Lipoprotein(a) further increases the risk of coronary events in men with high global cardiovascular risk

Lp(a) and risk of cardiovascular disease - A review of existing evidence and emerging concepts

Cardiovascular disease (CVD) remains the leading cause of death among adults in the United States. There has been significant advancement in the diagnosis and treatment of atherosclerotic cardiovascular disease (ASCVD) and its underlying risk factors. In certain populations, there remains a significant residual risk despite adequate lowering of low-density lipoprotein cholesterol (LDL-C) and control of traditional risk factors. This has led to an interest in research to identify additional risk factors that contribute to atherosclerotic cardiovascular disease. Elevated lipoprotein (a) [Lp(a)] has been identified as an independent risk factor contributing to an increased risk for CVD. There are also ethnic and racial disparities in Lp(a) inheritance that need to be understood. This paper reviews the current literature on lipoprotein a, proposed mechanisms of actions for cardiovascular disease, recommendations for testing, and the current and emerging therapies for lowering Lp(a).

Effect of Lipoprotein(a) on Stroke Recurrence Attenuates at Low LDL-C (Low-Density Lipoprotein) and Inflammation Levels

BACKGROUND

Lp(a) (lipoprotein(a)) contributes to cardiovascular disease mainly through proatherogenic and proinflammatory effects. Here, we aimed to evaluate whether a residual stroke risk of Lp(a) would remain when the LDL-C (low-density lipoprotein cholesterol) and inflammatory levels are maintained low.

METHODS

This prospective cohort study included 9899 patients with ischemic stroke or transient ischemic attack from the Third China National Stroke Registry who had measurements of plasma Lp(a) and were followed up for 1 year. Cutoffs were set at the 50 mg/dL for Lp(a). LDL-C was corrected for Lp(a)-derived cholesterol (LDL-Cc [LDL-C corrected]) and cutoffs were set at 55 and 70 mg/dL.The threshold values of IL-6 (interleukin 6) and hsCRP (high-sensitive C-reactive protein) were the median 2.65 ng/L and 2 mg/L. Multivariable-adjusted hazard ratio (HR) were calculated using Cox regression models for each category to investigate the associations of Lp(a) with stroke recurrence within 1 year.

RESULTS

Among all patients, those with Lp(a) ≥50 mg/dL were at higher stroke recurrence risk than those with Lp(a) <50 mg/dL (11.5% versus 9.4%; adjusted HR, 1.20 [95% CI, 1.02-1.42]). However, the risk associated with elevated Lp(a) was attenuated in patients with LDL-Cc <55 mg/dL (high Lp(a) versus low Lp(a): 8.9% versus 9.0%; adjusted HR, 0.92 [95% CI, 0.65-1.30]) or IL-6 <2.65 ng/L (9.0% versus 7.8%; adjusted HR, 1.14 [95% CI, 0.87-1.49]). Notably, in the group with both low LDL-Cc and inflammation levels, the rate of patients with high Lp(a) did not significantly different from the rate of patients with low Lp(a; LDL-Cc <55 mg/dL and IL-6 <2.65 ng/L: 6.2% versus 7.1%; adjusted HR, 0.86 [95% CI, 0.46-1.62]; LDL-Cc <55 mg/dL and hsCRP <2 mg/L: 7.7% versus 7.6%; adjusted HR, 0.97 [95% CI, 0.57-1.66]). However, there was no interaction between the LDL-Cc, IL-6, hsCRP, and Lp(a) levels on stroke recurrence risk.

CONCLUSIONS

Increased Lp(a) was significantly associated with stroke recurrence risk in patients with ischemic stroke/transient ischemic attack. However, at low LDL-Cc or IL-6 levels, the elevated Lp(a) -associated stroke recurrence risk was attenuated in a secondary prevention setting.

Contemporary perspectives on the genetics and clinical use of lipoprotein(a) in preventive cardiology

PURPOSE OF REVIEW

The pathogenicity of lipoprotein(a) [Lp(a)] as a risk factor for atherosclerotic cardiovascular disease (ASCVD) is well evidenced and recognized by international consensus-based guidelines. However, the measurement of Lp(a) is not routine clinical practice. Therapeutic agents targeting Lp(a) are now progressing through randomised clinical trials, and it is timely for clinicians to familiarize themselves with this complex and enigmatic lipoprotein particle.

RECENT FINDINGS

Recent developments in the understanding of genetic influences on the structure, plasma concentration and atherogenicity of Lp(a) have contextualized its clinical relevance. Mendelian randomization studies have enabled estimation of the contribution of Lp(a) to ASCVD risk. Genotyping individual patients with respect to Lp(a)-raising single nucleotide polymorphisms predicts ASCVD, but has not yet been shown to add value beyond the measurement of Lp(a) plasma concentrations, which should be done by Lp(a) isoform-independent assays capable of reporting in molar concentrations. Contemporary gene-silencing technology underpins small interfering RNA and antisense oligonucleotides, which are emerging as the leading Lp(a)-lowering therapeutic agents. The degree of Lp(a)-lowering required to achieve meaningful reductions in ASCVD risk has been estimated by Mendelian randomization, providing conceptual support.

SUMMARY

Measurement of Lp(a) in the clinical setting contributes to the assessment of ASCVD risk, and will become more important with the advent of specific Lp(a)-lowering therapies. Knowledge of an individual patient's genetic predisposition to increased Lp(a) appears to impart little or not additional clinical value beyond Lp(a) particle concentration.

Lipoprotein(a) and High Sensitivity C-Reactive Protein among Patients with HIV in Ghana: The Study on Cardiovascular Risk Profile of HIV-Infected Patients on HAART (SCRIPT)

Background:

Lipoprotein(a) [Lp(a)] and high-sensitivity C-reactive protein (hs-CRP) levels are associated with cardiovascular disease (CVD) in the general population, even after adjusting for conventional CVD risk factors. However, data are limited regarding the distribution of Lp(a) and hs-CRP among patients with HIV in Ghana. We explored levels of Lp(a), hs-CRP and other cardiovascular risk factors among people who were HIV positive (HIV+) on ART (HIV+ART+), HIV+ART–, and HIV–ART– in a Ghanaian population.

Methods:

We conducted a cross sectional study, recruited individuals who were HIV+ART+ and HIV+ART– from the largest HIV clinic in central Ghana between August 2018 and December 2019. HIV negative controls were recruited from communities and adjoining suburbs of Kumasi. Lipoprotein(a) was measured using Immunoturbidimetric assay and high sensitive-CRP concentrations were determined using particle-enhanced turbidimetric assay. We compared levels of Lp(a), hs-CRP, and conventional CVD risk factors among these groups and used multivariable stepwise logistic regression models to explore associations between them.

