Atherosclerotic risk factors are less intensively treated in patients with peripheral arterial disease than in patients with coronary artery disease

Aspirin nonsensitivity in patients with vascular disease: Assessment by light transmission aggregometry (aspirin nonsensitivity in vascular patients)

BACKGROUND

Aspirin is a key antiplatelet therapy for the prevention of thrombotic events in patients with cardiovascular disease. Studies suggest that ≈20% of patients with cardiac disease suffer from aspirin nonsensitivity, a phenomenon characterized by the inability of 81 mg aspirin to inhibit platelet aggregation and/or prevent adverse cardiovascular events.

OBJECTIVES

To investigate aspirin nonsensitivity in patients with vascular disease and assess the consequences of aspirin nonsensitivity.

METHODS

One hundred fifty patients presenting to St. Michael's Hospital's outpatient clinics with evidence of vascular disease (peripheral arterial disease or carotid artery stenosis) and a previous prescription of 81 mg of aspirin were recruited in this study. Light transmission aggregometry with arachidonic acid induction was used to determine sensitivity to aspirin. Patients with a maximum aggregation ≥20% in response to arachidonic acid were considered aspirin nonsensitive, as per previous studies.

RESULTS

Of the 150 patients recruited, 36 patients (24%) were nonsensitive to 81 mg of aspirin. Of these 36 nonsensitive patients, 30 patients provided a urine sample for urine salicyluric acid analysis (a major metabolite of aspirin). Urine analysis demonstrated that 14 patients were compliant and 16 were noncompliant with their aspirin therapy. Major adverse cardiovascular events and major adverse limb events were significantly higher in the nonsensitive patients compared to sensitive patients (hazard ratio, 3.68; P < 0.001).

CONCLUSION

These data highlight the high prevalence of aspirin nonsensitivity and noncompliance in patients with vascular disease and emphasizes the urgent need for improved medical management options for this patient population.

Elevated plasma levels of NT-proBNP in ambulatory patients with peripheral arterial disease

N-terminal pro B-type natriuretic peptide (NT-proBNP), a cardiac disease biomarker, has been demonstrated to be a strong independent predictor of cardiovascular events in patients without heart failure. Patients with peripheral arterial disease (PAD) are at high risk of cardiovascular events and death. In this study, we investigated levels of NT-proBNP in patients with PAD compared to non-PAD controls. A total of 355 patients were recruited from outpatient clinics at a tertiary care hospital network. Plasma NT-proBNP levels were quantified using protein multiplex. There were 279 patients with both clinical and diagnostic features of PAD and 76 control patients without PAD (non-PAD cohort). Compared with non-PAD patients, median (IQR) NT-proBNP levels in PAD patients were significantly higher (225 ng/L (120-363) vs 285 ng/L (188-425), p- value = 0.001, respectively). Regression analysis demonstrated that NT-proBNP remained significantly higher in patients with PAD relative to non-PAD despite adjusting for age, sex, hypercholesterolemia, smoking and hypertension [odds ratio = 1.28 (1.07-1.54), p-value <0.05]. Subgroup analysis showed elevated NT-proBNP levels in patients with PAD regardless of prior history of CHF, CAD, diabetes and hypercholesteremia (p-value <0.05). Finally, spearmen's correlation analysis demonstrated a negative correlation between NT-proBNP and ABI (ρ = -0.242; p-value < 0.001). In conclusion, our data shows that patients with PAD in an ambulatory care setting have elevated levels of NT-proBNP compared to non-PAD patients in the absence of cardiac symptoms.

The prescription of best medical therapy following infrainguinal bypass grafting in Australia and New Zealand: a multicentre Australasian audit

BACKGROUND

The benefits of best medical therapy (BMT) for secondary prevention of cardiovascular events in patients with peripheral arterial disease are well established. Guidelines recommend prescription of BMT should consist of anti-platelet, statins and angiotensin-converting enzyme inhibitor or angiotensin receptor blocking therapy, with evidence this regimen reduces cardiovascular mortality following vascular surgery and improves vascular bypass graft patency. This multicentre study examines the BMT prescription on discharge after infrainguinal bypass (IIB) in Australia and New Zealand (ANZ). Primary outcome measure was discharge prescription of three BMT pharmacological agents, defined for study purposes as an anti-platelet/anti-coagulant, a lipid-lowering agent, and an anti-hypertensive medication if hypertension was diagnosed.

METHODS

This study retrospectively examined discharge prescriptions and summaries of all patients discharged following IIB in five ANZ hospitals, between January 2015 and April 2018.

RESULTS

A total of 688 admissions for IIB were included (76.9% male; mean age 67.8 ± 12.0). A total of 72.4% of procedures were for chronic limb ischaemia, compared to acute limb ischaemia (12.6%), and aneurysmal disease (15%). The primary outcome of adherence with complete BMT prescription occurred in 66.9% of admissions. Anti-thrombotic agents were most frequently prescribed (96.4%), followed by anti-lipidaemic agents (82.1%). Of the patients with documented hypertension, 43.8% were not prescribed an angiotensin-converting enzyme inhibitor/angiotensin receptor blocking, while 19.2% were discharged without any anti-hypertensive medications.

CONCLUSION

Almost one third of patients were not prescribed complete BMT following IIB. There is potential to improve the outcomes after IIB in ANZ through a focus on risk-factor control and BMT prescription.

Long-Term Effectiveness and Safety of Initiating Statin Therapy After Index Revascularization In Patients With Peripheral Arterial Occlusive Disease

Background An increasing number of patients with a peripheral arterial occlusive disease were put on statins during the past years. This study assessed whether statin therapy was effective and safe for these new users. Methods and Results Using health insurance claims data from Germany's second-largest insurance fund, BARMER, we identified patients with peripheral arterial occlusive disease who had index revascularization between 2008 and 2018 without prior statin therapy. We compared patients with and without statin therapy in addition to antithrombotics during the first quarter after discharge (new users versus nonusers). Outcomes were all-cause mortality, cardiovascular events, and incident major amputation for effectiveness and incident diabetes mellitus and incident myopathy for safety. Propensity score matching was used to balance the study groups. All analyses were stratified into patients with chronic limb-threatening ischemia and intermittent claudication. A total of 22 208 patients (mean age 71.1 years and 50.3% women) were included in the study. In 10 922 matched patients, statin initiation was associated with lower all-cause mortality (chronic limb-threatening ischemia: hazard ratio [HR], 0.75 [95% CI, 0.68-0.84]; intermittent claudication: HR, 0.80 [95% CI, 0.70-0.92]), lower risk of major amputation in patients with chronic limb-threatening ischemia (HR, 0.73; 95% CI, 0.58-0.93) and lower risk of cardiovascular events (hazard ratio, 0.80; 95% CI, 0.70-0.92) in patients with intermittent claudication during 5 years of follow-up. Safety outcomes did not differ among the study groups. Conclusions Initiating statin therapy in patients with peripheral arterial occlusive disease after index revascularization is efficient and safe with an effect size comparable to earlier studies. Awareness campaigns for evidence-based optimal pharmacological treatment among patients are recommended.

Regenerative Potential of the Product "CardioCell" Derived from the Wharton's Jelly Mesenchymal Stem Cells for Treating Hindlimb Ischemia

In recent years, mesenchymal stem cells (MSCs) have emerged as a promising therapeutic modality in regenerative medicine. They hold great promise for treating civilization-wide diseases, including cardiovascular diseases, such as acute myocardial infarction and critical limb ischemia. MSCs isolated from Wharton's jelly (WJ-MSCs) may be utilized in both cell-based therapy and vascular graft engineering to restore vascular function, thereby providing therapeutic benefits for patients. The efficacy of WJ-MSCs lies in their multipotent differentiation ability toward vascular smooth muscle cells, endothelial cells and other cell types, as well as their capacity to secrete various trophic factors, which are potent in promoting angiogenesis, inhibiting apoptosis and modulating immunoreaction. Ischemic limb disease is caused by insufficient nutrient and oxygen supplies resulting from damaged peripheral arteries. The lack of nutrients and oxygen causes severe tissue damage in the limb, thereby resulting in severe morbidities and mortality. The therapeutic effects of the conventional treatments are still not sufficient. Cell transplantations in small animal model (mice) are vital for deciphering the mechanisms of MSCs' action in muscle regeneration. The stimulation of angiogenesis is a promising strategy for the treatment of ischemic limbs, restoring blood supply for the ischemic region. In the present study, we focus on the therapeutic properties of the human WJ-MSCs derived product, Cardio. We investigated the role of CardioCell in promoting angiogenesis and relieving hindlimb ischemia. Our results confirm the healing effect of CardioCell and strongly support the use of the WJ-MSCs in regenerative medicine.

