Temporal Changes in Secondary Prevention and Cardiovascular Outcomes After Revascularization for Peripheral Arterial Disease in Denmark: A Nationwide Cohort Study

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.

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.

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.

An audit of secondary prevention for peripheral arterial disease in primary care - scope for improved collaboration between vascular surgery and general practitioners

BACKGROUND

Symptomatic peripheral arterial disease (PAD) is a common cause for referral from primary care to vascular surgery. Best medical therapy (BMT), encompassing anti-platelets, statins, smoking cessation, blood pressure and glycaemic control, is a cornerstone of PAD management. However, these easily modifiable risk factors are often left unaddressed between referral and clinic review.

METHODS

A prospective audit of electronic 'Healthlink' referrals by GPs to the vascular department for symptomatic PAD between July 2021 and June 2022 was performed. Referrals were individually reviewed for demographics, symptoms, medical history, smoking status and medications. An information leaflet on BMT was posted to all GP practices in the Soalta region as part of an educational intervention, with plans to re-audit after 6 months.

RESULTS

One-hundred-and-seventy referrals were analysed. The median age was 68.5 years (range 33-94) and 69% (n = 117) were male. The typical vasculopath comorbidity profile was noted. Fifty-two percent (n = 88) were referred with claudication-type pain and 25% (n = 43) with critical limb ischaemia (CLI). Twenty-eight percent (n = 33) were active smokers and 31% (n = 36) had no smoking status documented. Regarding BMT, only 34.5% (n = 40) and 52% (n = 60) were on anti-platelets and statins, respectively. Suspected CLI was not significantly associated with BMT prescription at referral (p = 0.664). Only eleven referral letters mentioned risk factor optimisation.

CONCLUSIONS

Our first-cycle results identified significant scope for improvement in community-based risk factor modification for PAD referrals. We aim to continue supporting and educating our colleagues that effective medical management can start safely in primary care and further explore the barriers preventing this.

Epidemiological Trends and Projections of Incidence, Prevalence, and Disease Related Mortality Associated With Peripheral Arterial Disease: Observations Using Nationwide Danish Data

OBJECTIVE

Peripheral arterial disease (PAD) trends remain unclear because contemporary data are sparse and conflicting. This nationwide cohort study quantified changes in PAD incidence, prevalence, and all cause mortality, and projected prevalence development through to 2040.

METHODS

Population based registries covering the entire Danish population aged ≥ 40 years from 2000 to 2018 were linked to assess trends in PAD incidence, prevalence, and all cause mortality, overall and by sex and age groups. Based on observed trends in incidence and mortality, and estimated future annual age distribution and population mortality, the PAD prevalence through to 2040 was projected.

RESULTS

The Danish population aged 40 - 99 years in 2000 - 2018 included 4 811 281 individuals, among whom 145 870 incident PAD diagnoses were identified. The age and sex standardised PAD incidence decreased from 2.26 per 1 000 person years in 2000 to 1.65 in 2018 (incidence RR 0.74, 95% CI 0.72 - 0.77). The incidence was approximately 20% higher in men than women but declined similarly over time. Concurrently, PAD prevalence in the Danish adult population increased from 1.3% to 1.6% (prevalence ratio 1.28, 95% CI 1.26 - 1.30). Among patients aged ≥ 80 years, the prevalence reached 5.7% in women and 7.9% in men. The age and sex standardised annual mortality among patients with PAD decreased from 9.8% in 2000 to 7.2% in 2018 (mortality ratio 0.75, 95% CI 0.72 - 0.78). Projections of PAD prevalence demonstrated that the rising PAD prevalence will continue until around 2030, followed by a decline towards 2040. Among individuals aged ≥ 80 years, the prevalence was projected to plateau at 8.9% for men and 6.2% for women before declining.

CONCLUSION

Within an unselected nationwide population, the incidence and all cause mortality of PAD have declined over the last two decades. Concurrently, prevalence increased and is projected to increase further over the coming decade, emphasising the growing burden of this common atherosclerotic disease in ageing populations.

