C-reactive protein and brain natriuretic peptide as predictors of adverse events after lower extremity endovascular revascularization

Malondialdehyde-Modified Low-Density Lipoprotein as a Predictor of Major Adverse Limb Events after Endovascular Therapy in Patients with Lower Extremity Arterial Disease

AIM

Adverse limb events after endovascular therapy (EVT) are a major concern. This study aimed to investigate the relationship between serum malondialdehyde-modified low-density lipoprotein (MDA-LDL) level, a potentially potent indicator of atherosclerosis, and clinical outcomes after EVT in patients with lower extremity arterial disease (LEAD).

METHODS

A total of 208 LEAD patients who underwent EVT and MDA-LDL measurements were retrospectively analyzed. Those with chronic limb-threatening ischemia (CLTI) were included in the CLTI subgroup (n=106). Patients were further categorized into the High or Low MDA-LDL groups according to the cut-off value calculated by receiver operating characteristic analysis. Major adverse limb events (MALE), a composite of cardiovascular death, limb-related death, major amputation, and target-limb revascularization, were evaluated.

RESULTS

MALE occurred in 73 (35%) patients. The median follow-up interval was 17.4 months. The MDA-LDL cut-off values were 100.5 U/L (area under the curve [AUC] 0.651) in the overall population and 98.0 U/L (AUC 0.724) in the CLTI subgroup. Overall, the High MDA-LDL group showed significantly higher total cholesterol (189.7±37.5 mg/dL vs. 159.3±32.0 mg/dL, p＜0.01), low-density lipoprotein cholesterol (114.3±29.7 mg/dL vs. 87.3±25.3 mg/dL, p＜0.01), and triglyceride (166.9±91.1 mg/dL vs. 115.8±52.3 mg/dL, p＜0.01) than the Low MDA-LDL group. Multivariate Cox regression analyses revealed that MDA-LDL and C-reactive protein were independent predictors of MALE. In the CLTI subgroup, MDA-LDL was an independent predictor of MALE. The High MDA-LDL group showed worse MALE-free survival rates than the Low MDA-LDL group in overall (p＜0.01) and in the CLTI subgroup (p=0.01).

CONCLUSIONS

Serum MDA-LDL level was associated with MALE after EVT.

Development of a biomarker panel for assessing cardiovascular risk in diabetic patients with chronic limb-threatening ischemia (CLTI): a prospective study

BACKGROUND

Lower-extremity endovascular revascularization (LER) is often required for diabetic patients with chronic limb threatening ischemia (CLTI). During the post-revascularization period patients may unpredictably experience major adverse cardiac events (MACE) and major adverse limb events (MALE). Several families of cytokines are involved in the inflammatory process that underlies the progression of atherosclerosis. According to current evidence, we have identified a panel of possible biomarkers related with the risk of developing MACE and MALE after LER. The aim was to study the relationship between a panel of biomarkers - Interleukin-1 (IL-1) and 6 (IL-6), C-Reactive Protein (CRP), Tumor Necrosis Factor-α (TNF-α), High-Mobility Group Box-1 (HMGB-1), Osteoprotegerin (OPG), Sortilin and Omentin-1- at baseline, with cardiovascular outcomes (MACE and MALE) after LER in diabetic patients with CLTI.

METHODS

In this prospective non-randomized study, 264 diabetic patients with CLTI undergoing endovascular revascularization were enrolled. Serum levels of each biomarker were collected before revascularization and outcomes' incidence was evaluated after 1, 3, 6 and 12 months.

RESULTS

During the follow-up period, 42 cases of MACE and 81 cases of MALE occurred. There was a linear association for each biomarker at baseline and incident MACE and MALE, except Omentin-1 levels that were inversely related to the presence of MACE or MALE. After adjusting for traditional cardiovascular risk factors, the association between each biomarker baseline level and outcomes remained significant in multivariable analysis. Receiver operating characteristics (ROC) models were constructed using traditional clinical and laboratory risk factors and the inclusion of biomarkers significantly improved the prediction of incident events.

CONCLUSIONS

Elevated IL-1, IL-6, CRP, TNF-α, HMGB-1, OPG and Sortilin levels and low Omentin-1 levels at baseline correlate with worse vascular outcomes in diabetic patients with CLTI undergoing LER. Assessment of the inflammatory state with this panel of biomarkers may support physicians to identify a subset of patients more susceptible to the procedure failure and to develop cardiovascular adverse events after LER.

Serum levels of Matrix Metalloproteinases (MMPs) in patients undergoing endovascular intervention for peripheral arterial disease

OBJECTIVES

Matrix metalloproteinases (MMPs) play a significant role in the development and progression of atherosclerotic vascular disease. The purpose of this study was to measure and document the profile of plasma circulating MMPs in patients with peripheral arterial disease (PAD) undergoing endovascular revascularization.

METHODS

This was a single centre prospective observational study with 80 patients with PAD enrolled. They underwent percutaneous balloon angioplasty and/or angioplasty with stent. Exclusion criteria were acute limb ischemia, active inflammation, wet gangrene, liver disease, end stage renal failure and cancer. Patients that underwent open or hybrid (open and endovascular) approach, were also excluded from the study. Venous blood samples were taken preoperatively, 24 hours and 6 months postoperatively. The values of MMP-2, MMP-3, MMP-7, MMP-9 and their inhibitors (Tissue Inhibitor of metalloproteinases, TIMP), TIMP-1 and TIMP-2 were measured.

RESULTS

The mean age was 67.1 years and 66 of them (82.5%) were male. During the clinical follow up (mean 35.8% months), 12 patients died (16.4%), 15 (20.5%) of them had a major adverse limb event (MALE) and 14 (19.2%) of them had a major adverse cardiovascular event (MACE). There was a statistically significant raise in the values of MMP-2. MMP-3 and MMP-7 at 6 months postoperatively, when compared to the preoperative and 24 hours postoperative values. There was no correlation of MMP and TIMP values with mortality, MALE and MACE events.

CONCLUSIONS

The present single-centre prospective study documented increased circulating levels of MMPs post-operatively in PAD patients undergoing endovascular treatment. Vascular trauma caused by angioplasty, could trigger expression of MMPs and TIMPs, but the absence of any association with clinical complications requires further investigation.

Peri-procedural complications following endovascular revascularization for critical limb ischemia

OBJECTIVE

Revascularization procedures are considered the cornerstone of therapy in patients with critical limb ischemia (CLI) and multiple procedures are often required to attain limb salvage. The aim of the present study is to determine the prevalence of peri-procedural complications after endovascular procedure, and to determine the clinical and biological characteristics of patients associated to the risk of peri-procedural complications.

