Lipid-lowering treatment in peripheral artery disease

Analysis and Visualization of Confounders and Treatment Pathways Leading to Amputation and Non-Amputation in Peripheral Artery Disease Patients Using Sankey Diagrams: Enhancing Explainability

Background/Objectives: This study uses Sankey diagrams to analyze treatment pathways in patients with peripheral artery disease (PAD), which is a vascular condition characterized by atherosclerotic occlusion of the arteries, particularly in the lower limbs, affecting up to 14% of the general population. This study focuses on the treatment pathways that lead to amputation versus those that do not, utilizing the STARR dataset and the All of Us dataset. Methods: The study utilized Sankey diagrams to visualize treatment pathways, highlighting the progression from initial treatments to outcomes. Odds ratio analysis was performed to quantify the association between treatment pathways and outcomes. Recognizing potential confounders, analyses were conducted by filtering patients with PAD into subgroups based on these coexisting conditions. Sankey diagrams were then generated for each sub-cohort to visualize treatment pathways. Results: Pathways including antiplatelet and lipid-lowering treatments accounted for 56% of non-amputation cases in the STARR data and 50% in the All of Us data. Amputation pathways frequently included revascularization procedures, representing 15% of amputations in the STARR data and 20% in the All of Us data. Confounder analysis revealed that most amputated PAD patients were over 50 years old and had one or more conditions, such as diabetes, hypertension, or hyperlipidemia. Conclusions: These visualizations provide insights into treatment pathways and their associations with outcomes in PAD patients, highlighting the potential impact of specific treatments on amputation and non-amputation cases. Future work should build on these findings by incorporating predictive models using machine learning techniques to further explore and quantify these relationships.

Lesion Localization and Limb Outcomes in Elderly Patients with and Without Type 2 Diabetes Mellitus Who Undergo Atherectomy-Assisted Endovascular Revascularization due to Symptomatic Peripheral Artery Disease

Background/Objectives: Type 2 diabetes mellitus (T2DM) represents a major risk factor for peripheral artery disease (PAD). We aimed to evaluate the impact of T2DM on lesion localization and complexity, clinical presentation by Rutherford categories, and limb outcomes in elderly patients with symptomatic PAD undergoing endovascular revascularization. Methods: Five hundred consecutive patients with symptomatic infra-inguinal PAD who underwent rotational atherectomy-assisted endovascular revascularization were included. PAD clinical presentation and lesion localization were recorded. The primary endpoints were clinically driven target lesion revascularization (CD-TLR) and major amputation rates during follow-up. Results: Overall, 245/500 (49.0%) patients had T2DM, whereas 179 (35.8%) presented with lifestyle limiting claudication and 321 (64.2%) with critical limb-threatening ischemia (CLTI). Median age was 78.0 (IQR = 70.0-84.0) years, and 201 (40.2%) patients were female. The presence of T2DM was significantly more frequent in patients with CLTI vs. those with claudication (58.6 vs. 31.8%; p < 0.001). Furthermore, the percentage of patients with below-the-knee (BTK) lesions was significantly higher in patients with vs. without T2DM (40.7 vs. 27.5%, p = 0.0002). During median follow-up of 21.9 (IQR = 12.8-28.8) months, CD-TLR rates were similar in patients with vs. without T2DM (HR = 1.2, 95%CI = 0.8-2.0, p = 0.39). However, patients with T2DM had a ~5.5-fold increased risk for major above-the-ankle amputation (HR = 5.5, 95%CI = 1.6-19.0, p = 0.007). After adjustment for age, gender, lesion complexity, and calcification, T2DM remained predictive for major amputation (p = 0.04). Conclusions: T2DM is more frequently associated with CLTI, BTK-PAD, and amputations despite successful endovascular revascularization. More stringent surveillance of patients with PAD and T2DM is warranted to prevent atherosclerosis-related complications.