Feasibility and Clinical Relevance of a Mobile Intervention Using TrackPAD to Support Supervised Exercise Therapy in Patients With Peripheral Arterial Disease: Study Protocol for a Randomized Controlled Pilot Trial

Background

Peripheral arterial disease (PAD) is a common and severe disease with a highly increased cardiovascular morbidity and mortality. Through the circulatory disorder and the linked undersupply of oxygen carriers in the lower limbs, the ongoing decrease of the pain-free walking distance occurs with a significant reduction in patients’ quality of life. Studies including activity monitoring for patients with PAD are rare and digital support to increase activity via mobile health technologies is mainly targeted at patients with cardiovascular disease in general. The special requirement of patients with PAD is the need to reach a certain pain level to improve the pain-free walking distance. Unfortunately, both poor adherence and availability of institutional resources are major problems in patient-centered care.

Objective

The objective of this trackPAD pilot study is to evaluate the feasibility of a mobile phone–based self tracking app to promote physical activity and supervised exercise therapy (SET) in particular. We also aim for a subsequent patient centered adjustment of the app prototype based on the results of the app evaluation and process evaluation.

Methods

This study was designed as a closed user group trial, with assessors blinded, and parallel group study with face-to-face components for assessment with a follow-up of 3 months. Patients with symptomatic PAD (Fontaine stage IIa or IIb) and possession of a mobile phone were eligible. Eligible participants were randomly assigned into study and control group, stratified by their distance covered in the 6-min walk test, using the software TENALEA. Participants randomized to the study group received usual care and the mobile intervention (trackPAD) for the follow-up period of 3 months, whereas participants randomized to the control group received only usual care. TrackPAD records the frequency and duration of training sessions and pain level using manual user input. Clinical outcome data were collected at the baseline and after 3 months via validated tools (6-min walk test, ankle-brachial index, and duplex ultrasound at the lower arteries) and self-reported quality of life. Usability and quality of the app was determined using the user version of the Mobile Application Rating Scale.

Results

The study enrolled 45 participants with symptomatic PAD (44% male). Of these participants, 21 (47%) were randomized to the study group and 24 (53%) were randomized to the control group. The distance walked in the 6-min walk test was comparable in both groups at baseline (study group: mean 368.1m [SD 77.6] vs control group: mean 394.6m [SD 100.6]).

Conclusions

This is the first trial to test a mobile intervention called trackPAD that was designed especially for patients with PAD. Its results will provide important insights in terms of feasibility, effectiveness, and patient preferences of an app-based mobile intervention supporting SET for the conservative treatment of PAD.

International Registered Report Identifier (IRRID)

DERR1-10.2196/13651

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.

Impact of Coronary Artery Disease and Diabetes Mellitus on the Long-Term Follow-Up in Patients after Retrograde Recanalization of the Femoropopliteal Arterial Region

The most relevant comorbidities in patients with peripheral artery disease (PAD) are coronary artery disease (CAD) and diabetes mellitus (DM). However, data of long-term follow-up of patients with chronic total occlusion (CTO) are scarce. The aim of the study was to assess the impact of CAD and DM on long-term follow-up patients after superficial femoral artery (SFA) CTO retrograde recanalization. In this study, eighty-six patients with PAD with diagnosed CTO in the femoropopliteal region and at least one unsuccessful attempt of antegrade recanalization were enrolled in 2 clinical centers. Mean time of follow-up in all patients was 47.5 months (±40 months). Patients were divided into two groups depending on the presence of CAD (CAD group: n = 45 vs. non-CAD group: n = 41) and DM (DM group: n = 50 vs. non-DM group: n = 36). In long-term follow-up, major adverse peripheral events (MAPE) occurred in 66.6% of patients with CAD vs. 36.5% of patients without CAD and in 50% of patients with DM vs. 55% of non-DM subjects. There were no statistical differences in peripheral endpoints in both groups. However, there was a statistically significant difference in all-cause mortality: in the DM group, there were 6 deaths (12%) (P value = 0.038). To conclude, patients after retrograde recanalization, with coexisting CTO and DM, are at higher risk of death in long-term follow-up.

Guideline-directed statin intensification in patients with new or worsening symptoms of peripheral artery disease

BACKGROUND

The ACC/AHA cholesterol guidelines recommend patients with peripheral artery disease (PAD) be treated with a moderate to high-intensity statin. The extent to which patients with new or worsening PAD symptoms are offered guideline therapy is unknown.

HYPOTHESIS

There is significant variability in rate of guideline-directed statin intensification across clinical practices.

METHODS

In the PORTRAIT registry, patterns of statin therapy were assessed in 1144 patients at 16 PAD specialty clinics between June 2011 and December 2015 before and after an evaluation for new or worsening claudication symptoms. We documented whether patients were treated with a guideline statin as well as the incidence of statin intensification. Statin intensification was defined as transitioning from no statin or low-intensity statin to moderate or high-intensity statin treatment. Patient factors associated with intensification were examined. Site and provider-level variation in intensification was summarized using an adjusted median odds ratio (aMOR).

RESULTS

Among 1144 patients, 810 (70.8%) were initially on guideline therapy compared to 334 (29.2%) that were not. In the latter, 103 (30.8%) received intensification following evaluation. Patients with typical symptoms displayed greater odds of intensification (OR 3.74; 95% CI: 1.23-11.41) while older patients had lower odds of intensification (OR 0.60/decade; 95% CI: 0.41-0.88). Site variability for statin intensification was observed across sites (aMOR = 3.15; 95% CI 1.22-9.60, [P = 0.02]) but not providers (aMOR = 1.89; 95% CI 1.00-3.90, [P = 0.14]).

CONCLUSIONS

Most patients evaluated at a PAD specialty clinic for new or worsening claudication symptoms arrived on guideline statin therapy. Only 31% not receiving appropriate therapy underwent statin intensification. These findings highlight an important opportunity to optimize medical therapy for patients with PAD.

Association of Statin Dose With Amputation and Survival in Patients With Peripheral Artery Disease

BACKGROUND

Statin dose guidelines for patients with peripheral artery disease (PAD) are largely based on coronary artery disease and stroke data. The aim of this study is to determine the effect of statin intensity on PAD outcomes of amputation and mortality.

METHODS

Using an observational cohort study design and a validated algorithm, we identified patients with incident PAD (2003-2014) in the national Veterans Affairs data. Highest statin intensity exposure (high-intensity versus low-to-moderate-intensity versus antiplatelet therapy but no statin use) was determined within 1 year of diagnosis of PAD. Outcomes of interest were lower extremity amputations and death. The association of statin intensity with incident amputation and mortality was assessed with Kaplan-Meier plots, Cox proportional hazards modeling, propensity score-matched analysis, and sensitivity and subgroup analyses, as well, to reduce confounding.

RESULTS

In 155 647 patients with incident PAD, more than a quarter (28%) were not on statins. Use of high-intensity statins was lowest in patients with PAD only (6.4%) in comparison with comorbid coronary/carotid disease (18.4%). Incident amputation and mortality risk declined significantly with any statin use in comparison with the antiplatelet therapy-only group. In adjusted Cox models, the high-intensity statin users were associated with lower amputation risk and mortality in comparison with antiplatelet therapy-only users (hazard ratio, 0.67; 95% confidence interval, 0.61-0.74 and hazard ratio, 0.74; 95% confidence interval, 0.70-0.77, respectively). Low-to-moderate-intensity statins also had significant reductions in the risk of amputation and mortality (hazard ratio amputation, 0.81; 95% confidence interval, 0.75- 0.86; hazard ratio death, 0.83; 95% confidence interval, 0.81-0.86) in comparison with no statins (antiplatelet therapy only), but effect size was significantly weaker than the high-intensity statins (P<0.001). The association of high-intensity statins with lower amputation and death risk remained significant and robust in propensity score-matched, sensitivity, and subgroup analyses.