Diabetes- versus smoking-related thrombo-inflammation in peripheral artery disease

Peripheral artery disease (PAD) is a major health problem with increased cardiovascular mortality, morbidity and disabling critical limb threatening ischemia (CLTI) and amputation. Diabetes mellitus (DM) and cigarette smoke are the main risk factors for the development of PAD. Although diabetes related PAD shows an accelerated course with worse outcome regarding complications, mortality and amputations compared with non-diabetic patients, current medical treatment does not make this distinction and includes standard antiplatelet and lipid lowering drugs for all patients with PAD. In this review we discuss the pathophysiologic mechanisms of PAD, with focus on differences in thrombo-inflammatory processes between diabetes-related and smoking-related PAD, and hypothesize on possible mechanisms for the progressive course of PAD in DM. Furthermore, we comment on current medical treatment and speculate on alternative medical drug options for patients with PAD and DM.

Peripheral vascular remodeling during ischemia

About 230 million people worldwide suffer from peripheral arterial disease (PAD), and the prevalence is increasing year by year. Multiple risk factors, including smoking, dyslipidemia, diabetes, and hypertension, can contribute to the development of PAD. PAD is typically characterized by intermittent claudication and resting pain, and there is a risk of severe limb ischemia, leading to major adverse limb events, such as amputation. Currently, a major progress in the research field of the pathogenesis of vascular remodeling, including atherosclerosis and neointima hyperplasia has been made. For example, the molecular mechanisms of endothelial dysfunction and smooth muscle phenotype switching have been described. Interestingly, a series of focused studies on fibroblasts of the vessel wall has demonstrated their impact on smooth muscle proliferation and even endothelial function via cell-cell communications. In this review, we aim to focus on the functional changes of peripheral arterial cells and the mechanisms of the pathogenesis of PAD. At the same time, we summarize the progress of the current clinical treatment and potential therapeutic methods for PAD and shine a light on future perspectives.

Revascularisation for Symptomatic Peripheral Artery Disease: External Applicability of the VOYAGER PAD Trial

OBJECTIVE

In the VOYAGER PAD trial, rivaroxaban 2.5 mg plus aspirin significantly reduced the primary composite efficacy outcome of acute limb ischaemia, major amputation, myocardial infarction, ischaemic stroke, or cardiovascular death compared with aspirin alone. However, patients enrolled in the trial may not reflect patients encountered in daily clinical practice. This study described the proportion of patients eligible for VOYAGER PAD within the nationwide Danish Vascular Registry (DVR), reasons for ineligibility, and outcomes according to eligibility.

METHODS

In total, 32 911 patients who underwent lower extremity revascularisation for symptomatic peripheral arterial disease (PAD) in the DVR (2000-2016) were identified. Trial inclusion and exclusion criteria were applied, and the three year cumulative incidence of primary and secondary trial outcomes was estimated.

RESULTS

Altogether, 27.1% of patients with PAD in the DVR were "VOYAGER eligible". Of those not included, 30.7% had at least one exclusion criterion ("VOYAGER excluded"), and an additional 42.3% did not fulfil the inclusion criteria ("VOYAGER not included"). The main reasons for exclusion were atrial fibrillation (32.3%), poorly regulated hypertension (20.6%), requirement for long term dual antiplatelet therapy (10.9%), cytochrome P450 inhibitors or inducers (9.7%), and renal failure (9.3%). The three year rate of the primary efficacy outcome was 10.08 per 100 person years among the "VOYAGER eligible", 16.32 among "VOYAGER excluded", and 6.98 among the "VOYAGER not included". For the primary safety outcome of thrombolysis in myocardial infarction (TIMI) major bleeding, rates were 2.24, 3.76, and 1.17, respectively. Rates of secondary endpoints were also consistently lower for patients who did not meet the inclusion criteria (predominantly due to central aorto-iliac procedures) and highest for "VOYAGER excluded" patients. "VOYAGER eligible" patients experienced a higher cumulative incidence of most endpoints than patients enrolled in the control arm of the VOYAGER PAD trial.

CONCLUSION

Among patients in routine clinical practice, 27.1% were eligible for the VOYAGER PAD trial. These patients were older, had more severe vascular symptoms, higher bleeding risk, and worse prognosis than trial participants.

