Potential metabolic biomarkers of critical limb ischemia in people with type 2 diabetes mellitus

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is a significant risk factor for the development of critical limb ischemia (CLI), the most advanced stage of peripheral arterial disease. The concurrent existence of T2DM and CLI often leads to adverse outcomes, namely limb amputation.

OBJECTIVE

To identify biomarkers for improving the screening of CLI in high-risk people with T2DM.

METHODS

We investigated metabolome profiles in serum samples of 113 T2DM people with CLI (n = 23, G2) and without CLI (n = 45, G0: no lower limb stenosis (LLS) and n = 45, G1: LLS < 50%), using hydrogen nuclear magnetic resonance (¹H NMR) approach. Principle component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were used to analyze ¹H NMR data.

RESULTS

Twenty potential metabolites that could discriminate people with T2DM and CLI (G2) from non-CLI patients without LLS (G0) were determined in serum samples. The correct percent of classification for the PLS-DA model for the test set samples was 85% (n = 20) and 100% (n = 5) for G0 and G2 groups, respectively. Non-CLI patients with LLS < 50% (G1) were projected on the PCA abstract space built using 20 discriminatory metabolites. Eleven people with T2DM and LLS < 50% were prospectively followed, and their ankle-brachial index (ABI) was measured after 4 years. A promising agreement existed between the PCA model's predictions and those obtained by ABI values.

CONCLUSION

The findings suggest that confirmation of blood potential metabolic biomarkers as a complement to ABI for screening of CLI in a large group of high-risk people with T2DM is needed.

NT-proBNP as a surrogate for unknown heart failure and its predictive power for peripheral artery disease outcome and phenotype

Patients with peripheral artery disease (PAD) are at high risk of excess mortality despite major improvements in multimodal pharmacotherapy for cardiovascular disease. However, little is known about co-prevalences and implications for the combination of heart failure (HF) and PAD. Thus, NT-proBNP as a suggested surrogate for HF was evaluated in symptomatic PAD regarding long-term mortality. After approval by the institutional ethics committee a total of 1028 patients with PAD, both with intermittent claudication or critical limb ischemia were included after admission for endovascular repair and were followed up for a median of 4.6 years. Survival information was obtained from central death database queries. During the observation period a total of 336 patients died (calculated annual death rate of 7.1%). NT-proBNP (per one standard deviation increase) was highly associated with outcome in the general cohort in crude (HR 1.86, 95%CI 1.73-2.01) and multivariable-adjusted Cox-regression analyses with all-cause mortality (HR 1.71, 95%CI 1.56-1.89) and CV mortality (HR 1.86, 95% CI 1.55-2.15). Similar HR's were found in patients with previously documented HF (HR 1.90, 95% CI 1.54-2.38) and without (HR 1.88, 95%CI 1.72-2.05). NT-proBNP levels were independently associated with below-the-knee lesions or multisite target lesions (OR 1.14, 95% CI 1.01-1.30). Our data indicate that increasing NT-proBNP levels are independently associated with long-term mortality in symptomatic PAD patients irrespective of a previously documented HF diagnosis. HF might thus be highly underreported in PAD, especially in patients with the need for below-the-knee revascularization.

Impact of Modified H₂FPEF Score on Chronic Limb-Threatening Ischemia in Patients With Lower Extremity Artery Disease Who Underwent Endovascular Therapy

Background: Lower extremity artery disease (LEAD) is an arterial occlusive disease characterized by an insufficient blood supply to the lower limb arteries. The H₂FPEF score, comprising Heavy, Hypertensive, atrial Fibrillation, Pulmonary hypertension, Elder, and Filling pressure, has been developed to identify patients at high risk of heart failure (HF) with preserved ejection fraction. This study assessed the impact of modified H₂FPEF scores on chronic limb-threatening ischemia (CLTI) in patients with LEAD.