Inclisiran, Low-Density Lipoprotein Cholesterol and Lipoprotein (a)

Dyslipidemia treatment is of major importance in reducing the risk of atherosclerotic cardiovascular disease (ASCVD), which is still the most common cause of death worldwide. During the last decade, a novel lipid-lowering drug category has emerged, i.e., proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors. Apart from the two available anti-PCSK9 monoclonal antibodies (alirocumab and evolocumab), other nucleic acid-based therapies that inhibit or "silence" the expression of PCSK9 are being developed. Among them, inclisiran is the first-in-class small interfering RNA (siRNA) against PCSK9 that has been approved by both the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for the treatment of hypercholesterolemia. Importantly, inclisiran therapy may improve low-density lipoprotein cholesterol (LDL-C) target achievement by offering a prolonged and significant LDL-C-lowering effect with the administration of only two doses per year. The present narrative review discusses the ORION/VICTORION clinical trial program that has been designed to investigate the impact of inclisiran on atherogenic lipoproteins and major adverse cardiac events in different patient populations. The results of the completed clinical trials are presented, focusing on the effects of inclisiran on LDL-C and lipoprotein (a) (Lp(a)) levels as well as on other lipid parameters such as apolipoprotein B and non-high-density lipoprotein cholesterol (non-HDL-C). Ongoing clinical trials with inclisiran are also discussed.

Real world data from a multi-centre study on the effects of cilostazol on pain symptoms and walking distance in patients with peripheral arterial disease

OBJECTIVE

to assess the effects of cilostazol on pain-free walking distance in PAD patients with IC at 3 and 6 months in a real world, prospective, observational study. We included 1015 PAD patients presenting with IC (71.3% men, 93.5% white, mean age 69.2 ± 8.7 years). Patients were followed up for 6 months by their physicians.

RESULTS

Cilostazol significantly increased pain-free walking distance by a median of 285 and 387 m at 3 and 6 months, respectively (p < 0.01 for all comparisons). This effect was significant for patients 50-74 years (but not for those aged ≥ 75 years) and independent of smoking status, changes in physical activity, comorbidities and concomitant medication for PAD (i.e., acetylsalicylic acid and clopidogrel). Furthermore, significant reductions were observed in systolic (from 139 ± 16 to 133 ± 14 mmHg; p < 0.001) and diastolic blood pressure (from 84 ± 9 mmHg to 80 ± 10 mmHg; p < 0.001). Smoking cessation and increased physical activity were reported by the majority of participants. In conclusion, cilostazol was shown to safely decrease pain symptoms and improve pain-free walking in PAD patients with IC in a real world setting. Benefits also occurred in terms of BP and lifestyle changes.

Mortality Risk Assessment in Peripheral Arterial Disease-The Burden of Cardiovascular Risk Factors over the Years: A Single Center's Experience

Atherosclerosis is the basis of the cardiovascular continuum in peripheral artery disease (PAD) patients. Limiting functional decline and increasing quality of life are the main objectives for these patients. We conducted a prospective cohort study on 101 patients with PAD admitted to a single center in Northeast Romania. We used an index score to evaluate the 10-year mortality risk assessment and based on the scores we divided the patients into two groups: a low and low-intermediate risk mortality group (49 cases, 48.5%) and a high-intermediate and high-risk mortality group (52 cases, 51.5%). We analyzed demographics, comorbidities, clinical and paraclinical parameters and we aimed to identify the parameters associated with an unfavorable prognosis. Patients in the high-intermediate and high-risk mortality group were associated more with cardiovascular risk factors. Hypertension (p = 0.046), dyslipidemia (p < 0.001), diabetes mellitus (p < 0.001), and tobacco use (p = 0.018) were statistically significant factors. Lipid profile (low-density lipoprotein cholesterol, p = 0.005) and fasting blood glucose (p = 0.013) had higher mean serum values in the high-intermediate and high-risk mortality group, with a positive correlation between them and the ankle-brachial index value (p = 0.003). A multidisciplinary assessment and, especially, correction of associated cardiovascular risk factors prevent complications, and thus, improve the prognosis in the medium and long term.