METHODS

From November 2013 to May 2021, 324 consecutive patients were retrospectively included, of whom 99 underwent more than one revascularization procedure for contralateral CLI or clinical recurrence of CLI. A total of 532 revascularizations were performed. Clinical and biological parameters were recorded at baseline before endovascular revascularization. The occurrence of a peri-procedural complication (local complications, fatal and non-fatal major bleeding or cardiovascular events) was recorded up to 30days after revascularization. Univariate and multivariate analyses were performed to study the parameters associated with per-procedural complications. A P<0.05 was considered as statistically significant.

RESULTS

A total of 324 consecutive patients were included, 177 men and 147 women with CLI, with a mean age of 77.6±11.9years. Most of these patients had cardiovascular comorbidities (41% with a history of coronary heart disease, 78% treated hypertensive patients, 49% diabetic patients). Peri-procedural mortality occurred in 13 patients (4%) and 9 patients (2.8%) experienced major amputation at one-month following revascularization. Among the 532 revascularization procedures, 99 major bleeding events (22.8% of the cohort population) and 31 cardiovascular events (8.6% of the cohort population), were recorded in the peri-procedural period. Cardiovascular events were associated with peri-procedural mortality. Complications at the puncture site occurred during 38 of the 532 procedures (10.2% of the cohort population). Compared with patients undergoing a single revascularization procedure, patients with multiple procedures presented a higher risk of major bleeding events (48.5% vs. 11.6%, P<0.0001) and access site complications (20.2% vs. 5.78%, P<0.0001). In multivariate analysis, pulse pressure <60mmHg and hemoglobin level <10g/dl were correlated with the occurrence of major bleeding events; left ventricular ejection fraction<60% and the absence of statin treatment were correlated with the occurrence of cardiovascular complications; a high chronological rank of revascularization was correlated with the occurrence of local complication. Finally, age and gender were not associated with the occurrence of peri-procedural complication.

CONCLUSION

The present results highlight that multiple revascularization procedures for limb salvage are required in almost one third of the population with critical limb ischemia and were associated with the risk of major bleeding events and access site complications. The most frequent complications of peripheral vascular interventions were major bleeding events. Adverse cardiovascular events were related with peri-procedural mortality. Anemia, blood pressure, left ventricular ejection fraction and statin treatment are important parameters to consider for peri-procedural outcomes, independently of age, gender and the chronological rank of revascularization procedure.

Dietary Risk Factors and Eating Behaviors in Peripheral Arterial Disease (PAD)

Dietary risk factors play a fundamental role in the prevention and progression of atherosclerosis and PAD (Peripheral Arterial Disease). The impact of nutrition, however, defined as the process of taking in food and using it for growth, metabolism and repair, remains undefined with regard to PAD. This article describes the interplay between nutrition and the development/progression of PAD. We reviewed 688 articles, including key articles, narrative and systematic reviews, meta-analyses and clinical studies. We analyzed the interaction between nutrition and PAD predictors, and subsequently created four descriptive tables to summarize the relationship between PAD, dietary risk factors and outcomes. We comprehensively reviewed the role of well-studied diets (Mediterranean, vegetarian/vegan, low-carbohydrate ketogenic and intermittent fasting diet) and prevalent eating behaviors (emotional and binge eating, night eating and sleeping disorders, anorexia, bulimia, skipping meals, home cooking and fast/ultra-processed food consumption) on the traditional risk factors of PAD. Moreover, we analyzed the interplay between PAD and nutritional status, nutrients, dietary patterns and eating habits. Dietary patterns and eating disorders affect the development and progression of PAD, as well as its disabling complications including major adverse cardiovascular events (MACE) and major adverse limb events (MALE). Nutrition and dietary risk factor modification are important targets to reduce the risk of PAD as well as the subsequent development of MACE and MALE.

C-reactive Protein, Free Fatty Acid, and Uric Acid as Predictors of Adverse Events after Endovascular Revascularization of Arterial Femoropopliteal Occlusion Lesions

OBJECTIVES

This study aimed to investigate the relationship between pre-procedure high-sensitivity C-reactive protein (hsCRP), free fatty acid (FFA), and uric acid (UA) levels and post-procedure mortality and morbidity of endovascular revascularization of arterial femoropopliteal occlusion lesions.

METHODS

This was a retrospective review of clinical data retrieved from a prospectively held database in Peking Union Medical College Hospital. A total of 71 Patients who underwent endovascular treatment (EVT) for femoropopliteal occlusive disease between January 1, 2014 and November 1, 2017, were included in this study. Endpoints were defined as major adverse limb events (MALE; target vessel revascularization, amputation, or disease progression) and major adverse cardiovascular events (MACE; stroke, myocardial infarction, or all-cause death) during the entire follow-up period. Univariate and multivariate Cox proportional hazards regression models were used to evaluate the relationship of elevated biomarker levels (hsCRP, FFA and UA, measured by immunoturbidimetry assay, enzymatic assay and enzymatic assay, respectively) to MALE and MACE outcomes.

RESULTS

Seventy-one patients (72 limbs) with sufficient follow-up information were included in the analysis. The mean age was 69.7 ± 8.6 years; 21.1% were female. The Rutherford class of target limbs were ≥ 3. The median follow-up was 36 (range 18-59 months). Univariate analyses revealed that patients with elevated hsCRP levels had an increased risk of MALE (hazard ratio [HR], 2.682; 95% confidence interval [CI], 1.281-5.617, P = 0.009). High FFA levels were associated with an increased risk of MALE (HR, 2.658; 95% CI, 1.075-6.573; P = 0.034). Multivariate analyses demonstrated that elevated hsCRP values (HR, 4.015; 95% CI, 1.628-10.551; P = 0.003) and FFA value (HR, 3.034; 95% CI, 1.102-8.354; P = 0.032) were both significantly associated with increased MALE. Elevated UA levels predicted MACE in the presence of confounders (HR, 11.446; 95% CI, 1.367-95.801 P = 0.023).

CONCLUSION

Pre-procedure hsCRP and FFA levels could serve as predictors of adverse events after EVT in patients with arterial femoropopliteal occlusive disease. The role of UA in MACE may warrant further investigation, because the correlation is not as powerful as the other two in the study.