Methods and Results: This study was a prospective observational study. Because the definition of obesity differs by race, we calculated the modified H₂FPEF score using a body mass index >25 kg/m² to define obesity in 293 patients with LEAD who underwent first endovascular therapy. The primary endpoints were newly developed and recurrent CLTI. The secondary endpoint was a composite of events, including mortality and rehospitalization due to worsening HF and/or CLTI. The modified H₂FPEF score increased significantly with advancing Fontaine classes. Multivariate Cox proportional hazard analysis revealed that the modified H₂FPEF score was an independent predictor of newly developed and recurrent CLTI and composite events. The net reclassification index and integrated discrimination improvement were significantly improved by adding the modified H₂FPEF score to the basic predictors.

Conclusions: The modified H₂FPEF score was associated with LEAD severity and future CLTI development, suggesting that it could be a feasible marker for patients with LEAD.

Diabetes and other vascular risk factors in association with the risk of lower extremity amputation in chronic limb-threatening ischemia: a prospective cohort study

BACKGROUND

Patients with diabetes are at increased risk of developing chronic limb-threatening ischemia (CLTI) due to peripheral arterial disease, and this often results in lower extremity amputation (LEA). Little is known of the interaction between diabetes and other vascular risk factors in affecting the risk of CLTI.

METHODS

We investigated the association of diabetes, and its interaction with hypertension, body mass index (BMI) and smoking, with the risk of LEA due to CLTI in the population-based Singapore Chinese Health Study. Participants were interviewed at recruitment (1993-1998) and 656 incident LEA cases were identified via linkage with nationwide hospital database through 2017. Multivariate-adjusted Cox proportional hazards models were used to compute hazard ratios (HRs) and 95% CIs for the associations.

RESULTS

The HR (95% CI) for LEA risk was 13.41 (11.38-15.79) in participants with diabetes compared to their counterparts without diabetes, and the risk increased in a stepwise manner with duration of diabetes (P for trend < 0.0001). Hypertension and increased BMI independently increased LEA risk in those without diabetes but did not increase the risk in those with diabetes (P for interaction with diabetes ≤ 0.0006). Conversely, current smoking conferred a risk increment of about 40% regardless of diabetes status.

CONCLUSIONS

Although diabetes conferred more than tenfold increase in risk of LEA, hypertension and increased BMI did not further increase LEA risk among those with diabetes, suggesting a common mechanistic pathway for these risk factors. In contrast, smoking may act via an alternative pathway and thus confer additional risk regardless of diabetes status.

Impact of brain natriuretic peptide for predicting long-term life expectancy and cardiovascular or limb events in peripheral arterial disease

BACKGROUND

Brain natriuretic peptide (BNP) is introduced as a predictor of the degree of ventricular dysfunction and is associated with mortality. There are limited reports on the relationship of BNP with long-term all-cause death (AD) and cardiovascular or limb events in peripheral artery disease (PAD). We examined the relationship between BNP level and these events in PAD patients.

METHODS

We performed a prospective cohort study in 938 PAD patients. The patients were divided into four groups based on BNP levels with median (interquartile range): Q1: ≤20.4; Q2: 20.5-42.8; Q3: 42.9-103.4; and Q4: ≥103.5 pg/mL. The endpoints were AD, freedom from major adverse cardiovascular events (MACE), and MACE plus limb events (MALE).

RESULTS

The median follow-up time was 65 months. There were 383 deaths (40.8%) during follow-up period. AD depended on BNP levels (p<0.01), with 5-year freedom from AD rates of Q1: 94%, Q2: 84%, Q3: 69%, and Q4: 55%. The Kaplan-Meier estimates of freedom from AD, MACE, and MALE had significant differences among Q1- Q4 groups (p< 0.001). In multiple regression analysis, BNP had significant negative correlations with eGFR, serum albumin, and BMI and positive correlations with diabetes (p<0.05). In Cox multivariate analysis, higher BNP, age, CRP, D-dimer, lower BMI, ABI, serum albumin, and eGFR were related to AD; and higher BNP, age, lower ABI, serum albumin, CAD, and DM were related to MACE and MALE (p<0.05). Statins improved AD, MACE, and MALE (p<0.01).