Statins and statin intensity in peripheral artery disease

Background: Peripheral artery disease (PAD) affects more than 202 million people worldwide. Several studies have shown that patients with PAD are often undertreated, and that statin utilization is suboptimal. European and American guidelines highlight statins as the first-line lipid-lowering therapy to treat patients with PAD. Our objective with this meta-analysis was to further explore the impact of statins on lower extremities PAD endpoints and examine whether statin dose (high vs. low intensity) impacts outcomes. Patients and methods: We performed a systematic review and meta-analysis according to the PRISMA guidelines. Any study that presented a comparison of use of statins vs. no statins for PAD patients or studies comparing high vs. low intensity statins were considered to be potentially eligible. We excluded studies with only critical limb threatening ischemia (CLTI) patients. The Medline (PubMed) database was searched up to January 31, 2021. A random effects meta-analysis was performed. Results: In total, 39 studies and 275,670 patients were included in this meta-analysis. In total, 136,025 (49.34%) patients were on statins vs. 139,645 (50.66%) who were not on statins. Statin use was associated with a reduction in all cause-mortality by 42% (HR: 0.58, 95% CI: 0.49-0.67, p<0.01) and cardiovascular death by 43% (HR: 0.57, 95% CI: 0.40-0.74, p<0.01). Statin use was associated with an increase in amputation-free survival by 56% (HR: 0.44, 95% CI: 0.30-0.58, p<0.01). The risk of amputation and loss of patency were reduced by 35% (HR: 0.65, 95% CI: 0.41-0.89, p<0.01) and 46% (HR: 0.54, 95% CI: 0.34-0.74, p<0.01), respectively. Statin use was also associated with a reduction in the risk of major adverse cardiovascular events (MACE) by 35% (HR: 0.65, 95% CI: 0.51-0.80, p<0.01) and myocardial infarction rates by 41% (HR: 0.59, 95% CI: 0.33-0.86, p<0.01). Among patients treated with statins, the high-intensity treatment group was associated with a reduction in all cause-mortality by 36% (HR: 0.64, 95% CI: 0.54-0.74, p<0.01) compared to patients treated with low intensity statins. Conclusions: Statin treatment among patients with PAD was associated with a statistically significant reduction in all-cause mortality, cardiovascular mortality, MACE, risk for amputation, or loss of patency. Higher statin dose seems to be associated with improved outcomes.

Novel cholesterol efflux assay using immobilized liposome-bound gel beads: Confirmation and improvement for application in clinical laboratory

OBJECTIVES

Cholesterol efflux capacity (CEC), an atheroprotective function of high-density lipoprotein, is expected to be a potential biomarker for cardiovascular disease. However, CEC has not been widely introduced for application in clinical laboratories because of the complexity of the conventional CEC assay using cells and radioactive materials. Previously, we developed a novel CEC assay using immobilized liposome-bound gel beads (ILG), which solves these issues. We aimed to confirm the validation and further improve the ILG method for application in the clinical setting.

METHODS

Cholesterol efflux capacity values by the ILG method assayed for shorter incubation time (4 h) were compared to those assayed for 16 h (our previous ILG method). To investigate a reference material that can correct the variation between ILG manufacturing lots, bovine serum albumin, human gamma-globulins, and globulin complexes were evaluated. CEC values were also estimated in plasmas obtained with different anticoagulants, serum treated with freeze-thaw cycles, and serum mixed with several interference substances.

RESULTS

The CEC of 4- and 16-h incubation times were well correlated. Globulin complexes may be used as a reference material. Plasma can be used as the specimen. The serum and stored temperature of the specimen did not largely affect CEC. Hemoglobin and chyle did not have an effect on CEC, whereas high-bilirubin serum showed elevated CEC. The effect of bilirubin was nearly canceled by subtracting basal fluorescence intensity.

CONCLUSIONS

Present ILG method further fulfills some requirements for application in clinical laboratory. Using this reliable simple method, evaluation for clinical significance of CEC is expected.

High Apolipoprotein E Levels Predict Adverse Limb Events in Patients with Peripheral Artery Disease Due to Peripheral Artery Disease Undergoing Endovascular Treatment and On-Statin Treatment

Little is known about the association between limb prognosis in peripheral artery disease and apolipoprotein E (apoE). We evaluated the long-term impact of apoE on adverse limb events in patients with intermittent claudication receiving statin treatment.A total of 218 consecutive patients (mean age, 73 ± 8 years; 81% men) with intermittent claudication who underwent their first intervention between 2009 and 2020 were included in this study. All patients had achieved LDL-C < 100 mg/dL on statin treatment and were divided into two groups based on the apoE value (≥ 4.7 or < 4.7 mg/dL). We evaluated the incidence of major adverse limb events (MALEs), including vessel revascularization and limb ischemia development.A total of 39 and 179 patients were allocated to the higher and lower apoE groups, respectively. Compared to the lower apoE group, the higher apoE group had a significantly higher total cholesterol level, triglyceride level, and non-high-density lipoprotein cholesterol level. During the median follow-up period of 3.6 years, 30 patients (13.8%) developed MALEs. Kaplan-Meier analysis revealed that the cumulative incidence of MALEs in the higher apoE group was significantly higher than that in the lower apoE group (44.0% versus 21.6%, log-rank test, P = 0.002). During multivariable Cox hazard analysis, higher apoE level (≥ 4.7 mg/dL) (hazard ratio, 2.61; 95% confidence interval, 1.18-5.70, P = 0.019) was the only strong independent predictor of MALEs.ApoE levels could be a strong predictor and residual risk for long-term limb prognosis in patients with intermittent claudication and achieving LDL-C < 100 mg/dL with statin treatment.