Principal predictors of major adverse limb events in diabetic peripheral artery disease: A narrative review

Background and aims

The increasing prevalence of diabetes mellitus is causing a massive growth of peripheral artery disease incidences, a disabling complication of diabetic atherosclerosis, which leads often to the amputation of the affected limb. Critical limb ischemia is the terminal disease stage, which requires a prompt intervention to relieve pain and save limbs. However, patients undergoing revascularization often suffer from cardiovascular, cerebrovascular and major adverse limb events with poor outcomes. Furthermore, the same procedure performed in apparently similar patients has various outcomes and lack of an outcome predictive support causes a high lower limb arterial revascularization rate with disastrous effects for patients. We collected the main risk factors of major adverse limb events in a more readable and immediate format of the topic, to propose an overview of parameters to manage effectively peripheral artery disease patients and to propose basics of a new predictive tool to prevent from disabling vascular complications of the disease.

Methods

Most recent and updated literature about the prevalence of major adverse limb events in peripheral artery disease was reviewed to identify possible main predictors.

Results

In this article, we summarized major risk factors of limb revascularization failure and disabling vascular complications collecting those parameters principally responsible for major adverse limb events, which provides physio-pathological explanation of their role in peripheral artery disease.

Conclusion

We evaluated and listed a panel of possible predictors of MALE (Major Adverse Limb Event) in order to contribute to the development of a predictive score, based on a summary of the main risk factors reported in scientific articles, which could improve the management of peripheral artery disease by preventing vascular accidents.

Long-term impact of high-sensitivity C-reactive protein in patients with intermittent claudication due to peripheral artery disease following endovascular treatment

Little is known about the prognostic impact of high-sensitivity C-reactive protein (hs-CRP) levels on causes of death during long-term follow-up. We, therefore, investigated the associations between hs-CRP and clinical outcomes in the patients with intermittent claudication. Three hundred thirty-five consecutive patients (mean age, 72 ± 8 years, 82% men) undergoing first intervention for de novo iliac and/or femoropopliteal artery lesions from 2009 to 2020 were studied. Patients were divided into 2 groups based on the optimal cutoff value of hs-CRP (> or ≤ 0.15 mg/dL). The median follow-up duration was 3.6 years (interquartile range, 1.0-6.2 years). Although the cumulative incidence rate of major adverse cardiovascular limb events was not significantly different between the higher and lower hs-CRP groups (29.0 and 22.1%, respectively; log-rank test, p = 0.410), that of all-cause death was significantly higher in the higher hs-CRP group than in the lower hs-CRP group (18.7 vs. 5.8%, log-rank test, p = 0.007), even in cardiovascular-related death and malignancy-related death (log-rank test, p = 0.030 and 0.046, respectively). Higher hs-CRP levels at the time of intervention were significantly associated with higher frequency of all-cause death, even after adjusting for other risk factors (hazard ratio 2.79; 95% confidence interval 1.66-7.17, p = 0.024). In addition, malignancy-related death was most frequent as high as 60% (21/35 deaths), and elevated hs-CRP levels and the Brinkman index were strongly independent predictors of malignancy-related death. In conclusion, elevated hs-CRP levels were significantly associated with cardiovascular-related and malignancy-related deaths in patients with intermittent claudication. Furthermore, the result that cancer mortality exceeds cardiovascular mortality is different from previous reports, so the present findings warrant further investigation.

The Role of Circulating Biomarkers in Peripheral Arterial Disease

Peripheral arterial disease (PAD) of the lower extremities is a chronic illness predominantly of atherosclerotic aetiology, associated to traditional cardiovascular (CV) risk factors. It is one of the most prevalent CV conditions worldwide in subjects >65 years, estimated to increase greatly with the aging of the population, becoming a severe socioeconomic problem in the future. The narrowing and thrombotic occlusion of the lower limb arteries impairs the walking function as the disease progresses, increasing the risk of CV events (myocardial infarction and stroke), amputation and death. Despite its poor prognosis, PAD patients are scarcely identified until the disease is advanced, highlighting the need for reliable biomarkers for PAD patient stratification, that might also contribute to define more personalized medical treatments. In this review, we will discuss the usefulness of inflammatory molecules, matrix metalloproteinases (MMPs), and cardiac damage markers, as well as novel components of the liquid biopsy, extracellular vesicles (EVs), and non-coding RNAs for lower limb PAD identification, stratification, and outcome assessment. We will also explore the potential of machine learning methods to build prediction models to refine PAD assessment. In this line, the usefulness of multimarker approaches to evaluate this complex multifactorial disease will be also discussed.

A systematic review and meta-analysis on the association between C-reactive protein levels and adverse limb events after revascularization in patients with peripheral arterial disease

OBJECTIVE

Patients with peripheral arterial disease (PAD) are predisposed to postprocedure adverse limb events (ALE). Previous single-center studies investigating the relationship between baseline C-reactive protein (CRP) levels and postprocedure ALE have reported inconsistent results. Therefore, we performed a systematic review and meta-analysis of reported data to determine the association between CRP levels and the occurrence of postprocedure ALE in patients with PAD.

METHODS

Studies investigating the association between the CRP levels and postprocedure ALE (ie, target vessel revascularization, amputation, restenosis, disease progression, composite endpoint of any of these ALE) were identified in the Medline, EMBASE, and Cochrane databases. Meta-analyses of the reported hazard ratios (HRs) were conducted using an inverse variance-weighted random effects model. Subgroup analyses were performed to determine the differences in outcomes between open surgery and endovascular treatment. Pooled estimates are reported as HRs to compare higher and lower CRP levels and odds ratio or relative risk per unit increase in log_eCRP (natural logarithm C-reactive protein).

RESULTS

A total of eight studies involving 1460 participants were included in our meta-analysis. Patients with higher baseline CRP levels had a greater risk of ALE (HR, 1.09; 95% confidence interval, 1.00-1.18; P = .04) compared with those with lower baseline CRP levels. The pooled estimate of odds ratio and relative risk for ALE was 2.25 (95% confidence interval, 1.49-3.41; P < .01) per unit increase in log_eCRP. Subgroup analyses found no significant differences in the pooled estimates in studies of open surgery vs endovascular treatment.

CONCLUSIONS

Our results have demonstrated that high baseline CRP levels are predictive of ALE in patients with PAD after lower limb revascularization.

Outcomes of Lower Extremity Endovascular Revascularization: Potential Predictors and Prevention Strategies

Peripheral artery disease (PAD) is a manifestation of atherosclerosis, which may affect arteries of the lower extremities. The most dangerous PAD complication is chronic limb-threatening ischemia (CLTI). Without revascularization, CLTI often causes limb loss. However, neither open surgical revascularization nor endovascular treatment (EVT) ensure long-term success and freedom from restenosis and revascularization failure. In recent years, EVT has gained growing acceptance among all vascular specialties, becoming the primary approach of revascularization in patients with CLTI. In clinical practice, different clinical outcomes after EVT in patients with similar comorbidities undergoing the same procedure (in terms of revascularization technique and localization of the disease) cause unsolved issues that need to be addressed. Nowadays, risk management of revascularization failure is one of the major challenges in the vascular field. The aim of this literature review is to identify potential predictors for lower extremity endovascular revascularization outcomes and possible prevention strategies.