CONCLUSIONS

Statins, especially high-intensity formulations, are underused in patients with PAD. This is the first population-based study to show that high-intensity statin use at the time of PAD diagnosis is associated with a significant reduction in limb loss and mortality in comparison with low-to-moderate-intensity statin users, and patients treated only with antiplatelet medications but not with statins, as well.

Hindlimb Ischemia Impairs Endothelial Recovery and Increases Neointimal Proliferation in the Carotid Artery

Peripheral ischemia is associated with higher degree of endothelial dysfunction and a worse prognosis after percutaneous coronary interventions (PCI). However, the role of peripheral ischemia on vascular remodeling in remote districts remains poorly understood. Here we show that the presence of hindlimb ischemia significantly enhances neointima formation and impairs endothelial recovery in balloon-injured carotid arteries. Endothelial-derived microRNAs are involved in the modulation of these processes. Indeed, endothelial miR-16 is remarkably upregulated after vascular injury in the presences of hindlimb ischemia and exerts a negative effect on endothelial repair through the inhibition of RhoGDIα and nitric oxide (NO) production. We showed that the repression of RhoGDIα by means of miR-16 induces RhoA, with consequent reduction of NO bioavailability. Thus, hindlimb ischemia affects negative carotid remodeling increasing neointima formation after injury, while systemic antagonizzation of miR-16 is able to prevent these negative effects.

Coronary artery calcium score and coronary computed tomography angiography for patients with asymptomatic polyvascular (non-coronary) atherosclerosis

INTRODUCTION

The primary endpoint of this study was to determine the prevalence of coronary artery disease (CAD) and coronary artery calcium score (CACS) using coronary computed tomography angiography (CCTA) among patients with polyvascular atherosclerosis (PVA). Secondary endpoints were to evaluate the prevalence of cardiovascular risk factors and determine the predictors of PVA.

METHODS

The presence of atherosclerotic disease was assessed using ultrasonographic vascular examination in 515 asymptomatic patients. All patients with presence of stenosis over 50% and moderate-to-severe cardiovascular risk profile underwent CCTA to identify atherosclerotic coronary disease.

RESULTS

Among 515 participants, 143 patients had no evidence of atherosclerotic plaque. Of the 372 patients with atherosclerotic plaque, 184 patients had single-vessel disease, 111 patients had double-vessel disease and 77 patients had triple-vessel disease; among these patients, those who also presented with stenosis > 50% underwent CCTA. Coronary stenosis categories included: normal (6.4%); haemodynamically insignificant (34.6%); intermediate (28.7%); significant (26.6%); and total artery occlusion (3.7%). Based on the coronary vessel involved, the patients were categorised as having single- (41.0%), double- (42.0%) or triple- (17.0%) coronary disease. CACS was significantly higher in patients with double- or triple-vessel disease when compared to those with single-vessel disease.

CONCLUSION

Our study confirmed not only the high sensitivity of CCTA for highlighting CAD, but also its negative predictive value for excluding the presence of coronary stenosis or ischaemia. We found good correlation between PVA and CACS, and were able to confirm the risk factors for PVA.

Nutritional status and body composition in patients with peripheral arterial disease: A cross-sectional examination of disease severity and quality of life

Nutritional and body weight recommendations for cardiovascular diseases are well established, yet there are no equivalent guidelines for peripheral arterial disease (PAD). This cross-sectional study measured the prevalence of cardiovascular-related nutritional and body composition risk factors in sixty PAD patients and their association with PAD severity. A diet that exceeds daily recommended intake of fat and that falls short of recommended intakes of fiber, folate, and vitamin D was associated with increased leg pain and walking difficulty. Increased body fat and waist circumference were associated with diminished walking ability and poorer psychosocial quality of life. Future prospective investigations are merited to inform both PAD clinical care and disease management guidelines.

Current therapies and investigational drugs for peripheral arterial disease

Peripheral artery disease (PAD) is associated with elevated morbidity and mortality with cardiovascular (CV) disease. The guideline recommends smoking cessation and antiplatelet/antithrombotic drugs for asymptomatic and symptomatic PAD patients. It also recommends that PAD patients with critical limb ischemia (CLI) should be considered to receive endovascular and open surgical treatment for limb salvage. Although PAD patients with CLI receive these treatments, they are sometimes unable to deliver sufficient blood flow to eliminate their symptoms. Thus specific strategies are needed to promote enough blood flow. To establish the effective method, many investigations have been performed using cell-based therapy. Endothelial progenitor cells, mononuclear cells and mesenchymal stem cells have been well investigated in clinical settings. To induce angiogenesis, vascular endothelial growth factor, fibroblast growth factor and hepatocyte growth factor (HGF) have also been transfected in PAD patients. Among them, HGF is the most promising factor because it can induce angiogenesis without the induction of vascular inflammation and increased permeability. In this review article, we summarize current treatments and investigational drugs of PAD.

Co-existence of vascular disease in different arterial beds: Peripheral artery disease and carotid artery stenosis--Data from Life Line Screening(®)

BACKGROUND

Atherosclerosis is a systemic vascular disorder, involving multiple arterial territories. This project sought to investigate the relationship between lower extremity peripheral artery disease (PAD) and carotid artery stenosis (CAS) in a large self-referred population.

METHODS

Data from the ankle brachial index (ABI) and carotid duplex ultrasound were analyzed from 3.67 million US subjects in the Life Line Screening program between 2004 and 2008. PAD was defined by ABI<0.9 and CAS was defined by greater than 50% stenosis. Multivariate logistic regression analysis was used to estimate odds of CAS by PAD status and severity.

RESULTS

Mean age of the population was 63.7 ± 10.6 years and 64% were women. The prevalence of PAD and CAS was 4.1% and 3.9%, respectively. Subjects with PAD had a higher prevalence of CAS than those without PAD (18.8% vs. 3.3%, P < 0.0001). In multivariate analysis, PAD was associated with greater odds of CAS (OR 3.28, 95% CI 3.22-3.34). Both symptomatic (OR 3.66, 95% CI 3.58-3.75) and asymptomatic PAD (OR 2.91, 95% CI 2.84-2.98) was associated with CAS. Increasing severity of PAD was associated with greater odds of CAS (OR 2.32, 3.61, 4.19, 5.14, and 7.59 for ABI categories 0.81-0.90, 0.71-0.80, 0.61-0.70, 0.41-0.60, ≤0.40, respectively).

CONCLUSION

Presence and severity of PAD was associated with prevalence of CAS in the large self-referred and self-paying Life Line cohort, regardless of lower extremity symptoms.

Pneumoconiosis increases the risk of peripheral arterial disease: a nationwide population-based study

This nationwide population-based retrospective cohort study was used to evaluate the association between pneumoconiosis and peripheral arterial disease (PAD). We identified 3374 patients with pneumoconiosis from the catastrophic illness registry who were newly diagnosed from 2000 to 2005; 13,496 patients without pneumoconiosis from Longitudinal Health Insurance Database 2000 (LHID2000) were randomly frequency matched according to sex, age, and index year and used as a nonpneumoconiosis group. Multivariate Cox proportional hazards regression was used to calculate adjusted hazard ratios (HRs) of PAD in the pneumoconiosis group compared with the nonpneumoconiosis group. The mean follow-up years were 7.44 years in the pneumoconiosis group and 8.17 years in the nonpneumoconiosis group. The incidence density rate of PAD was 1.25 times greater in the pneumoconiosis group than in the nonpneumoconiosis group (8.37 vs 6.70 per 1000 person-years). After adjusting for sex, age, and comorbidities, the adjusted HRs of PAD for the pneumoconiosis group were 1.30 (95% CI = 1.08-1.57), compared with the nonpneumoconiosis group. The combined impacts of patients with pneumoconiosis and diabetes, hyperlipidemia, hypertension, ischemic heart disease, chronic obstructive pulmonary disease, and asthma showed a significant by joint association with PAD risk compared with patients with no pneumoconiosis and no counterpart comorbidity. Patients with pneumoconiosis have an independently higher risk of developing PAD. Physicians should include pneumoconiosis in evaluating PAD risk.

