Lipoprotein (a) level and mortality in patients with critical lower limb ischaemia

Circulating lipoprotein (a) and all-cause and cause-specific mortality: a systematic review and dose-response meta-analysis

AIMS

To investigate the association between circulating lipoprotein(a) (Lp(a)) and risk of all-cause and cause-specific mortality in the general population and in patients with chronic diseases, and to elucidate the dose-response relations.

METHODS AND RESULTS

We searched literature to find prospective studies reporting adjusted risk estimates on the association of Lp(a) and mortality outcomes. Forty-three publications, reporting on 75 studies (957,253 participants), were included. The hazard ratios (HRs) and 95% confidence intervals (95%CI ) for the top versus bottom tertile of Lp(a) levels and risk of all-cause mortality were 1.09 (95%CI: 1.01-1.18, I²: 75.34%, n = 19) in the general population and 1.18 (95%CI: 1.04-1.34, I²: 52.5%, n = 12) in patients with cardiovascular diseases (CVD). The HRs for CVD mortality were 1.33 (95%CI: 1.11-1.58, I²: 82.8%, n = 31) in the general population, 1.25 (95%CI: 1.10-1.43, I²: 54.3%, n = 17) in patients with CVD and 2.53 (95%CI: 1.13-5.64, I²: 66%, n = 4) in patients with diabetes mellitus. Linear dose-response analyses revealed that each 50 mg/dL increase in Lp(a) levels was associated with 31% and 15% greater risk of CVD death in the general population and in patients with CVD. No non-linear dose-response association was observed between Lp(a) levels and risk of all-cause or CVD mortality in the general population or in patients with CVD (P_nonlinearity > 0.05).

CONCLUSION

This study provides further evidence that higher Lp(a) levels are associated with higher risk of all-cause mortality and CVD-death in the general population and in patients with CVD. These findings support the ESC/EAS Guidelines that recommend Lp(a) should be measured at least once in each adult person's lifetime, since our study suggests those with higher Lp(a) might also have higher risk of mortality.

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.

Peripheral Artery Disease and Venous Thromboembolic Events After Acute Coronary Syndrome: Role of Lipoprotein(a) and Modification by Alirocumab: Prespecified Analysis of the ODYSSEY OUTCOMES Randomized Clinical Trial

Supplemental Digital Content is available in the text.

Patients with acute coronary syndrome are at risk for peripheral artery disease (PAD) events and venous thromboembolism (VTE). PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitors reduce lipoprotein(a) and low-density lipoprotein cholesterol (LDL-C) levels. Our objective was to ascertain whether PCSK9 inhibition reduces the risk of PAD events or VTE after acute coronary syndrome, and if such effects are related to levels of lipoprotein(a) or LDL-C.

Lipoprotein(a): An independent, genetic, and causal factor for cardiovascular disease and acute myocardial infarction

Lipoprotein(a) [Lp(a)] is a circulating lipoprotein, and its level is largely determined by variation in the Lp(a) gene (LPA) locus encoding apo(a). Genetic variation in the LPA gene that increases Lp(a) level also increases coronary artery disease (CAD) risk, suggesting that Lp(a) is a causal factor for CAD risk. Lp(a) is the preferential lipoprotein carrier for oxidized phospholipids (OxPL), a proatherogenic and proinflammatory biomarker. Lp(a) adversely affects endothelial function, inflammation, oxidative stress, fibrinolysis, and plaque stability, leading to accelerated atherothrombosis and premature CAD. The INTER-HEART Study has established the usefulness of Lp(a) in assessing the risk of acute myocardial infarction in ethnically diverse populations with South Asians having the highest risk and population attributable risk. The 2018 Cholesterol Clinical Practice Guideline have recognized elevated Lp(a) as an atherosclerotic cardiovascular disease risk enhancer for initiating or intensifying statin therapy.

Coronary Artery Disease Severity and Cardiovascular Biomarkers in Patients with Peripheral Artery Disease

Cardiovascular mortality in peripheral artery disease (PAD) patients is higher in critical limb ischemia (CLI) than in intermittent claudication (IC). We sought to evaluate differential characteristics of coronary artery disease (CAD) severity and prognostic biomarkers for cardiovascular events between CLI and IC patients. Coronary angiography was performed on 242 PAD patients (age 73 ± 8 years) with either CLI or IC. High-sensitivity troponin T (hs-TnT), eicosapentaenoic acid-arachidonic acid ratio (EPA/AA), and lipoprotein(a), as biomarkers for prognostic factors, were measured from blood samples. The study patients were divided into a CLI-group (n = 42) and IC-group (n = 200). The Gensini score as an indicator of coronary angiographic severity was higher in the CLI-group than in the IC-group (39.1 ± 31.2 vs. 8.5 ± 8.3, p < 0.0001). Hs-TnT and lipoprotein(a) values were higher in the CLI-group than in the IC-group (0.152 ± 0.186 ng/mL vs. 0.046 ± 0.091, p < 0.0001, 45.9 ± 23.3 mg/dL vs. 26.2 ± 27.7, p = 0.0002, respectively) and EPA/AA was lower in the CLI-group than in the IC-group (0.22 ± 0.11 vs. 0.38 ± 0.29, p = 0.0049, respectively). Greater CAD severity, higher hs-TnT, and lipoprotein(a), and lower EPA/AA were observed in the CLI-group, which may explain higher cardiovascular events in patients with CLI.

