly following surgery. The effect of heparin is unpredictable in the individual patient, and the optimal dosage of this anticoagulant has not yet been established. Using the activated clotting time (ACT), the anticoagulatory effect of heparin can be monitored periprocedurally. Previous research on the incidence of both ATEC and bleeding complications, or on the optimal dosage of heparin administration, is scarce. This study aims to investigate the incidence of ATEC and bleeding complications between 2 different dosage protocols of heparin-a standard bolus of 5000 IU or ACT-guided heparinization-and thereby provide clarity on the optimal dose of heparin during peripheral arterial interventions for PAD.

Artificial intelligence-based predictive models in vascular diseases

Cardiovascular disease represents a source of major health problems worldwide, and although medical and technical advances have been achieved, they are still associated with high morbidity and mortality rates. Personalized medicine would benefit from novel tools to better predict individual prognosis and outcomes after intervention. Artificial intelligence (AI) has brought new insights to cardiovascular medicine, especially with the use of machine learning techniques that allow the identification of hidden patterns and complex associations in health data without any a priori assumptions. This review provides an overview on the use of artificial intelligence-based prediction models in vascular diseases, specifically focusing on aortic aneurysm, lower extremity arterial disease, and carotid stenosis. Potential benefits include the development of precision medicine in patients with vascular diseases. In addition, the main challenges that remain to be overcome to integrate artificial intelligence-based predictive models in clinical practice are discussed.

Nationwide Study in France To Predict One Year Major Bleeding and Validate the OAC3-PAD Score in Patients Undergoing Revascularisation for Lower Extremity Arterial Disease

OBJECTIVE

Antithrombotic strategies are currently recommended for the treatment of lower extremity artery disease (LEAD) but specific scores to assess the risk of bleeding in these patients are scarce. To fill the gap, the OAC3-PAD bleeding score was recently developed and validated in German cohorts. The aim of this study was to determine whether this score performs appropriately in another real world nationwide cohort.

METHODS

This 10 year retrospective, multicentre study based on French national electronic health data included patients who underwent revascularisation for LEAD between January 2013 and June 2022. The OAC3-PAD score was calculated and from this, the population was classified into four groups: low, low to moderate, moderate to high and high risk. A binary logistic regression model was applied, with major bleeding occurring at one year (defined using the International Classification of Diseases ICD-10) as the dependent variable. The performance of the OAC3-PAD bleeding score was investigated using a receiver operating characteristic curve.

RESULTS

Among 161 205 patients hospitalised for LEAD treatment in French institutions, the one year incidence of major bleeding was 13 672 patients (8.5%). The distribution of the population according to the OAC3-PAD bleeding score was: 88 835 patients (55.1%), 34 369 (21.3%), 27 914 (17.3%), and 10 087 (6.3%) in the low, low to moderate, moderate to high, and high risk groups, respectively; with an incidence of one year major bleeding of 5.0%, 9.8%, 13.2%, and 21.3%. The OAC3-PAD model achieved an AUC of 0.650 to predict one year major bleeding following LEAD repair (95% CI 0.645 - 0.655), with a sensitivity of 0.67 and a specificity of 0.57.

CONCLUSION

This nationwide analysis confirmed the accuracy of the OAC3-PAD model to predict one year major bleeding and served as external validation. Although further studies are required, it adds evidence and perspectives to further generalise its use to guide the management of patients with LEAD.

Preventing Lower Limb Graft Thrombosis after Infrainguinal Arterial Bypass Surgery with Antithrombotic Agents (PATENT Study): An International Expert Based Delphi Consensus

(1) Background: High-level evidence on antithrombotic therapy after infrainguinal arterial bypass surgery in specific clinical scenarios is lacking. (2) Methods: A modified Delphi procedure was used to develop consensus statements. Experts voted on antithrombotic treatment regimens for three types of infrainguinal arterial bypass procedures: above-the-knee popliteal artery; below-the-knee popliteal artery; and distal, using vein, prosthetic, or biological grafts. The treatment regimens for these nine procedures were then voted on in three clinical scenarios: isolated PAOD, atrial fibrillation, and recent coronary intervention. (3) Results: The survey was conducted with 28 experts from 15 European countries, resulting in consensus statements on 25/27 scenarios. Experts recommended single antiplatelet therapy after above-the-knee popliteal artery bypasses regardless of the graft material used. For below-the-knee popliteal artery bypasses, experts suggested combining single antiplatelet therapy with low-dose rivaroxaban if the graft material used was autologous or biological. They did not recommend switching to triple therapy for patients on oral anticoagulants for atrial fibrillation or dual antiplatelet therapy in any scenario. (4) Conclusions: Great inconsistency in the antithrombotic therapy administered was found in this study. This consensus offers guidance for scenarios that are not covered in the current ESVS guidelines but must be interpreted within its limitations.