Results:

Among HIV+ART+ (n = 156), HIV+ART– (n = 131), and HIV–ART– (n = 147), mean(SD) ages were 48 (9.1) years, 41 (11.1) years and 45 (11.9) years, p = <0.001, proportion of females were 71.2%, 67.9% and 73.5% respectively. Median(IQR) concentrations of hs-CRP in mg/L were 1.7 (0.8,4.5), 2.03 (0.5,8.58) and 1.0 (0.45,2.74) across respective groups and the proportion of elevated Lp(a) concentrations (Lp[a] > 30mg/dL) were 70%, 48% and 62% among HIV+ART+,HIV+ART– and HIV–ART– participants respectively. Diabetes mellitus, dyslipidemia, waist-to-hip ratio and metabolic syndrome were associated with higher hs-CRP levels. Compared to HIV–ART–, HIV+ patients had higher odds of having hs-CRP > 3mg/L while HIV+ART+ patients had higher odds of elevated Lp(a) than HIV+ART– after multivariable adjustment.

Conclusion:

PLWHA in Ghana are associated with higher odds of elevated hs-CRP, regardless of ART use. HIV+ART+ is significantly associated with higher odds of elevated Lp(a) levels compared to HIV+ART–; even after multivariable adjustments. Reasons for this and potential clinical implications merit further study.

The role of Lipoprotein(a) in cardiovascular disease: Current concepts and future perspectives

High lipoprotein(a) [Lp(a)] levels are associated with the development of atherosclerotic cardiovascular disease (ASCVD) and with calcific aortic valve stenosis (CAVS) both observationally and causally from human genetic studies. The mechanisms are not well characterized but likely involve its role as a carrier of oxidized phospholipids (OxPLs), which are known to be increased in pro-inflammatory states, to induce pro-inflammatory changes in monocytes leading to plaque instability, and to impair vascular endothelial cell function, a driver of acute and recurrent ischemic events. In addition, Lp(a) itself has prothrombotic activity. Current lipid-lowering strategies do not sufficiently lower Lp(a) serum levels. Lp(a)-specific-lowering drugs, targeting apolipoprotein(a) synthesis, lower Lp(a) by up to 90% and are being evaluated in ongoing clinical outcome trials. This review summarizes the current knowledge on the associations of Lp(a) with ASCVD and CAVS, the current role of Lp(a) assessment in the clinical setting, and emerging Lp(a)-specific-lowering therapies.

Prognostic impact of lipoprotein (a) on long-term clinical outcomes in diabetic patients on statin treatment after percutaneous coronary intervention

BACKGROUND

Serum levels of lipoprotein (a) [Lp(a)] have been reported as a residual risk marker for adverse events in patients with coronary artery disease (CAD). However, the prognostic impact of Lp(a) on long-term clinical outcomes among diabetic patients on statin therapy after percutaneous coronary intervention (PCI) remains unclear.

METHODS

The present investigation was a single-center, observational, retrospective cohort study. Among consecutive patients with CAD who underwent first PCI in our institution from 2000 to 2016, we enrolled diabetic patients on statin treatment. As a result, 927 patients (81% men; mean age, 67 years) were enrolled and divided into 2 groups according to a median Lp(a) level of 19.5 mg/dL. The incidence of major adverse cardiac events (MACE), including all-cause death, non-fatal myocardial infarction (MI), and non-fatal cerebral infarction (CI), was evaluated.

RESULT

No significant differences were seen in age, sex, smoking habits, hypertension, chronic kidney disease, or body mass index between high and low Lp(a) groups. During follow-up (median, 5.0 years; interquartile range, 1.9-9.7 years), MACE occurred in 90 cases (17.6%), including 40 (7.9%) cardiac deaths, 18 (3.6%) non-fatal MI, and 37 (7.9%) non-fatal CI. Frequency of MACE was significantly higher in the high-Lp(a) group than in the low-Lp(a) group (log-rank test, p = 0.002). Higher Lp(a) level at the time of PCI was significantly associated with higher frequency of MACE, even after adjusting for other covariates, including other lipid profiles (hazard ratio, 1.91; 95% confidence interval, 1.20-3.09; p = 0.006).

CONCLUSION

Our results demonstrated that in diabetic patients with CAD on statin treatment, increased Lp(a) levels could offer a good residual lipid risk marker. Assessing Lp(a) levels may be useful for risk stratification of long-term clinical outcomes after PCI, especially in diabetic patients.

Interaction of lipoprotein(a) with low-density lipoprotein cholesterol on first incident acute myocardial infarction

OBJECTIVE

To evaluate the interaction effects between lipoprotein (a) (Lp(a)) and low-density lipoprotein cholesterol (LDL-C) on first incident acute myocardial infarction (AMI) among Chinese Han population.

METHODS

1522 cases and 1691 controls were retrospectively analyzed. All subjects were grouped by Lp(a) or LDL-C level.

RESULTS

Compared with reference group (LDL-C < 2.6 mmol/L and in the 1st quintile of Lp(a)), multivariable-adjusted analysis revealed that OR(95%CI) of first incident AMI for higher LDL-C alone is 2.66(1.78-3.98); that ORs(95%CI) for higher Lp(a) alone are 1.51(1.07-2.15), 1.84(1.28-2.64), 1.86(1.30-2.67) and 2.66(1.88-3.76) across the Lp(a) quintiles; and that ORs(95%CI) for both higher LDL-C and higher Lp(a) are 3.95(2.64-5.92), 3.20(2.21-4.64), 5.64(3.80-8.36) and 7.48(4.90-11.44) which were greater than the sum of the risks of both alone across the Lp(a) quintiles. Relative excess risks due to interaction were 1.78(95% CI, 0.12-3.44, P = 0.036) and 3.01(0.58-5.44, P = 0.015) at the 4th and 5th quintile of Lp(a), confirming the presence of additive interaction between Lp(a) and LDL-C on initial AMI.

CONCLUSIONS

Lp(a) interacts with LDL-C in first incident AMI on additive scale in Chinese Han population. The risk of initial AMI from exposure of elevated Lp(a) combined with elevated LDL-C is much greater than the sum of the risks from that of both alone.

Molecular, Population, and Clinical Aspects of Lipoprotein(a): A Bridge Too Far?

There is now significant evidence to support an independent causal role for lipoprotein(a) (Lp(a)) as a risk factor for atherosclerotic cardiovascular disease. Plasma Lp(a) concentrations are predominantly determined by genetic factors. However, research into Lp(a) has been hampered by incomplete understanding of its metabolism and proatherogeneic properties and by a lack of suitable animal models. Furthermore, a lack of standardized assays to measure Lp(a) and no universal consensus on optimal plasma levels remain significant obstacles. In addition, there are currently no approved specific therapies that target and lower elevated plasma Lp(a), although there are recent but limited clinical outcome data suggesting benefits of such reduction. Despite this, international guidelines now recognize elevated Lp(a) as a risk enhancing factor for risk reclassification. This review summarises the current literature on Lp(a), including its discovery and recognition as an atherosclerotic cardiovascular disease risk factor, attempts to standardise analytical measurement, interpopulation studies, and emerging therapies for lowering elevated Lp(a) levels.