The association of preprocedural C-reactive protein/albumin ratio with in-stent restenosis in patients undergoing iliac artery stenting

Introduction: In-stent restenosis (ISR) still constitutes a major problem after percutaneous vascular interventions and the inflammation has a pivotal role in the pathogenesis of such event. The C-reactive protein/albumin ratio (CAR) is a newly identified inflammatory biomarker, and it may be used as an indicator to predict ISR in subjects with coronary artery stenting. In light of these data, our main objective was to investigate the relationship between the preprocedural CAR and ISR in patients undergoing successful iliac artery stent implantation.

Methods: In total, 138 consecutive patients who had successful iliac artery stent implantation in a tertiary heart center between 2015 and 2018 were enrolled in the study. The study population was categorized into two groups; patients with ISR and those without ISR during follow-up. The CAR was determined by dividing CRP by serum albumin.

Results: In the multivariable regression analysis; the CAR (HR: 2.66, 95% CI: 1.66-4.25, P < 0.01), stent length (HR: 1.01, 95% CI: 0.99-1.02, P = 0.04), and HbA1c levels (HR: 1.22, 95% CI: 0.99-1.51, P = 0.04) were independently related with ISR. A receiver operating curve analysis displayed that the CAR value of >0.29 predicted ISR with sensitivity of 97.5% and specificity of 88.8% (AUC 0.94, P < 0.01).

Conclusion: Our findings provide evidence that the CAR may be an applicable inflammatory biomarker in predicting ISR in subjects undergoing iliac artery stenting for the treatment of peripheral artery disease (PAD). Also, the stent length and poor glycemic control were found to be associated with ISR.

Plasma Biomarkers to Predict Cardiovascular Outcome in Patients With Peripheral Artery Disease: A Systematic Review and Meta-Analysis

Supplemental Digital Content is available in the text.

Patients with lower extremity peripheral artery disease (PAD) are at increased risk of major adverse cardiovascular events. Numerous plasma biomarkers have been investigated in lower extremity PAD, but none are used for clinical risk assessment. We aimed to provide a comprehensive overview of biomarker testing in PAD as a first step to improve risk stratification.

Mortality and chronic obstructive pulmonary disease in patients treated with endovascular revascularization of the infra-inguinal lower limb arteries from retrograde access

Background

In this trial, our objective was to evaluate the relationship between long-term clinical outcomes in patients with peripheral arterial disease (PAD) treated with retrograde endovascular recanalization (ER) of chronic total occlusions (CTOs) regarding the infra-inguinal lower limb arteries and chronic obstructive pulmonary disease (COPD).

Methods

A total of 834 consecutive subjects were enrolled in the study. The mean age was 67.8±10.6 years (62.6% males). COPD was diagnosed in 98 patients (11.7%). The infra-inguinal location included the deep, superficial and common femoral artery, popliteal artery or below the knee arteries. During follow-up, we evaluated major adverse cardiac and cerebrovascular events (MACCE) and major adverse limb events (MALE). MACCE was considered as death, stroke/transient ischemic attack, myocardial infarction, percutaneous coronary intervention or coronary artery bypass grafting operation, while MALE regarded amputation, target lesion re-intervention, target vessel re-intervention and surgical action.

Results

The mean follow-up was 1,144.9±664.3 days and the interquartile range was 1,110.5 (504.5–1,734.7). Data were collected between 2006 and 2016. We noticed significant differences in death rates among the COPD and non-COPD groups. The cumulative number of events (deaths) was 12.2%, 17.3%, 18.4%, 22.4%, 23.5%, 23.5% and 23.5% in the COPD group and 6.1%, 7.5%, 10.5%, 11.3%, 11.4% 11.5% and 11.5% in the non-COPD group after 1, 2, 3, 4, 5, 6 and 7 years of follow-up, and was notably greater for COPD (P=0.0007).

Conclusions

Patients with COPD and PAD treated with the ER and retrograde approach due to CTOs are related to higher mortality than non-COPD patients.

Association between Circulating B-Type Natriuretic Peptide and Diabetic Peripheral Neuropathy: A Cross-Sectional Study of a Chinese Type 2 Diabetic Population

Cardiovascular disease which is associated with cardiac dysfunction, usually measured with circulating levels of B-type natriuretic peptide (BNP), has been associated with incidence and progression of diabetic peripheral neuropathy (DPN). The potential relationship of circulating physiological levels of BNP with DPN, however, has not been reported. Circulating levels of BNP were measured in 258 patients with type 2 diabetes mellitus (T2DM), and participants were divided into a DPN group (n = 61) and no DPN group (n = 197). The relationship between circulating physiological levels of BNP and DPN and other parameters was analyzed. Circulating levels of BNP were significantly elevated in T2DM patients with DPN compared to those without (P = 0.001). Circulating levels of BNP were significantly and positively associated with systolic blood pressure (P = 0.035), neutrophil-to-lymphocyte ratio (P = 0.007), creatinine (P = 0.030), vibration perception threshold values (P = 0.021), and the prevalence of diabetic foot ulceration (P = 0.039), peripheral arterial disease (P = 0.013), DPN (P = 0.032), and diabetic nephropathy (P = 0.020) and negatively with lymphocyte count (P = 0.003) and ankle-brachial index (P = 0.038), irrespective of age, sex, and body mass index. Moreover, circulating levels of BNP was an independent decisive factor for the presence of DPN after multivariate adjustment (odds ratio, 1.044; 95% confidence interval, 1.006-1.084; P = 0.024). Additionally, the higher quartiles of circulating BNP were related significantly to an increased risk of DPN compared to the lowest quartile (P = 0.003). Last but most importantly, the analysis of receiver operating characteristic curves revealed that the best cutoff value for circulating levels of BNP to predict DPN was 15.18 pg/mL (sensitivity 78.7% and specificity 48.2%). These findings suggest that high circulating physiological levels of BNP may be associated with the development of DPN and may be a potential biomarker for DPN in patients with T2DM.

Inflammatory Cytokines Associated With Failure of Lower-Extremity Endovascular Revascularization (LER): A Prospective Study of a Population With Diabetes

OBJECTIVE

Peripheral artery disease (PAD) is one of the most relevant complications of diabetes. Although several pharmacological and revascularization approaches are available for treating patients with diabetes and PAD, an endovascular approach is often associated with postprocedural complications that can increase the risk for acute limb ischemia or amputation. However, no definitive molecular associations have been described that could explain the difference in outcomes after endovascular treatment in patients with diabetes, PAD, and chronic limb-threatening ischemia (CLTI).