Adherence to guideline-recommended therapies among patients with diverse manifestations of vascular disease

Background

Current guidelines recommend aspirin, statins, angiotensin-converting enzyme inhibitors (ACEIs), and smoking abstinence for all patients with vascular disease. There is little data on the variation in adherence to guideline-recommended therapies among patients with different clinical manifestations of vascular disease.

Purpose

To analyze the variation in adherence to guideline-recommended therapies among patients with diverse manifestations of vascular disease.

Methods

We analyzed a comprehensive database of all patients with critical limb ischemia, claudication, acute limb ischemia, carotid artery stenosis, subclavian artery stenosis, renal artery stenosis, or mesenteric ischemia who underwent angiography between 2006 and 2013 at a multidisciplinary vascular center.

Results

Among 1,114 patients with vascular disease, adherence to guideline-recommended therapy at time of angiography included use of aspirin in 936 (84%), statins in 753 (68%), ACEIs in 673 (60%), and smoking abstinence in 788 (71%). A total of 335 (30%) patients utilized all four guideline-recommended therapies. Adherence to four guideline-recommended therapies was lowest among patients with acute limb ischemia (14%) and highest among patients with renal artery stenosis (37%). Among all patients with vascular disease, the range of adherence to individual guidelines was 64%–91% for aspirin, 43%–83% for statins, 49%–66% for ACEIs, and 47%–78% for smoking abstention.

Conclusion

The majority of patients with diverse manifestations of vascular disease take aspirin and abstain from smoking while fewer patients are prescribed ACEIs and statins. Among the current recommendations, statins have the widest variation in adherence. Less than one-third of patients with diverse manifestations of vascular disease are prescribed all four guideline-recommended therapies.

Adherence to guideline-recommended therapy is associated with decreased major adverse cardiovascular events and major adverse limb events among patients with peripheral arterial disease

BACKGROUND

Current guidelines recommend that patients with peripheral arterial disease (PAD) cease smoking and be treated with aspirin, statin medications, and angiotensin-converting enzyme (ACE) inhibitors. The combined effects of multiple guideline-recommended therapies in patients with symptomatic PAD have not been well characterized.

METHODS AND RESULTS

We analyzed a comprehensive database of all patients with claudication or critical limb ischemia (CLI) who underwent diagnostic or interventional lower-extremity angiography between June 1, 2006 and May 1, 2013 at a multidisciplinary vascular center. Baseline demographics, clinical data, and long-term outcomes were obtained. Inverse probability of treatment propensity weighting was used to determine the 3-year risk of major adverse cardiovascular or cerebrovascular events (MACE; myocardial infarction, stroke, or death) and major adverse limb events (MALE; major amputation, thrombolysis, or surgical bypass). Among 739 patients with PAD, 325 (44%) had claudication and 414 (56%) had CLI. Guideline-recommended therapies at baseline included use of aspirin in 651 (88%), statin medications in 496 (67%), ACE inhibitors in 445 (60%), and smoking abstention in 528 (71%) patients. A total of 237 (32%) patients met all four guideline-recommended therapies. After adjustment for baseline covariates, patients adhering to all four guideline-recommended therapies had decreased MACE (hazard ratio [HR], 0.64; 95% CI, 0.45 to 0.89; P=0.009), MALE (HR, 0.55; 95% CI, 0.37 to 0.83; P=0.005), and mortality (HR, 0.56; 95% CI, 0.38 to 0.82; P=0.003), compared to patients receiving less than four of the recommended therapies.

CONCLUSIONS

In patients with claudication or CLI, combination treatment with four guideline-recommended therapies is associated with significant reductions in MACE, MALE, and mortality.

Statin therapy and long-term adverse limb outcomes in patients with peripheral artery disease: insights from the REACH registry

AIMS

Due to a high burden of systemic cardiovascular events, current guidelines recommend the use of statins in all patients with peripheral artery disease (PAD). We sought to study the impact of statin use on limb prognosis in patients with symptomatic PAD enrolled in the international REACH registry.

METHODS

Statin use was assessed at study enrolment, as well as a time-varying covariate. Rates of the primary adverse limb outcome (worsening claudication/new episode of critical limb ischaemia, new percutaneous/surgical revascularization, or amputation) at 4 years and the composite of cardiovascular death/myocardial infarction/stroke were compared among statin users vs. non-users.

RESULTS

A total of 5861 patients with symptomatic PAD were included. Statin use at baseline was 62.2%. Patients who were on statins had a significantly lower risk of the primary adverse limb outcome at 4 years when compared with those who were not taking statins [22.0 vs. 26.2%; hazard ratio (HR), 0.82; 95% confidence interval (CI), 0.72-0.92; P = 0.0013]. Results were similar when statin use was considered as a time-dependent variable (P = 0.018) and on propensity analysis (P < 0.0001). The composite of cardiovascular death/myocardial infarction/stroke was similarly reduced (HR, 0.83; 95% CI, 0.73-0.96; P = 0.01).

CONCLUSION

Among patients with PAD in the REACH registry, statin use was associated with an ∼18% lower rate of adverse limb outcomes, including worsening symptoms, peripheral revascularization, and ischaemic amputations. These findings suggest that statin therapy not only reduces the risk of adverse cardiovascular events, but also favourably affects limb prognosis in patients with PAD.

The combination of 9p21.3 genotype and biomarker profile improves a peripheral artery disease risk prediction model

Peripheral artery disease (PAD) is a highly morbid condition affecting more than 8 million Americans. Frequently, PAD patients are unrecognized and therefore do not receive appropriate therapies. Therefore, new methods to identify PAD have been pursued, but have thus far had only modest success. Here we describe a new approach combining genomic and metabolic information to enhance the diagnosis of PAD. We measured the genotype of the chromosome 9p21 cardiovascular-risk polymorphism rs10757269 as well as the biomarkers C-reactive protein, cystatin C, β2-microglobulin, and plasma glucose in a study population of 393 patients undergoing coronary angiography. The rs10757269 allele was associated with PAD status (ankle-brachial index < 0.9) independent of biomarkers and traditional cardiovascular risk factors (odds ratio = 1.92; 95% confidence interval, 1.29-2.85). Importantly, compared to a previously validated risk factor-based PAD prediction model, the addition of biomarkers and rs10757269 significantly and incrementally improved PAD risk prediction as assessed by the net reclassification index (NRI = 33.5%; p = 0.001) and integrated discrimination improvement (IDI = 0.016; p = 0.017). In conclusion, a model including a panel of biomarkers, which includes both genomic information (which is reflective of heritable risk) and metabolic information (which integrates environmental exposures), predicts the presence or absence of PAD better than established risk models, suggesting clinical utility for the diagnosis of PAD.

Disease location is associated with survival in patients with peripheral arterial disease

BACKGROUND

We investigated whether disease location influences survival in patients with peripheral arterial disease.

METHODS AND RESULTS

Patients (n = 12,731; mean age, 67.5 ± 12.7 years; 57.4% male) who underwent outpatient noninvasive lower extremity arterial evaluation were followed up for 5.9 ± 3.1 years for all-cause mortality. Peripheral arterial disease (n = 8930) was defined as a resting or postexercise ankle-brachial index (ABI) ≤ 0.90, and normal ABI (n = 3,801) was defined as a resting and postexercise ABI of 1.00 to 1.30. Presence or absence of disease at the proximal location or distal location was determined on the basis of Doppler signals in leg arteries; 42% had no PD or DD, 45% had proximal (14% postexercise PD only), 30% had distal disease, 17% had both proximal and distal disease, 28% had proximal only and 14% had distal only. We performed multivariable logistic regression to identify factors associated with disease location, and Cox proportional hazard regression to assess the respective effects of proximal or distal disease on survival. Older age, male sex, diabetes, heart failure, and critical limb ischemia were associated with distal disease, whereas female sex, smoking, hypertension, dyslipidemia, coronary heart disease, cerebrovascular disease, chronic obstructive pulmonary disease, and critical limb ischemia were associated with proximal disease. Over a mean follow-up of 5.9 ± 3.1 years, 3039 patients (23.9%) died. After adjustment for potential confounders, the hazard ratios (HRs) of death associated with PD only and DD only were 1.3 (1.3 to 1.4) and 1.5 (1.4 to 1.6), respectively. After additional adjustment for resting ABI, there was no significant association between proximal disease and death, whereas the association of distal disease with death remained significant (HR, 1.2; 95% CI, 1.1 to 1.3).