Epidemiological aspects of atherosclerosis in patients treated for acute atherothrombosis of extremity arteries

Introduction:

Risk factors for development of extremity artery atherosclerosis are the same as for coronary and cerebrovascular atherosclerosis namely, diabetes mellitus, hyperlipidemia, arterial hypertension, age and smoking. Atherosclerosis is polyarterial disease that clinically manifests itself most frequently in the form coronary, cerebrovascular or peripheral arterial disease (PAD). All of them have common, ominous and final pathologic step – atherosclerotic plaque rupture that might eventually lead to atherothrombosis and signs of ischemia. There are few studies of risk factor for peripheral artery disease (PAD). Aim of study: To identify prevalence of known risk factors for atherosclerosis in patients treated for acute atherothrombosis of extremity arteries.

Patients and methods:

Eighty patient were analyzed with regard to the prevalence of five risk factors for atherosclerosis (diabetes mellitus, smoking, hypertension, hyperlipidemia and age). 80 patients were divided into two groups (Group A and B) depending on country i.e. hospital where they received treatment for acute atherothrombosis of extremity artery. Group A consisted of patients treated at Clinic for vascular surgery in Sarajevo, while patients in Group B were treated in Trollhattan in Sweden at NAL hospital. This study was clinical, comparative, retrospective-prospective.

Results:

In group A, 20% of patients had diabetes mellitus while in group B prevalence of diabetics was lower (12,5%) but difference was not statistically significant p>0.05. Sixty percent of patients (60%) in group A were smokers. In Sweden, habit of smoking is not as common as in Balkan countries and consequently only 22,5% of patients were smokers in Group l, difference was statistically significant, p<0.05. In patients assigned to group A, 42.5% of them had diagnosis of hypertension while in Group B, 35% of patients were hypertensive. Difference was not statistically significant, p>0.05. 37.5% of patients in group A and 20% of patients in group B had hyperlipidemia. Difference was not statistically significant, p>0.05. In Group A mean age of patients was 67.85 years while mean age in Group B was 73.63. Age difference was statistically significant, p<0.05.

Conclusion:

Prevalence of risk factors of atherosclerosis in peripheral artery disease were evaluated in this study. Significant difference in prevalence of two risk factors were determined namely, smoking and mean age of occurrence of atherothrombosis. Quiting smoking and adopting healthier life habits may lead to reduction of prevalence PAD in younger patients in Bosnia and Herzegovina.

The Role of Statin Drugs in the Management of the Peripheral Vascular Patient

The impact of statin therapy on established vascular conditions and recurrent disease is most relevant for long-term care. Patients receiving statin therapy have been shown to experience less recurrent stenosis following carotid endarterectomy and stent angioplasty, reduced cardiac events following cardiac and noncardiac vascular surgery, and reduction in aneurysm development. In patients with peripheral arterial disease, claudication distance is increased, as well as patency rates following infrainguinal arterial bypass grafting. Of note, statins drugs may also prove beneficial in the prevention of certain cancers, Alzheimer's disease, and osteoporosis (all diseases frequently seen concurrently in the patient with peripheral arterial disease). As such, it is becoming all the more necessary that vascular surgeons remain informed about clinical research initiatives related to statin use and lipid management in general. The following is a review of lipid metabolism as it applies to statins as well as a review of the beneficial effects of statins.

Influence and interaction of diabetes and lipoprotein (a) serum levels on mortality of patients with peripheral artery disease

BACKGROUND

Diabetes mellitus is a risk factor for early complications and mortality in patients with peripheral artery disease. Lipoprotein (a) [Lp(a)] is also suggested to be a marker of increased cardiovascular risk. We investigated the association and interaction between diabetes mellitus, lipoprotein(a) and mortality in high risk patients with peripheral artery disease (PAD).

METHODS

We studied 700 consecutive patients [median age 73 years, interquartile range (IQR) 62-80, 393 male (56%)] with PAD from a registry database. Atherothrombotic risk factors (diabetes, smoking, hyperlipidaemia, arterial hypertension) and Lp(a) serum levels were recorded. We used stratified multivariate Cox proportional hazard analyses to assess the mortality risk at a given patient's age with respect to the presence of diabetes and Lp(a) serum levels (in tertiles).