RESEARCH DESIGN AND METHODS

We evaluated the relationship between the levels of the main cytokines associated with diabetic atherosclerosis and the outcomes after endovascular procedures in patients with diabetes, PAD, and CLTI.

RESULTS

A total of 299 patients with below-the-knee occlusive disease who were undergoing an angioplasty procedure were enrolled. The levels of key cytokines-osteoprotegerin (OPG), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and C-reactive protein (CRP)-were measured, and major adverse limb events (MALE) and major adverse cardiovascular events (MACE) were assessed 1, 3, 6, and 12 months after the procedure. There was a linear trend from the lowest to the highest quartile for each cytokine at baseline and incident MALE. A linear association was also observed between increasing levels of each cytokine and incident MACE. Receiver operating characteristics models were constructed using clinical and laboratory risk factors, and the inclusion of cytokines significantly improved the prediction of incident events.

CONCLUSIONS

We demonstrated that elevated OPG, TNF-α, IL-6, and CRP levels at baseline correlate with worse vascular outcomes in patients with diabetes, PAD, and CLTI undergoing an endovascular procedure.

Cardiac biomarkers but not measures of vascular atherosclerosis predict mortality in patients with peripheral artery disease

BACKGROUND

Peripheral artery disease (PAD) becomes more prevalent with advancing age and is associated with elevated risk of cardiovascular events and shortened life expectancy. We investigated the prognostic performance of cardiac and vascular biomarkers in a cohort of PAD patients.

METHODS

A total of 95 PAD patients were enrolled (mean age 68 years, range 47 to 86 years, 73 males). Carotid intima-media thickness (cIMT), ankle brachial index (ABI), high sensitive cardiac troponin T, and N-terminal pro-B-type Natriuretic Peptide (NT-proBNP) were measured.

RESULTS

During a median follow-up time of 9.5 years, 44 patients died and 51 patients survived. Upon Kaplan-Meier survival analysis hs-TnT (P < .001) or NT-proBNP levels (P < .001) above the median but not cIMT above the median (P = .488) or ABI below the median (P < .436)were associated with reduced survival rate. Upon univariate cox regression and after adjustment for age, gender, prior cerebral artery disease, and diabetes mellitus only the association between hs-cTnT and mortality remained significant (HR 1.93, 95% CI 1.33-2.79, P < .001). In receiver operating curve analysis hs-cTnT (area under the curve [AUC]: 0.77, 95% CI: 0.67-0.87, P < .001) NT-proBNP (AUC: 0.74, 95% CI: 0.64-0.84, P < .001) as well as hs-cTnT, and NT-proBNP combined (AUC: 0.79, 95% CI: 0.69-0.88, P < .001) were superior to cIMT (AUC: 0.64, 95%, CI: 0.53-0.76, P = .022) and ABI (AUC: 0.57, 95% CI: 0.44-0.68, P = .313) in discriminating risk for mortality.

CONCLUSION

hs-cTnT and NT-proBNP should be taken into account for prognosis of patients with PAD.

Cardiac Biomarkers Predicting MACE in Patients Undergoing Noncardiac Surgery: A Meta-Analysis

Objective: The present meta-analysis was aimed to systematically evaluate the effectiveness and accuracy of brain natriuretic peptide (BNP), cardiac troponin (cTn), high sensitive C reactive protein (hs-CRP) and CRP for predicting postoperative major adverse cardiovascular events (MACE) in patients undergoing noncardiac surgery.

Methods: A total of 26 relevant studies with 7,877 participants were collected from five databases, namely PubMed, Embase, China National Knowledge Infrastructure (CNKI), CQVIP and the Wanfang Database until August 10, 2018. And the Review Manager Version 5.3 and Stata/SE 12 software were used for data syntheses in the meta-analysis.

Results: Strong relationships of BNP/NT-proBNP, cTnI/cTnT and hs-CRP with MACE were detected in patients undergoing noncardiac surgery, and the five biomarkers all increased the risk of MACE. Compared to normal levels, elevated BNP/NT-proBNP could increase the MACE risk by almost 4-fold [RR:3.92, 95%CI: 3.23–4.75, P < 0.001]; elevated BNP corresponded to a 4.5-fold risk [RR:4.57, 95%CI: 3.37–6.20, P < 0.001]; elevated NT-proBNP led to a 3-fold higher risk [RR:3.48, 95%CI: 2.71–4.46, P < 0.001]. Comparing with normal levels of cTnI/cTnT, increased cTnI/cTnT was associated with nearly 5-fold more higher risk of MACE [RR:5.52, 95%CI: 4.62–6.58, P < 0.001]; elevated cTnI faced a 5-fold risk [RR:5.21, 95%CI: 3.96–6.86, P < 0.001]; elevated cTnT resulted in nearly 6-fold higher risk [RR:5.73, 95%CI: 4.55–7.22, P < 0.001]. The elevation of hs-CRP was associated with nearly 4-fold higher risk of MACE in comparison with normal concentration [RR:3.73, 95%CI: 2.63–5.30, P < 0.001].

Conclusion: According to the results of our meta-analysis, the elevations of BNP/NT-proBNP, cTnI/cTnT, and hs-CRP, pre-operation or post-operation immediately, can predict much higher risk of postoperative MACE in patients undergoing noncardiac surgery.

Anti-phosphorylcholine IgM, an Anti-inflammatory Mediator, Predicts Peripheral Vein Graft Failure: A Prospective Observational Study

OBJECTIVES

One third of infrainguinal vein bypasses may fail within the first 1.5 years. Pro- and anti-inflammatory mechanisms are thought to be involved in these graft stenoses and occlusions. In previous studies, low levels of anti-phosphorylcholine IgM (anti-PC IgM, an innate anti-inflammatory IgM) have been associated with increased cardiovascular events. In this study, the peri-operative dynamics of anti-PC IgM levels were established during leg bypass surgery, and associations assessed between anti-PC IgM levels and primary graft patency.

DESIGN AND METHODS

This was a prospective, observational cohort study of infrainguinal autogenous vein bypass for peripheral arterial occlusive disease involving four university affiliated hospitals. Plasma cytokine and anti-PC IgM levels were measured pre- and post-operatively. The outcome of interest was loss of primary graft patency because of occlusion or intervention for graft stenosis.