Contrast-induced nephropathy in non-cardiac vascular procedures, a narrative review: Part 2

This is Part 2 of a narrative review summarizing the literature on CIN after non-cardiac vascular diagnostic or therapeutic procedures, focusing on peripheral artery disease (PAD) and renal artery stenosis (RAS). Part 1 discussed CIN in relation to aortic aneurysms and carotid stenosis. We comment on the incidence, biomarkers, risk factors, and consequences of CIN in patients with PAD or RAS, as well as on strategies to prevent CIN. Future perspectives in the field of CIN in relation to non-cardiac vascular procedures are also considered.

Risk factors in acute diabetic foot syndrome: analysis of 75 consecutive patients referred to a tertiary center in Modena, Italy

Aim: Diabetic foot syndrome (DFS) is a complication of diabetes in which the presence of infections, ulceration and/or destruction of deep tissue associated with neuropathy, peripheral atherosclerosis and comorbidity affect the prognosis, the need for limb amputation and quality of life. Purpose of the present study is to report the features of patients with acute DFS admitted to our Diabetic Foot Unit tertiary Center in 2019. Methods: In all patients admitted, the approach was performed through a multidisciplinary team (Diabetic Foot Care Team) and described in a specific diagnostic-therapeutic-assistance program. Criteria of inclusion were presence of sepsis and/or suspected osteomyelitis and/or critical limb ischemia. Clinical features and interventions performed were registered. Primary endpoints were mortality and amputation (major, minor). Secondary endpoints were length of hospitalization, type of revascularization and duration of antibiotic therapy. Results: Among 75 consecutive patients (mean age 70.9 years) enrolled, prevalence of acute DFS was higher among men (M/F 3:1). Poor glycemic control [mean hemoglobin A1c (HbA1c) 67.9 ± 22.3 mmol/mol], long duration of diabetes (mean 19 ± 16.3 years), high low-density lipoprotein-cholesterol (mean 89.5 ± 45.1 mg/ dL) and obesity (mean Body Mass Index 30.2 ± 7.6 kg/m2) were common. Diabetes-related complications as peripheral arterial disease (PAD) (76%), ischemic heart disease (48%), retinopathy (40.5%), hepatic steatosis (50%), heart failure (17.8%) were present. During hospitalization, 21 subjects (28.4%) underwent lower limb amputations (overall rate of major amputation 4%), and 41.3% underwent percutaneous angioplasty. Long period of hospitalization (18.4 ± 7.9 days) and prolonged antibiotic therapy (23.9 ± 15.9 days) were observed. Major amputation was associated with C-reactive protein > 6.5 mg/dL (P = 0.03), osteomyelitis (P = 0.001), prior insulin therapy (P = 0.015). Conclusions: Male sex, co-morbidity, PAD, systemic inflammation and poor glycemic control are major features of acute hospitalized DFS. An approach through a multidisciplinary team is recommended in order to treat vascular and extra-vascular complications aimed at reducing mortality and at improving quality of life.

The modulation of PCSK-9 and GAGs by 10-dehydrogingerdione and pentoxifylline in hyperlipidemic rabbits

The hypolipidemic effect of 10-DHGD was previously reported owing to its anti-inflammatory and anti-oxidant properties. We further investigated the anti-inflammatory role of 10-DHGD in modulating atherogenicity by targeting proproteinconvertasesubtilisinkexin-9 (PCSK-9). Rabbits fed high cholesterol diet (HCD) containing 0.2% w/w cholesterol for12-weeks received either 10-DHGD (10-mg/kg), pentoxifylline (PTX, 40-mg/kg) or their combination concurrently with HCD. Lipid profile, serum PCSK-9, macrophage migration inhibitory factor (MIF), aorta tumor necrosis factor- alpha (TNF-α) and glycosaminoglycans (GAGs) were measured. Atherogenicity and increased PCSK-9, MIF and TNF-α and GAGs (p < 0.001) was proved HCD-fed rabbits. The concurrent administration of 10-DHGD or PTX with HCD feeding prevented this atheogenicity by modulating the release of PCSK-9, inflammatory markers and GAGs. The combined PTX and 10-DHGD in HCD fed rabbits not only lowered hyperlipidemia, but also targeted arterial inflammation to a better extent. In conclusion PTX and 10-DHGD can prevent hyperlipidemia and associated inflammatory process modifying factors predisposing to atherosclerosis.

