Lipoprotein(a) and incident ischemic stroke: the Atherosclerosis Risk in Communities (ARIC) study

Lipoprotein (a) and cerebrovascular disease

The role of lipoprotein (a) [Lp(a)] in cerebrovascular disease is a topic of importance. In this narrative review, pertinent studies have been leveraged to comprehensively examine this relationship from diverse perspectives.Lp(a) shares structural traits with low-density lipoprotein cholesterol. Lp(a) is synthesized by hepatocytes, and its plasma levels are genetically determined by the LPA gene, which produces apolipoprotein (a).Numerous epidemiological studies have confirmed the positive correlation between elevated serum Lp(a) levels and the occurrence or recurrence of cerebrovascular events, especially ischemic strokes, in adults. It should be noted that the correlation strength varies among studies and is marginal in Mendelian randomization studies.Regarding pediatric patients, screening is currently limited to those with a relevant medical history. Lp(a) seems to play a significant role in the pathogenesis of arterial ischemic stroke in children because environmental thrombotic and atherogenic factors are generally not present.Phase 3 trials of novel Lp(a) targeting agents, such as pelacarsen and olpasiran, are anticipated to demonstrate their efficacy in reducing the incidence of stroke. Given the richness of the literature, new guidelines regarding Lp(a) screening and management in targeted populations are warranted to provide more effective primary and secondary prevention.

Associations between lipoprotein(a), oxidized phospholipids, and extracoronary vascular disease

The roles of lipoprotein(a) [Lp(a)] and related oxidized phospholipids (OxPLs) in the development and progression of coronary disease is known, but their influence on extracoronary vascular disease is not well-established. We sought to evaluate associations between Lp(a), OxPL apolipoprotein B (OxPL-apoB), and apolipoprotein(a) (OxPL-apo(a)) with angiographic extracoronary vascular disease and incident major adverse limb events (MALEs). Four hundred forty-six participants who underwent coronary and/or peripheral angiography were followed up for a median of 3.7 years. Lp(a) and OxPLs were measured before angiography. Elevated Lp(a) was defined as ≥150 nmol/L. Elevated OxPL-apoB and OxPL-apo(a) were defined as greater than or equal to the 75th percentile (OxPL-apoB ≥8.2 nmol/L and OxPL-apo(a) ≥35.8 nmol/L, respectively). Elevated Lp(a) had a stronger association with the presence of extracoronary vascular disease compared to OxPLs and was minimally improved with the addition of OxPLs in multivariable models. Compared to participants with normal Lp(a) and OxPL concentrations, participants with elevated Lp(a) levels were twice as likely to experience a MALE (odds ratio: 2.14, 95% confidence interval: 1.03, 4.44), and the strength of the association as well as the C statistic of 0.82 was largely unchanged with the addition of OxPL-apoB and OxPL-apo(a). Elevated Lp(a) and OxPLs are risk factors for progression and complications of extracoronary vascular disease. However, the addition of OxPLs to Lp(a) does not provide additional information about risk of extracoronary vascular disease. Therefore, Lp(a) alone captures the risk profile of Lp(a), OxPL-apoB, and OxPL-apo(a) in the development and progression of atherosclerotic plaque in peripheral arteries.

Impaired endogenous fibrinolysis status: a potential prognostic predictor in ischemic stroke

Stroke confers a severe global healthcare burden, hence exploring risk factors for stroke occurrence and prognosis is important for stroke prevention and post-stroke management strategies. Endogenous fibrinolysis is a spontaneous physiological protective mechanism that dissolves thrombus to maintain vascular patency. Recently, impaired endogenous fibrinolysis has been considered as a potential novel cardiovascular risk factor, but its link with ischaemic stroke in the past has been underappreciated. In this review, we summarize the latest mechanisms of endogenous fibrinolysis, review the current evidence and data on endogenous fibrinolysis in ischemic stroke. It includes the structure of thrombus in ischemic stroke patients, the effect of fibrin structure on the endogenous fibrinolytic efficiency, and the association between intravenous thrombolytic therapy and endogenous fibrinolysis in ischemic stroke. It also includes the single factors (tissue plasminogen activator, urokinase plasminogen activator, plasminogen activator inhibitor-1, thrombin activatable fibrinolysis inhibitor, complement component 3, complement component 5, alpha-2-antiplasmin, plasmin-alpha-2-antiplasmin complex, and lipoprotein[a]), and the global assessments of endogenous fibrinolysis status (thromboelastography, rotational thromboelastometry, and global thrombosis test), and their potential as predictors to identify occurrence or unfavorable functional outcomes of ischemic stroke. All of these assessments present advantages and limitations, and we suggest that the global thrombosis test may be more appropriate for detecting impaired endogenous fibrinolysis status in ischemic stroke patients.

Lipoprotein(a): Emerging insights and therapeutics

The strong association between lipoprotein (a) [Lp(a)] and atherosclerotic cardiovascular disease has led to considerations of Lp(a) being a potential target for mitigating residual cardiovascular risk. While approximately 20 % of the population has an Lp(a) level greater than 50 mg/dL, there are no currently available pharmacological lipid-lowering therapies that have demonstrated substantial reduction in Lp(a). Novel therapies to lower Lp(a) include antisense oligonucleotides and small-interfering ribonucleic acid molecules and have shown promising results in phase 2 trials. Phase 3 trials are currently underway and will test the causal relationship between Lp(a) and ASCVD and whether lowering Lp(a) reduces cardiovascular outcomes. In this review, we summarize emerging insights related to Lp(a)'s role as a risk-enhancing factor for ASCVD, association with calcific aortic stenosis, effects of existing therapies on Lp(a) levels, and variations amongst patient populations. The evolving therapeutic landscape of emerging therapeutics is further discussed.

The Association of High Lipoprotein(a) Concentration and Risk of Ischaemic Stroke in Atrial Fibrillation Patients

Background

Lipoprotein(a) [Lp(a)] is a well-established risk factor for ischaemic stroke (IS). It is unclear whether Lp(a) is associated with IS in patients with atrial fibrillation (AF). The aim of this study is to explore the association between the concentration of Lp(a) and the risk of IS in AF patients, hope to find the potential risk factor for the IS in AF patients.

Methods

This study is a retrospective cohort study. The screened AF patients between January 2017 and July 2021 were matched at 1:1 by the propensity score matching (PSM) method in the Second Affiliated Hospital of Nanchang University. Associations between Lp(a) and ischaemic stroke were analysed using logistic regression models, stratified analysis and sensitivity analysis. Statistical analyses were conducted using IBM SPSS software.

Results

The number of enrolled participates is 2258, which contains 1129 non-AF patients and 1129 AF patients. Among IS patients, the median Lp(a) concentration was higher than that of controls (17.03 vs. 15.36 mg/dL, P = 0.032). The Spearman rank-order correlation coefficients revealed significant positive relationships between IS and Lp(a) (P = 0.032). In addition, a significant increase in IS risk was associated with Lp(a) levels >30.00 mg/dL in unadjusted model [OR:1.263, 95% CI(1.046-1.523), P = 0.015], model 1 [OR:1.284, 95% CI(1.062,1.552), P = 0.010], model 2 [OR: 1.297, 95% CI(1.07,1.573). P = 0.008], and model 3 [OR: 1.290, 95% CI (1.064, 1.562). P = 0.009]. The stratified analysis indicated that this correlation was not affected by female sex [1.484 (1.117, 1.972), P = 0.006], age ≤ 60 [1.864 (1.067-3.254), P=0.029], hypertension [1.359 (1.074, 1.721), P = 0.011], or non-coronary heart disease (CHD) [1.388 (1.108, 1.738), P = 0.004].

Conclusion

High levels of Lp(a) were significantly related to IS in AF patients and may be a potential risk factor in the onset of an IS in AF patients.

Lipoprotein(a): A Residual Cardiovascular Risk Factor in Statin-Treated Stroke Survivors: Insights From the SPARCL Trial

Background

In the SPARCL (Stroke Prevention by Aggressive Reduction in Cholesterol levels) trial, atorvastatin (80 mg/d) was compared to placebo in patients with recent stroke or transient ischemic attack (TIA) and no known coronary artery disease.

Objectives

This study aimed to assess the contribution of lipoprotein(a) [Lp(a)] to subsequent cerebrovascular and cardiovascular events in stroke/TIA survivors.

