The risk of peripheral artery disease in older adults - seven-year results of the getABI study

Does residential exposure to air pollutants influence mortality and cardiovascular morbidity of older people from primary care?

BACKGROUND

Diseases affecting the cardiovascular system are the most common cause of death worldwide. In addition to classical risk factors of atherosclerosis, long-term exposure to particulate matter with particles of size up to 10 µm (PM10) in the atmosphere has become an increasing focus of scientific attention in recent decades. This study analyses the associations of residential-associated air pollutants exposure with all-cause mortality and cardiovascular morbidity of older patients in a primary care setting.

METHODS

The "German Epidemiological Trial on Ankle Brachial Index" (getABI) is a prospective cohort study that started in 2001 and included 6,880 primary care patients with a follow-up of 7 years. The PM10 and nitrogen dioxide (NO₂) concentrations in the atmosphere are interpolated values from the study "Mapping of background air pollution at a fine spatial scale across the European Union". The primary outcome in this analysis is death of any cause, a secondary outcome is onset of PAD. Cox proportional hazards regression was used in a two-step modelling, the first step with basic adjustment only for age, sex, and one or more air pollutants, the second with additional risk factors.

RESULTS

A total of 6,819 getABI patients were included in this analysis. 1,243 of them died during the study period. The hazard ratio (HR) (1.218, 95%-confidence-interval (CI) 0.949-1.562) for the risk of death from any cause was elevated by 22% per 10 µg/m³ increase of PM10 in the fully adjusted model, although not statistically significant. Increased PM10 exposure in combination with the presence of PAD had a significantly increased risk (HR = 1.560, 95%-CI: 1.059-2.298) for this endpoint in the basic adjustment, but not in the fully adjusted model. 736 patients developed peripheral artery disease (PAD) during the course of the study. There was no association of air pollutants and the onset of PAD.

CONCLUSIONS

Our analysis renders some hints for the impact of air pollutants (PM10, NO₂, and proximity to major road) on mortality. Interaction of PAD with PM10 was found. There was no association of air pollutants and the onset of PAD.

TRIAL REGISTRATION

German Clinical Trials Register: DRKS00029733 (19/09/2022).

Selected Plant-Derived Polyphenols as Potential Therapeutic Agents for Peripheral Artery Disease: Molecular Mechanisms, Efficacy and Safety

Vascular diseases, such as peripheral artery disease (PAD), are associated with diabetes mellitus and a higher risk of cardiovascular disease and even death. Surgical revascularization and pharmacological treatments (mainly antiplatelet, lipid-lowering drugs, and antidiabetic agents) have some effectiveness, but the response and efficacy of therapy are overly dependent on the patient’s conditions. Thus, the demand for new cures exists. In this regard, new studies on natural polyphenols that act on key points involved in the pathogenesis of vascular diseases and, thus, on PAD are of great urgency. The purpose of this review is to take into account the mechanisms that lead to endothelium dysfunction, such as the glycoxidation process and the production of advanced glycation end-products (AGEs) that result in protein misfolding, and to suggest plant-derived polyphenols that could be useful in PAD. Thus, five polyphenols are considered, baicalein, curcumin, mangiferin, quercetin and resveratrol, reviewing the literature in PubMed. The key molecular mechanisms and preclinical and clinical studies of each selected compound are examined. Furthermore, the safety profiles of the polyphenols are outlined, together with the unwanted effects reported in humans, also by searching the WHO database (VigiBase).

Effects of Three Different Methods Defining Onset of Peripheral Artery Disease on the Assessments of Incidence and Important Predictors - Results from the German Epidemiological Trial on Ankle Brachial Index (getABI)

Purpose

The common definition of asymptomatic peripheral artery disease (PAD) by a single determination of the ankle brachial index (ABI) has some uncertainty due to measurement errors. This may impact estimates of PAD incidence and assessment of PAD risk factors. To investigate this issue, we used three methods to define asymptomatic PAD and made use of data from the German Epidemiological Trial on Ankle Brachial Index (getABI).