Changes over-time in blood pressure of women with preeclampsia compared to those with normotensive pregnancies: A 15 year population-based cohort study

OBJECTIVES

To estimate the incidence of hypertension and the trend of systolic and diastolic blood pressure changes and relating factors influencing women with and without prior preeclampsia (PE).

STUDY DESIGN

This prospective population based study included a total of 3022 eligible women (355 with PE and 2667 non-PE) recruited from participants of the Tehran Lipid and Glucose Study (TLGS) who were assessed for progression to subsequent hypertension over 15-year follow up. Pooled logistic regression model was utilized to estimate odds ratio (OR) of hypertension. The generalized estimating equation (GEE) was used to evaluate the trend of changes in hypertension parameters over time.

RESULTS

At the end of follow-ups, 109 women (30.7%) in the PE group and 575 (21.5%) in the non-PE group had hypertension. The total cumulative incident rate of hypertension was 34/1000 person-years for PE groups and 22/1000 person years for non-PE groups (P < 0.001). Pooled logistic regression analysis showed that compared to non-PE women, OR of hypertension progression in women with PE was 3.70 after adjustment for age, body mass index (BMI), parity, triglycerides (TG) and high-density lipoprotein (HDL-C) (P-value < 0.001). Based on GEE analysis, mean changes of systolic and diastolic blood pressure in PE women increased by 4.66 and 2.55 mmHg, respectively, compared to the non-PE group, after adjustment for age, and BMI at baseline (P < 0.001), although the interaction term (follow-up year × PE) was not statistically significant.

CONCLUSION

This study demonstrated increased chances of developing hypertension among women with prior PE, particularly in those who develop additional risk factors in their later life, compared to the non-PE women. While the trajectory of blood pressure change over time is similar between women with and without preeclampsia, women with a history of preeclampsia consistently have higher levels of blood pressure.

To test, or not to test: that is the question for the future of lipoprotein(a)

INTRODUCTION

Lipoprotein(a) [Lp(a)] is a potent, highly heritable and common risk factor for atherosclerotic cardiovascular disease (ASCVD). Evidence for a causal association between elevated Lp(a) and ASCVD has been provided by large epidemiological investigations that have demonstrated a curvilinear association with increased risk, as well as from genetic examinations and cellular and transgenic animal studies. Although there are several therapies available for lowering Lp(a), none are selective for Lp(a) and there is no clinical trial data that has specifically shown that lowering Lp(a) reduces the risk of ASCVD. Hence, screening for elevated Lp(a) is not routinely incorporated into clinical practice. Areas covered: This paper reviews the current evidence supporting the causal role of Lp(a) in the primary and secondary prevention of ASCVD, screening approaches for high Lp(a), current guidelines on testing Lp(a), and barriers to the routine screening of elevated Lp(a) in clinical practice. Expert opinion: At present, there is a moderate level of evidence supporting the routine screening of elevated Lp(a). Current guidelines recommend testing for elevated Lp(a) in individuals at intermediate or high risk of ASCVD.

Management of cardiovascular risk factors in patients with ANCA-associated vasculitis

OBJECTIVES

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is accompanied by increased cardiovascular (CV) risk. Treatment of AAV patients includes the management of conventional CV risk factors, primarily hypertension and hypercholesterolemia, while lipoprotein(a) (LP(a)) is an emerging potential target.

METHODS

We performed a multicenter, retrospective study in Germany. Patients were considered if they were between 18 and 90 years old and presented with AAV. Patients with arterial hypertension but no autoimmune disease were used as a control group (HTN reference group).

RESULTS

Compared to the reference group (n = 52), CV disease burden was significantly greater in patients with AAV (n = 53). Hypercholesterolemia was also more common in the AAV patients (71.7% vs 46.2% for the HTN; P = .008). Lipoprotein(a) levels were elevated in both groups, with 11.3% and 17.3% of the AAV and HTN groups, respectively, displaying a level above 0.6 g/l (P = .083). Guideline-recommended targets for low-density lipoprotein cholesterol and blood pressure levels were rarely met. According to Kidney Disease: Improving Global Outcomes guidelines, 72.5% of the patients with AAV should have been taking statins and/or ezetimibe for treatment of hyperlipidemia; however, only 24.3% of them were receiving such treatment. Blood pressure below ≤140/90 mmHg was reached in 78.6% of the patients with chronic kidney disease. However, for patients with chronic kidney disease and an albumin excretion rate of >30 mg/day, the recommended blood pressure is ≤130/80 mmHg, a value that was not reached in 65% of the AAV patients.

CONCLUSION

Patients with AAV are at high CV risk, but management of the associated risk factors is poor. In addition to improving the treatment of hypercholesterolemia and hypertension, lipoprotein(a) is a further potential target for reducing CV risk in individuals with AAV.

Lipoprotein(a) and coronary atheroma progression rates during long-term high-intensity statin therapy: Insights from SATURN

BACKGROUND & AIMS

Lipoprotein(a) [Lp(a)] is a low-density lipoprotein (LDL)-like particle that associates with major adverse cardiovascular events (MACE). We examined relationships between Lp(a) measurements and changes in coronary atheroma volume following long-term maximally-intensive statin therapy in coronary artery disease patients.

METHODS

Study of coronary atheroma by intravascular ultrasound: Effect of Rosuvastatin Versus Atorvastatin (SATURN) used serial intravascular ultrasound measures of coronary atheroma volume in patients treated with rosuvastatin 40 mg or atorvastatin 80 mg for 24 months. Baseline and follow-up Lp(a) levels were measured in 915 of the 1039 SATURN participants, and were correlated with changes in percent atheroma volume (ΔPAV).

RESULTS

Mean age was 57.7 ± 8.6 years, 74% were men, 96% were Caucasian, with statin use prior to study enrolment occurring in 59.3% of participants. Baseline [median (IQR)] LDL-cholesterol (LDL-C) and measured Lp(a) levels (mg/dL) were 114 (99, 137) and 17.4 (7.6, 52.9) respectively; follow-up measures were 60 (47, 77), and 16.5 (6.7, 57.7) (change from baseline: p < 0.001, p = 0.31 respectively). At baseline, there were 676 patients with Lp(a) levels <50 mg/dL [median Lp(a) of 10.9 mg/dL], and 239 patients with Lp(a) levels ≥ 50 mg/dL [median Lp(a) of 83.2 mg/dL]. Quartiles of baseline and follow-up Lp(a) did not associate with ΔPAV. Irrespective of the achieved LDL-C (<vs. ≥70 mg/dL), neither baseline nor on-treatment (<vs. ≥median) Lp(a) levels significantly associated with ΔPAV. No significant differences were observed in ΔPAV in Lp(a) risers versus non-risers, nor in those patients with baseline or on-treatment Lp(a) levels <vs. > 50 mg/dL.

CONCLUSIONS

In coronary artery disease patients prescribed long-term maximally intensive statin therapy with low on-treatment LDL-C levels, measured Lp(a) levels (predominantly below the 50 mg/dL threshold) do not associate with coronary atheroma progression. Alternative biomarkers may thus associate with residual cardiovascular risk in such patients.