Patient Characteristics in the Recording Courses of Vascular Diseases (Reccord) Registry: Comparison with the Voyager Pad Endovascular Cohort

Background: To compare the characteristics of a “real world” population included in a prospective registry to patients enrolled in a randomized, controlled trial (RCT) after endovascular revascularization (EVR) for symptomatic peripheral artery disease (PAD). Methods: The RECcording COurses of vasculaR Diseases (RECCORD) registry is an observational registry prospectively recruiting patients undergoing EVR for symptomatic PAD in Germany. VOYAGER PAD was an RCT which demonstrated the superiority of rivaroxaban and aspirin versus aspirin to reduce major cardiac and ischemic limb events following infrainguinal revascularization for symptomatic PAD. For this exploratory analysis, the clinical characteristics of 2.498 patients enrolled in RECCORD and of 4.293 patients from VOYAGER PAD who underwent EVR were compared. Results: The rate of patients aged ≥ 75 years was considerably higher in the registry (37.7 vs. 22.5%). More patients in the registry had undergone previous EVR (50.7 vs. 38.7%) or suffered from critical limb threatening ischemia (24.3 vs. 19.5%). Registry patients were more commonly active smokers (51.8 vs. 33.6%), but less frequently suffered from diabetes mellitus (36.4 vs. 44.7%). While statins (70.5 vs. 81.7%) were less frequently used, antiproliferative catheter technologies (45.6 vs. 31.4%) and postinterventional dual antiplatelet therapy (64.5 vs. 53.6%) were more commonly applied in the registry. Conclusions: There were many similarities but some clinically meaningful differences in clinical characteristics between PAD patients who underwent EVR and were included in a nationwide registry and PAD patients from the VOYAGER PAD trial.

Bleeding Risk in Patients with Peripheral Arterial Disease

Patients with peripheral arterial disease (PAD) are at high risk of major adverse cardiac events (MACE) and major adverse limb events (MALE). Recently, antithrombotic therapies employing antiplatelet and anticoagulant drugs have proven to be valid in reducing MACE in patients with PAD and polyvascular disease and MALE, particularly in patients who have already been revascularized and remain at increased risk of MALE. However, more aggressive antithrombotic therapies lead to an increased risk of bleeding. Antithrombotic therapy and revascularization procedures entail an increased hemorrhagic risk that is also linked to having received more vigorous antithrombotic therapies. Therefore, it appears crucial to have specifically targeted scores for a PAD patient to assess bleeding and thrombotic risks. The correct utilization of a risk score will determine the variable risk factors for bleeding that can be corrected or modified, as well as identify patients at high risk that require regular reexamination and follow-up. Clinical risk scores do not represent the absolute reality, and inter-score variability must be taken into account. Moreover, several risk scores have been created to be basic and to facilitate and improve clinical decisions in daily practice. Many risk scores based on points vary according to the configuration of the studies, population type, and ethnic group, and many of the risk factor elements in a specific score are unlikely to sustain same weight for that risk. The best approach continues to be devising an uncomplicated, functional, validated, and precise score that can be adjusted to different clinical contexts and populations, while considering the mutable composition of clinical risk.

Now Is the Time to Bring a Common but Unpopular Noncommunicable Disease into Focus: Peripheral Arterial Disease Takes Limbs and Lives, but It Must Also Touch Our Hearts!

We have all learned a great deal from the ongoing pandemic that has already taken more than five million lives in less than three years [...]

Antithrombotic Treatment Patterns of Patients with Symptomatic Peripheral Arterial Occlusive Disease in Germany: Evidence from Health Insurance Claims Data

