Lipoprotein(a) and Coronary Artery Disease Risk Without a Family History of Heart Disease

Joint Association of Lipoprotein(a) and a Family History of Coronary Artery Disease with the Cardiovascular Outcomes in Patients with Chronic Coronary Syndrome

AIM

No data are currently available regarding the association between Lp(a) and the cardiovascular outcomes in patients with coronary artery disease (CAD) according to their family history (FHx) of CAD. This study aimed to evaluate the significance of Lp(a) in predicting major adverse cardiovascular events (MACEs) in patients with chronic coronary syndrome (CCS) with or without FHx.

METHODS

A total of 6056 patients with CCS were enrolled. Information on FHx was collected, and the plasma Lp(a) levels were measured. All patients were followed up regularly. The independent and joint associations of Lp(a) and FHx with the risk of MACEs, including cardiovascular death, nonfatal myocardial infarction, and stroke, were analyzed.

RESULTS

With over an average of 50.35±18.58 months follow-up, 378 MACEs were recorded. A Cox regression analysis showed an elevated Lp(a) level to be an independent predictor for MACEs in patients with [hazard ratio (HR): 2.77, 95% confidence interval (CI): 1.38-5.54] or without FHx (HR: 1.35, 95% CI: 1.02-1.77). In comparison to subjects with non-elevated Lp(a) and negative FHx, patients with elevated Lp(a) alone were at a nominally higher risk of MACEs (HR: 1.26, 95% CI: 0.96-1.67), while those with both had the highest risk (HR: 1.93, 95% CI: 1.14-3.28). Moreover, adding Lp(a) to the original model increased the C-statistic by 0.048 in subjects with FHx (p=0.004) and by 0.004 in those without FHx (p=0.391).

CONCLUSIONS

The present study is the first to suggest that Lp(a) could be used to predict MACEs in CCS patients with or without FHx; however, its prognostic significance was more noteworthy in patients with FHx.

A focused update to the 2019 NLA scientific statement on use of lipoprotein(a) in clinical practice

Since the 2019 National Lipid Association (NLA) Scientific Statement on Use of Lipoprotein(a) in Clinical Practice was issued, accumulating epidemiological data have clarified the relationship between lipoprotein(a) [Lp(a)] level and cardiovascular disease risk and risk reduction. Therefore, the NLA developed this focused update to guide clinicians in applying this emerging evidence in clinical practice. We now have sufficient evidence to support the recommendation to measure Lp(a) levels at least once in every adult for risk stratification. Individuals with Lp(a) levels <75 nmol/L (30 mg/dL) are considered low risk, individuals with Lp(a) levels ≥125 nmol/L (50 mg/dL) are considered high risk, and individuals with Lp(a) levels between 75 and 125 nmol/L (30-50 mg/dL) are at intermediate risk. Cascade screening of first-degree relatives of patients with elevated Lp(a) can identify additional individuals at risk who require intervention. Patients with elevated Lp(a) should receive early, more-intensive risk factor management, including lifestyle modification and lipid-lowering drug therapy in high-risk individuals, primarily to reduce low-density lipoprotein cholesterol (LDL-C) levels. The U.S. Food and Drug Administration approved an indication for lipoprotein apheresis (which reduces both Lp(a) and LDL-C) in high-risk patients with familial hypercholesterolemia and documented coronary or peripheral artery disease whose Lp(a) level remains ≥60 mg/dL [∼150 nmol/L)] and LDL-C ≥ 100 mg/dL on maximally tolerated lipid-lowering therapy. Although Lp(a) is an established independent causal risk factor for cardiovascular disease, and despite the high prevalence of Lp(a) elevation (∼1 of 5 individuals), measurement rates are low, warranting improved screening strategies for cardiovascular disease prevention.

A Systematic Review on the Risk Modulators of Myocardial Infarction in the "Young"-Implications of Lipoprotein (a)

The presence of a myocardial infarction at a younger age is of special interest, considering the psychological and socioeconomic impact, as well as long-term morbidity and mortality. However, this group has a unique risk profile, with less traditional cardiovascular risk factors that are not well studied. This systematic review aims to evaluate traditional risk factors of myocardial infarction in the "young", highlighting the clinical implications of lipoprotein (a). We performed a comprehensive search using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) standards; we systematically searched the PubMed, EMBASE, and Science Direct Scopus databases, using the terms: "myocardial infarction", "young", "lipoprotein (a)", "low-density lipoprotein", "risk factors". The search identified 334 articles which were screened, and, at the end, 9 original research articles regarding the implications of lipoprotein (a) in myocardial infarction in the "young" were included in the qualitative synthesis. Elevated lipoprotein (a) levels were independently associated with an increased risk of coronary artery disease, especially in young patients, where this risk increased by threefold. Thus, it is recommended to measure the lipoprotein (a) levels in individuals with suspected familial hypercholesterolaemia or with premature atherosclerotic cardiovascular disease and no other identifiable risk factors, in order to identify patients who might benefit from a more intensive therapeutic approach and follow-up.