Levels of Apolipoprotein A1, B100 and Lipoprotein (a) in Controlled and Uncontrolled Diabetic Patients and in Non-Diabetic Healthy People

INTRODUCTION

Diabetes Mellitus (DM) is always a multifactorial metabolic disorder having a wide range of abnormalities in carbohydrate, lipid and protein metabolism. Dyslipidemia is a natural process of DM causing abnormal variations of different lipoproteins and it is one of the significant risk factors for Cardiovascular Disorder (CVD). There is a need to closely evaluate newer approaches in case of DM because even if dyslipidemia is treated, there is always a risk of CVDs in DM patients because of the hyperglycemia itself. So, lipid abnormalities should be assessed aggressively and treated as part of diabetes care. Apolipoprotein B100 (Apo B100), Apolipoprotein A1 (Apo A1) and Lipoprotein (a) {Lp(a)} are newer markers which are always welcome and necessary as many of the reported cases with normal conventional lipid profile have developed cardiac events.

AIM

Study the correlation between glycemic control and the levels of Apo A1, Apo B100 and Lp(a).

MATERIALS AND METHODS

Total 56 patients of (DM) diagnosed on the basis of American Diabetic Association guidelines were recruited, out of which 28 were identified as uncontrolled-diabetic patients and remaining 28 as controlled-diabetics on the basis of Glycosylated HbA1c (HbA1c). The control group consisted of normal healthy 28 individuals. Apo B100, Apo A1 and Lp(a) along with traditional lipid profile, Fasting Blood Sugar (FBS) and HbA1c were estimated in all the subjects.

RESULTS

Apo B100/Apo A1 ratio and Lp(a) levels showed highly significant difference (p-value <0.001) between uncontrolled diabetics, controlled diabetics and healthy Controls. Apo B100/Apo A1 ratio and Lp(a) showed significant positive correlations with HbA1c (r= 0.494, p <0.0001) and with each other.

CONCLUSION

Apo B100/Apo A1 ratio and Lp(a) show a highly significant positive relationship with glucose tolerance of the patients as reflected in the HbA1c values. If proper glycemic control is maintained, the levels of Apo B100/Apo A1 ratio and Lp(a) can be controlled as reflected by the lower levels of these parameters observed in controlled diabetics in comparison to uncontrolled diabetics.

Lipoprotein(a): new insights from modern genomics

PURPOSE OF REVIEW

Lipoprotein(a) [Lp(a)] is the strongest independent genetic risk factor for both myocardial infarction and aortic stenosis. It has also been associated with other forms of atherosclerotic cardiovascular disease (CVD) including ischemic stroke. Its levels are genetically determined and remain fairly stable throughout life. Elevated Lp(a), above 50 mg/dl, affects one in five individuals worldwide.

RECENT FINDINGS

Herein, we review the recent epidemiologic and genetic evidence supporting the causal role of Lp(a) in CVD, highlight recommendations made by European and Canadian guidelines regarding Lp(a) and summarize the rapidly evolving field of Lp(a)-lowering therapies including antisense therapies and Proprotein Convertase Subtilisin/Kexin Type 9 inhibitors.

SUMMARY

With novel therapies on the horizon, Lp(a) is poised to gain significant clinical relevance and its lowering could have a significant impact on the burden of CVD. VIDEO ABSTRACT.

Primary and secondary prevention of cardiovascular disease in patients with hyperlipoproteinemia (a)

General lipoprotein (Lp) (a) screening can help to identify patients at high risk for cardiovascular disease. Non-invasive methods allow early detection of clinically asymptomatic incipient atherosclerotic disease. Medical treatment options are still unsatisfactory. Lp(a) apheresis is an established treatment in Germany for secondary prevention of progressive cardiovascular disease. Statin-based lowering of LDL cholesterol and thrombocyte aggregation inhibitors still represent the basis of medical treatment. Target levels for LDL-cholesterol should be modified in patients with hyperlipoproteinemia (a).

Prevention of cardiovascular complications in patients with Lp(a)-hyperlipoproteinemia and progressive cardiovascular disease by long-term lipoprotein apheresis according to German national guidelines

Lipoprotein(a) (Lp(a)) is an independent cardiovascular risk factor playing a causal role for atherosclerotic cardiovascular disease (CVD). Lipoprotein apheresis (LA) is a safe well-tolerated outpatient treatment to lower LDL-C and Lp(a) by 60–70%, and is the ultimate escalating therapeutic option in patients with hyperlipoproteinemias (HLP) involving LDL particles. Major therapeutic effect of LA is preventing cardiovascular events. Lp(a)-HLP associated with progressive CVD has been approved as indication for regular LA in Germany since 2008. The Pro(a)LiFe-study investigated with a prospective multicenter design the long-term preventive effect of LA on incidence rates of cardiovascular events prospectively over a period of 5 years in 170 consecutive patients who commenced regular LA. During a median period of 4.7 years of the pre-LA period, Lp(a) associated progressive CVD became apparent. Apolipoprotein(a) (apo(a)) isoforms and polymorphisms at the apo(a) gene (LPA) were analyzed to assess hypothetical clinical correlations. 154 patients (90.6%) completed 5‑years follow-up. Significant decline of the mean annual major adverse cardiac event (MACE) rate was observed from 0.41 ± 0.45 two years prior to regular LA to 0.06 ± 0.11 during 5 years with regular LA (p < 0.0001). 95.3% of patients expressed at least one small apo(a) isoform. Calculation of isoform specific concentrations allowed to confirm the equivalence of 60 mg/dl or 120 nmol/l as Lp(a) thresholds of the German LA guideline. Results of 5 years prospective follow-up confirmed that LA has a lasting effect on prevention of cardiovascular events in patients with Lp(a)-HLP and afore progressive CVD.

The Rationale for Intervention to Reduce the Risk of Coronary Heart Disease

Cardiovascular diseases remain extremely common and the United States and are the single most common cause for death in both men and women. Many risk factors including cigarette smoking, elevated cholesterol, high blood pressure, obesity and in inactive lifestyle carry a significant lifestyle component. This fact is recognized in the National Guidelines for the Treatment of many risk factors for cardiovascular disease. Moreover, lifestyle intervention, in combination with proper medical and/or surgical therapy can play a significant role in the management of existing cardiovascular disease. In this review, we provide background and rationale for interventions to reduce the risk of coronary heart disease with a particular emphasis on intervening to improve lifestyle related issues. To achieve the best outcomes clinicians must be skilled not only in pharmacologic and surgical therapies but also in counseling patients on various lifestyle interventions to lower the risk of cardiovascular disease.