Patients and Methods

A total of 6,880 unselected subjects aged ≥65 years, enrolled by 344 trained general practitioners, had ABI assessments at baseline and four visits during follow-up. The first approach defined asymptomatic PAD onset as soon as a single ABI value was below 0.9 (single ABI). The second approach employed a regression method using all available ABI values (regression A), while for the third approach (regression B), an extended regression beyond the last valid ABI value for the observation time of the study was allowed. For each approach, we calculated PAD incidence rates and assessed the effect of important PAD predictors using multivariable Cox proportional hazards regression.

Results

The regression method A showed the lowest (25.0 events per 1,000 person years) and the single ABI method the highest incidence rate (41.2). The regression methods assigned greater impact to several risk factors of incident PAD. Using regression A, the hazard ratios (HR) of active smoking (2.36; 95% CI 1.92 to 2.90) and of diabetes (1.33; 95% CI 1.13 to 1.56), using regression B the HR of older age (1.72; 95% CI 1.50 to 1.97) were about twice as high as the corresponding HR of the single ABI approach.

Conclusion

Use of the single ABI method leads to higher PAD incidence rates and to lower impact of important PAD predictors compared to regression methods. For an alert risk factor management, multiple ABI determination may be useful.

Socioeconomic factors and the onset of peripheral artery disease in older adults

Background: As evidence concerning the impact of socioeconomic factors on the risk of peripheral artery disease (PAD) is sparse, we assessed the association of education and area-level factors (population density, type of municipality and local unemployment rate) on the onset of PAD in older adults. Patients and methods: The analysis used data of the getABI study, a prospective cohort study with seven years of follow-up. Onset of PAD was determined by ankle brachial index (<0.9) or PAD symptoms. Cox regression analysis was employed. Results: Out of 5,444 primary care attendees without PAD at baseline, there were 1,381 participants with PAD onset (cumulative observation time 31,739 years), yielding an event rate of 43.5 (0.95 confidence interval [0.95 CI] 41.2-45.8) per 1,000 person-years. Multivariable Cox regression analysis showed an association of PAD onset with low education (hazard ratio 1.29; 0.95 CI 1.14-1.46; P<0.001), high population density (0.93; 0.89-0.98; P=0.002), small cities (compared to large cities) (0.71; 0.53-0.96; P=0.027) and high local unemployment rate (1.04; 1.00-1.07; P=0.032). The impact of low education on PAD onset was higher for men (2.11; 1.64-2.72) than for women (1.22; 1.07-1.40) (interaction term P=0.013). Conclusions: Socioeconomic factors, education as well as area-level socioeconomic indicators, make independent contributions to PAD onset in older adults.

2D-Perfusion Angiography Using Carbon Dioxide (CO2): A Feasible Tool to Monitor Immediate Treatment Response to Endovascular Therapy of Peripheral Arterial Disease?

PURPOSE

Patients with peripheral arterial disease (PAD) or critical limb ischemia (CLI) require revascularization. Traditionally, endovascular therapy (EVT) is performed with iodinated contrast agent (ICM), which can provoke potential deterioration in renal function. CO2 is a safe negative contrast agent to guide vascular procedures, but interpretation of CO2 angiography is challenging. Changes in blood flow following iodine-aided EVT are assessable with 2D-perfusion angiography (2D-PA). The aim of this study was to evaluate 2D-PA as a tool to monitor blood flow changes during CO₂-aided EVT.

MATERIAL AND METHODS

2D-PA was performed before and after ten EVTs (nine stents; one endoprosthesis; 10/2012-02/2020) in nine patients (six men; 65 ± 10y) with Fontaine stage IIb (n = 8) and IV (n = 1). A reference ROI (ROI_INFLOW) was placed in the artery before the targeted obstruction and a target ROI (ROI_OUTFLOW) distally. Corresponding ROIs were used pre- and post-EVT. Time to peak (TTP), peak density (PD) and area under the curve (AUC) were computed. The reference/target ROI ratios (TTP_OUTFLOW/TTP_INFLOW; PD_OUTFLOW/PD_INFLOW; AUC_OUTFLOW/AUC_INFLOW) were calculated.