Circulating Biomarkers for Laboratory Diagnostics of Atherosclerosis-Literature Review

Atherosclerosis is still considered a disease burden with long-term damaging processes towards the cardiovascular system. Evaluation of atherosclerotic stages requires the use of independent markers such as those already considered traditional, that remain the main therapeutic target for patients with atherosclerosis, together with emerging biomarkers. The challenge is finding models of predictive markers that are particularly tailored to detect and evaluate the evolution of incipient vascular lesions. Important advances have been made in this field, resulting in a more comprehensible and stronger linkage between the lipidic profile and the continuous inflammatory process. In this paper, we analysed the most recent data from the literature studying the molecular mechanisms of biomarkers and their involvement in the cascade of events that occur in the pathophysiology of atherosclerosis.

Assessing cardiovascular disease: looking beyond cholesterol

PURPOSE OF REVIEW

The low-density lipoprotein (LDL)-cholesterol level is a weak predictor of developing cardiovascular (CV) disease and can only explain a small proportion of CV risk. It is not used to determine CV risk on either the atherosclerotic cardiovascular disease (ASCVD) calculator in the United States, or the Qrisk3 in the UK.A study in JAMA in 2022 suggested that ' the absolute benefits of statins are modest and may not be strongly mediated through the degree of LDL reduction '. Perhaps it is time to look beyond cholesterol to a different causal model - the 'thrombogenic' model of ASCVD.

RECENT FINDINGS

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) pandemic demonstrated that infectious agents damage the endothelium and the glycocalyx - the glycoprotein layer protecting underlying endothelial cells. There are numerous other conditions leading to this kind of damage, which can trigger thrombus formation, causing strokes and myocardial infarctions.Although these are acute events, they highlight a mechanism for the development of ASCVD which centres on endothelial damage and thrombus formation as both the primary causal mechanism for acute events, and the driver behind progression towards atherosclerotic plaque development.

SUMMARY

The cholesterol hypothesis, that a raised LDL is directly causal for ASCVD, does not adequately explain cardiovascular risk in individuals, or populations. An alternative 'thrombogenic' hypothesis is proposed as a more valid causal model.

Elevated lipoprotein(a) levels as an independent predictor of long-term recurrent events in patients with acute coronary syndrome: an observational, retrospective cohort study

BACKGROUND

Whether lipoprotein(a) [Lp(a)] is associated with recurrent cardiovascular events (RCVEs) still remains controversial. The present study aimed to investigate the prognostic value of Lp(a) for long-term RCVEs and each component of it in people with acute coronary syndrome (ACS).

METHODS

This multicenter, observational and retrospective study enrolled 765 ACS patients at 11 hospitals in Chengdu from January 2014 to June 2019. Patients were assigned to low-Lp(a) group [Lp(a) < 30 mg/dl] and high-Lp(a) group [Lp(a) ≥ 30 mg/dl]. The primary and secondary endpoints were defined as RCVEs and their elements, including all-cause death, nonfatal myocardial infarction (MI), nonfatal stroke and unplanned revascularization.

RESULTS

Over a median 17-month follow-up, 113 (14.8%) patients presented with RCVEs were reported, among which we observed 57 (7.5%) all-cause deaths, 22 (2.9%) cases of nonfatal stroke, 13 (1.7%) cases of nonfatal MI and 33 (4.3%) cases of unplanned revascularization. The incidences of RCVEs and revascularization in the high-Lp(a) group were significantly higher than those in the low-Lp(a) group ( P < 0.05), whereas rates of all-cause death, nonfatal stroke and nonfatal MI were not statistically different ( P > 0.05). Kaplan-Meier analysis also revealed the same trend. Multivariate Cox proportional hazards analysis showed that 1-SD increase of Lp(a) was independently associated with both the primary endpoint event [hazard ratio (HR), 1.285 per 1-SD; 95% confidence interval (CI), 1.112-1.484; P < 0.001] and revascularization (HR, 1.588 per 1-SD; 95% CI, 1.305-1.932; P < 0.001), but not with the other secondary events.

CONCLUSION

Increased Lp(a) is an independent predictor of RCVEs and unplanned revascularization in patients with ACS.

Association between new markers of cardiovascular risk and hepatic insulin resistance in those at high risk of developing type 2 diabetes

AIM/HYPOTHESIS

Hepatic insulin resistance (HIR) is considered to be an independent predictor of metabolic disorders and plays an important role in systemic inflammation, which contributes to abnormalities in cardiovascular disease (CVD) risk factors. The aim of this study was to investigate the relationship between HIR and new markers of cardiovascular risks, including leptin/adiponectin ratio (L/A), lipoprotein(a) [Lp(a)], and tumor necrosis factor alpha (TNF-α), at comparable whole body insulin sensitivity in non-diabetic individuals with or without CVD and at high risk of developing type 2 diabetes.