Methods

Lp(a) levels and apolipoprotein(a) [apo(a)] isoform size were determined by liquid-chromatography mass spectrometry in samples collected at baseline from 2,814 SPARCL participants (1,418 randomized to atorvastatin and 1,396 to placebo). Within each treatment arm, patients in the highest quartile (≥84.0 nmol/L) were compared with those in the lowest quartiles of Lp(a) concentrations. Patients in the lowest quartile (≤25.9 Kringle IV domains) of apo(a) isoform sizes were compared with those in the highest quartiles. Multivariable-adjusted HRs were calculated using Cox proportional regression models.

Results

There was no significant association between Lp(a) concentrations or apo(a) isoform sizes and the risk of recurrent stroke, the primary outcome of SPARCL, or cerebrovascular events in patients randomized to atorvastatin or placebo. In contrast, in patients randomized to atorvastatin, elevated Lp(a) concentrations and short apo(a) isoforms were positively and independently associated with an increased risk of coronary events (HR: 1.607 [95% CI: 1.007-2.563] and HR: 2.052 [95% CI: 1.303-3.232]). No such association was found in patients randomized to placebo (HR: 1.025 [95% CI: 0.675-1.555] and HR: 1.097 [95% CI: 0.735-1.637]).

Conclusions

Lp(a) contributes to the residual coronary artery disease risk of statin-treated stroke/TIA survivors, paving the way for use of therapies targeting Lp(a) in this population with stroke. (Lipitor In The Prevention Of Stroke, For Patients Who Have Had A Previous Stroke [SPARCL]; NCT00147602).

Plasma tissue-type plasminogen activator is associated with lipoprotein(a) and clinical outcomes in hospitalized patients with COVID-19

Background

Patients with COVID-19 have a higher risk of thrombosis and thromboembolism, but the underlying mechanism(s) remain to be fully elucidated. In patients with COVID-19, high lipoprotein(a) (Lp(a)) is positively associated with the risk of ischemic heart disease. Lp(a), composed of an apoB-containing particle and apolipoprotein(a) (apo(a)), inhibits the key fibrinolytic enzyme, tissue-type plasminogen activator (tPA). However, whether the higher Lp(a) associates with lower tPA activity, the longitudinal changes of these parameters in hospitalized patients with COVID-19, and their correlation with clinical outcomes are unknown.

Objectives

To assess if Lp(a) associates with lower tPA activity in COVID-19 patients, and how in COVID-19 populations Lp(a) and tPA change post infection.

Methods

Endogenous tPA enzymatic activity, tPA or Lp(a) concentration were measured in plasma from hospitalized patients with and without COVID-19. The association between plasma tPA and adverse clinical outcomes was assessed.

Results

In hospitalized patients with COVID-19, we found lower tPA enzymatic activity and higher plasma Lp(a) than that in non-COVID-19 controls. During hospitalization, Lp(a) increased and tPA activity decreased, which associates with mortality. Among those who survived, Lp(a) decreased and tPA enzymatic activity increased during recovery. In patients with COVID-19, tPA activity is inversely correlated with tPA concentrations, thus, in another larger COVID-19 cohort, we utilized plasma tPA concentration as a surrogate to inversely reflect tPA activity. The tPA concentration was positively associated with death, disease severity, plasma inflammatory, and prothrombotic markers, and with length of hospitalization among those who were discharged.

Conclusion

High Lp(a) concentration provides a possible explanation for low endogenous tPA enzymatic activity, and poor clinical outcomes in patients with COVID-19.

Current Management and Future Perspectives in the Treatment of Lp(a) with a Focus on the Prevention of Cardiovascular Diseases

Lipoprotein(a) [Lp(a)] is a lipid molecule with atherogenic, inflammatory, thrombotic, and antifibrinolytic effects, whose concentrations are predominantly genetically determined. The association between Lp(a) and cardiovascular diseases (CVDs) has been well-established in numerous studies, and the ability to measure Lp(a) levels is widely available in the community. As such, there has been increasing interest in Lp(a) as a therapeutic target for the prevention of CVD. The impact of the currently available lipid-modifying agents on Lp(a) is modest and heterogeneous, except for the monoclonal antibody proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i), which demonstrated a significant reduction in Lp(a) levels. However, the absolute reduction in Lp(a) to significantly decrease CVD outcomes has not been definitely established, and the magnitude of the effect of PCSK9i seems insufficient to directly reduce the Lp(a)-related CVD risk. Therefore, emerging therapies are being developed that specifically aim to lower Lp(a) levels and the risk of CVD, including RNA interference (RNAi) agents, which have the capacity for temporary and reversible downregulation of gene expression. This review article aims to summarize the effects of Lp(a) on CVD and to evaluate the available evidence on established and emerging therapies targeting Lp(a) levels, focusing on the potential reduction of CVD risk attributable to Lp(a) concentrations.

Cardiovascular Disease Risk Factors in Women: The Impact of Race and Ethnicity: A Scientific Statement From the American Heart Association

Cardiovascular disease is the leading cause of death in women, yet differences exist among certain racial and ethnic groups. Aside from traditional risk factors, behavioral and environmental factors and social determinants of health affect cardiovascular health and risk in women. Language barriers, discrimination, acculturation, and health care access disproportionately affect women of underrepresented races and ethnicities. These factors result in a higher prevalence of cardiovascular disease and significant challenges in the diagnosis and treatment of cardiovascular conditions. Culturally sensitive, peer-led community and health care professional education is a necessary step in the prevention of cardiovascular disease. Equitable access to evidence-based cardiovascular preventive health care should be available for all women regardless of race and ethnicity; however, these guidelines are not equally incorporated into clinical practice. This scientific statement reviews the current evidence on racial and ethnic differences in cardiovascular risk factors and current cardiovascular preventive therapies for women in the United States.

Molecular mechanisms underlying some major common risk factors of stroke

Ischemic and hemorrhagic strokes are the most common known cerebrovascular disease which can be induced by modifiable and non-modifiable risk factors. Age and race are the most common non-modifiable risk factors of stroke. However, hypertension, diabetes, obesity, dyslipidemia, physical inactivity, and cardiovascular disorders are major modifiable risk factors. Understanding the molecular mechanism mediating each of these risk factors is expected to contribute significantly to reducing the risk of stroke, preventing neural damage, enhancing rehabilitation, and designing suitable treatments. Abnormalities in the structure of the blood-brain barrier and blood vessels, thrombosis, vasoconstriction, atherosclerosis, reduced cerebral blood flow, neural oxidative stress, inflammation, and apoptosis, impaired synaptic transmission, excitotoxicity, altered expression/activities of many channels and signaling proteins are the most knows mechanisms responsible for stroke induction. However, the molecular role of risk factors in each of these mechanisms is not well understood and requires a lot of search and reading. This review was designed to provide the reader with a single source of information that discusses the current update of the prevalence, pathophysiology, and all possible molecular mechanisms underlying some major risk factors of stroke namely, hypertension, diabetes mellitus, dyslipidemia, and lipid fraction, and physical inactivity. This provides a full resource for understanding the molecular effect of each of these risk factors in stroke.

Lipoprotein(a) in Cardiovascular Diseases: Insight From a Bibliometric Study

Lipoprotein(a) [Lp(a)] is a complex polymorphic lipoprotein comprised of a low-density lipoprotein particle with one molecule of apolipoprotein B100 and an additional apolipoprotein(a) connected through a disulfide bond. The serum concentration is mostly genetically determined and only modestly influenced by diet and other lifestyle modifications. In recent years it has garnered increasing attention due to its causal role in pre-mature atherosclerotic cardiovascular disease and calcific aortic valve stenosis, while novel effective therapeutic options are emerging [apolipoprotein(a) antisense oligonucleotides and ribonucleic acid interference therapy]. Bibliometric descriptive analysis and mapping of the research literature were made using Scopus built-in services. We focused on the distribution of documents, literature production dynamics, most prolific source titles, institutions, and countries. Additionally, we identified historical and influential papers using Reference Publication Year Spectrography (RPYS) and the CRExplorer software. An analysis of author keywords showed that Lp(a) was most intensively studied regarding inflammation, atherosclerosis, cardiovascular risk assessment, treatment options, and hormonal changes in post-menopausal women. The results provide a comprehensive view of the current Lp(a)-related literature with a specific interest in its role in calcific aortic valve stenosis and potential emerging pharmacological interventions. It will help the reader understand broader aspects of Lp(a) research and its translation into clinical practice.