CONCLUSIONS

BNP was a promising biomarker for AD, MACE, and MALE in patients with PAD.

Myocardial injury after endovascular revascularization in critical limb ischemia predicts 1-year mortality: a prospective observational cohort study

BACKGROUND

Patients with critical limb ischemia (CLI) are at increased risk of cardiovascular complications and mortality. To determine (1) incidence of myocardial injury following endovascular revascularization, and (2) relationship between myocardial injury with 1-year mortality and major adverse cardiovascular events (MACE; i.e., composite of myocardial infarction, stroke, and death).

METHODS AND RESULTS

Single-center, prospective cohort study of CLI patients ≥ 45 years of age, who underwent endovascular revascularization with overnight hospitalization. High-sensitive troponins T (hsTnTs) were measured on admission, 3-6 h after endovascular revascularization and the subsequent morning. Myocardial injury after endovascular revascularization was defined as an hsTnT ≥ 14 ng/L with a relative increase ≥ 30% from the baseline value. We also evaluated other myocardial injury hsTnT thresholds (i.e., ≥ 30, ≥ 40, ≥ 60, and ≥ 80 ng/L). 239 consecutive patients (56% male, mean age 71.5 ± 10.1 years) were included; one patient was lost to follow-up. At 1 year, there were 34 deaths (14.2%), and 48 MACE (20.5%). Myocardial injury with the hsTnT threshold of 14 ng/L and relative increase by ≥ 30% from the baseline level occurred in 61 patients (25.5%). Myocardial injury was independently associated with 1-year mortality ([aHR], 2.44; 95% CI 1.18-5.06, for hsTnT ≥ 14 ng/L to aHR, 3.34; 95% CI 1.29-8.65 for hsTnT ≥ 80 ng/L). Myocardial injury was also independently associated with 1-year MACE ([AOR] 2.89; 95% CI 1.41-5.92 for hsTnT ≥ 14 ng/L to AOR, 6.69; 95% CI 2.17-20.68 for hsTnT ≥ 80 ng/L). 85.2% patients who had myocardial injury did not have ischemic clinical symptoms or electrocardiography changes. In sensitive analysis with exclusion of symptomatic patients that developed myocardial injury for the hsTnT ≥ 14 ng/L threshold, both the 1-year mortality (aHR: 2.19; CI 1.02-4.68; p = 0.04), and 1-year MACE (OR 2.25; CI 1.06-4.77; p = 0.036) remained significant.

CONCLUSIONS

Myocardial injury is common following endovascular revascularization for CLI and associated with the risk of 1-year mortality and MACE.

Percutaneous endovascular treatment of infrainguinal PAOD: Results of the PSI register study in 74 German vascular centers

Background

The percutaneous infrainguinal stent (PSI) register study aimed to collate all percutaneous endovascular procedures for infrainguinal peripheral arterial occlusive disease (PAOD) conducted in 74 German vascular centers between September and November 2015 (3 months). In order to obtain representative results all consecutive treatment procedures had to be submitted by the participating trial centers.

Material and methods

This was a prospective, nonrandomized multicenter study design. All patients suffering from intermittent claudication (IC, Fontaine stage II) or critical limb ischemia (CLI, Fontaine stages III and IV) were included. Trial centers with less than 5 cases reported within the 3‑month trial period or centers that could not ensure the submission of all treated patients were excluded.