RESULTS

2D-PA was technically feasible in all cases. A significant increase of 82% in PD_OUTFLOW/PD_INFLOW (0.44 ± 0.4 to 0.8 ± 0.63; p = 0.002) and of 132% in AUC_OUTFLOW/AUC_INFLOW (0.34 ± 0.22 to 0.79 ± 0.59; p = 0.002) was seen. A trend for a decrease in TTP_OUTFLOW/TTP_INFLOW was observed (- 24%; 5.57 ± 3.66 s-4.25 ± 1.64 s; p = 0.6).

CONCLUSION

The presented 2D-PA technique facilitates the assessment of arterial flow in CO2-aided EVTs and has the potential to simplify the assessment of immediate treatment response.

Diabetes as a risk factor for incident peripheral arterial disease in women compared to men: a systematic review and meta-analysis

Aims/hypothesis

Previous meta-analyses have suggested that diabetes confers a greater excess risk of coronary heart disease, stroke, vascular dementia, and heart failure in women compared to men. While the underlying mechanism that explains such greater excess risk is unknown, in the current meta-analysis we hypothesized that we would find a similar sex difference in the relationship between diabetes and peripheral arterial disease (PAD).

Methods

PubMed MEDLINE, the Cochrane Database of Systematic Reviews, and Embase were systematically searched for prospective population-based cohort studies, with no restriction on publication date, language, or country. We included studies that reported the relative risk (RR), and its variability, for incident PAD associated with diabetes in both sexes. We excluded studies that did not adjust at least for age, and in which participants had pre-existing PAD. In cases where sex-specific results were not reported, study authors were contacted. Random-effects meta-analyses with inverse variance weighting were used to obtain summary sex-specific RRs and the women: men ratio of RRs for PAD. The Newcastle–Ottawa scale was used to assess study quality.

Results

Data from seven cohorts, totalling 2071,260 participants (49.8% women), were included. The relative risk for incident PAD associated with diabetes compared with no diabetes was 1.96 (95% CI 1.29–2.63) in women and 1.84 (95% CI 1.29–2.86) in men, after adjusting for potential confounders. The multiple-adjusted RR ratio was 1.05 (95% CI 0.90–1.22), with virtually no heterogeneity between studies (I² = 0%). All studies scored 6–8, on the Newcastle–Ottawa scale of 0–9, indicating good quality. Eleven of the 12 studies that met review inclusion criteria did not report sex-specific relative risk, and these data were collected through direct correspondence with the study authors.

Conclusion/interpretation

Consistent with other studies, we found evidence that diabetes is an independent risk factor for PAD. However, in contrast to similar studies of other types of cardiovascular disease, we did not find evidence that diabetes confers a greater excess risk in women compared to men for PAD. More research is needed to explain this sex differential between PAD and other forms of CVD, in the sequelae of diabetes. In addition, we found that very few studies reported the sex-specific relative risk for the association between diabetes and PAD, adding to existing evidence for the need for improved reporting of sex-disaggregated results in cardiovascular disease research.

A randomized cross-over trial in patients suspected of PAD on diagnostic accuracy of ankle-brachial index by Doppler-based versus four-point oscillometry based measurements

Summary. Background: For diagnosis of peripheral arterial occlusive disease (PAD), a Doppler-based ankle-brachial-index (dABI) is recommended as the first non-invasive measurement. Due to limitations of dABI, oscillometry might be used as an alternative. The aim of our study was to investigate whether a semi-automatic, four-point oscillometric device provides comparable diagnostic accuracy. Furthermore, time requirements and patient preferences were evaluated. Patients and methods: 286 patients were recruited for the study; 140 without and 146 with PAD. The Doppler-based (dABI) and oscillometric (oABI and pulse wave index – PWI) measurements were performed on the same day in a randomized cross-over design. Specificity and sensitivity against verified PAD diagnosis were computed and compared by McNemar tests. ROC analyses were performed and areas under the curve were compared by non-parametric methods. Results: oABI had significantly lower sensitivity (65.8%, 95% CI: 59.2%–71.9%) compared to dABI (87.3%, CI: 81.9–91.3%) but significantly higher specificity (79.7%, 74.7–83.9% vs. 67.0%, 61.3–72.2%). PWI had a comparable sensitivity to dABI. The combination of oABI and PWI had the highest sensitivity (88.8%, 85.7–91.4%). ROC analysis revealed that PWI had the largest area under the curve, but no significant differences between oABI and dABI were observed. Time requirement for oABI was significantly shorter by about 5 min and significantly more patients would prefer oABI for future testing. Conclusions: Semi-automatic oABI measurements using the AngER-device provide comparable diagnostic results to the conventional Doppler method while PWI performed best. The time saved by oscillometry could be important, especially in high volume centers and epidemiologic studies.