CONCLUSIONS

In patients with peripheral arterial disease, proximal and distal disease locations were associated with distinctive risk factor and comorbidity profiles. Distal disease was associated with worse survival even after adjustment for risk factors, comorbidities, and resting ABI.

Impact of critical limb ischemia on long-term cardiac mortality in diabetic patients undergoing percutaneous coronary revascularization

OBJECTIVE

Development of critical limb ischemia (CLI) has been reported as an independent predictor of cardiac mortality in diabetic patients. We aimed to determine whether CLI, managed in a structured setting of close collaboration between different vascular specialists and treated with early endovascular intervention, has any impact on long-term cardiac mortality of diabetic patients initially presenting with symptomatic coronary artery disease (CAD).

RESEARCH DESIGN AND METHODS

We designed a prospective observational study of 764 consecutive diabetic patients undergoing percutaneous coronary intervention (PCI) in whom development of CLI was assessed by a dedicated diabetic foot clinic. Cardiac mortality at 4-year follow-up was the primary end point of the study.

RESULTS

Among the 764 patients, 111 (14%) developed CLI (PCI-CLI group) and underwent revascularization of 145 limbs, with procedural success in 140 (96%). PCI-CLI patients at baseline had lower left ventricular ejection fraction (51 ± 11% vs. 53 ± 10%, P = 0.008), higher prevalence of dialysis (7% vs. 0.3%, P < 0.0001), and longer diabetes duration (13 ± 8 vs. 11 ± 7 years, P = 0.02) compared with PCI-only patients. At 4-year follow-up, cardiac mortality occurred in 10 (9%) PCI-CLI patients vs. 42 (6%) PCI-only patients (P = 0.2). Time-dependent Cox regression model for cardiac death revealed that CLI was not associated with an increased risk of cardiac mortality (hazard ratio 1.08 [95% CI 0.89-3.85]; P = 0.1).

CONCLUSIONS

The development of promptly assessed and aggressively treated CLI was not significantly associated with increased risk of long-term cardiac mortality in diabetic patients initially presenting with symptomatic CAD.

The role of nutrition and body composition in peripheral arterial disease

Peripheral arterial disease (PAD) has not been as extensively investigated as other cardiovascular diseases. However, the available data suggest that nutrition-based treatment strategies have the potential to reduce the cost-economic burden of PAD substantially. Abdominal obesity is associated with PAD and prospective and cross-sectional studies have shown that a low dietary intake of folate and reduced synthesis of vitamin D are associated with an increased risk of PAD and severe walking impairment in patients who have the disease. However, dietary patterns that are associated with decreased cardiovascular risk might protect against PAD. A small number of clinical trials have provided evidence that increased intakes of niacin and insoluble fiber might be associated with decreased levels of LDL cholesterol and thrombogenic biomarkers, as well as increased serum levels of HDL cholesterol in patients with PAD. However, little evidence that antioxidants, vitamins B(6) and B(12), or essential fatty acid supplements improve clinical outcomes in these patients exists. Overall, data on the effects of nutrition, body composition, and nutritional supplementation on the risk, progression, and prognosis of PAD are scarce. Further research into these areas is required to allow the development of evidence-based nutritional guidelines for the prevention and treatment of the disease.

Dietary intake of participants with peripheral artery disease and claudication

We compared the dietary intake of participants with peripheral artery disease (PAD) and claudication with diet recommendations of the National Cholesterol Education Program (NCEP) and dietary reference intake values recommended by the Institute of Medicine (IOM) of the National Academy of Sciences. Forty-six participants consumed a mean macronutrient composition of 17% protein, 51% carbohydrate, and 30% fat. Compared to the NCEP and IOM recommendations, few participants met the recommended daily intake for sodium (0%), vitamin E (0%), folate (13%), saturated fat (20%), fiber (26%), and cholesterol (39%). Participants with PAD and claudication have poor nutrition, with diets particularly high in saturated fat, sodium, and cholesterol, and low in fiber, vitamin E, and folate intakes. Participants should be encouraged to reduce consumption of dietary fat, saturated fat, cholesterol, and sodium and to increase fiber and vitamin intakes to meet recommendations of the NCEP and IOM.

Activating peripheral arterial disease patients to reduce cholesterol: a randomized trial

BACKGROUND

Peripheral arterial disease patients are less likely than other high-risk patients to achieve ideal low-density lipoprotein (LDL) cholesterol levels. This randomized controlled trial assessed whether a telephone counseling intervention, designed to help peripheral arterial disease patients request more intensive cholesterol-lowering therapy from their physician, achieved lower LDL cholesterol levels than 2 control conditions.

METHODS

There were 355 peripheral arterial disease participants with baseline LDL cholesterol ≥70 mg/dL enrolled. The primary outcome was change in LDL cholesterol level at 12-month follow-up. There were 3 parallel arms: telephone counseling intervention, attention control condition, and usual care. The intervention consisted of patient-centered counseling, delivered every 6 weeks, encouraging participants to request increases in cholesterol-lowering therapy from their physician. The attention control condition consisted of telephone calls every 6 weeks providing information only. The usual care condition participated in baseline and follow-up testing.

RESULTS

At 12-month follow-up, participants in the intervention improved their LDL cholesterol level, compared with those in attention control (-18.4 mg/dL vs -6.8 mg/dL, P=.010) but not compared with those in usual care (-18.4 mg/dL vs -11.1 mg/dL, P=.208). Intervention participants were more likely to start a cholesterol-lowering medication or increase their cholesterol-lowering medication dose than those in the attention control (54% vs 18%, P=.001) and usual care (54% vs 31%, P <.001) conditions.

CONCLUSION

Telephone counseling that helped peripheral arterial disease patients request more intensive cholesterol-lowering therapy from their physician achieved greater LDL cholesterol decreases than an attention control arm that provided health information alone.

Protective vascular treatment of patients with peripheral arterial disease: guideline adherence according to year, age and gender

OBJECTIVES

To evaluate vasoprotective pharmacological treatment of patients with peripheral arterial disease (PAD) according to: 1) year, 2) age and 3) gender.

METHODS

An observational retrospective study was conducted to evaluate the systemic vascular treatment of a population-based cohort of patients with PAD > or = 50 years old, discharged from a tertiary-care teaching hospital between January 1, 1997 and December 11, 2006. Data were obtained from the Régie de l'assurance maladie du Québec. Drugs evaluated included antiplatelet agents (APs), statins (STs) and angiotensin converting enzyme inhibitors (ACEIs), and a combination of all three. Proportions of patients treated were compared according to year, age and gender using Chi-square.

RESULTS

The mean age of the study population (5962 individuals) was 73.2 +/- 9.1 years; 43.8% were women. After hospital discharge, 71.6%, 47.6%, 42.2% and 20.6% were taking respectively, an AP, statin, ACEI or all three. Protective treatment improved significantly from 1997 to 2006. Significantly more subjects 50-64 years used a statin or all three agents, compared to subjects > or = 65 years (statins: 56.6% vs. 45.8%, all three: 26.2% vs. 19.5%; p < 0.001). Significantly more men than women used statins (49.1% vs. 45.6%; p < 0.001) and ACEIs (44.5% vs. 39.3%; p < 0.001). Similarily, use of all three agents was 22.4% for men and 18.2% for women (p < 0.001).

CONCLUSIONS

Although systemic vascular treatment received by patients with PAD has increased in the past years, it remains suboptimal, particularly for older patients and women. Strategies to improve adherence to treatment guidelines should be developed for these high-risk populations.