Results

In the final assessment 2798 treated cases from 74 trial centers were reported of which 65 (87.8 %) centers were under the leadership of a vascular surgeon. Approximately 33 % of the interventions in centers under the leadership of vascular surgeons were conducted by radiologists. Risk factors, especially chronic renal disease, diabetes and cardiac risk factors were significantly different between patients with IC and CLI. Of the patients with Fontaine stage II PAOD 41.3 % had 3 patent crural vessels compared to only 10.8 % of patients with Fontaine stage IV. With respect to peri-interventional complications, percutaneous endovascular treatment of IC was a safe procedure with severe complications in less than 1 % and no fatalities. Only 4.5 % of the procedures were conducted under ambulatory conditions. In the supragenual region self-expanding bare metal stents, standard percutaneous transluminal angioplasty (PTA) and drug-coated balloons were the most frequently used procedures. For interventions below the knee, standard PTA was the most commonly employed treatment.

Conclusion

The main aim of the PSI study was to obtain a realistic picture of percutaneous endovascular techniques used to treat suprapopliteal and infrapopliteal PAOD lesions and to describe the treatment procedures used by vascular specialists in Germany. To investigate the change in trends for treatment over time, this study has to be repeated in the future in order to test how quickly the results of randomized studies can be implemented in practice.

Electronic supplementary material

A complete list of the PSI study collaborators is available under doi: 10.1007/s00772-016-0202-2.

Effects of strontium ranelate on markers of cardiovascular risk in postmenopausal osteoporotic women

Recent pooled analyses have shown that strontium ranelate increases the incidence of venous thromboembolism and non-fatal myocardial infarction, but no explanations were given. The aim of our study was to assess the effects a 12-month treatment with strontium ranelate on hemostasis factors and markers of cardiovascular risk in postmenopausal osteoporotic women. Forty osteoporotic postmenopausal women received orally strontium ranelate 2 g daily, plus calcium and colecalcipherol for 12 months. Forty postmenopausal osteopenic women matched for age, menopausal age, and body mass index served as controls and received orally calcium and colecalcipherol for 12 months. Biochemical cardiovascular risk factors and hemostatic indices were assayed prior to treatment, and after 3, 6, and 12 months of therapy. These indices included fibrinogen, fasting glucose, total serum cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, plasma levels of D-dimer, homocysteine, partial thromboplastin time, and prothrombin time. In addition, we evaluated possible changes in blood pressure and occurrence of venous thromboembolic events. At baseline, no statistically significance was observed between the two groups except for bone mineral density at lumbar spine, femoral neck, and total femur, which was lower in strontium ranelate group. After 12 months of treatment, there was no statistically significant change in cardiovascular risk factors and hemostatic parameters. None of the 40 women developed any clinical venous thromboembolic event. A 12-month treatment with strontium ranelate did not alter hemostasis factors or markers of cardiovascular risk, suggesting that reported increased risk of venous thromboembolism and myocardial infarction with strontium is mediated by other factors.

Prediction of Development of Critical Limb Ischemia in Hemodialysis Patients

Hemodialysis (HD) patients with critical limb ischemia (CLI) suffer chronic inflammation and repeated infection, require intervention, and may have a protracted hospital stay. Therefore, early prediction is particularly important for management of CLI in patients with suspected peripheral artery disease. The purpose of this study is to develop a simple score for predicting the incidence of CLI in HD patients with suspected peripheral artery disease. The subjects were 139 asymptomatic patients receiving maintenance HD and with ABI <1.0. Multivariate logistic regression analysis was used to identify factors associated with development of CLI. These factors were subsequently weighted and integrated into a scoring system for the prediction of onset of CLI. Twenty-five patients had onset of CLI. Five factors selected from the multivariate model were weighted proportionally using their respective odds ratio (OR) for incidence of CLI (history of cerebral vascular disease, OR 6.42 [3 points]; diabetes, OR 3.92 [2 points]; hypoesthesia, OR 4.21 [2 points]; left ventricular ejection fraction <50%, OR 3.89 [2 points]; serum albumin <3.5 g/dL, OR 4.39 [2 points]). Three strata of risk were defined (low risk, 0 to 3 points; intermediate risk, 4 to 6 points; and high risk 7 to 11 points) with excellent prognostic accuracy for progression to CLI using the Kaplan-Meier method. Five factors were identified that increased the risk of progression to CLI in HD patients with suspected peripheral artery disease. A combination of those factors permitted establishment of three risk strata for accurate prediction of onset of CLI.