Cardiovascular Outcomes After Lower Extremity Endovascular or Surgical Revascularization: The EUCLID Trial

BACKGROUND

Lower extremity revascularization (LER) is a common treatment in patients with peripheral artery disease (PAD), but long-term outcomes are poorly defined.

OBJECTIVES

The aim was to analyze LER in the EUCLID (Examining Use of tiCagreLor In paD) trial to determine predictors and cardiovascular outcomes.

METHODS

Patients were grouped according to whether they received a post-randomization LER (n = 1,738) or not (n = 12,147). All variables were assessed for significance in univariable and parsimonious multivariable models. The primary endpoint was myocardial infarction, ischemic stroke, or cardiovascular death; major adverse limb events (MALE) included acute limb ischemia or major amputation.

RESULTS

A post-randomization LER occurred in 12.5% of patients and was an endovascular LER in 74.7%. Endovascular LERs were performed more often in North America, whereas surgical procedures occurred more frequently in Europe. Independent factors predicting LER were prior and type of prior LER, geographic region, limb symptoms, diabetes, and smoking. A post-randomization LER was associated with an increased risk for the primary endpoint (hazard ratio: 1.60; 95% confidence interval: 1.35 to 1.90; p < 0.0001) and MALE (hazard ratio: 12.0; 95% confidence interval: 9.47 to 15.30; p < 0.0001). Event rates for the primary endpoint after LER were numerically higher in the surgical subgroup, but MALE were similar between surgical and endovascular LER.

CONCLUSIONS

In the EUCLID trial, LER was most often endovascular. Following LER, there was an increased hazard for the primary endpoint (with higher event rates in the surgical group) and a markedly increased risk for MALE events (with similar event rates between surgical and endovascular LER procedures). (A Study Comparing Cardiovascular Effects of Ticagrelor and Clopidogrel in Patients With Peripheral Artery Disease [EUCLID]; NCT01732822).

Unmet medical needs in intermittent Claudication with diabetes and coronary artery disease-A "real-world" analysis on 21 197 PAD patients

BACKGROUND

Peripheral artery disease (PAD) is frequently co-prevalent with coronary artery disease (CAD) and diabetes (DM). The study aims to define the burden of CAD and/ or DM in PAD patients at moderate stages and further to evaluate its impact on therapy and outcome.

METHODS

Study is based on health insurance claims data of the BARMER reflecting an unselected "real-world" scenario. Retrospective analyses were based on 21 197 patients hospitalized for PAD Rutherford 1-3 between 1 January 2009 to 31 December 2011, including a 4-year follow-up (median 775 days).

RESULTS

In PAD patients, CAD is prevalent in 25.3% (n = 5355), DM in 23.5% (n = 4976), and both CAD and DM in 8.2% (n = 1741). Overall, in-hospital mortality was 0.4%, being increased if CAD was present (CAD alone: OR 1.849; 95%-CI 1.066-3.208; DM alone: OR 1.028; 95%-CI 0.520-2.033; CAD and DM: OR 3.115; 95%-CI 1.720-5.641). Both, CAD and DM increased long-term mortality (CAD alone: HR 1.234; 95%-CI 1.106-1.376; DM alone: HR 1.260; 95%-CI 1.125-1.412; CAD and DM: HR 1.76; 95%-CI 1.552-1.995). DM further increased long-term amputation risk (DM alone: HR 2.238; 95%-CI 1.849-2.710; DM and CAD: HR 2.199; 95%-CI 1.732-2.792), whereas CAD (alone) did not.