Peripheral artery disease: current insight into the disease and its diagnosis and management

Peripheral artery disease (PAD), which comprises atherosclerosis of the abdominal aorta, iliac, and lower-extremity arteries, is underdiagnosed, undertreated, and poorly understood by the medical community. Patients with PAD may experience a multitude of problems, such as claudication, ischemic rest pain, ischemic ulcerations, repeated hospitalizations, revascularizations, and limb loss. This may lead to a poor quality of life and a high rate of depression. From the standpoint of the limb, the prognosis of patients with PAD is favorable in that the claudication remains stable in 70% to 80% of patients over a 10-year period. However, the rate of myocardial infarction, stroke, and cardiovascular death in patients with both symptomatic and asymptomatic PAD is markedly increased. The ankle brachial index is an excellent screening test for the presence of PAD. Imaging studies (duplex ultrasonography, computed tomographic angiography, magnetic resonance angiography, catheter-based angiography) may provide additional anatomic information if revascularization is planned. The goals of therapy are to improve symptoms and thus quality of life and to decrease the cardiovascular event rate (myocardial infarction, stroke, cardiovascular death). The former is accomplished by establishing a supervised exercise program and administering cilostazol or performing a revascularization procedure if medical therapy is ineffective. A comprehensive program of cardiovascular risk modification (discontinuation of tobacco use and control of lipids, blood pressure, and diabetes) will help to prevent the latter.

Attitudes and behavior of peripheral arterial disease patients toward influencing their physician's prescription of cholesterol-lowering medication

Among 355 peripheral arterial disease (PAD) patients with low density lipoprotein cholesterol (LDL-C) levels > or = 70 mg/dl, we assessed knowledge regarding optimal LDL levels and the importance of LDL-C-lowering therapy. We also assessed PAD participants' behaviors and attitudes regarding their engagement with their physician in treatment decisions for LDL-C lowering. The average baseline LDL-C level of participants was 103.4 mg/dl +/- 30.7 mg/dl. Seventy-six percent of participants were taking at least one cholesterol-lowering medication. Sixty-six percent were unable to define their optimal LDL-C. Only 47% strongly agreed that their own actions and decisions could reduce their LDL-C. Just 29.8% were aware that patients who request specific medications from their physician were more likely to receive them, and 16% had asked their physician whether they should be taking more cholesterol-lowering medication. These findings suggest that further study is needed to identify effective interventions to educate PAD patients and their physicians about the importance of cholesterol-lowering therapy and to encourage PAD patients to participate with their physician in decisions regarding cholesterol-lowering treatment. Clinical Trial Registration - URL: http://www.clinicaltrials.gov. Unique identifier: NCT00217919.

Three-dimensional T2-weighted MRI of the human femoral arterial vessel wall at 3.0 Tesla

OBJECTIVES

To evaluate the potential use of a novel 3D turbo spin-echo (TSE) T2-weighted (T2w) technique for assessing the vessel wall in the superficial femoral artery at 3.0 T.

BACKGROUND

Magnetic resonance imaging can be used for the noninvasive assessment of atherosclerotic plaque burden in the peripheral circulation. Although black-blood 2D TSE techniques have been used for femoral arterial wall imaging, these techniques require prolonged imaging time to cover a large field of view required to cover the leg. Recently, variable-flip-angle 3D TSE T2w (SPACE) has been introduced as a fast vessel wall imaging technique with submillimeter spatial resolution. A systematic investigation of the application of this technique to femoral arterial wall imaging has yet to be performed.

METHODS

Fifteen healthy volunteers and 3 patients with peripheral arterial disease (PAD) underwent 3D SPACE imaging of the superficial femoral artery at 3.0 T, with the conventional 2D TSE T2w imaging as a reference. Muscle-lumen contrast to noise ratio (CNR) and wall/lumen volumes (WV, LV) were measured at the matched locations on the 3D and 2D image sets. Statistical comparison on a per-subject basis was conducted to determine the difference and agreement between 3D SPACE and the 2D TSE techniques.

RESULTS

The 3D SPACE data sets enabled vessel visualization from arbitrary orientation through multiplanar reformation technique. Muscle-lumen CNR was significantly higher with 3D SPACE than with the 2D TSE (3.12 +/- 0.84 vs. 2.17 +/- 0.34, P < 0.01). This trend was confirmed when CNR efficiency (CNR(eff)) values were further compared. A similar trend was observed in PAD patients (SPACE vs. 2D TSE T2w: CNR 2.35 +/- 0.13 vs. 1.77 +/- 0.25; CNR(eff) 15.35 +/- 0.61 vs. 3.59 +/- 2.62. all P < 0.05). Measurements of WV and LV from the 3D and 2D techniques were highly correlated in volunteers and PAD patients (volunteers, WV: linear regression r2 = 0.98, LV: r2 = 0.98, P < 0.001 for both; patients, WV: linear regression r2 = 0.96, LV: r2 = 0.94, P < 0.001 for both).

CONCLUSION

We established the feasibility of using the 3D SPACE technique for vessel wall imaging in the superficial femoral artery at 3.0T. High, isotropic-resolution SPACE images, with the aid of multiplanar reformation, enable superior vessel wall visualization. Superior blood signal suppression comparable to vessel wall morphologic measurements, and superior time efficiency compared to conventional 2D TSE imaging indicate the great potential of the SPACE method as a noninvasive imaging technique for the assessment of atherosclerotic plaque burden in PAD patients.

Self-reported peripheral arterial disease predicts future vascular events in a community-based cohort

BACKGROUND

Lower extremity peripheral arterial disease (PAD) is highly prevalent and strongly associated with cardiovascular morbidity and mortality. The ankle-brachial index used to screen for PAD is not routinely performed in primary care settings.

OBJECTIVE

To determine if self-reported PAD is an independent predictor of combined vascular events (myocardial infarction, ischemic stroke, and vascular death).

DESIGN

Ongoing population-based prospective cohort (the Northern Manhattan Study). Subjects enrolled between July 1993 and June 2001 with a mean follow-up time of 7.1 years.

PATIENTS

Subjects (n = 2,977), aged 40 years or older and free of prior stroke or myocardial infarction, were classified as having self-reported PAD if they answered affirmatively to one of two questions regarding exercise-induced leg pain or a prior diagnosis of PAD.

MAIN OUTCOME MEASURES

Combined vascular outcome defined as incident myocardial infarction, incident ischemic stroke, or vascular death.

RESULTS

The mean age of the cohort was 68.9 +/- 10.4 years; 64% were women; 54% Hispanic, 25% African-American, 21% Caucasian; 15% reported having PAD. After a mean follow-up of 7.1 years, self-reported PAD was significantly predictive of combined events (n = 484) in the univariate model (HR 1.5, 95% CI, 1.2-1.9) and after adjustment for traditional cardiovascular risk factors (HR 1.3, 95% CI, 1.0-1.7).

CONCLUSION

Self-reported PAD is an independent risk factor for future vascular events in this predominantly non-white cohort. The addition of two simple PAD questions to the routine medical history in general medicine settings could identify high-risk patients who would benefit from further vascular evaluation and risk factor modification.

Angina pectoris is a stronger indicator of diffuse vascular atherosclerosis than intermittent claudication: Framingham study

OBJECTIVE

To compare implications of Angina Pectoris (AP) and Intermittent Claudication (IC) as indicators of clinical atherosclerosis in other vascular territories.

STUDY DESIGN AND SETTING

Prospective cohort study of cardiovascular disease (CVD) in 5,209 men and women of Framingham, MA, aged 28-62 years at enrollment in 1948-1951, who received biennial examinations during the first 36 years of follow-up. Comparative 10-year incidence of subsequent atherosclerotic CVD in participants with IC and AP relative to a reference sample free of CVD was determined.

RESULTS

On follow-up, 95 CVD events occurred in 186 participants with IC and 206 of 413 with AP. After age, sex, and risk-factor adjustment, the proportion acquiring other CVD was 34.0% for IC and 43.4% for AP. Relative to the reference sample, those with IC had a 2.73-fold higher age and sex-adjusted 10-year hazard of CVD (95% CI 2.21, 3.38) and for AP was 3.17 (95% CI 2.73, 3.69). CVD hazard ratios remained more elevated for AP and statistically significant after standard risk factor adjustment. Risk factors accounted for more of the excess CVD risk associated with IC (34.8%) than AP (9.5%).