RESULTS

One hundred and forty-two consecutive patients were enrolled: mean age 66 (46-91); 91% white race and male; 72.5% critical limb ischaemia (Fontaine III or IV). Median pre-operative anti-PC IgM levels were 49 units/mL (IQR 32.3-107.7, mean 89.8 + 101 sd). During follow up of an average of 1.8 years (1 month-7.4 years), 50 (35.2%) grafts lost primary patency. Pre-operative levels of interleukin 6 or C-reactive protein did not predict graft failure. Patients with pre-operative anti-PC IgM values in the lowest quartile had a twofold increased risk of graft failure (multivariable Cox proportional hazard, p = .03, HR 2.11, 95% CI 1.09-4.07), even after accounting for the other significant factors of conduit diameter, distal anastomosis, smoking, and the severity of leg ischaemia.

CONCLUSIONS

Low levels of anti-PC IgM are associated with vein bypass graft failure. This biological mediator may be a useful marker to identify patients at higher risk, and offers the potential for novel, directed therapies for vascular inflammation and its consequences.

The heart matters in diabetes: 10-Year outcomes of peripheral artery disease

Objectives:

Mortality rates at 10 years are higher in diabetic patients with chronic lower extremity peripheral arterial disease than in non-diabetic peripheral arterial disease patients. We tested the hypothesis that the predictors of mortality differ between diabetic and non-diabetic peripheral arterial disease patients.

Methods:

We studied 331 consecutive patients who were <75 years of age, symptomatic for peripheral arterial disease, and admitted to a tertiary care hospital. Our cohort included 216 patients without diabetes mellitus and 115 with diabetes mellitus. The outcome measure was all-cause mortality at 10 years post-admission.

Results:

Mortality rates at 10 years were 29% among non-diabetic peripheral arterial disease patients and 58% among diabetic peripheral arterial disease patients. We identified the following independent predictors of death in the 216 peripheral arterial disease patients without diabetes: age ≥65 years (risk ratio: 2.15; 95% confidence interval: 1.28–3.59), ankle brachial index <0.60 mmHg/mmHg (risk ratio: 1.88; 95% confidence interval: 1.14–3.08), history of peripheral arterial disease-specific intervention (risk ratio: 1.81; 95% confidence interval: 1.10–2.97), and high-sensitivity C-reactive protein ≥5.0 mg/L (risk ratio: 2.11; 95% confidence interval: 1.28–3.47). For the 115 peripheral arterial disease patients with diabetes, independent predictors of mortality were as follows: age ≥65 years (risk ratio: 1.72; 95% confidence interval: 1.05–2.83) and amino-terminal pro-B-type natriuretic peptide ≥125 ng/L (risk ratio: 2.10; 95% confidence interval: 1.22–3.60).

Conclusion:

In this study, the predictors of death at 10 years differed between peripheral arterial disease patients with and without diabetes. Among the biomarkers tested, high-sensitivity C-reactive protein was independently associated with outcomes in non-diabetic patients, whereas amino-terminal pro-B-type natriuretic peptide was an independent predictor of death in patients with diabetes. Our findings suggest that in future studies, risk assessment and treatment strategies should be differentially applied to the two peripheral arterial disease subgroups.

Systematic Review and Meta-Analysis of the Association Between C-Reactive Protein and Major Cardiovascular Events in Patients with Peripheral Artery Disease

BACKGROUND

Patients with peripheral artery disease (PAD) are at substantial risk of cardiovascular events. There is interest in using blood markers, such as C-reactive protein (CRP), to monitor prognosis and treatment efficacy in PAD patients. The aim of this meta-analysis was to assess the association between CRP and major cardiovascular events in PAD patients.

METHOD

Studies evaluating the association between CRP and major cardiovascular events (myocardial infarction, stroke, cardiac revascularisation and mortality) were identified using MEDLINE and the Cochrane library. Studies that did not include participants with PAD, measure CRP, or follow-up patients for cardiovascular events were excluded. Meta-analyses of published adjusted hazard ratios (HR) were conducted using an inverse variance-weighted random effects model, and heterogeneity was assessed with the I² index.

RESULTS

A total of 16 studies involving 5041 participants met the inclusion criteria for the systematic review. Eight studies were included in the meta-analyses. Summary effect estimates were reported as HR comparing higher and lower quantiles, and HR per unit increase in log_eCRP. PAD patients with higher CRP had a significantly greater risk of major cardiovascular events compared with those with lower CRP (HR 2.26, 95% CI 1.65-3.09, p < 0.001). The HR for major cardiovascular events was 1.38 (95% CI 1.16-1.63, p < 0.001) per unit increase in log_eCRP.

CONCLUSIONS

The present findings suggest that high circulating CRP is predictive of major cardiovascular events in PAD patients.

C-reactive protein levels and genetic variants of CRP as prognostic markers for combined cardiovascular endpoint (cardiovascular death, death from stroke, myocardial infarction, and stroke/TIA)

BACKGROUND

The aim of this analysis was to evaluate the importance of C-reactive protein levels and genetic variants of CRP as prognostic markers for further cardiovascular (CV) events (3-year follow-up) in a cohort of in-patients with cardiovascular disease (CVD) patients.

METHODS AND RESULTS

Patients with angiographic proven CVD (n=939) were prospectively included. The three-year CV outcome of the patients was evaluated considering the predefined, combined endpoint (CV death, death from stroke, myocardial infarction, and stroke/TIA). Polymorphisms rs1800947, rs1417938, rs1130864, rs3093077 were analysed. In Kaplan-Meier survival curve and Cox regression increased CRP levels of ⩾5mg/l (log-rank test: p=0.001, Cox regression: hazard ratio=1.77, 95% CI: 1.2-2.7) and the GG genotype of rs1800947 (log-rank test: p=0.01, Cox regression: hazard ratio=1.99, 95% CI: 1.1-3.6) were associated with the incidence of the combined endpoint.

CONCLUSIONS

Both a CRP level ⩾5mg/l and SNP rs1800947 of the CRP gene were independent risk factors for further adverse CV events among patients with CVD within three years follow-up.

The Impact of Biochemical Markers on Major Adverse Cardiovascular Events and Contralateral Carotid Artery Stenosis Progression Following Carotid Interventions

BACKGROUD

To determine if elevated preintervention high-sensitivity C-reactive protein (hsCRP) and B-type natriuretic peptide (BNP) levels associate with major adverse cardiovascular events (MACE) or disease progression after carotid revascularization.

METHODS

We retrospectively examined patients receiving elective carotid endarterectomy (CEA) or carotid artery stenting (CAS) at our institution from 2007 to 2014. All included patients had preintervention hsCRP and BNP levels. Examined outcomes of interest included contralateral carotid disease progression (increased stenosis or need for revascularization) and MACE (composite of death, stroke, myocardial infarction, need for coronary artery bypass graft or percutaneous coronary intervention) at 3 years after procedure. The relationship between baseline hsCRP and BNP levels and time to event was examined by univariate and multivariate Cox proportional hazard regression analyses.