Lipoprotein (a) as a cause of cardiovascular disease: insights from epidemiology, genetics, and biology

Human epidemiologic and genetic evidence using the Mendelian randomization approach in large-scale studies now strongly supports that elevated lipoprotein (a) [Lp(a)] is a causal risk factor for cardiovascular disease, that is, for myocardial infarction, atherosclerotic stenosis, and aortic valve stenosis. The Mendelian randomization approach used to infer causality is generally not affected by confounding and reverse causation, the major problems of observational epidemiology. This approach is particularly valuable to study causality of Lp(a), as single genetic variants exist that explain 27-28% of all variation in plasma Lp(a). The most important genetic variant likely is the kringle IV type 2 (KIV-2) copy number variant, as the apo(a) product of this variant influences fibrinolysis and thereby thrombosis, as opposed to the Lp(a) particle per se. We speculate that the physiological role of KIV-2 in Lp(a) could be through wound healing during childbirth, infections, and injury, a role that, in addition, could lead to more blood clots promoting stenosis of arteries and the aortic valve, and myocardial infarction. Randomized placebo-controlled trials of Lp(a) reduction in individuals with very high concentrations to reduce cardiovascular disease are awaited. Recent genetic evidence documents elevated Lp(a) as a cause of myocardial infarction, atherosclerotic stenosis, and aortic valve stenosis.

Dyslipidaemia among Indo-Asians strategies for identification and management

ndo-Asians have the highest rates of coronary artery disease (CAD) despite the fact that nearly half are lifelong vegetarians. The incidence, prevalence, and mortality from CAD among overseas Indo-Asians have been 50% to 300% higher than the Europeans, Americans, and other Asians with a higher risk at younger ages. Approximately 10% of the adults in urban India have CAD, a rate similar to overseas Indians. Traditional risk factors do not fully explain the excess burden of CAD in Indo-Asians. Therefore, conventional approaches to testing and treatment of risk factors are not sufficient in this population. Indo-Asians have a higher prevalence of glucose intolerance, metabolic syndrome, diabetes, elevated concentrations of lipoprotein(a) (LP[a]), and homocysteine, and low concentrations of high density lipoprotein (HDL). HDL particles are also smaller in Indo-Asians than Whites. A more aggressive approach to all risk factors, including HDL, LP(a), triglycerides and homocysteine is warranted. The current evidence of established safety and broad spectrum lipoprotein benefits of niacin and statins would make these invaluable agents in the armamentarium against dyslipidaemia, especially in Indo-Asians. This is particularly true for those with metabolic syndrome, diabetic dyslipidaemia and Lp(a) excess.

Genetic markers: Potential candidates for cardiovascular disease

The effective prevention of cardiovascular disease depends upon the ability to recognize the high-risk individuals at an early stage of the disease or long before the development of adverse events. Evolving technologies in the fields of proteomics, metabolomics, and genomics have played a significant role in the discovery of cardiovascular biomarkers, but so far these methods have achieved the modest success. Hence, there is a crucial need for more reliable, suitable, and lasting diagnostic and therapeutic markers to screen the disease well in time to start the clinical aid to the patients. Gene polymorphisms associated with the cardiovascular disease play a decisive role in the disease onset. Therefore, the genetic marker evaluation to classify high-risk patients from low-risk patients trends an effective approach to patient management and care. Currently, there are no genetic markers available for extensive adoption as risk factors for coronary vascular disease, yet, there are numerous promising, biologically acceptable candidates. Many of these gene biomarkers, alone or in combination, can play an essential role in the prediction of cardiovascular risk. The present review highlights some putative emerging genetic biomarkers that could facilitate more authentic and fast diagnosis of CVD. This review also briefly describes few technological approaches employed in the biomarker search.

Lipoprotein(a) Interactions With Low-Density Lipoprotein Cholesterol and Other Cardiovascular Risk Factors in Premature Acute Coronary Syndrome (ACS)

Background

Current recommendations for lipoprotein(a) (Lp[a]) focus on the control of other risk factors, including lowering low‐density lipoprotein cholesterol (LDL‐C), with little evidence to support this approach. Identifying interactions between Lp(a) and other risk factors could identify individuals at increased risk for Lp(a)‐mediated disease.

Methods and Results

We used a case‐only study design and included 939 participants (median age=49 years, interquartile range 46–53, women=33.1%) from the GENdEr and Sex determInantS of cardiovascular disease: from bench to beyond‐Premature Acute Coronary Syndrome (GENESIS‐PRAXY) study, a multicenter prospective cohort study of premature acute coronary syndrome. There was a higher prevalence of elevated Lp(a) levels (>50 mg/dL; 80th percentile) in PRAXY participants as compared to the general population (31% versus 20%; P<0.001). Lp(a) was strongly associated with LDL‐C (adjusted β 0.17; P<0.001). Individuals with high Lp(a) were more likely to have LDL‐C >2.5 mmol/L, indicating a synergistic interaction (adjusted odds ratio 1.51; 95% CI 1.08–2.09; P=0.015). The interaction with high Lp(a) was stronger at increasing LDL‐C levels (LDL‐C >3.5, adjusted odds ratio 1.87; LDL‐C >4.5, adjusted odds ratio 2.72). In a polytomous logistic model comparing mutually exclusive LDL‐C categories, the interaction with high Lp(a) became attenuated at LDL‐C ≤3.5 mmol/L (odds ratio 1.16; 95% CI 0.80–1.68, P=0.447). Other risk factors were not associated with high Lp(a).

Conclusions

In young acute coronary syndrome patients, high Lp(a) is more prevalent than in the general population and is strongly associated with high LDL‐C, suggesting that Lp(a) confers greater risk for acute coronary syndrome when LDL‐C is elevated. Individuals with high Lp(a) and LDL‐C >3.5 mmol/L may warrant aggressive LDL‐C lowering.

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.

[Lipoprotein(a): influence on cardiovascular manifestation]

The clinical relevance of lipoprotein(a) (Lp(a)) as a cardiovascular risk factor is currently underestimated. The aim of our study was to assess the influence of increased Lp(a) values on the development and severity of coronary artery disease (CAD).In our retrospective analysis of 31,274 patients, who were hospitalized for the first time, we compared patients with isolated increased Lp(a) (> 110 mg/dl) and normal Lp(a) (< 30 mg/dl), with increased Lp(a) concentrations (30-60 mg/dl, 61-90 mg/dl, 91-110 mg/dl), and in a third analysis with additionally increased LDL cholesterol and HbA1c values.Patients with high Lp(a) levels showed a significantly higher incidence of advanced CAD with a three-vessel disease being present in 50.2 vs. 25.1 %. Patients with high Lp(a) levels had a significantly more frequent history of myocardial infarction (34.6 vs. 16.6 %, p < 0.001), surgical myocardial revascularization (40.8 vs. 20.8 %, p < 0.001) and percutaneous coronary intervention (55.3 vs. 33.6 %, p < 0.001). In addition, there was a marked difference in gender to the disadvantage of male patients regarding development and severity of CAD. CAD risk (Odds ratio) was increased 5.5-fold in patients with Lp(a) ≥ 110 mg/dl. Additionally elevated LDL and HbA1c levels were not associated with increased manifestation and severity of CAD.High Lp(a) concentration leads to an increased manifestation and severity of coronary artery disease. Additional risk factors do not aggravate manifestation of CAD.