Elevated Lipoprotein(a): Background, Current Insights and Future Potential Therapies

Lipoprotein(a) forms a subfraction of the lipid profile and is characterized by the addition of apolipprotein(a) (apo(a)) to apoB100 derived particles. Its levels are mostly genetically determined inversely related to the number of protein domain (kringle) repeats in apo(a). In epidemiological studies, it shows consistent association with cardiovascular disease (CVD) and most recently with extent of aortic stenosis. Issues with standardizing the measurement of Lp(a) are being resolved and consensus statements favor its measurement in patients at high risk of, or with family histories of CVD events. Major lipid-lowering therapies such as statin, fibrates, and ezetimibe have little effect on Lp(a) levels. Therapies such as niacin or cholesterol ester transfer protein (CETP) inhibitors lower Lp(a) as well as reducing other lipid-related risk factors but have failed to clearly reduce CVD events. Proprotein convertase subtilisin kexin-9 (PCSK9) inhibitors reduce cholesterol and Lp(a) as well as reducing CVD events. New antisense therapies specifically targeting apo(a) and hence Lp(a) have greater and more specific effects and will help clarify the extent to which intervention in Lp(a) levels will reduce CVD events.

Epidemiology and risk factors for stroke in young individuals: implications for prevention

PURPOSE OF REVIEW

Summarize and examine the epidemiology, etiologies, risk factors, and treatment of stroke among young adults and highlight the importance of early recognition, treatment, and primordial prevention of risk factors that lead to stroke.

RECENT FINDINGS

Incidence of stroke, predominantly ischemic, among young adults has increased over the past two decades. This parallels an increase in traditional risk factors such as hypertension, diabetes, and use of tobacco, and use of illicit substances among young stroke patients. Compared to older patients, there is a much higher proportion of intracerebral and subarachnoid hemorrhage in young adults. The cause of ischemic stroke in young adults is also more diverse compared to older adults with 1/3rd classified as stroke of undetermined etiology due to inadequate effort or time spent on investigating these diverse and rare etiologies. Young premature Atherosclerotic Cardiovascular Disease patients have suboptimal secondary prevention care compared to older patients with lower use of antiplatelets and statin therapy and lower adherence to statins.

SUMMARY

Among young patients, time-critical diagnosis and management remain challenging, due to atypical stroke presentations, vast etiologies, statin hesitancy, and provider clinical inertia. Early recognition and aggressive risk profile modification along with primary and secondary prevention therapy optimization are imperative to reduce the burden of stroke among young adults and save potential disability-adjusted life years.

Lipoprotein(a): Knowns, unknowns and uncertainties

Over the last 10 years, there have been advances on several aspects of lipoprotein(a) which are reviewed in the present article. Since the standard immunoassays for measuring lipoprotein(a) are not fully apo(a) isoform-insensitive, the application of an LC-MS/MS method for assaying molar concentrations of lipoprotein(a) has been advocated. Genome wide association, epidemiological, and clinical studies have established high lipoprotein(a) as a causal risk factor for atherosclerotic cardiovascular diseases (ASCVD). However, the relative importance of molar concentration, apo(a) isoform size or variants within the LPA gene is still controversial. Lipoprotein(a)-raising single nucleotide polymorphisms has not been shown to add on value in predicting ASCVD beyond lipoprotein(a) concentrations. Although hyperlipoproteinemia(a) represents an important confounder in the diagnosis of familial hypercholesterolemia (FH), it enhances the risk of ASCVD in these patients. Thus, identification of new cases of hyperlipoproteinemia(a) during cascade testing can increase the identification of high-risk individuals. However, it remains unclear whether FH itself increases lipoprotein(a). The ASCVD risk associated with lipoprotein(a) seems to follow a linear gradient across the distribution, regardless of racial subgroups and other risk factors. The inverse association with the risk of developing type 2 diabetes needs consideration as effective lipoprotein(a) lowering therapies are progressing towards the market. Considering that Mendelian randomization analyses have identified the degree of lipoprotein(a)-lowering that is required to achieve ASCVD benefit, the findings of the ongoing outcome trial with pelacarsen will clarify whether dramatically lowering lipoprotein(a) levels can reduce the risk of ASCVD.

Using Serum Biomarkers for Identifying Unstable Carotid Plaque: Update of Current Evidence

Carotid atherosclerosis is responsible for a great proportion of ischemic strokes. Early identification of unstable or vulnerable carotid plaques, and therefore, of patients at high risk for stroke, is of significant medical and socioeconomical value. We reviewed the current literature and discussed the potential role of the most important serum biomarkers in identifying patients with carotid atherosclerosis who are at high risk for atheroembolic stroke.

Lipoprotein (a) level as a risk factor for stroke and its subtype: A systematic review and meta-analysis

The role of lipoprotein-A [Lp (a)] as a risk factor for stroke is less well documented than for coronary heart disease. Hence, we conducted a systematic review and meta-analysis for the published observational studies in order to investigate the association of Lp (a) levels with the risk of stroke and its subtypes. In our meta-analysis, 41 studies involving 7874 ischemic stroke (IS) patients and 32,138 controls; 13 studies for the IS subtypes based on TOAST classification and 7 studies with 871 Intracerebral hemorrhage (ICH) cases and 2865 control subjects were included. A significant association between increased levels of Lp (a) and risk of IS as compared to control subjects was observed (standardized mean difference (SMD) 0.76; 95% confidence interval (CIs) 0.53-0.99). Lp (a) levels were also found to be significantly associated with the risk of large artery atherosclerosis (LAA) subtype of IS (SMD 0.68; 95% CI 0.01-1.34) as well as significantly associated with the risk of ICH (SMD 0.65; 95% CI 0.13-1.17) as compared to controls. Increased Lp (a) levels could be considered as a predictive marker for identifying individuals who are at risk of developing IS, LAA and ICH.

Lipoprotein(a) is associated with large artery atherosclerosis stroke aetiology and stroke recurrence among patients below the age of 60 years: results from the BIOSIGNAL study

AIMS

Lipoprotein(a) [Lp(a)] is a recognized causal risk factor for atherosclerotic cardiovascular disease but its role for acute ischaemic stroke (AIS) is controversial. In this study, we evaluated the association of Lp(a) with large artery atherosclerosis (LAA) stroke and risk of recurrent cerebrovascular events in AIS patients.

METHODS AND RESULTS

For this analysis of the prospective, observational, multicentre BIOSIGNAL cohort study we measured Lp(a) levels in plasma samples of 1733 primarily Caucasian (98.6%) AIS patients, collected within 24 h after symptom onset. Primary outcomes were LAA stroke aetiology and recurrent cerebrovascular events (ischaemic stroke or transient ischaemic attack) within 1 year. We showed that Lp(a) levels are independently associated with LAA stroke aetiology [adjusted odds ratio 1.48, 95% confidence interval (CI) 1.14-1.90, per unit log10Lp(a) increase] and identified age as a potent effect modifier (Pinteraction =0.031) of this association. The adjusted odds ratio for LAA stroke in patients aged <60 years was 3.64 (95% CI 1.76-7.52) per unit log10Lp(a) increase and 4.04 (95% CI 1.73-9.43) using the established cut-off ≥100 nmol/l. For 152 recurrent cerebrovascular events, we did not find a significant association in the whole cohort. However, Lp(a) levels ≥100 nmol/l were associated with an increased risk for recurrent events among patients who were either <60 years [adjusted hazard ratio (HR) 2.40, 95% CI 1.05-5.47], had evident LAA stroke aetiology (adjusted HR 2.18, 95% CI 1.08-4.40), or had no known atrial fibrillation (adjusted HR 1.60, 95% CI 1.03-2.48).

CONCLUSION

Elevated Lp(a) was independently associated with LAA stroke aetiology and risk of recurrent cerebrovascular events among primarily Caucasian individuals aged <60 years or with evident arteriosclerotic disease.

Characterisation of recent trends in cardiovascular risk factors in young and middle-aged patients with ischaemic stroke and/or transient ischaemic attack

BACKGROUND

Strokes in the young and middle-aged are associated with a disproportionately large economic and social impact in addition to their clinical effects. Standard Modifiable Cardiovascular Risk Factors (SMuRFs; hypercholesterolaemia, hypertension, diabetes mellitus and smoking) are key drivers of cardiovascular disease including strokes, however recent temporal trends in the younger stroke population have not been well characterised. We aimed to evaluate recent trends of SMuRFs in a cohort of younger patients with ischaemic stroke.