Objectives: Patients with peripheral arterial occlusive disease (PAOD) are at risk of worsening limb symptoms, major adverse cardiovascular events and exhibit an impaired life expectancy. There is a lack of evidence on the extent of pharmacological secondary prevention in PAOD patients. This study assesses treatment patterns of antithrombotic agents in symptomatic PAOD patients. Methods: This is a retrospective cohort study using data from the second largest insurance fund in Germany, BARMER. We included symptomatic PAOD patients undergoing in-hospital treatment with an index admission between 1 January 2010 and 31 December 2017. Outcomes were proportions of single antiplatelets (SAPT), dual antiplatelets (DAPT), vitamin-K antagonists (VKA), or direct oral anticoagulants (DOAC) in the 12 months prior and 6 months after the index hospitalization. Non-parametric cumulative incidence for competing risks was estimated to account for censoring and death after discharge from hospital stay. Patient flows were visualised by alluvial diagrams. All analyses were stratified by intermittent claudication (IC) and chronic limb-threatening ischaemia (CLTI). The protocol was registered to ClinicalTrials.gov (NCT03909022). Results: A total of 80,426 unique patient encounters were identified. Mean age was 72.7 (46.3% female). Amongst all patients, 25.6% were on SAPT, 4.1% on DAPT, 9.1% on VKA, 3.9% on DOAC, 3.9% on both antiplatelets and oral anticoagulation, and 53.3% without any antithrombotic therapy during the 12 months before index stay. The estimated cumulative incidence was 37.9% SAPT, 14.8% DAPT, 7.5% VKA, 4.3% DOAC, 7.4% both, and 28.1% without any antithrombotic therapy during the 6 months after index stay. The considerable increases in antiplatelet therapy were mainly driven by the group of patients without antithrombotics before index stay. As compared with IC, patients who suffered from CLTI received less often antiplatelets but more often anticoagulants both before and after index stay. Conclusions: Utilisation rates of antithrombotic therapy increased considerably after in-hospital treatment for PAOD. Yet, remarkably high rates of symptomatic patients without any blood-thinning therapy constitute a major concern with respect to adequate secondary prevention of PAOD patients.

The Impact of Chronic Kidney Disease on Mid-Term Outcomes after Revascularisation of Peripheral Arterial Occlusive Disease: Results from a Prospective Cohort Study

OBJECTIVE

The current study aimed to determine the relationship between chronic kidney disease (CKD) and major 12-month outcomes for patients with in-hospital treatment for symptomatic peripheral arterial occlusive disease (PAOD).

METHODS

An analysis of the prospective longitudinal multicentric cohort study with 12-month follow-up was conducted including patients who underwent endovascular or open surgery for symptomatic PAOD at 35 German vascular centres (initial study protocol: NCT03098290). Severity of CKD was grouped into four stages combining information about the estimated glomerular filtration rate (eGFR) at baseline and dialysis dependency. Outcomes included overall mortality as well as the two composite endpoints of amputation or death, and of major cardiovascular events (MACE). 12-month incidences and adjusted hazard ratios were estimated using the Kaplan-Meier function and Cox proportional hazard models.

RESULTS

A total of 4354 patients (32% female, 69 years mean age, 68% intermittent claudication, 69% percutaneous endovascular revascularisation) were included and followed for 244 days in median. Thereof, 22% had any CKD and 5% had end stage kidney disease (ESKD) at baseline. The 12-month overall mortality rate was 3.6% (95% CI 2.3-4.9) with 96 events in the entire cohort: 147 were amputated or died (5.3%, 95% CI 5.2-5.3), and 277 had a MACE (9.5%, 95% CI 9.4-9.5). When compared with patients without kidney disease, ESKD was significantly associated with overall mortality (HR 1.9; 95% CI 1.1-3.5), amputation or death (HR 2.4; 95% CI 1.4-4.1), and MACE (HR 2.0; 95% CI 1.3-3.2).

CONCLUSIONS

In the current study on mid-term outcomes after invasive revascularisation for symptomatic PAOD, one out of five patients suffered from any CKD while those few with ESKD had twice the odds of death, of amputation or death, and of major adverse cardiovascular events after twelve months. These results emphasise that concomitant CKD and its impact on outcomes should be considered by severity while mild and moderate grades should not lead to ineffectual treatment strategies.

Vorhersage von schweren Blutungsereignissen bei Patienten mit peripherer arterieller Verschlusskrankheit: Der OAC3-PAD-Risikoscore

Obwohl Patient:innen mit einer peripheren arteriellen Verschlusskrankheit (PAVK) aufgrund ihres Komorbiditäts- und Risikoprofils ein insgesamt erhöhtes Blutungsrisiko aufweisen, standen bisher keine validierten Werkzeuge zur Vorhersage des Blutungsrisikos zur Verfügung. Erschwerend kommt hinzu, dass viele randomisierte und kontrollierte Studien zu antithrombotischen Therapien Patient:innen mit erhöhtem Blutungsrisiko ausgeschlossen haben. Anhand von Routinedaten der Krankenkasse wurde mittels Verfahren des maschinellen Lernens ein pragmatisches Vorhersagemodell entwickelt und intern validiert. Mit dem OAC³-PAD-Risikoscore wurden acht Variablen identifiziert, die das Risiko von schweren Blutungsereignissen innerhalb eines Jahres nach stationärer Behandlung der PAVK vorhersagen können. Dieser Risikoscore kann dabei helfen, eine patientenzentrierte Risiko-Nutzen-Abwägung durchzuführen, um das maximale Potenzial aus den verfügbaren antithrombotischen Therapiestrategien zu schöpfen.