Lipoprotein (a) measurements for clinical application

The high degree of size heterogeneity of apo(a), the distinct protein component of lipoprotein (a) [Lp(a)], renders the development and selection of specific antibodies directed to apo(a) more difficult and poses significant challenges to the development of immunoassays to measure its concentration in plasma or serum samples. Apo(a) is extremely variable in size not only between but also within individuals because of the presence of two different, genetically determined apo(a) isoform sizes. Therefore, the antigenic determinants per particle available to interact with the antibodies will vary in the samples and the calibrators, thus contributing to apo(a) size-dependent inaccuracy of different methods. The lack of rigorous validation of the immunoassays and common means of expressing Lp(a) concentrations hinder the harmonization of results obtained by different studies and contribute to the lack of common cut points for identification of individuals at risk for coronary artery disease or for interventions aimed at reducing Lp(a) levels. The aim of our review is to present and critically evaluate the issues surrounding the measurements of Lp(a), their impact on the clinical interpretation of the data, and the obstacles we need to overcome to achieve the standardization of Lp(a) measurements.

Relationship between Lipoprotein(a) and Thyroid Hormones in Hypothyroid Patients

BACKGROUND AND OBJECTIVE

Changes in plasma lipid concentrations are well known metabolic consequences of thyroid dysfunction. The alterations are most prominent in hypothyroidism which is typically associated with pronounced hypercholesterolaemia and frequently with moderate hypertriglyceridaemia. In cases of hypothyroidism, how the serum Lp(a) levels are influenced by thyroid hormone remains unknown and contradictory results on the effect of thyroid hormone on serum Lp(a) levels have been reported. There is substantial evidence to suggest that elevated serum Lp(a) levels contribute significantly to the development of CHD. The present study was designed to determine the lipoprotein(a) [Lp(a)], lipid profile and thyroid hormone levels in newly diagnosed hypothyroid patients and to find any correlation that existed between Lp(a) and other parameters.

MATERIALS AND METHODS

Untreated hypothyroid (n=50) patients were included in the study. We also included 40 normal healthy subjects as controls. Lipid profile, Lp(a) and thyroid profile were estimated by using autoanalyzers.

RESULTS

The results of this study showed that levels of HDL-cholesterol were significantly decreased (p<0.001), whereas those of other lipid parameters and Lp(a) levels were found to be significantly increased (p<0.001) in hypothyroid patients as compared to those in controls. Correlation study revealed a significant positive correlation between Lp(a) and TSH levels in hypothyroid patients.

CONCLUSION

Our present findings indicated that hypothyroidism could be strongly associated with lipid abnormalities that enhanced the development of cardiovascular diseases. Also, Lp(a) and non-HDL-C should be estimated with other lipid parameters as a useful index for measuring the cardiac risk in hypothyroid patients. A recommended screening should be advised for any patient with thyroid dysfunction, especially hypothyroidism, to assess lipid abnormalities by using Lp(a) and non- HDL-C and he/she should treated at the earliest.

Lipoprotein(a), cardiovascular disease, and contemporary management

Elevated lipoprotein(a) (Lp[a]) is a causal genetic risk factor for cardiovascular disease. To determine if current evidence supports both screening and treatment for elevated Lp(a) in high-risk patients, an English-language search of PubMed and MEDLINE was conducted. In population studies, there is a continuous association between Lp(a) concentrations and cardiovascular risk, with synergistic effects when low-density lipoprotein (LDL) is also elevated. Candidates for Lp(a) screening include patients with a personal or family history of premature cardiovascular disease, familial hypercholesterolemia, recurrent cardiovascular events, or inadequate LDL cholesterol (LDL-C) responses to statins. Given the comparative strength of clinical evidence, reducing LDL-C to the lowest attainable value with a high-potency statin should be the primary focus of lipid-modifying therapies. If the Lp(a) level is 30 mg/dL or higher in a patient who has the aforementioned characteristics plus residual LDL-C elevations (≥70-100 mg/dL) despite maximum-potency statins or combination statin therapy, the clinician may consider adding niacin (up to 2 g/d). If, after these interventions, the patient has progressive coronary heart disease (CHD) or LDL-C levels of 160-200 mg/dL or higher, LDL apheresis should be contemplated. Although Lp(a) is a major causal risk factor for CHD, no currently available controlled studies have suggested that lowering it through either pharmacotherapy or LDL apheresis specifically and significantly reduces coronary risk. Further research is needed to (1) optimize management in order to reduce CHD risk associated with elevated Lp(a) and (2) determine what other intermediate- or high-risk groups might benefit from Lp(a) screening.

Lipoprotein(a) is not related to markers of insulin resistance in pregnancy

BACKGROUND

Dyslipidemia, a major risk factor for cardiovascular disease is a common finding in patients with type 2 diabetes and among women with gestational diabetes. Elevated levels of lipoprotein(a) [Lp(a)] are linked to increased risk of cardiovascular disease. However, its relationship with insulin resistance, type 2 diabetes and gestational diabetes is controversial and unproven. Here we aimed to clarify whether Lp(a) levels are associated with insulin sensitivity in pregnancy.

METHODS

Sixty-four women with gestational diabetes and 165 with normal glucose tolerance were enrolled in the study. Fasting Lp(a) serum levels were measured in all women at 24-28 weeks of gestation.

RESULTS

In pregnancy, there was no significant difference in serum Lp(a) concentrations between the two groups. Its level did not correlate with markers of insulin resistance (HOMA-IR), insulin sensitivity (HOMA-S%), pancreatic beta-cell function (HOMA-B%) and insulin sensitivity in dynamic conditions (OGIS). In addition, fasting glucose and insulin levels and those throughout an oral glucose tolerance test were independent of Lp(a) concentrations in our study group.

CONCLUSIONS

Lp(a) levels in pregnant women do not differ with respect to the presence or absence of gestational diabetes. Although influenced by some components of the lipid profile, such as triglycerides and HDL-C, insulin resistance in pregnancy is not affected by Lp(a).

When should we measure lipoprotein (a)?

Recently published epidemiological and genetic studies strongly suggest a causal relationship of elevated concentrations of lipoprotein (a) [Lp(a)] with cardiovascular disease (CVD), independent of low-density lipoproteins (LDLs), reduced high density lipoproteins (HDL), and other traditional CVD risk factors. The atherogenicity of Lp(a) at a molecular and cellular level is caused by interference with the fibrinolytic system, the affinity to secretory phospholipase A2, the interaction with extracellular matrix glycoproteins, and the binding to scavenger receptors on macrophages. Lipoprotein (a) plasma concentrations correlate significantly with the synthetic rate of apo(a) and recent studies demonstrate that apo(a) expression is inhibited by ligands for farnesoid X receptor. Numerous gaps in our knowledge on Lp(a) function, biosynthesis, and the site of catabolism still exist. Nevertheless, new classes of therapeutic agents that have a significant Lp(a)-lowering effect such as apoB antisense oligonucleotides, microsomal triglyceride transfer protein inhibitors, cholesterol ester transfer protein inhibitors, and PCSK-9 inhibitors are currently in trials. Consensus reports of scientific societies are still prudent in recommending the measurement of Lp(a) routinely for assessing CVD risk. This is mainly caused by the lack of definite intervention studies demonstrating that lowering Lp(a) reduces hard CVD endpoints, a lack of effective medications for lowering Lp(a), the highly variable Lp(a) concentrations among different ethnic groups and the challenges associated with Lp(a) measurement. Here, we present our view on when to measure Lp(a) and how to deal with elevated Lp(a) levels in moderate and high-risk individuals.