High-sensitivity C-reactive Protein, Lipoprotein(a) and Homocysteine are Risk Factors for Coronary Artery Disease in Japanese Patients with Peripheral Arterial Disease

AIM

The goal of the study was to investigate the relationships between coronary artery disease (CAD) and risk factors, including the serum levels of high-sensitivity C-reactive protein (hs-CRP), lipoprotein(a) (Lp(a)) and homocysteine, in Japanese patients with peripheral arterial disease (PAD).

METHODS

Coronary angiography was performed in 451 patients with PAD, among whom the prevalence and clinical characteristics of CAD were analyzed. A multiple logistic analysis was used to evaluate the relationships between CAD and the risk factors. The relationships between the severity of coronary arterial lesions and the risk factors were evaluated using multiple regression analysis.

RESULTS

The prevalence of CAD (≥70% luminal diameter narrowing or a history of CAD) and coronary artery stenosis (≥50%) was 55.9% and 74.1%, respectively, and the rate of CAD (≥70%) with single-, double- and triple-vessel disease was 25.9%, 13.5% and 10.6%, respectively. The prevalence of diabetes was higher among the patients with CAD than among those without. The serum levels of hs-CRP, Lp(a), and homocysteine were higher in the patients with CAD, whereas the estimated glomerular filtration rates and HDL-cholesterol levels were lower in these patients. According to the multiple logistic analysis, CAD was related to diabetes (hazard ratio [HR]: 2.253; 95% confidence interval [CI]: 1.137-4.464, p=0.020), hs-CRP (HR: 1.721; 95% CI: 1.030-2.875, p=0.038), Lp(a) (HR: 1.015; 95% CI: 1.001-1.029, p=0.041) and homocysteine (HR: 1.084; 95% CI: 1.012-1.162, p=0.021). Furthermore, diabetes and the D-dimer and LDL-cholesterol levels exhibited significant relationships with the number of stenotic coronary lesions in the stepwise multiple regression analysis (p＜0.05).

CONCLUSIONS

Diabetes, hs-CRP, Lp(a), homocysteine and lipid abnormalities are critical risk factors for CAD in Japanese patients with PAD.

Shared and additional risk factors for decrease of toe-brachial index compared to ankle-brachial index in Japanese patients with diabetes mellitus

OBJECTIVE

Some diabetic patients have a low toe-brachial index (TBI) despite their normal ankle-brachial index (ABI). We statistically investigated whether the impact of risk factors on TBI would be different compared to ABI.

RESEARCH DESIGN AND METHODS

We used a database of 1738 limbs of consecutive 869 Japanese diabetic patients whose ABI and TBI were simultaneously evaluated. We developed a common regression model to ABI and TBI by extending the linear mixed model, and statistically detected the difference in the impact of risk factors between the two indices.

RESULTS

Sex, smoking, proteinuria, hypertension, and history of stroke and coronary artery disease were common independent risk factors for the decrease of ABI and TBI; their impacts on ABI and TBI were not significantly different. On the other hand, the impact of age, diabetic duration, and body mass index was significantly different between the two indices (all p < 0.05). Age and body mass index were significantly associated with TBI but not with ABI. Diabetic duration had a significant impact both on TBI and ABI, but the impact on TBI was significantly greater than that on ABI (β = -0.144 vs. -0.087; p < 0.05). In the population with normal ABI, patients with these risk factors had a higher prevalence of decreased TBI.

CONCLUSIONS

The risk factors for the decrease of ABI and TBI were not identical in Japanese diabetic patients. Age, diabetic duration and body mass index were associated with reduced TBI in patients with normal ABI.