METHODS

Consecutive patients aged <65 years with clinical and/or radiological diagnosis of ischaemic stroke or transient ischaemic attack in a tertiary referral centre (2013-2017) were retrospectively appraised. The demographic and clinical comorbidities of these patients were assessed including their SMuRF profile. The prevalence over time and clinical associations of patients with no SMuRFs were studied and compared to patients with SMuRFs.

RESULTS

Of 487 patients (53.49 ± 9.13 yrs., 60% men) analysed, 23% did not have SMuRFs. The proportion of "non-SMuRF" patients increased over time (p < 0.01) and this trend was not influenced by age (p = 0.48) or gender (p = 0.68). The presence of SMuRFs was not associated with in-hospital outcomes, however patients without SMuRFs were significantly less likely to be discharged on blood pressure (p < 0.01) and lipid-lowering therapies (p = 0.03).

CONCLUSIONS

The proportion of younger stroke patients without SMuRFs is substantial and has increased over time. Our findings highlight the need for further research to better understand the mechanisms underlying stroke development in this population and whether less risk factor treatment in this population could impact longer term outcomes.

Elevated Lipoprotein(a) and Risk of Ischemic Stroke

BACKGROUND

High lipoprotein(a) is associated with increased risk of myocardial infarction and aortic valve stenosis. Previous studies have examined the association of lipoprotein(a) and risk of stroke; however, the results are conflicting.

OBJECTIVES

The purpose of this study was to test if high lipoprotein(a) is associated with high risk of ischemic stroke observationally and causally from human genetics.

METHODS

The study included 49,699 individuals from the Copenhagen General Population Study and 10,813 individuals from the Copenhagen City Heart Study with measurements of plasma lipoprotein(a), LPA kringle-IV type 2 number of repeats, and LPA rs10455872. The endpoint of ischemic stroke was ascertained from Danish national health registries and validated by medical doctors.

RESULTS

Compared with individuals with lipoprotein(a) levels <10 mg/dl (<18 nmol/l: first to 50th percentile), the multivariable-adjusted hazard ratio for ischemic stroke was 1.60 (95% confidence interval [CI]:1.24 to 2.05) for individuals with lipoprotein(a) levels >93mg/dl (>199 nmol/L: 96th to 100th percentile). In observational analyses for a 50 mg/dl (105 nmol/l) higher lipoprotein(a) level the age- and sex-adjusted hazard ratio for ischemic stroke was 1.20 (95% CI: 1.13 to 1.28), while the corresponding age- and sex-adjusted genetic causal risk ratio for KIV-2 number of repeats was 1.20 (95% CI: 1.02 to 1.43) and for rs10455872 was 1.27 (95% CI: 1.06 to 1.51). The highest absolute 10-year risk of ischemic stroke was 17% in active smoking individuals >70 years of age with hypertension and lipoprotein(a) levels >93 mg/dl (>199 nmol/l: 96th to 100th percentile). In the Copenhagen City Heart Study, risk estimates for high levels of lipoprotein(a) were in the same direction but did not reach statistical significance.

CONCLUSIONS

In a large contemporary general population study, high plasma levels of lipoprotein(a) were associated with increased risk of ischemic stroke both observationally and causally from human genetics.

Causal Effect of Lp(a) [Lipoprotein(a)] Level on Ischemic Stroke and Alzheimer Disease: A Mendelian Randomization Study

Background and Purpose- Stroke and Alzheimer disease are 2 major causes of neurological disability in aged people and shared overlapping predictors. In recent prospective studies, high Lp(a) [lipoprotein(a)] level is associated with high risk of stroke but low risk of Alzheimer disease. Whether this reflects a causal association remains to be established. The aim of this study is to examine the causal associations of Lp(a) concentrations on ischemic stroke, ischemic stroke subtypes, and Alzheimer disease. Methods- We used 9 single-nucleotide polymorphisms associated with Lp(a) concentrations as instrumental variables. Summary-level data on ischemic stroke and its subtypes were obtained from the Multiancestry Genome-Wide Association Study of Stroke consortium with European individuals ≤446 696 individuals. Summary-level data on Alzheimer disease were obtained from the International Genomics of Alzheimer Project With European individuals ≤54 162 individuals. Two-sample Mendelian randomization (MR) estimates were calculated with inverse-variance weighted, penalized inverse-variance weighted, simple median, weighted median, and MR Pleiotropy Residual Sum and Outlier approaches, and MR-Egger regression was used to explore pleiotropy. Results- Genetically predicted 1-SD log-transformed increase in Lp(a) concentrations was associated with a substantial increase in risk of large artery stroke (odds ratio, 1.20; 95% CI, 1.11-1.30; P<0.001) and a reduce in risk of small vessel stroke (odds ratio, 0.92; 95% CI, 0.88-0.97; P=0.001) and Alzheimer disease (odds ratio, 0.94; 95% CI, 0.91-0.97; P<0.001) using inverse-variance weighted method. No significant association was observed for total ischemic stroke or cardioembolic stroke. MR-Egger indicated no evidence of pleiotropic bias. Results were broadly consistent in sensitivity analyses using penalized inverse-variance weighted, simple median, weighted median, and MR Pleiotropy Residual Sum and Outlier approaches accounting for potential genetic pleiotropy or outliers. Conclusions- This study provides evidence to support that high Lp(a) concentrations was causally associated with an increased risk of large artery stroke but a decreased risk of small vessel stroke and Alzheimer disease. The mechanism underlying the double-edged sword effect of Lp(a) concentrations on neurological system requires further investigation.

Serum lipoprotein (a) is associated with increased risk of stroke in Chinese adults: A prospective study

BACKGROUND AND AIMS

Epidemiological evidence on the association between elevated lipoprotein (a) (Lp (a)) with risk of stroke remains inconsistent. We aimed to investigate the association between serum Lp (a) level and the risk of stroke among middle-aged and elderly Chinese.

METHODS

A community-based prospective cohort study of 8500 participants aged 40 years or older was conducted in Jiading district, Shanghai, China, in 2010. The incident strokes were documented at follow-up visit during 2014-2015.

RESULTS

During a mean follow-up of 5.1 years, 444 incident cases of stroke occurred. The incidences of stroke were 4.44%, 5.14% and 6.14% from the lowest to the highest serum Lp (a) tertile, respectively. A significant association between serum Lp (a) tertile and the risk of incident stroke was observed (p for trend<0.05). Compared with individuals in the lowest tertile of serum Lp (a), the multivariable adjusted hazards ratio (HR) and 95% confidence interval (CI) for incident stroke in Lp (a) tertile 3 were 1.34 (1.06-1.70).

CONCLUSIONS

Serum Lp (a) concentration was associated with increased risk of incident stroke in Chinese adults.

Lipoprotein(a) and Risk of Ischemic Stroke in the REGARDS Study

Objective- Increased Lp(a) [lipoprotein(a)] is associated with coronary heart disease risk, but links with stroke are less consistent. Blacks have higher Lp(a) levels and stroke incidence than whites but have been underrepresented in studies. We hypothesized that Lp(a) is a risk factor for ischemic stroke and that risk differs by race. Approach and Results- REGARDS (Reasons for Geographic and Racial Differences in Stroke) recruited 30 239 black and white US adults aged ≥45 in 2003-2007 to study regional and racial differences in stroke mortality. We measured baseline Lp(a) by immunonephelometric assay in 572 cases of incident ischemic stroke and a 967-person cohort random sample. The hazard ratio of stroke by baseline Lp(a) was calculated using Cox proportional hazards models, stratified by race. Lp(a) was modeled in sex- and race-specific quartiles, given known differences in distributions by race and sex. Interactions were tested by including interaction terms in the proportional hazards models, with P<0.10 considered statistically significant. After adjustment for age, sex, and stroke risk factors, being in the fourth versus the first Lp(a) quartile was weakly associated with ischemic stroke overall, hazard ratio, 1.45 (95% CI, 0.96-2.19). In blacks, the hazard ratio was 1.96 (95% CI, 1.10-3.46), whereas in whites HR was 1.14 (95% CI, 0.64-2.04); P interaction=0.12. Lp(a) was lower in men than women, but associations with stroke in men and women were similar. Conclusions- We confirm that Lp(a) is a risk factor for ischemic stroke. Further research is needed to confirm the role of racial differences of the Lp(a) risk multiplier in ischemic stroke.