Lipoprotein (a) Levels in Relation to Severity of Coronary Artery Disease in North Indian Patients

BACKGROUND

Lipoprotein (a) [Lp (a)] is an established risk marker of coronary artery disease which is independent from other risk factors.

OBJECTIVE

The aim was to address the association between Lp (a) and CAD risk in North Indians. To evaluate whether high levels of lipoprotein (a) [Lp (a)] is a predictor of risk and is related to the severity of CAD.

MATERIALS AND METHODS

This was a cross-sectional study done on 360 patients presenting with chest pain. Coronary angiography revealed CAD in 270 patients and 90 patients without CAD. Lipoprotein (a) level, lipid profile, fasting blood glucose, anthropometric and clinical parameters were analyzed.

RESULTS

Lipoprotein (a) 21.0 mg/dL is associated with the presence of coronary lesions (P = 0.0001). A highly significant difference in Lp (a) levels was observed between normal coronaries vs. single-vessel disease, double-and triple-vessel disease ( P < 0.0001). Body mass index (BMI) was significantly raised in CAD group compared to normal coronary.

CONCLUSION

Multivariate analysis found that Lp (a) was considered an independent predictor for severity of CAD and Lp (a) levels 21.0 mg/dL are associated with severe patterns of coronary atherosclerosis.

Lipoprotein(a) and SYNTAX Score Association with Severity of Coronary Artery Atherosclerosis in North India

OBJECTIVES

This cross-sectional study investigated the association of lipoprotein(a) [Lp(a)] levels as an atherosclerosis predictor and their relationship to the severity of coronary artery disease (CAD).

METHODS

360 consecutive patients at Sanjay Gandhi Postgraduate Institute of Medical Sciences and King George's Medical University hospitals, Lucknow, North India, with chest pains, CAD symptoms and on lipid-lowering therapy were enrolled between June 2009 and October 2011. Before coronary artery angiography (CAG), a fasting blood sample was assessed for lipid and Lp(a) levels. The synergy between percutaneous coronary intervention with taxus and cardiac surgery (SYNTAX) score was calculated according to the CAG results. Patients were divided into 3 groups based on CAD severity and SYNTAX scores.

RESULTS

Angiography revealed CAD in 270 patients. Lp(a) levels were higher in CAD compared to non-CAD patients (48.7 ± 23.8 mg/dl versus 18.9 ± 11.1 mg/dl [P <0.0001]). The levels of Lp(a) were lower in single than in double and triple vessels (39.3 ± 18.4 mg/dl versus 58.0 ± 23.0 mg/dl, and 69.2 ± 24.1 mg/dl, [P <0.05]). Lp(a) levels were significantly higher in severe CAD with SYNTAX score >30 (88.0±24.0 mg/dl). Lp(a) levels correlated significantly with SYNTAX scores (r = 0.70, P <0.0001).

CONCLUSION

In this study, Lp(a) levels were positively associated with a patient's SYNTAX score in diseased vessels. Furthermore, an elevated Lp(a) level was a causal, independent risk factor of CAD. Lowering Lp(a) levels would reduce CAD in primary and secondary prevention settings. There is an urgent need to define more precisely which patients to treat and which to target for earlier interventions.

Lipoprotein (A): Better assessor of coronary heart disease risk in south Indian population

In an attempt to search for risk factors which can explain the increasing prevalence of coronary heart disease (CHD) in Indian population, we conducted a case-control study to assess the association of Lipoprotein (a)(Lp(a)) with CHD. One hundred and fifty one consecutive patients with clinical and angiographic evidence of CHD and forty-nine healthy controls were drawn for the study. Triglycerides, very low density cholesterol (VLDL-C), total cholesterol (total-C)/high density cholesterol (HDL-C) ratio, low density cholesterol (LDL-C)/HDL cholesterol ratio and Lp(a) were found to be higher in patients than controls. In female sex and in those with family history of CHD, higher total and LDL cholesterol levels were observed to be associated with higher Lp(a) levels. Lp(a) levels were also found to be higher in triple vessel disease than other vessel disease patients. Significant difference in Lp(a) levels were observed between normal coronaries vs. single and triple vessel disease(P<0.05) and also between single vs. double and triple vessel disease (P<0.01).Lp(a) levels correlated positively with vessel severity(P<0.005). Lp(a) levels >25 mg/dl were associated with coronary heart disease (Odds ratio 1.98 P<0.05 95% CI 0.007-1.18). Our findings suggest a cut-off level of 25mg/dl for determination of risk of CHD. Studies from different areas involving larger sample size are needed to confirm the findings of the present study.

Lipoprotein(a) as a cardiovascular risk factor: current status

AIMS

The aims of the study were, first, to critically evaluate lipoprotein(a) [Lp(a)] as a cardiovascular risk factor and, second, to advise on screening for elevated plasma Lp(a), on desirable levels, and on therapeutic strategies.

METHODS AND RESULTS

The robust and specific association between elevated Lp(a) levels and increased cardiovascular disease (CVD)/coronary heart disease (CHD) risk, together with recent genetic findings, indicates that elevated Lp(a), like elevated LDL-cholesterol, is causally related to premature CVD/CHD. The association is continuous without a threshold or dependence on LDL- or non-HDL-cholesterol levels. Mechanistically, elevated Lp(a) levels may either induce a prothrombotic/anti-fibrinolytic effect as apolipoprotein(a) resembles both plasminogen and plasmin but has no fibrinolytic activity, or may accelerate atherosclerosis because, like LDL, the Lp(a) particle is cholesterol-rich, or both. We advise that Lp(a) be measured once, using an isoform-insensitive assay, in subjects at intermediate or high CVD/CHD risk with premature CVD, familial hypercholesterolaemia, a family history of premature CVD and/or elevated Lp(a), recurrent CVD despite statin treatment, ≥3% 10-year risk of fatal CVD according to European guidelines, and/or ≥10% 10-year risk of fatal + non-fatal CHD according to US guidelines. As a secondary priority after LDL-cholesterol reduction, we recommend a desirable level for Lp(a) <80th percentile (less than ∼50 mg/dL). Treatment should primarily be niacin 1-3 g/day, as a meta-analysis of randomized, controlled intervention trials demonstrates reduced CVD by niacin treatment. In extreme cases, LDL-apheresis is efficacious in removing Lp(a).