CONCLUSION

AP is as useful as IC as a hallmark of diffuse atherosclerotic CVD and an indication for comprehensive preventive measures.

Combined effect of chronic kidney disease and peripheral arterial disease on all-cause mortality in a high-risk population

BACKGROUND AND OBJECTIVES

Chronic kidney disease (estimated glomerular filtration rate <60 ml/min per 1.73 m(2)) and peripheral arterial disease (ankle-brachial index <0.9) independently predict mortality. It was hypothesized that the risk for death is higher in patients with both chronic kidney disease and peripheral arterial disease compared with those with chronic kidney disease or peripheral arterial disease alone.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A total of 1079 patients who had an ankle-brachial index and serum creatinine recorded within 90 d of each other in 1999 were studied retrospectively. Glomerular filtration rate was estimated using the Modification of Diet in Renal Disease equation. Patients were categorized into four groups: Chronic kidney disease and peripheral arterial disease, chronic kidney disease alone, peripheral arterial disease alone, or no chronic kidney disease or peripheral arterial disease.

RESULTS

The overall 6-yr mortality rate was 28% (n = 284). Patients with both chronic kidney disease and peripheral arterial disease had the highest mortality rate (45%) compared with patients with chronic kidney disease alone (28%), peripheral arterial disease alone (26%), and neither condition (18%). After adjustment for clinical and demographic variables, the chronic kidney disease and peripheral arterial disease group had an increased odds for death when compared with the no chronic kidney disease or peripheral arterial disease group or the single disease groups.

CONCLUSIONS

These findings indicate that patients with both chronic kidney disease and peripheral arterial disease have a significantly higher risk for death than patients with either disease alone.

Peripheral arterial occlusive disease: magnetic resonance imaging and the role of aggressive medical management

Atherosclerosis accounts for most peripheral arterial occlusive disease (PAD). Although many of the risk factors for atherosclerotic coronary artery disease (CAD) such as hyperlipidemia have been identified as risk factors for peripheral arterial disease, strong evidence is lacking that risk factor modification is effective in halting progression or improving outcomes. A better understanding is needed regarding the clinical and pathophysiologic responses to risk factor modification. This review describes current advances in the medical management for PAD including lipid modification antiplatelet therapy, angiotensin-converting enzyme (ACE) inhibitors, beta-blockers, exercise, and endovascular intervention. In addition, we discuss our active ELIMIT Trial (Effect of Lipid Modification on Peripheral Arterial Disease after Endovascular Intervention). We test the hypothesis that an aggressive regimen of serum lipid modification will inhibit the progression of atherosclerosis in femoral arteries and reduce the incidence of restenosis of femoral arteries following endovascular stenting by decreasing thrombosis and inflammation. This study will provide a novel strategy for retarding or preventing progression of atherosclerosis and re-stenosis of peripheral arterial disease following arterial revascularization procedures. Importantly, our magnetic resonance imaging studies will provide quantitative data on the vascular lesions in PAD. These studies will advance our understanding of the molecular mechanisms of inflammation and thrombosis associated with aggressive lipid modification.

Mortality in peripheral arterial disease: a comparison of patients managed by vascular specialists and general practitioners

BACKGROUND

Peripheral arterial disease (PAD) is undertreated by general practitioners (GPs). However, the impact of the suboptimal clinical management is unknown.

OBJECTIVE

To assess the mortality rate of PAD patients in relation to the type of physician who provides their care (GP or vascular specialist).

DESIGN

Prospective study.

SETTING

Primary care practice and academic vascular laboratory.

PARTICIPANTS

GP patients (n = 60) were those of the Peripheral Arteriopathy and Cardiovascular Events study (PACE). Patients managed by specialists (n = 82) were consecutive subjects with established PAD who were referred to our vascular laboratory during the enrollment period of the PACE study.

MEASUREMENTS

All-cause and cardiovascular mortality.

RESULTS

After 32 months of follow-up, specialist management was associated with a lower rate of all-cause mortality (RR = 0.04; 95% CI 0.01-0.34; p = .003) and cardiovascular mortality (RR = 0.07; 95% CI 0.01-0.65; p = .020), after adjustment for patients' characteristics. Specialists were more likely to use antiplatelet agents (93% vs 73%, p < .001), statins (62% vs 25%, p < .001) and beta blockers (28% vs 3%, p < .001). Survival differences between specialists and GPs disappeared once the use of pharmacotherapies was added to the proportional hazard model. The fully adjusted model showed that the use of statins was significantly associated with a reduced risk of all-cause mortality (RR = 0.02; 95% CI 0.01-0.73, p = .034) and cardiovascular mortality (RR = 0.02; 95% CI 0.01-0.71, p = .033).

CONCLUSIONS

Specialist management of patients with symptomatic PAD resulted in better survival than generalist management. This effect appears to be mainly caused by the more frequent use of effective medicines by specialists.

The Unsung Perils of Peripheral Arterial Disease: A Malady in Search of a Patient

Peripheral arterial disease (PAD) is increasingly recognized as a strong predictor of mortality and morbidity from atherosclerotic events, especially from coronary heart disease. Since vascular disease remains the most common cause of death in the world, the substantial prevalence, ease of diagnosis, and ominous prognosis have increased interest in PAD among the prevention community. The association with coronary heart disease is strong enough that for prevention purposes, PAD should be considered a high-risk condition that demands aggressive therapy to reduce incident vascular events. Unlike other forms of atherosclerotic disease, PAD is easily diagnosed in the outpatient clinic noninvasively, using the ankle brachial index. Because its diagnosis can thus be seamlessly integrated into the routine clinical encounter, the ankle brachial index has emerged as a tool for global risk assessment. This article will review the relationship between PAD and other vascular disease, emphasizing the role of PAD in prevention efforts.

The significance of lower extremity peripheral arterial disease

The role of the cardiologist is expanding and involves the management of patients with lower extremity atherosclerotic occlusive arterial disease. Peripheral arterial disease (PAD) remains an underdiagnosed and undertreated disease. The purpose of this review is to educate the clinician on the significance of lower extremity atherosclerotic occlusive arterial disease. Pathophysiology and anatomy are briefly reviewed. The definition of PAD is based upon both anatomic and functional considerations. Risk factors for PAD include traditional atherosclerotic risk factors. There is a considerable overlap between coronary and cerebrovascular diseases and PAD. Diagnosis is made mainly by history and physical examination. Noninvasive and invasive tests help diagnosis and localize disease. Expanded therapies to improve outcomes include lifestyle changes, medical treatment, interventional cardiovascular procedures, or surgical intervention.

Incidence of and factors associated with achieving target lipid levels in patients with peripheral arterial disease

BACKGROUND

Patients with peripheral arterial disease (PAD) have increased mortality compared with patients without PAD. Coronary artery disease (CAD) accounts for almost 75% of deaths in PAD patients. Studies suggest that PAD is underdiagnosed and atherosclerotic risk factors undertreated when compared with CAD.

OBJECTIVE

To determine whether cholesterol guidelines are being met in patients with PAD and to determine whether any independent factors increase the likelihood of reaching goal low-density lipoprotein (LDL).

DESIGN

A retrospective chart review of subjects diagnosed with PAD in 2001 at 2 Veterans Affairs Medical Centers.

MEASUREMENTS

Univariate analysis compares baseline characteristics between those reaching goal and those who do not. Multivariate logistic regression analysis identified predictors of meeting LDL goal among PAD patients.

RESULTS

Of 315 patients, 62% reached goal LDL. Those more likely to reach goal were older, had hypertension, and a history of CAD and stroke. Positive predictors of LDL goal were age and CAD, while smoking was a negative predictor.

CONCLUSION

The majority of veterans with PAD received lipid-lowering medication and achieve goal LDL, but they are more likely to do so if they are older than 70 and have a history of CAD.