Neurological effects of proprotein convertase subtilisin/kexin type 9 inhibitors: direct comparisons

Aims

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors considerably alter the lipid profile. We sought to examine the rates of ischaemic stroke and neurocognitive deficits in patients treated with and without PCSK9 inhibitors.

Methods and results

Randomized controlled trials (RCTs) reporting rates of ischaemic stroke and neurocognitive deficits in patients using PCSK9 inhibitors were identified. Standard meta-analysis techniques were used to compare these outcomes among patients treated with and without PCSK9 inhibitors and the two US Food and Drug Administration-approved PCSK9 inhibitors, evolocumab and alirocumab. The results were presented in terms of risk ratio (RR) with 95% confidence intervals (CIs). Sixteen RCTs with 39 104 patients were included. Evolocumab was used in six RCTs with 33 450 patients, whereas alirocumab was used in 10 RCTs with 5654 patients. We observed a significantly lower risk of ischaemic stroke among those treated with PCSK9 inhibitors (RR 0.77, 95% CI 0.64-0.93) when compared with those without. We did not observe any difference in the risk of neurocognitive deficits between the aforementioned groups (RR 1.11, 95% CI 0.93-1.32). The lower stroke risk in the PCSK9 inhibitors group was driven by evolocumab studies. We observed no difference in the risk of neurocognitive deficits among evolocumab and alirocumab when compared with no PCSK9 inhibitors group.

Conclusion

Treatment with PCSK9 inhibitors significantly lowers the risk of ischaemic stroke, without any increased risk of neurocognitive deficits. PCSK9 inhibitors are neuroprotective due to the decrease in ischaemic-mediated neurovascular events and should be considered cognitively innocuous medications.

Lipoprotein(a) and abdominal aortic aneurysm risk: The Atherosclerosis Risk in Communities study

BACKGROUND AND AIMS

No prospective study has investigated whether elevated lipoprotein(a) concentrations are associated with an increased risk of abdominal aortic aneurysm (AAA). We aimed to prospectively investigate this association.

METHODS

In 1987-1989, the Atherosclerosis Risk in Communities study measured plasma lipoprotein(a) in 13,683 participants aged 45-64 years, without a history of AAA surgery. We followed them for incident, clinical AAA events through 2011.

RESULTS

During the 272,914 person-years of follow-up, over a median of 22.6 years, we documented 505 incident AAA events. The age-, sex-, and race-adjusted model showed that individuals in the highest quintile of plasma lipoprotein(a) had an increased risk of AAA. Further adjustment for the other potential confounding factors, including other plasma lipids (high- and low-density lipoprotein cholesterol and triglyceride concentrations), attenuated the association, but individuals in the highest versus lowest quintile of plasma lipoprotein(a) still had a significantly increased risk of AAA [hazard ratio (95% confidence interval): 1.57 (1.19-2.08)]. Interaction testing suggested no difference in the associations for whites and African Americans (p for interaction = 0.96). A restricted cubic spline analysis demonstrated a positive dose-response relation of plasma lipoprotein(a) with AAA, with a steep increase in AAA risk above the 75th percentile (p for overall association = 0.0086, p for non-linear association = 0.097).

CONCLUSIONS

In this population-based cohort study, elevated lipoprotein(a) concentrations were independently associated with an increased risk of AAA. The association reflected a threshold of increased AAA risk at high lipoprotein(a) concentrations, rather than a steady monotonic association.

The Effects of Tamoxifen on Plasma Lipoprotein(a) Concentrations: Systematic Review and Meta-Analysis

Introduction

Tamoxifen is a selective estrogen receptor modulator widely used in the treatment of breast cancer. Tamoxifen therapy is associated with lower circulating low-density lipoprotein cholesterol and increased triglycerides, but its effects on other lipids are less well studied.

Aims

We aimed to investigate the effect of tamoxifen on circulating concentrations of lipoprotein(a) [Lp(a)] through a meta-analysis of available randomized controlled trials (RCTs) and observational studies.

Methods

This study was registered in the PROSPERO database (CRD42016036890). Scopus, MEDLINE and EMBASE were searched from inception until 22 March 2016 to identify studies investigating the effect of tamoxifen on Lp(a) values in humans. Meta-analysis was performed using an inverse variance-weighted, random-effects model with standardized mean difference (SMD) as the effect size estimate.

Results

Meta-analysis of five studies with 215 participants suggested a statistically significant reduction of Lp(a) levels following tamoxifen treatment (SMD −0.41, 95% confidence interval −0.68 to −0.14, p = 0.003). This effect was robust in the sensitivity analysis.

Conclusions

Meta-analysis suggested a statistically significant reduction of Lp(a) levels following tamoxifen treatment. Further well-designed trials are required to validate these results.

The association of lipoprotein(a) with incident heart failure hospitalization: Atherosclerosis Risk in Communities study

BACKGROUND AND AIMS

Lipoprotein(a) [Lp(a)] is a proatherogenic lipoprotein associated with coronary heart disease, ischemic stroke, and more recently aortic stenosis and heart failure (HF). We examined the association of Lp(a) levels with incident HF hospitalization in the Atherosclerosis Risk in Communities (ARIC) study. We also assessed the relationship between Lp(a) levels and arterial stiffness as a potential mechanism for development of HF.

METHODS

Lp(a) was measured in 14,154 ARIC participants without prevalent HF at ARIC visit 1 (1987-1989). The association of Lp(a) quintiles with incident HF hospitalization was assessed using Cox proportional-hazards models. Arterial stiffness parameters were stratified based on Lp(a) quintiles, and p-trend was calculated across ordered groups.

RESULTS

At a median follow-up of 23.4 years, there were 2605 incident HF hospitalizations. Lp(a) levels were directly associated with incident HF hospitalization in models adjusted for age, race, gender, systolic blood pressure, history of hypertension, diabetes, smoking status, body mass index, heart rate, and high-density lipoprotein cholesterol (quintile 5 vs. quintile 1: hazard ratio [HR] 1.24, 95% confidence interval [CI] 1.09-1.41; p-trend across increasing quintiles <0.01), but not after excluding prevalent and incident myocardial infarction cases (HR 1.07, 95% CI 0.91-1.27; p-trend = 0.70). When adjusted for age, gender, and race, Lp(a) quintiles were not significantly associated with arterial stiffness parameters.

CONCLUSIONS

Increased Lp(a) levels were associated with increased risk of incident HF hospitalization. After excluding prevalent and incident myocardial infarction, the association was no longer significant. Lp(a) levels were not associated with arterial stiffness parameters.

A Comparative Analysis of Serum Lipids in Patients with Chronic Hepatitis C, Nonalcoholic Fatty Liver Disease and Healthy Controls

Serum lipids abnormalities are widespread among patients with chronic hepatitis C (CHC), but the impact of concomitant hepatic steatosis [steatosis, nonalcoholic steatosis (NAS)], as well as distinctions between it and nonalcoholic fatty liver disease (NAFLD) are not well established yet. The aim of the study was to assess and compare the serum lipids in patients with genotype 1 CHC with and without steatosis, those with NAFLD, and healthy controls (HC). A total of 1010 subjects were included in this study: 366 CHC genotype 1 patients with steatosis (n = 227) and without steatosis (n = 139), 403 NAFLD patients, and 241 HC without fatty liver or other disease, matched for age and gender. Serum lipids, body mass index (BMI), components of metabolic syndrome (MS), and serum insulin levels were evaluated. In addition serum lipoprotein (a) [Lp(a)] levels were studied in 112 CHC and 80 NAFLD patients. The mean levels of total cholesterol, LDL-cholesterol and triglycerides (Tg) were higher and the mean levels of HDL-cholesterol were lower in all patients with steatosis (CHC and NAFLD) than in CHC cases without steatosis (p < 0.05 and p = 0.001, resp.). Higher prevalence and severity of lipid abnormalities, including Lp(a), were observed in patients with NAFLD than in those with CHC (p < 0.001). No difference was found between CHC patients without steatosis and HC. Higher prevalence and grade of glucose metabolic abnormalities were also observed in patients with NAFLD and CHC with steatosis than in cases without steatosis (p < 0.05 and p = 0.001, resp.). Lipid and glucose metabolic abnormalities in patients with CHC were dependent on steatosis. CHC with steatosis and NAFLD were associated with insulin resistant type dyslipidemia, with total cholesterol and LDL-cholesterol being generally lower in CHC.