Statins and Peripheral Arterial Disease: A Narrative Review

Peripheral arterial disease (PAD) is a highly prevalent atherosclerotic condition. In patients with PAD, the presence of intermittent claudication leads to a deterioration in quality of life. In addition, even in asymptomatic cases, patients with PAD are at high risk of cardiac or cerebrovascular events. Treatment of PAD is based on lifestyle modifications; regular exercise; smoking cessation; and control of cardiovascular risk factors, including hypercholesterolemia. A growing number of studies have shown that statins reduce cardiovascular risk and improve symptoms associated with PAD. Current guidelines recommend the use of statins in all patients with PAD in order to decrease cardiovascular events and mortality. However, the prescribing of statins in patients with PAD is lower than in those with coronary heart disease. This review provides relevant information from the literature that supports the use of statins in patients with PAD and shows their potential benefit in decreasing lower limb complications as well as cardiovascular morbidity and mortality.

Low-dose rivaroxaban plus aspirin in older patients with peripheral artery disease undergoing acute limb revascularization: insights from the VOYAGER PAD trial

AIMS

In this secondary analysis of the VOYAGER trial, rivaroxaban 2.5 mg twice/day plus aspirin 100 mg/day was assessed in older adults. Advanced age is associated with elevated bleeding risk and unfavourable net benefit for dual antiplatelet therapy in chronic coronary artery disease. The risk-benefit of low-dose rivaroxaban in patients ≥75 years with peripheral artery disease (PAD) after lower extremity revascularization (LER) has not been described.

METHODS AND RESULTS

The primary endpoint was a composite of acute limb ischaemia, major amputation, myocardial infarction, ischaemic stroke, or cardiovascular death. The principal safety outcome was thrombolysis in myocardial infarction (TIMI) major bleeding analysed by the pre-specified age cut-off of 75 years. Of 6564 patients randomized, 1330 (20%) were >75 years. Absolute 3-year Kaplan-Meier cumulative incidence rates for primary efficacy (23.4% vs. 19.0%) and safety (3.5% vs. 1.5%) endpoints were higher in elderly vs. non-elderly patients. Efficacy of rivaroxaban (P-interaction 0.83) and safety (P-interaction 0.38) was consistent irrespective of age. The combination of intracranial and fatal bleeding was not increased in patients >75 years (2 rivaroxaban vs. 8 placebo). Overall, benefits (absolute risk reduction 3.8%, number needed to treat 26 for the primary endpoint) exceeded risks (absolute risk increase 0.81%, number needed to harm 123 for TIMI major bleeding).

CONCLUSION

Patients ≥75 years with PAD are at both heightened ischaemic and bleeding risk after LER. No excess harm with respect to major, intracranial or fatal bleeding was seen in older patients yet numerically greater absolute benefits were observed. This suggests that low-dose rivaroxaban combined with aspirin should be considered in PAD after LER regardless of age.

Antithrombotic Therapy in Patients with Peripheral Artery Disease: A Focused Review on Oral Anticoagulation

Peripheral artery disease (PAD) is a major cause of morbidity and mortality but it is usually underdiagnosed and undertreated. Patients with PAD present dysregulated procoagulant, anticoagulant, and fibrinolytic pathways leading to arterial and venous thrombosis. The risk of several ischemic-related complications could be mitigated with appropriate antithrombotic therapy, which plays a central role in all types of PAD. For years, antiplatelets have been indicated in patients with symptomatic PAD or those who have undergone revascularization. Unfortunately, a non-negligible proportion of patients with PAD will suffer from adverse events during the follow-up, even despite proper medical therapies for the prevention of PAD complications. Thus, there is room for improving clinical outcomes in these patients. Given the implication of both, primary and secondary hemostasis in arterial thrombosis and the pathophysiology of PAD, the combination of antiplatelets and anticoagulants has emerged as a potential antithrombotic alternative to antiplatelets alone. In this narrative review article, we have highlighted the most recent evidence about antithrombotic therapy in PAD patients, with a special focus on oral anticoagulation. Certainly, COMPASS and VOYAGER PAD trials have shown promising results. Thus, rivaroxaban in combination with aspirin seem to reduce cardiovascular outcomes with a similar bleeding risk compared to aspirin alone. Nevertheless, results from real-world studies are needed to confirm these observations, and other trials will provide novel evidence about the safety and efficacy of emerging anticoagulant agents.