Delayed calf muscle phosphocreatine recovery after exercise identifies peripheral arterial disease

OBJECTIVES

In this study we intend to characterize phosphocreatine (PCr) recovery kinetics with phosphorus-31 ((31)P) magnetic resonance spectroscopy in symptomatic peripheral arterial disease (PAD) patients compared with control subjects and determine the diagnostic value and reproducibility of this parameter.

BACKGROUND

Due to the inconsistent relationship between flow and function in PAD, novel techniques focused on the end-organ are needed to assess disease severity and measure therapeutic response.

METHODS

Fourteen normal subjects (5 men, age 45 +/- 14 years) and 20 patients with mild-to-moderate symptomatic PAD (12 men, age 67 +/- 10 years, mean ankle brachial index 0.62 +/- 0.13) were studied. Subjects exercised one leg to exhaustion while supine in a 1.5-T magnetic resonance scanner using a custom-built plantar flexion device. Surface coil-localized, free induction decay acquisition localized to the mid-calf was used. Each 31P spectrum consisted of 25 signal averages at a repetition time of 550 ms. The PCr recovery time constant was calculated by monoexponential fit of PCr versus time, beginning at exercise completion.

RESULTS

Median exercise time was 195.0 s in normal subjects and 162.5 s in PAD patients (p = 0.06). Despite shorter exercise times in patients, the median recovery time constant of PCr was 34.7 s in normal subjects and 91.0 s in PAD patients. Area under the receiver-operating characteristic curve was 0.925 +/- 0.045. Test-retest reliability was excellent.

CONCLUSIONS

The PCr recovery time constant is prolonged in patients with symptomatic PAD compared with normal subjects. The method is reproducible and may be useful in the identification of disease. Further study of this parameter's ability to track response to therapy as well as its prognostic capability is warranted.

Risk factors, medical therapies and perioperative events in limb salvage surgery: observations from the PREVENT III multicenter trial

OBJECTIVES

Patients who require infrainguinal revascularization for critical limb ischemia (CLI) are at elevated risk for cardiovascular events. The PREVENT III study was a prospective, randomized, multicenter, phase 3 trial of edifoligide for the prevention of vein graft failure in patients with CLI. We examined the baseline characteristics, perioperative medical therapies, and 30-day incidence of major cardiovascular events in the PREVENT III cohort.

METHODS

Demographics, medical and surgical history, mode of presentation for the index limb, procedural details, and concomitant medications were reviewed for all patients enrolled in PREVENT III (N = 1,404). Major adverse cardiovascular events, including death, myocardial infarction, or cerebrovascular event (stroke or transient ischemic attack) were tabulated. Univariate and multivariate analyses were performed to discern factors that were associated with the utilization of medical therapies and with perioperative events.

RESULTS

Demographics and comorbidities reflected a population with diffuse, advanced atherosclerosis. Perioperative mortality was 2.7%, and major morbidity included myocardial infarction in 4.7% and stroke/transient ischemic attack in 1.4%. Among this population of CLI patients, 33% were not on antiplatelet therapy at study entry, and 24% were not receiving antithrombotics of any type. In addition, 54% of patients were not receiving lipid-lowering therapy, and 52% were not prescribed beta-blocker medications at study entry. On multivariate analysis, race was a significant determinant of antithrombotic utilization, with African-American patients less frequently treated both at baseline and discharge (adjusted odd ratios, 0.5 and 0.6, P < .0001). Antithrombotic and beta-blocker drug usage increased in the overall cohort from baseline (76% and 48%) to discharge (88% and 60%; P < .0001). Patients treated in a university hospital setting were more likely to be prescribed antiplatelet, lipid-lowering, and beta-blocker medications. Advanced age (>75 years), coronary artery disease (prior myocardial infarction or revascularization), and dialysis-dependent renal failure were associated with an increased 30-day risk of death, myocardial infarction, or stroke. Protective effects of beta-blocker and lipid-lowering medications were noted in these defined subgroups.

CONCLUSIONS

A significant percentage of the population that undergoes surgical revascularization for CLI is not prescribed therapies of proven benefit in reducing cardiovascular events. Utilization of antithrombotics and beta-blockers increases during hospitalization for limb salvage surgery but that of lipid-lowering therapy does not. African-American patients appear to be at greater risk for undertreatment with antithrombotics, and the data suggest that patients undergoing leg bypass surgery in a university hospital setting receive more comprehensive medical treatment of atherosclerosis. Treatment guidelines for medical therapy are needed to standardize care and improve outcomes for patients with CLI.

The morbidity and mortality following a diagnosis of peripheral arterial disease: long-term follow-up of a large database

BACKGROUND

Awareness of the significance of peripheral arterial disease is increasing, but quantitative estimates of the ensuing burden and the impact of other risk factors remains limited. The objective of this study was to fill this need.

METHODS

Morbidity and mortality were examined in 16,440 index patients diagnosed with peripheral arterial disease in Saskatchewan, Canada between 1985 and 1995. Medical history and patient characteristics were available retrospectively to January 1980 and follow-up was complete to March 1998. Crude and adjusted event rates were calculated and Kaplan-Meier survival curves estimated. Cox proportional hazards analyses were conducted to examine the effect of risk factors on these rates. Patients suffering a myocardial infarction or ischemic stroke in Saskatchewan provided two reference populations.

RESULTS

Half of the index patients were male; the majority was over age 65; 73% had at least one additional risk factor at index diagnosis; 10% suffered a subsequent stroke, another 10% a myocardial infarction, and 49% died within the mean follow-up of 5.9 years. Annual mortality (8.2%) was higher among patients with PAD than after a myocardial infarction (6.3%) but slightly lower than that in patients suffering a stroke (11.3%). Index patients with comorbid disease (e.g., diabetes) were at highest risk of death and other events.

CONCLUSION

A diagnosis of peripheral arterial disease is critical evidence of more widespread atherothrombotic disease, with substantial risks of subsequent cardiovascular events and death. Given that the majority has additional comorbidities, these risks are further increased.

Atherosclerotic risk factor reduction in peripheral arterial diseasea: results of a national physician survey

OBJECTIVE

Individuals with peripheral arterial disease (PAD) have a 3- to 6-fold increased risk of coronary heart disease and stroke compared to those without PAD. We documented physician-reported practice behavior, knowledge, and attitudes regarding atherosclerotic risk factor reduction in patients with PAD.

DESIGN

National physician survey.

PATIENTS/PARTICIPANTS

General internists (N = 406), family practitioners (N = 435), cardiologists (N = 473), and vascular surgeons (N = 264) randomly identified using the American Medical Association's physician database.

MEASUREMENTS AND MAIN RESULTS

Physicians were randomized to 1 of 3 questionnaires describing a) a 55- to 65-year-old patient with PAD; b) a 55- to 65-year-old patient with coronary artery disease (CAD), or c) a 55- to 65-year-old patient without clinically evident atherosclerosis (no disease). A mailed questionnaire was used to compare physician behavior, knowledge, and attitude regarding risk factor reduction for each patient. Rates of prescribed antiplatelet therapy were significantly lower for the patient with PAD than for the patient with CAD. Average low-density lipoprotein levels at which physicians "almost always" initiated lipid-lowering drugs were 121.6 +/- 23.5 mg/dL, 136.3 +/- 28.9 mg/dL, and 149.7 +/- 24.4 mg/dL for the CAD, PAD, and no-disease patients, respectively (P <.001). Physicians stated that antiplatelet therapy (P <.001) and cholesterol-lowering therapy (P <.001) were extremely important significantly more often for the CAD than for the PAD patient. Perceived importance of risk factor interventions was highly correlated with practice behavior. Compared to other specialties, cardiologists had lowest thresholds, whereas vascular surgeons had the highest thresholds for initiating cholesterol-lowering interventions for the patient with PAD. Cardiologists were significantly more likely to report "almost always" prescribing antiplatelet therapy for the patient with PAD than were all other physicians.

CONCLUSIONS

Deficiencies in physician knowledge and attitudes contribute to lower rates of atherosclerotic risk factor reduction for patients with PAD. Reversing these deficiencies may reduce the high rates of cardiovascular morbidity and mortality associated with PAD.