What is the association of lipid levels and incident stroke?

BACKGROUND

The association between lipid levels and stroke rates is less than lipid levels and coronary heart disease (CHD).

OBJECTIVE

To assess if there are geographic, racial, and ethnic differences in total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and triglyceride levels with incident stroke.

METHODS

From the REasons for Geographic And Racial Differences in Stroke (REGARDS) study we evaluated baseline levels of LDL-C, HCL-C, TC, Non-HDL-C (Total-HDL-C) and triglycerides in participants free of prevalent stroke at baseline. Cox Proportional-Hazard models were the main analytical tool used to examine the association between incident stroke and lipids. For each adjusted lipid measure (LDL-C, HDL-C, triglycerides, TC, and non-HDL-C) we calculated a series of incremental models.

RESULTS

The analysis cohort was 23,867 participants with a mean follow-up time of 7.5±2.9years, and 1031 centrally adjudicated strokes (874 ischemic and 77 hemorrhagic strokes). HDL-C baseline level was associated with an overall unadjusted 13% risk reduction (HR 0.87, 95% confidence interval [CI]: 0.81-0.93; p<0.05; 14% for ischemic and 16% for hemorrhagic strokes), and TC with an 8% (HR 0.92, 95%CI: 0.87-0.99; p<0.05) risk reduction of all strokes. When the results were fully adjusted a significant association was observed only for LDL-C and non-HDL-C and ischemic stroke. There were no significant differences in these associations when adjusted for age, race, age∗race, gender, education, region, or income.

CONCLUSION

In a disease free population, LDL-C and non-HDL-C baseline levels are significantly associated with the risk of ischemic stroke.

The relationship between Lp(a) and CVD outcomes: a systematic review

Robust associations between lipoprotein(a) [Lp(a)] and CVD outcomes among general populations have been published in previous studies. However, associations in high risk primary prevention and secondary prevention populations are less well defined. In order to investigate this further, a systematic review was performed including prospective studies, which assessed the relationship between Lp(a) and CVD outcomes using multivariable analyses. Additional information was gathered on Lp(a) assays, multivariable modelling and population characteristics. Literature searches from inception up to December 2015 retrieved 2850 records. From these 60 studies were included. Across 39 primary prevention studies in the general population (hazard ratios ranged from 1.16 to 2.97) and seven high risk primary prevention studies (hazard ratios ranged from 1.01 to 3.7), there was evidence of a statistically significant relationship between increased Lp(a) and an increased risk of future CVD. Results in 14 studies of secondary prevention populations were also suggestive of a modest statistically significant relationship (hazard ratios ranged from 0.75 to 3.7).Therefore current evidence would suggest that increased Lp(a) levels are associated with modest increases in the risk of future CVD events in both general and higher risk populations. However, further studies are required to confirm these findings.

Lipoprotein (a), an independent cardiovascular risk marker

Epidemiological and genetic studies have identified elevated levels of lipoprotein (a) ((Lp(a)) as a causal and independent risk factor for cardiovascular diseases (CVD). The Lp(a)-induced increased risk of CVD may be mediated by both its proatherogenic and prothrombotic mechanisms. Several guidelines recommend screening of Lp(a) level; however, there are few treatment options for the management of patients with elevated Lp(a). Several new medications for Lp(a) are under development. PCSK9 inhibitors, apolipoprotein (a)-antisense, and apolipoprotein(B-100)-antisense mipomersen have shown promising results. Lp(a) reduction will continue to be an active area of investigation.

Targeting lipoprotein (a): an evolving therapeutic landscape

Robust epidemiologic and genetic studies have solidified the role of lipoprotein (a) [Lp(a)] as an independent and causal risk factor for cardiovascular disease. The increased cardiovascular risk of Lp(a) is mediated through both proatherogenic and prothrombotic/antifibrinolytic mechanisms. Several societies recommend Lp(a) screening for patients with high cardiovascular risk, although no consensus exists on the management of patients with elevated Lp(a). However, numerous pharmacologic approaches are being evaluated that have the potential to reduce Lp(a) and will be the focus of this review. The majority of these interventions have been developed for other lipid-lowering indications, but also lower Lp(a). There are also novel therapies in development that specifically target Lp(a). The efficacy of these therapies varies, and their role in the evolving lipoprotein therapeutic landscape has yet to be determined. Nevertheless, targeted Lp(a) reduction is certainly intriguing and will likely continue to be an active area of investigation in the future.

Lipoprotein (a) as a risk factor for ischemic stroke: a meta-analysis

OBJECTIVE

Lipoprotein (a) [Lp(a)] harbors atherogenic potential but its role as a risk factor for ischemic stroke remains controversial. We conducted a meta-analysis to determine the relative strength of the association between Lp(a) and ischemic stroke and identify potential subgroup-specific risk differences.

METHODS

A systematic search using the MeSH terms "lipoproteins" OR "lipoprotein a" AND "stroke" was performed in PubMed and ScienceDirect for case-control studies from June 2006 and prospective cohort studies from April 2009 until December 20th 2014. Data from eligible papers published before these dates were reviewed and extracted from previous meta-analyses. Studies that assessed the relationship between Lp(a) levels and ischemic stroke and reported generic data-i.e. odds ratio [OR], hazard ratio, or risk ratio [RR]-were eligible for inclusion. Studies that not distinguish between ischemic and hemorrhagic stroke and transient ischemic attack were excluded. Random effects meta-analyses with mixed-effects meta-regression were performed by pooling adjusted OR or RR.

RESULTS

A total of 20 articles comprising 90,904 subjects and 5029 stroke events were eligible for the meta-analysis. Comparing high with low Lp(a) levels, the pooled estimated OR was 1.41 (95% CI, 1.26-1.57) for case-control studies (n = 11) and the pooled estimated RR was 1.29 (95% CI, 1.06-1.58) for prospective studies (n = 9). Sex-specific differences in RR were inconsistent between case-control and prospective studies. Study populations with a mean age of ≤55 years had an increased RR compared to older study populations. Reported Lp(a) contrast levels and ischemic stroke subtype significantly contributed to the heterogeneity observed in the analyses.

CONCLUSION

Elevated Lp(a) is an independent risk factor for ischemic stroke and may be especially relevant for young stroke patients. Sex-specific risk differences remain conflicting. Further studies in these subgroups may be warranted.

Lipoprotein (a): structure, pathophysiology and clinical implications

The chemical structure of lipoprotein (a) is similar to that of LDL, from which it differs due to the presence of apolipoprotein (a) bound to apo B100 via one disulfide bridge. Lipoprotein (a) is synthesized in the liver and its plasma concentration, which can be determined by use of monoclonal antibody-based methods, ranges from < 1 mg to > 1,000 mg/dL. Lipoprotein (a) levels over 20-30 mg/dL are associated with a two-fold risk of developing coronary artery disease. Usually, black subjects have higher lipoprotein (a) levels that, differently from Caucasians and Orientals, are not related to coronary artery disease. However, the risk of black subjects must be considered. Sex and age have little influence on lipoprotein (a) levels. Lipoprotein (a) homology with plasminogen might lead to interference with the fibrinolytic cascade, accounting for an atherogenic mechanism of that lipoprotein. Nevertheless, direct deposition of lipoprotein (a) on arterial wall is also a possible mechanism, lipoprotein (a) being more prone to oxidation than LDL. Most prospective studies have confirmed lipoprotein (a) as a predisposing factor to atherosclerosis. Statin treatment does not lower lipoprotein (a) levels, differently from niacin and ezetimibe, which tend to reduce lipoprotein (a), although confirmation of ezetimibe effects is pending. The reduction in lipoprotein (a) concentrations has not been demonstrated to reduce the risk for coronary artery disease. Whenever higher lipoprotein (a) concentrations are found, and in the absence of more effective and well-tolerated drugs, a more strict and vigorous control of the other coronary artery disease risk factors should be sought.

Healthy dietary interventions and lipoprotein (a) plasma levels: results from the Omni Heart Trial

BACKGROUND

Increased lipoprotein(a) [Lp(a)] levels are associated with atherosclerotic cardiovascular disease. Studies of dietary interventions on changes in Lp(a) are sparse. We aimed to compare the effects of three healthy dietary interventions differing in macronutrient content on Lp(a) concentration.