Lipid management in people with peripheral artery disease

PURPOSE OF REVIEW

To summarize recent data on the role of dyslipidaemia and the benefit from managing this in people with disease of the abdominal aorta and its peripheral branches (peripheral artery disease, PAD).

RECENT FINDINGS

Findings from the Further Cardiovascular Outcomes Research with Proprotein convertase subtilisin/kexin type 9 (PCSK9) Inhibition in Subjects with Elevated Risk (FOURIER) trial demonstrate the benefit of intensely lowering low-density lipoprotein-cholesterol (LDL-c) in people with PAD to substantially reduce the incidence of major cardiovascular events (MACE; myocardial infarction, stroke or cardiovascular death) and major adverse limb events (MALE). Despite the evidence of substantial benefits from lowering LDL-c, the uptake of drug therapies to lower LDL-c remains sub-optimal in people with PAD.

SUMMARY

Effective methods to educate physicians and patients on best medical management are needed. Further research is needed to examine the benefit of LDL-c lowering and other lipid therapies for PAD-specific problems like abdominal aortic aneurysm progression and walking impairment. Other novel lipid therapies, such as those that lower lipoprotein (a), maybe particularly beneficial to people with PAD given the evidence indicating high concentrations in this population and the high incidence of MACE in these individuals.

Sodium-glucose co-transporter-2 inhibitors (SGLT2i) use and risk of amputation: an expert panel overview of the evidence

Sodium-glucose co-transporter-2 inhibitors (SGLT2i) are oral antidiabetic agents that exert their glucose-lowering effect by increasing renal excretion of glucose. These drugs have been reported to beneficially affect cardiovascular (CV) and renal outcomes. However, concerns have recently been raised in relation to increased risk of lower-extremities amputation with canagliflozin and it remains unclear whether and to what extent this side effect could also occur with other SGLT2i. The present expert panel overview focuses on the three SGLT2i available and widely used in the US and Europe, i.e. empagliflozin, canagliflozin and dapagliflozin and only refers briefly to other SGLT2i for which less data are available. The results of large CV outcome trials with these SGLT2i are presented, focusing specifically on the data in relation to amputation risk. The potential pathophysiological mechanisms involved in this side effect are discussed. Furthermore, available data reporting amputation cases in SGLT2i users are critically reviewed. The expert panel concludes that, based on current data, increased amputation risk seems to be related only to canagliflozin, thus representing a drug-effect rather than a SGLT2i class-effect. The exact pathways underlying this drug-induced adverse event, possibly related to off-target drug effects rather than SGLT2 inhibition per se, should be elucidated in future studies. Continuous monitoring and pharmacovigilance is necessary and head to head trials would also be essential to provide definitive conclusions.

Lipids: a personal view of the past decade

The past decade has witnessed considerable progress in the field of lipids. New drugs have been "rapidly" developed and some of these drugs have already been evaluated in event-based large trials. This evidence has led to the guidelines recommending new, more aggressive treatment goals for low-density lipoprotein cholesterol (LDL-C) levels. Although LDL-C remains the principal goal for cardiovascular disease (CVD) risk reduction, there has also been considerable interest in other lipid variables, such as high-density lipoprotein cholesterol, triglycerides, and lipoprotein(a). Statin intolerance is now considered a very important topic in daily clinical practice. This has resulted in more attention focusing on non-statin drugs [e.g., ezetimibe and proprotein convertase subtilisin/kexin 9 (PCSK9) inhibitors] and statin-related side effects. The latter mainly involve muscles, but there is also a need to consider other adverse effects associated with statin use (e.g., new onset diabetes). New specific areas of statin use have attracted interest. For example, statin-loading before procedures (e.g., coronary stenting), the prevention of stroke, and the treatment of non-alcoholic fatty liver disease (NAFLD). Statins will remain the most widely used drugs to treat dyslipidaemia and decrease CVD risk. However, we also need to briefly consider some other lipid-lowering drugs, including those that may become available in the future.

Genetic Markers for Coronary Artery Disease

Coronary artery disease (CAD) and myocardial infarction (MI) are recognized as leading causes of mortality in developed countries. Although typically associated with behavioral risk factors, such as smoking, sedentary lifestyle, and poor dietary habits, such vascular phenotypes have also long been recognized as being related to genetic background. We review the currently available data concerning genetic markers for CAD in English and non-English articles with English abstracts published between 2003 and 2018. As genetic testing is increasingly available, it may be possible to identify adequate genetic markers representing the risk profile and to use them in a clinical setting.