CONCLUSION

We recommend screening for elevated Lp(a) in those at intermediate or high CVD/CHD risk, a desirable level <50 mg/dL as a function of global cardiovascular risk, and use of niacin for Lp(a) and CVD/CHD risk reduction.

Lipoprotein a: where are we now?

PURPOSE OF REVIEW

To provide an update of the literature describing the link between lipoprotein a and vascular disease.

RECENT FINDINGS

There is evidence that elevated plasma lipoprotein a levels are associated with coronary heart disease, stroke and other manifestations of atherosclerosis. Several mechanisms may be implicated, including proinflammatory actions and impaired fibrinolysis.

SUMMARY

Lipoprotein a potentially represents a useful tool for risk stratification in the primary and secondary prevention setting. However, there are still unresolved methodological issues regarding the measurement of lipoprotein a levels. Targeting lipoprotein a in order to reduce vascular risk is hampered by the lack of well tolerated and effective pharmacological interventions. Moreover, it has not yet been established whether such a reduction will result in fewer vascular events. The risk attributed to lipoprotein a may be reduced by aggressively tackling other vascular risk factors, such as low-density lipoprotein cholesterol.

Lipoprotein(a) levels and long-term cardiovascular risk in the contemporary era of statin therapy

Lipoprotein(a) [Lp(a)] has enhanced atherothrombotic properties. The ability of Lp(a) levels to predict adverse cardiovascular outcomes in patients undergoing coronary angiography has not been examined. The relationship between serum Lp(a) levels and both the extent of angiographic disease and 3-year incidence of major adverse cardiovascular events (MACE: death, myocardial infarction, stroke, and coronary revascularization) was investigated in 2,769 patients who underwent coronary angiography [median Lp(a) 16.4 mg/dl, elevated levels (≥30 mg/dl) in 38%]. An elevated Lp(a) was associated with a 2.3-fold [95% confidence interval (CI), 1.7-3.2, P < 0.001] greater likelihood of having a significant angiographic stenosis and 1.5-fold (95 CI, 1.3-1.7, P < 0.001) greater chance of three-vessel disease. Lp(a)≥30 mg/dl was associated with a greater rate of MACE (41.8 vs. 35.8%, P = 0.005), primarily due to a greater need for coronary revascularization (30.9 vs. 26.0%, P = 0.02). A relationship between Lp(a) levels and cardiovascular outcome was observed in patients with an LDL cholesterol (LDL-C) ≥70-100 mg/dl (P = 0.049) and >100 mg/dl (P = 0.02), but not <70 mg/dl (P = 0.77). Polymorphisms of Lp(a) were also associated with both plasma Lp(a) levels and coronary stenosis, but not a greater rate of MACE. Lp(a) levels correlate with the extent of obstructive disease and predict the need for coronary revascularization in subjects with suboptimal LDL-C control. This supports the need to intensify lipid management in patients with elevated Lp(a) levels.

Lipoprotein(a) and ischemic heart disease--a causal association? A review

The aim of this review is to summarize present evidence of a causal association of lipoprotein(a) with risk of ischemic heart disease (IHD). Evidence for causality includes reproducible associations of a proposed risk factor with risk of disease in epidemiological studies, evidence from in vitro and animal studies in support of pathophysiological effects of the risk factor, and preferably evidence from randomized clinical trials documenting reduced morbidity in response to interventions targeting the risk factor. Elevated and in particular extreme lipoprotein(a) levels have in prospective studies repeatedly been associated with increased risk of IHD, although results from early studies are inconsistent. Data from in vitro and animal studies implicate lipoprotein(a), consisting of a low density lipoprotein particle covalently bound to the plasminogen-like glycoprotein apolipoprotein(a), in both atherosclerosis and thrombosis, including accumulation of lipoprotein(a) in atherosclerotic plaques and attenuation of t-PA mediated plasminogen activation. No randomized clinical trial of the effect of lowering lipoprotein(a) levels on IHD prevention has ever been conducted. Lacking evidence from randomized clinical trials, genetic studies, such as Mendelian randomization studies, can also support claims of causality. Levels of lipoprotein(a) are primarily determined by variation in the LPA gene coding for the apolipoprotein(a) moiety of lipoprotein(a), and genetic epidemiologic studies have documented association of LPA copy number variants, influencing levels of lipoprotein(a), with risk of IHD. In conclusion, results from epidemiologic, in vitro, animal, and genetic epidemiologic studies support a causal association of lipoprotein(a) with risk of IHD, while results from randomized clinical trials are presently lacking.

Epidemiology of cardiovascular disease in type 2 diabetes: the Indian scenario

Noncommunicable diseases, of which coronary artery disease (CAD) and diabetes top the list, have overtaken communicable diseases with respect to overall mortality, even in developing countries like India. High prevalence rates of diabetes and CAD are seen not only in affluent migrant Indians, but also in those living within the subcontinent. Indeed the epidemic of diabetes and CAD is now spreading to the middle- and lower-income groups in India. The risk for CAD is two to four times higher in diabetic subjects, and in Indians, CAD occurs prematurely, i.e., one to two decades earlier than in the West. Thus there is an urgent need for studies on CAD in diabetic and nondiabetic subjects in India. The Chennai Urban Population Study, a population-based study in Chennai, in South India, showed a prevalence of CAD of 11%, which is 10 times more than what it was in 1970. Clustering of risk factors for CAD such as hyperglycemia, central body obesity, dyslipidemia, and hypertension tends to occur, and interplay of these risk factors could explain the enhanced CAD risk in Indians. Additionally, low-grade inflammation and a possible inherent genetic susceptibility are other contributing factors. Preventive measures such as lifestyle modification with healthy diet, adequate physical activity, and decrease in stress could help prevent the twin epidemics of diabetes and CAD.

Metabolic syndrome and cardiovascular disease in South Asians

This review discusses the prevalence of metabolic syndrome and cardiovascular disease in the South Asian population, evaluates conventional and emerging risk factors, and reinforces the need for ethnic-specific redefinition of guidelines used to diagnose metabolic syndrome. We reviewed recent and past literature using Ovid Medline and PubMed databases. South Asians represent one of the largest and fastest growing ethnic groups in the world. With this growth, a dramatic rise in the rates of acute myocardial infarction and diabetes is being seen in this population. Potential etiologies for this phenomenon include dietary westernization, poor lifestyle measures, adverse body fat patterning, and genetics. While traditional risk factors for diabetes and cardiovascular disease should not be overlooked, early metabolic syndrome has now been shown in the South Asian pediatric population, suggesting that "metabolic programming" and perinatal influences may likely play a substantial role. Health care practitioners must be aware that current guidelines used to identify individuals with metabolic syndrome are underestimating South Asian individuals at risk. New ethnic-specific guidelines and prevention strategies are discussed in this review and should be applied by clinicians to their South Asian patients.