METHODS

Secondary analysis of a randomized, 3-period crossover feeding study including 155 (89 blacks; 66 whites) individuals. Participants were given DASH-type healthy diets rich in carbohydrates [Carb], in protein [Prot] or in unsaturated fat [Unsat Fat] for 6 weeks each. Plasma Lp(a) concentration was assessed at baseline and after each diet.

RESULTS

Compared to baseline, all interventional diets increased mean Lp(a) by 2 to 5 mg/dl. Unsat Fat increased Lp(a) less than Prot with a difference of 1.0 mg/dl (95% CI, -0.5, 2.5; p = 0.196) in whites and 3.7 mg/dl (95% CI, 2.4, 5.0; p < 0.001) in blacks (p-value between races = 0.008); Unsat Fat increased Lp(a) less than Carb with a difference of -0.6 mg/dl, 95% CI, -2.1, 0.9; p = 0.441) in whites and -1.5 mg/dl (95% CI, -0.2, -2.8; p = 0.021) in blacks (p-value between races = 0.354). Prot increased Lp(a) more than Carb with a difference of 0.4 mg/dl (95% CI, -1.1, 1.9; p = 0.597) in whites and 2.2 mg/dl (95%CI, 0.9, 3.5; p = 0.001) in blacks (p-value between races = 0.082).

CONCLUSION

Diets high in unsaturated fat increased Lp(a) levels less than diets rich in carbohydrate or protein with greater changes in blacks than whites. Our results suggest that substitutions with dietary mono- and polyunsaturated fatty acids in healthy diets may be preferable over protein or carbohydrates with regards to Lp(a).

TRIAL REGISTRATION

Clinicaltrials.gov NCT00051350.

Guidelines for the primary prevention of stroke: a statement for healthcare professionals from the American Heart Association/American Stroke Association

The aim of this updated statement is to provide comprehensive and timely evidence-based recommendations on the prevention of stroke among individuals who have not previously experienced a stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches to atherosclerotic disease of the cervicocephalic circulation, and antithrombotic treatments for preventing thrombotic and thromboembolic stroke. Further recommendations are provided for genetic and pharmacogenetic testing and for the prevention of stroke in a variety of other specific circumstances, including sickle cell disease and patent foramen ovale.

Gallstone disease and the risk of stroke: a nationwide population-based study

BACKGROUND

Gallstone disease (GD) and stroke share a number of risk factors including diabetes and hyperlipidemia. This nationwide population-based study was designed to estimate the risk of stroke after a diagnosis of GD.

METHODS

Data were obtained from the Taiwan National Health Insurance Research Database. A total of 135,512 patients with a diagnosis of GD and 271,024 age- and gender-matched non-GD control patients were included to assess the risk of stroke using Cox proportional hazard regression.

RESULTS

During the study period (2000-2003), 12,234 (153.67/10,000 person-years) strokes occurred among the GD patients, and 20,680 (114.83/10,000 person-years) among the controls. The diagnosis of GD carried a higher risk of developing ischemic and hemorrhagic stroke, with a hazard ratio (HR) of 1.28 and 1.33 (95% confidence interval [CI], 1.25-1.31 and 1.25-1.41, both P < .0001), respectively. Stroke risk was increased in both genders but at a higher rate in younger age. The GD group had significantly higher prevalence rate of comorbidities that are known stroke risk factors, including hypertension, diabetes, and coronary artery disease. Stroke risk was higher in the GD group with or without any of these comorbidities.

CONCLUSIONS

In this population-based longitudinal follow-up study, GD carried a significantly higher stroke risk, particularly for younger age with or without stroke risk factors. Stroke preventive measures maybe needed for patients with GD, especially those of younger age and with stroke risk factor(s).

Statins in chronic kidney disease and kidney transplantation

HMG-CoA reductase inhibitors (statins) have been shown to improve cardiovascular (CV) outcomes in the general population as well as in patients with cardiovascular disease (CVD). Statins' beneficial effects have been attributed to both cholesterol-lowering and cholesterol-independent "pleiotropic" properties. By their pleiotropic effects statins have been shown to reduce inflammation, alleviate oxidative stress, modify the immunologic responses, improve endothelial function and suppress platelet aggregation. Patients with chronic kidney disease (CKD) exhibit an enormous increase in CVD rates even from early CKD stages. As considerable differences exist in dyslipidemia characteristics and the pathogenesis of CVD in CKD, statins' CV benefits in CKD patients (including those with a kidney graft) should not be considered unequivocal. Indeed, accumulating clinical evidence suggests that statins exert diverse effects on dialysis and non-dialysis CKD patients. Therefore, it seems that statins improve CV outcomes in non-dialysis patients whereas exert little (if any) benefit in the dialysis population. It has also been proposed that dyslipidemia might play a causative role or even accelerate renal injury. Moreover, ample experimental evidence suggests that statins ameliorate renal damage. However, a high quality randomized controlled trial (RCT) and metaanalyses do not support a beneficial role of statins in renal outcomes in terms of proteinuria reduction or retardation of glomerular filtration rate (GFR) decline.

LPA rs10455872 polymorphism is associated with coronary lesions in Brazilian patients submitted to coronary angiography

BACKGROUND

Polymorphisms in the LPA gene were associated with coronary artery disease (CAD). However, there are differences in the allelic frequencies, Lp(a) levels, and significant association with CAD according to ethnic groups. In this scenario, the main aim of this study was to assess the influence of the LPA polymorphisms on coronary lesions in Brazilian patients.

METHODS

1,394 consecutive patients submitted to coronary angiography to study suggestive CAD and twenty coronary segments were scored. Genotyping for the LPA rs10455872 and rs3798220 polymorphisms were performed by high resolution melting analysis.

RESULTS

The frequencies of the rs10455872 G and rs3798220 C variant alleles were 6.4% and 6.2%, respectively. LPA rs10455872 G variant allele was associated with higher odds ratio of having coronary lesions in an adjusted model (OR = 2.02, 95% CI = 1.10-3.72, p = 0.02). Scores of coronary lesions (extension, severity, and Gensini scores) were significantly different among rs10455872 genotype groups. Coronary lesions was not associated with LPA rs3798220 (OR = 1.09, 95% CI = 0.67-1.76, p = 0.73) and scores of coronary lesions were not different among rs3798220 genotypes.

CONCLUSIONS

We confirmed the association of the LPA rs10455872 with CAD in a large sample of Brazilian patients. For the LPA rs3798220, our finding is consistent with studies which showed the lack of this genetic association.

Baseline LDL-C and Lp(a) elevations portend a high risk of coronary revascularization in patients after stent placement

Background and Aim. Incidence of coronary restenosis after stent placement is high. Our study was going to investigate whether Lp(a) elevation was potential for predicting coronary restenosis and whether the effects of Lp(a) elevation on coronary restenosis were dependent on LDL-C level. Methods and Results. Totally 832 participants eligible for stent placement were enrolled and followed up for monitoring clinical end points. Baseline characteristics were collected. According to the cut point of Lp(a), participants were divided into low Lp(a) group (Lp(a) < 30 mg/dL) and high Lp(a) group (Lp(a) ≥ 30 mg/dL). Furthermore, based on baseline LDL-C level, participants were divided into LDL-C < 1.8 mmol/L and ≥1.8 mmol/L subgroups. Clinical end points including major adverse cardiovascular events (MACE), cardiovascular death, nonfatal myocardial infarction, ischemic stroke, and coronary revascularization (CR) were compared. Patients in high Lp(a) groups more frequently presented with acute coronary syndrome and three vessel stenoses. In subgroup of LDL-C < 1.8 mmol/L, no significant differences of cardiovascular outcomes were found between low and high Lp(a) groups. While in the subgroup of LDL-C ≥ 1.8 mmol/L, incidences of MACE and CR were significantly higher in high Lp(a) group, and odds ratio for CR was 2.05. Conclusion. With baseline LDL-C and Lp(a) elevations, incidence of CR is significantly increased after stent placement.

Inverse association between serum lipoprotein(a) and cerebral hemorrhage in the Japanese population

INTRODUCTION

Although lipoprotein(a) (Lp(a)) is involved in cardiometabolic disease processes, the association between serum Lp(a) and stroke and/or its subtypes has not yet been elucidated among Japanese people. This study investigated the association between Lp(a) and the incidence of stroke and/or its subtypes in the general Japanese population.