RESULTS

Patients with Lp(a) levels above 36 mg dL(-1) (highest tertile) and insulin-dependent type II diabetes had a 3.01-fold increased adjusted risk for death (95% confidence interval 1.28-6.64, P = 0.011) compared to patients without diabetes or patients with non-insulin-dependent type II diabetes. In patients with Lp(a) serum levels below 36 mg dL(-1) (lower and middle tertile), diabetes mellitus was not associated with an increased risk for death.

CONCLUSION

Insulin-dependent type II diabetes mellitus seems to be associated with an increased risk for mortality in PAD patients with Lp(a) serum levels above 36 mg dL(-1). PAD patients with non-insulin-dependent type II diabetes, and patients with diabetes and Lp(a) levels below 36 mg dL(-1) showed survival rates comparable to PAD patients without diabetes.

Managing Risk Factors for Atherosclerosis in Critical Limb Ischaemia

OBJECTIVE

To review the best medical management of critical limb ischaemia (CLI).

METHODS

Published studies dealing with CLI and risk factors were searched for via PUBMED.

FINDINGS AND CONCLUSIONS

Patients with critical limb ischaemia (CLI) have a one and ten year mortality of approximately 20% and 75% respectively. Risk factors for the development of peripheral atherosclerosis are the same as for coronary and cerebrovascular atherosclerosis namely diabetes mellitus, hyperlipidaemia, arterial hypertension, and smoking. As there are few studies of risk factor for peripheral arterial occlusive disease (PAOD), treatment recommendations are often based on studies in patients with coronary or cerebrovascular atherosclerosis. While waiting for specific studies, CLI patients should be treated according to current guidelines for other atherosclerotic patients.

Serum lipoprotein (a) levels in patients with diabetic foot lesions

Our aim was to see the levels of lipoprotein (a) (Lp (a)) in patients with gangrenous or non-gangrenous diabetic foot lesions. Twenty-two patients with gangrenous foot lesions, 11 with non-gangrenous foot lesions and 10 healthy subjects were included in the study. All the patients had similar glycemic control and duration of diabetes. The main outcome measure was serum Lp (a) levels in both group of patients with diabetes and healthy subjects. Diabetic patients with gangrenous foot lesions had significantly higher Lp (a) levels (83.8+/-8.3 mg/dl) than the patients with non-gangrenous foot lesions (38.3+/-5.8 mg/dl) and healthy subjects (35.6+/-4.2 mg/dl). Lp (a) levels were not significantly different in healthy subjects and in patients with non-gangrenous foot lesions. Lp (a) levels may have a pathogenetic role in the development of gangrenous foot lesions in patients with diabetes mellitus.

Inflammatory mediators are associated with 1-year mortality in critical limb ischemia

OBJECTIVE

The atherosclerotic process has inflammatory features. Patients with peripheral atherosclerosis and critical limb ischemia have a poor prognosis. This study evaluated the hypothesis that inflammatory markers are associated with mortality among patients admitted to the hospital because of critical limb ischemia.

METHODS

This was a prospective, single-center, 1-year, follow-up study of 259 consecutive patients with critical limb ischemia who were admitted to a secondary referral center of vascular diseases. Interventions included evaluation of intercurrent disease, ankle and arm blood pressures, plasma glucose and lipid levels, plasma homocysteine, cardiolipin antibodies, resistance to activated protein C, plasma endothelin-1, and the inflammatory mediators tumor necrosis factor-alpha, interleukin-6, neopterin, high-sensitivity C-reactive protein, CD40 ligand, and 8-iso-prostaglandin F alpha in plasma. The main outcome measure was total mortality and causes of death assessed 1 year after admission.

RESULTS

During the first year after admission, 61 patients (24%) died. These patients were older (P < .0001), showed a higher leukocyte count (P = .0011) and levels of serum creatinine (P < .0001), lower levels of high-density lipoprotein (HDL) cholesterol (P = .003) and frequency of active treatment (P = .014) than the 198 (76%) survivors. More nonsurvivors had gangrene (P < .0001), and fewer (P = .004) had lipid-lowering treatment. The plasma levels of interleukin-6 (P < .0001), tumor necrosis factor-alpha (P < .0001), neopterin (P < .0001), and high-sensitivity C-reactive protein (P = .002) at admission for critical limb ischemia were all significantly lower in the survivors, whereas there was no difference concerning CD40 ligand. In logistic regression adjusted for age, sex, lipid-lowering therapy, active treatment, gangrene, leukocyte count, creatinine, and serum HDL cholesterol, the inflammatory mediators tumor necrosis factor-alpha (P = .0084), neopterin (P = .0035), but not interleukin-6 (P = .585) or high-sensitivity C-reactive protein (P = .314) were independent risk variables of death within 1 year.

CONCLUSIONS

Increased age, leukocyte count, creatinine, and inflammatory mediators, together with gangrene, were associated with 1-year mortality despite intervention in critical limb ischemia. For tumor necrosis factor-alpha and neopterin in plasma, this association was independent of the other parameters.