RESULTS

A total of 248 patients were included in the analysis (mean age: 68 ± 10 years), with 14% receiving CAS and 86% CEA. A total of 61 patients (25%) had 1 or more MACE by 3 years. Elevated hsCRP (>3 mg/L) trended toward associating with MACE but failed to reach significance (hazard ratio [HR]: 1.6 [1.0-2.7], P = 0.07). Multivariate analysis found that elevated BNP (>100pg/mL, HR: 2.2 [1.3-3.7], P = 0.002) and diabetes mellitus (HR: 1.9 [1.2-3.2], P = 0.01) predicted MACE. Having elevated preprocedural levels of both hsCRP and BNP significantly increased patients' likelihood of experiencing MACE (HR: 3.4 [1.6-7.1], P = 0.001). About 175 patients received contralateral carotid imaging postprocedure and of those patients, 31 (18%) experienced stenosis progression and/or revascularization within 3 years. However, neither elevated hsCRP (HR: 1.2 [0.6-2.3], P = 0.68) nor BNP (HR: 1.1 [0.5-2.5], P = 0.88) associated with disease progression.

CONCLUSIONS

BNP elevation at the time of carotid intervention is associated with MACE in long-term follow-up. hsCRP does not appear to correlate with either disease progression of the contralateral artery or MACE.

Biochemical markers in patients with open reconstructions with peripheral arterial disease

The purpose of our study was to determine outcome differences as a function of baseline high-sensitivity C-reactive protein (hsCRP) and B-type natriuretic peptide (BNP) levels in patients receiving lower extremity open reconstructions for the treatment of peripheral arterial occlusive disease. We retrospectively examined patients who underwent surgical reconstructions performed by a single operator during a seven-year time span who received preoperative hsCRP and BNP testing and post-procedure imaging. Outcomes of interest included major adverse limb events, a composite end point of target vessel revascularization, limb amputation, and disease progression, and major adverse cardiovascular events comprised of stroke, myocardial infarction, and death. A total of 89 limbs in 82 patients were included in analysis. Multivariate analysis demonstrated that higher hsCRP levels (>3.0 mg/L) trended toward, but failed to significantly associate with major adverse limb events at 24 months (hazard ratio: 2.2 [1.0–5.2], p = 0.06), however the use of a vein bypass conduit (vs. prosthetic reconstruction) significantly predicted major adverse limb events (hazard ratio: 3.2 [1.5–6.9], p < 0.01). Elevated BNP levels (>100 pg/ml), but not hsCRP, associated with major adverse cardiovascular events (hazard ratio: 3.5 [1.2–10.3], p = 0.03). Preoperative biochemical markers may assist in clinical decision making and stratifying patients regarding adverse events following open reconstructions.

Renal tubular damage is associated with poor clinical outcome in patients with peripheral artery disease who underwent endovascular therapy

BACKGROUND

Kidney dysfunction is associated with adverse outcome in patients with peripheral artery disease (PAD). Renal tubulointerstitial damage (RTD) is another type of kidney dysfunction from glomerular damage. RTD is reported to be a risk for future cardiac event in patients with heart disease. However, it remains to be determined whether RTD is predictive of poor clinical outcome in patients with PAD.

METHODS AND RESULTS

RTD markers (urinary N-acetyl-β-D-glucosamidase; NAG and urinary β-2 microglobulin to creatinine ratio) and Glomerular damage markers (cystatin C-based estimated glomerular filtration rate, proteinuria, and microalbuminuria) were measured in 265 consecutive PAD patients who underwent endovascular therapy. Patients were prospectively followed for a median length of 804days, with end points of major adverse cardiovascular and cerebrovascular events (MACCE). Overall, 73% of patients exhibited excess urinary NAG excretion, and values were higher in patients with critical limb ischemia. A multivariate Cox proportional hazard analysis revealed that NAG was an independent predictor of MACCE. When patients were divided according to NAG level, Kaplan-Meier analysis demonstrated that the third tertile was associated with the greatest risk for MACCE. The C index in NAG was the greatest among kidney dysfunction markers. Moreover, the net reclassification index was improved by the addition of NAG to basic predictors including glomerular damage markers.

CONCLUSION

RTD is common and associated with disease severity and clinical outcome in patients with PAD, indicating that it could be the additional clinical information to glomerular damage in patients with PAD.

The role of inflammation in cardiovascular diseases: the predictive value of neutrophil-lymphocyte ratio as a marker in peripheral arterial disease

Peripheral arterial disease (PAD) is an important manifestation of atherosclerosis, with increasing prevalence worldwide. A growing body of evidence shows that the systemic inflammatory response is closely related to the development, progression, and prognosis of atherosclerosis. In the last decade, several studies have suggested the role of measured inflammatory biomarkers as predictors of severity and prognosis in PAD in an effort to stratify the risk of these patients, to improve treatment selection, and to predict the results after interventions. A simple inflammatory marker, more available than any other, is the neutrophil-lymphocyte ratio (NLR), which can be easily obtained in clinical practice, based on the absolute count of neutrophils and lymphocytes from the differential leukocytes count. Many researchers evaluated vigorously the NLR as a potential prognostic biomarker predicting pathological and survival outcomes in patients with atherosclerosis. In this work, we aim to present the role of NLR as a prognostic marker in patients with PAD through a thorough review of the literature.

C-reactive protein and endovascular treatment of lower limb peripheral artery disease: an independent prognostic factor

PURPOSE

To determine if C-reactive protein (CRP) can predict the outcomes of lower extremity endovascular therapy (EVT) in patients with peripheral artery disease and to calculate a cutoff value that may be useful in identifying patients with a higher risk of EVT failure at 1 year.

METHODS

In this prospective single-center study, 121 patients (94 men; mean age 67.7±9.8 years) undergoing EVT of lower limb lesions in an 18-month period were enrolled as a derivation set. In the subsequent 6 months, 53 patients (39 men; mean age 70.1±10.0 years) were enrolled as the validation set. Blood samples were collected before EVT and at 1 month postintervention from both sets of patients to measure CRP levels. The cohorts were followed for 1 year, and data on reinterventions were recorded. A cutoff CRP value was calculated with the highest sensitivity and specificity for EVT failure based on receiver operator characteristic (ROC) curve analysis. The cutoff value was confirmed in the validation set. Cox proportional hazards analysis was performed to evaluate the independent contribution of CRP levels and other variables to the risk of reintervention; results are given as the hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

The area under the ROC curve relating preprocedure CRP levels to 1-year reintervention was 0.77±0.05. The highest likelihood ratio corresponded to a pre-EVT CRP value of 9.8 mg/L (likelihood ratio test=133, df=1, p<0.001). Reintervention before the first year after EVT was related to preprocedure CRP levels (HR 1.1, 95% CI 1.05 to 1.2; p<0.001). These results were confirmed in the validation set (HR 1.1, 95% CI 1.02 to 1.18; p=0.008).