MATERIALS AND METHODS

This population-based prospective cohort study included 10,494 community-dwelling participants (4,030 males/6,464 females). The incidence of stroke and its subtypes was the primary outcome. The subjects were divided into tertiles based on their Lp(a) levels, and the risk of all stroke and stroke subtypes was examined using Cox's proportional hazard model.

RESULTS

A total of 393 subjects (199 males and 194 females) with stroke were identified during a follow-up duration of 10.7years. The multivariate-adjusted hazard ratios for all stroke events were 0.55 (95% confidence interval: 0.38-0.81) and 0.69 (0.49-0.99) in the 2nd (9-19mg/dl) and 3rd tertiles (≥20mg/dl) of Lp(a) in reference to the 1st tertile (<9mg/dl) in males, and 0.85 (0.59-1.24) and 0.76 (0.52-1.11) in 2nd (10-22mg/dl) and 3rd tertiles (≥23mg/dl) of Lp(a) in reference to the 1st tertile (<10mg/dl) in females. The multivariate-adjusted hazard ratios for cerebral hemorrhage were 0.26 (0.10-0.67) and 0.34 (0.15-0.76) in the 2nd and 3rd tertiles of Lp(a) in reference to the 1st tertile in males, and were 0.48 (0.23-1.04) and 0.44 (0.21-0.96) in the 2nd and 3rd tertiles of Lp(a) in females.

CONCLUSIONS

Lp(a) was associated with the incidence of cerebral hemorrhage in the general Japanese population, particularly among males, while a similar trend was seen among females. A low Lp(a) level may be a marker of the risk of cerebral hemorrhage in this population.

Association study of lipoprotein(a) genetic markers, traditional risk factors, and coronary heart disease in HIV-1-infected patients

Objectives: General population studies have shown associations between copy number variation (CNV) of the LPA gene Kringle-IV type-2 (KIV-2) coding region, single-nucleotide polymorphism (SNP) rs6415084 in LPA and coronary heart disease (CHD). Because risk factors for HIV-infected patients may differ from the general population, we aimed to assess whether these potential associations also occur in HIV-infected patients. Methods: A unicenter, retrospective, case–control (1:3) study. Eighteen HIV-patients with confirmed diagnosis of acute myocardial infarction (AMI) were adjusted for age, gender, and time since HIV diagnosis to 54 HIV-patients without CHD. After gDNA extraction from frozen blood, both CNV and SNP genotyping were performed using real-time quantitative PCR. All genetic and non-genetic variables for AMI were assessed in a logistic regression analysis. Results: Our results did not confirm any association in terms of lipoprotein(a) LPA structural genetic variants when comparing KIV-2 CNV (p = 0.67) and SNP genotypes (p = 0.44) between AMI cases and controls. However, traditional risk factors such as diabetes mellitus, hypertension, and CD4⁺ T cell count showed association (p < 0.05) with CHD. Conclusion: Although significant associations of AMI with diabetes, hypertension and CD4⁺ T cell count in HIV-patients were found, this study could not confirm the feasibility neither of KIV-2 CNV nor rs6415084 in LPA as genetic markers of CHD in HIV-infected patients.

Highlights:

● Individuals with HIV infection are at higher risk of coronary heart disease (CHD) than the non-infected population.

● Our results showed no evidence of LPA structural genetic variants associated with CHD in HIV-1-infected patients.

● Associations were found between diabetes mellitus, arterial hypertension, CD4⁺ T cell count, and CHD.

● The clinical usefulness of these biomarkers to predict CHD in HIV-1-infected population remains unproven.

● Further studies are needed to assess the contribution of common genetic variations to CHD in HIV-infected individuals.

Low lipoprotein(a) concentration is associated with cancer and all-cause deaths: a population-based cohort study (the JMS cohort study)

BACKGROUND

Experimental studies support the anti-neoplastic effect of apo(a), but several clinical studies have reported contradictory results. The purpose of this study was to determine whether a low lipoprotein(a) [Lp(a)] concentration is related to mortality from major causes of death, especially cancer.

METHODS

The subjects were 10,413 participants (4,005 men and 6,408 women) from a multi-center population-based cohort study in Japan (The Jichi Medical School cohort study). The average age at registration was 55.0 years, and the median observation period was 4,559 days. As the estimated hazard ratio was high for both the low and very high Lp(a) levels, we defined two Lp(a) groups: a low Lp(a) group [Lp(a)<80 mg/L] and an intermediate-to-high Lp(a) group [Lp(a) ≥ 80]. Participants who died from malignant neoplasms (n = 316), cardiovascular disease (202), or other causes (312) during the observation period were examined.

RESULTS

Cumulative incidence plots showed higher cumulative death rates for the low Lp(a) group than for the intermediate-to-high Lp(a) group for all-cause, cancer, and miscellaneous-cause deaths (p<0.001, p = 0.03, and p = 0.03, respectively). Cox proportional hazards analyses with the sex and age of the participants, body mass index, and smoking and drinking histories as covariates showed that a low Lp(a) level was a significant risk for all-cause, cancer, and miscellaneous-cause deaths (p<0.001, p = 0.003, and p = 0.01, respectively). The hazard ratio (95% CI) [1.48, 1.15-1.92] of a low Lp(a) level for cancer deaths was almost the same as that for a male sex (1.46, 1.00-2.13).

CONCLUSIONS

This is the first report to describe the association between a low Lp(a) level and all-cause or cancer death, supporting the anti-neoplastic effect of Lp(a). Further epidemiological studies are needed to confirm the present results.

Associations between lipoprotein(a) levels and cardiovascular outcomes in black and white subjects: the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

On the basis of studies with limited statistical power, lipoprotein(a) [Lp(a)] is not considered a risk factor for cardiovascular disease (CVD) in blacks. We evaluated associations between Lp(a) and incident CVD events in blacks and whites in the Atherosclerosis Risk in Communities (ARIC) study.

METHODS AND RESULTS

Plasma Lp(a) was measured in blacks (n=3467) and whites (n=9851). Hazards ratios (HRs) for incident CVD events (coronary heart disease and ischemic strokes) were calculated. Lp(a) levels were higher with wider interindividual variation in blacks (median [interquartile range], 12.8 [7.1-21.7] mg/dL) than whites (4.3 [1.7-9.5] mg/dL; P<0.0001). At 20 years of follow-up, 676 CVD events occurred in blacks, and 1821 events occurred in whites. Adjusted HRs (95% confidence interval) per race-specific 1-SD-greater log-transformed Lp(a) were 1.13 (1.04-1.23) for incident CVD, 1.11 (1.00-1.22) for incident coronary heart disease, and 1.21 (1.06-1.39) for ischemic strokes in blacks. For whites, the respective HRs (95% confidence intervals) were 1.09 (1.04-1.15), 1.10 (1.05-1.16), and 1.07 (0.97-1.19). Quintile analyses showed that risk for incident CVD was graded but statistically significant only for the highest compared with the lowest quintile (HR [95% confidence interval], 1.35 [1.06-1.74] for blacks and 1.27 [1.10-1.47] for whites). Similar results were obtained with the use of Lp(a) cutoffs of ≤10 mg/dL, >10 to ≤20 mg/dL, >20 to ≤30 mg/dL, and >30 mg/dL.

CONCLUSIONS

Lp(a) levels were positively associated with CVD events. Associations were at least as strong, with a larger range of Lp(a) concentrations, in blacks compared with whites.

Epidemiology and risk factors of cerebral ischemia and ischemic heart diseases: similarities and differences

Cerebral ischemia and ischemic heart diseases, common entities nowadays, are the main manifestation of circulatory diseases. Cardiovascular diseases, followed by stroke, represent the leading cause of mortality worldwide. Both entities share risk factors, pathophisiology and etiologic aspects by means of a main common mechanism, atherosclerosis. However, each entity has its own particularities. Ischemic stroke shows a variety of pathogenic mechanisms not present in ischemic heart disease. An ischemic stroke increases the risk of suffering a coronary heart disease, and viceversa. The aim of this chapter is to review data on epidemiology, pathophisiology and risk factors for both entities, considering the differences and similarities that could be found in between them. We discuss traditional risk factors, obtained from epidemiological data, and also some novel ones, such as hyperhomocisteinemia or sleep apnea. We separate risk factors, as clasically, in two groups: nonmodifiables, which includes age, sex, or ethnicity, and modifiables, including hypertension, dyslipidemia or diabetis, in order to discuss the role of each factor in both ischemic events, ischemic stroke and coronary heart disease.