CONCLUSIONS

In a greater perspective, the data identify also mild to modest stage PAD patients at particular risk for adverse outcomes in presence of CAD and/or DM. CAD and DM both are related with a highly increased risk of long-term mortality even in intermittent claudication, and DM independently increased amputation risk.

Decline in ankle-brachial index is stronger in poorly than in well controlled diabetes: Results from the Heinz Nixdorf Recall cohort study

BACKGROUND AND AIMS

The ankle-brachial index (ABI) is a marker of atherosclerosis and a diagnostic criterion for peripheral arterial disease (PAD). We studied the association between HbA1c and ABI in subjects with and without diabetes.

METHODS

In the Heinz Nixdorf Recall Study, a population-based cohort study in Germany (N = 4,814, age 45-75 years), ABI was measured at baseline, at 5- and 10-year follow-up. Subjects with ABI <0.9, ABI >1.4 or self-reported PAD at baseline were excluded from analyses. In 3199 participants, we assessed associations between HbA1c and incident PAD (ABI < 0.9) and change in ABI, respectively, using logistic and linear regression models. Subjects without diabetes, with HbA1c < 5.7% were used as reference group.

RESULTS

Compared to the reference group, 10-year decline in ABI was -0.066 (95% confidence interval: -0.117; -0.016) and -0.021 (-0.063; 0.021) in subjects with poorly (≥7.0% HbA1c) and well (<7.0% HbA1c) controlled previously known diabetes; -0.010 (-0.054; 0.034) in those with newly detected diabetes diagnosed by HbA1c ≥ 6.5%, and -0.005 (-0.023; 0.013) in those without diabetes, with HbA1c 5.7-6.4%. For poorly controlled diabetes, odds ratios for low ABI (<0.9) were 3.5 (1.6-7.9), and 3.1 (1.3-7.0) after 5- and 10-year follow-up, respectively. The incidence of Mönckeberg disease (ABI > 1.4) was low (6/288 (2.4%) over 5 years).

CONCLUSIONS

Decline in ABI was stronger in poorly than well-controlled diabetes. Subjects with newly detected diabetes diagnosed by the new HbA1c criterion (≥6.5%) did not show an increased decline in ABI over 10 years.

Homocysteine and age-associated disorders

There are numerous theories of aging, a process which still seems inevitable. Aging leads to cancer and multi-systemic disorders as well as chronic diseases. Decline in age- associated cellular functions leads to neurodegeneration and cognitive decline that affect the quality of life. Accumulation of damage, mutations, metabolic changes, failure in cellular energy production and clearance of altered proteins over the lifetime, and hyperhomocysteinemia, ultimately result in tissue degeneration. The decline in renal functions, nutritional deficiencies, deregulation of methionine cycle and deficiencies of homocysteine remethylation and transsulfuration cofactors cause elevation of homocysteine with advancing age. Abnormal accumulation of homocysteine is a risk factor of cardiovascular, neurodegenerative and chronic kidney disease. Moreover, approximately 50% of people, aged 65 years and older develop hypertension and are at a high risk of developing cardiovascular insufficiency and incurable neurodegenerative disorders. Increasing evidence suggests inverse relation between cognitive impairment, cerebrovascular and cardiovascular events and renal function. Oxidative stress, inactivation of nitric oxide synthase pathway and mitochondria dysfunction associated with impaired homocysteine metabolism lead to aging tissue degeneration. In this review, we examine impact of high homocysteine levels on changes observed with aging that contribute to development and progression of age associated diseases.

Diabetic foot syndrome in elderly patients

In elderly patients with diabetes mellitus and mild deterioration of the lower extremities, peripheral artery disease and diabetic peripheral neuropathy may contribute to the development of a diabetic foot syndrome. Early diagnosis and intervention can help to preserve the foot and thus significantly increase quality of life with diagnostic and therapeutic procedures being the same in elderly and in young patients.

Non-invasive diagnosis is possible in most bed-ridden patients and should take into account reasonable therapeutic options against the background of overall morbidity, physical performance and quality of life, which should be discussed with the patient and his relatives. Multidisciplinary care structures facilitate treatment and might lead to reduced amputation rates and an improved well-being.