CONCLUSION

CRP values can be used as an independent marker of EVT outcome. Baseline CRP levels >9.8 mg/L indicate increased risk of secondary interventions, which are often open surgical procedures.

Heart-type fatty acid binding protein and high-sensitivity troponin T are myocardial damage markers that could predict adverse clinical outcomes in patients with peripheral artery disease

Background

Despite many recent advances in endovascular therapy (EVT), peripheral artery disease (PAD) is an increasing health problem with high mortality. Heart-type fatty acid-binding protein (H-FABP) and high-sensitivity troponin T (hsTnT) are markers of ongoing myocardial damage and have been reported to be useful indicators of future cardiovascular events. However, it remains to be determined whether H-FABP and hsTnT can predict adverse clinical outcomes in patients with PAD.

Methods and results

We enrolled 208 de novo PAD patients who underwent EVT. Serum H-FABP and hsTnT were measured in all patients before EVT. During the median follow-up period of 694 days, there were 40 major adverse cardiovascular and cerebrovascular events (MACCEs) including all-cause deaths, and re-hospitalizations due to cardiovascular and cerebrovascular diseases and amputations. H-FABP and hsTnT were found to be higher in patients with critical limb ischemia (CLI) compared to those without this condition. Multivariate Cox proportional hazard regression analysis revealed that both H-FABP and hsTnT were independent predictors of MACCEs after adjustment for confounding factors. Kaplan–Meier analysis demonstrated that patients in the highest tertile according to H-FABP levels, as well as those in the highest hsTnT tertile, were at greatest risk for MACCEs. The net reclassification index was significantly improved by the addition of H-FABP as well as the addition of hsTnT to traditional risk factors.

Conclusion

The myocardial damage markers H-FABP and hsTnT were increased in PAD patients with CLI and could predict MACCEs in PAD patients.

Systemic inflammation as a predictor of clinical outcomes after lower extremity angioplasty/stenting

OBJECTIVE

The activation state of the systemic inflammatory milieu has been proposed as a critical regulator of vascular repair after injury. We evaluated the early inflammatory response after endovascular intervention for symptomatic peripheral arterial disease to determine its association with clinical success or failure.

METHODS

Blood samples were obtained from 14 patients undergoing lower extremity angioplasty/stenting and analyzed using high-throughput gene arrays, multiplex serum protein analyses, and flow cytometry.

RESULTS

Time-dependent plasma protein and monocyte phenotype analyses demonstrated endovascular revascularization had a modest influence on the overall activation state of the systemic inflammatory system, with baseline variability exceeding the perturbations induced by the intervention. In contrast, specific time-dependent changes in the monocyte genome are evident in the initial 28 days, predominately in those genes associated with leukocyte extravasation. Investigating the relationship between inflammation and the 1-year success or failure of the intervention showed no single plasma protein was correlated with outcome, but a more comprehensive cluster analysis revealed a clear pattern of protein expression that was closely related to the clinical phenotype. Corresponding examination of the monocyte genome identified a gene subset at 1 day postprocedure that was predictive of clinical outcome, with most of these genes active in cell-cycle signaling.

CONCLUSIONS

Although the global influence of angioplasty/stenting on systemic inflammation was modest, circulating cytokine and monocyte genome analyses support a pattern of early inflammation that is associated with ultimate intervention success vs failure. Molecular profiles incorporating genes involved in monocyte cell-cycle progression and homing, or proinflammatory cytokines, or both, offer the most promise for the development of class prediction tools for clinical application.

A review of the pathophysiology and potential biomarkers for peripheral artery disease

Peripheral artery disease (PAD) is due to the blockage of the arteries supplying blood to the lower limbs usually secondary to atherosclerosis. The most severe clinical manifestation of PAD is critical limb ischemia (CLI), which is associated with a risk of limb loss and mortality due to cardiovascular events. Currently CLI is mainly treated by surgical or endovascular revascularization, with few other treatments in routine clinical practice. There are a number of problems with current PAD management strategies, such as the difficulty in selecting the appropriate treatments for individual patients. Many patients undergo repeated attempts at revascularization surgery, but ultimately require an amputation. There is great interest in developing new methods to identify patients who are unlikely to benefit from revascularization and to improve management of patients unsuitable for surgery. Circulating biomarkers that predict the progression of PAD and the response to therapies could assist in the management of patients. This review provides an overview of the pathophysiology of PAD and examines the association between circulating biomarkers and PAD presence, severity and prognosis. While some currently identified circulating markers show promise, further larger studies focused on the clinical value of the biomarkers over existing risk predictors are needed.

Inflammatory biomarkers in peripheral arterial disease

Biochemical markers have the potential to aid the vascular specialist in many ways. On a daily basis, we rely on such markers as d-dimer to help exclude thromboembolic disease and thus limit low-probability ultrasound imaging. Additionally, we use troponin levels to determine myocardial events perioperatively. During the past decade, use of the inflammatory marker C-reactive protein has been recommended by the American Heart Association to further stratify patient cardiovascular risk, and has been studied more extensively in patients with peripheral vascular disease. This review details clinical information published during the past several decades on the application of serum C-reactive protein levels in peripheral arterial disease patients in correlation with disease severity and likelihood of future cardiovascular events, including recent predictive models.

Infrainguinal bypass for critical limb ischemia: tips and tricks

A thoughtful but aggressive approach to care of patients with critical limb ischemia (CLI) is required to alleviate lower-extremity pain/tissue injury and achieve durable limb salvage. Specific subsets of CLI patients have been identified to clearly benefit from open surgical revascularization based on presenting signs (extensive tissue loss), multi-level, long-segment arterial occlusive disease, healthy saphenous conduit, and nondiseased tibial artery target vessel with continuous patency to the pedal arch. When other clinical scenarios exist, the treatment strategy requires consideration of patient's medical and surgical risk factors, anatomic distribution of atherosclerotic disease, and the clinical status of the limb affected by CLI. Infrainguinal saphenous vein bypass is the most durable technique for limb salvage and when properly performed is associated with excellent wound healing rates and improvement in quality of life. In this review, we detail our approach to infrainguinal arterial vein bypass in patients with CLI, including patient selection criteria, surgical planning based on arterial imaging studies, and operative technical requirements required for successful open lower-extremity bypass procedures.