METHODS

The HIR index, L/A, Lp(a), and TNF-α were measured in 50 participants with CVD and in 200 without CVD (1:4 ratio). These were also matched for the homeostatic model assessment for insulin resistance (HOMA-IR) and Matsuda-insulin sensitivity index (ISI) in an observational study design.

RESULTS

The HIR index (1.52 ± 0.14 vs. 1.45 ± 0.17, p < 0.02), L/A (3.22 ± 3.10 vs. 2.09 ± 2.27, p < 0.004), and levels of Lp(a) (66.6 ± 49.5 vs. 37.9 ± 3 6.8 mg/dL, p < 0.0001) and TNF-α (18.9 ± 21.8 vs. 5.4 ± 7.1 pg/mL, p < 0.0001) were higher in those with CVD than those without CVD. HOMA-IR and ISI were not significantly different (p = 0.88 and p = 0.35, respectively). The HIR index was directly correlated with L/A (r = 0.41, p < 0.0001), Lp(a) (r = 0.20, p < 0.002), TNF- α (r = 0.14, p < 0.03), and diastolic blood pressure (DBP) (r = 0.13, p < 0.03). The stepwise model analysis showed that L/A, Lp(a), and TNF-α explained about 20% of the variation in the HIR indices of all the participants (p < 0.02).

CONCLUSIONS/INTERPRETATIONS

Our results suggest a positive association between HIR and new markers of cardiovascular risk [L/A, Lp(a), and TNF- α] at comparable whole body insulin sensitivity in those with or without CVD and at high risk of developing type 2 diabetes.

Lipoprotein (a) and Cardiovascular Disease: A Missing Link for Premature Atherosclerotic Heart Disease and/or Residual Risk

ABSTRACT

Lipoprotein(a) or lipoprotein "little a" is an under-recognized causal risk factor for cardiovascular (CV) disease (CVD), including coronary atherosclerosis, aortic valvular stenosis, ischemic stroke, heart failure and peripheral arterial disease. Elevated plasma Lp(a) (≥50 mg/dL or ≥100 nmol/L) is commonly encountered in almost 1 in 5 individuals and confers a higher CV risk compared to those with normal Lp(a) levels, although such normal levels have not been generally agreed upon. Elevated Lp(a) is considered a cause of premature and accelerated atherosclerotic CVD. Thus, in patients with a positive family or personal history of premature coronary artery disease (CAD), Lp(a) should be measured. However, elevated Lp(a) may confer increased risk for incident CAD even in the absence of a family history of CAD, and even in those who have guideline-lowered LDL-cholesterol (<70 mg/dl) and continue to have a persisting CV residual risk. Thus, measurement of Lp(a) will have a significant clinical impact on the assessment of atherosclerotic CVD risk, and will assume a more important role in managing patients with CVD with the advent and clinical application of specific Lp(a)-lowering therapies. Conventional therapeutic approaches like lifestyle modification and statin therapy remain ineffective at lowering Lp(a). Newer treatment modalities, such as gene silencing via RNA interference with use of antisense oligonucleotide(s) or small interfering RNA molecules targeting Lp(a) seem very promising. These issues are herein reviewed, accumulated data are scrutinized, meta-analyses and current guidelines are tabulated and Lp(a)-related CVDs and newer therapeutic modalities are pictorially illustrated.

The impact of race and ethnicity on lipoprotein(a) levels and cardiovascular risk

PURPOSE OF REVIEW

Lipoprotein(a) [Lp(a)] is a plasma circulating apoB100 (apoB) containing lipoprotein. It has a unique glycoprotein bound to the apoB100, apolipoprotein(a) [apo(a)]. The majority of the population expresses two apo(a) isoforms, when bound to apoB100 they create two circulating Lp(a) particles. Lp(a) levels are genetically determined and epidemiological studies have established elevated levels of Lp(a) to be a causal risk factor of cardiovascular disease (CVD). Lp(a) levels differ across racial groups and Blacks of Sub-Saharan decent have higher levels when compared to white. In comparison to white populations, studies in minorities are less represented in the published literature. Additionally, there is a lack of standardization in the commercial assays used to measured Lp(a) levels, and hence it is difficult to assess risk based on individual Lp(a) levels, but risk seems to occur in the upper percentiles of the population.

RECENT FINDINGS

A recent study using data from the UK biobank highlights the racial differences in Lp(a) levels and the increase risk in CVD amongst all races.

SUMMARY

This review will highlight Lp(a) biology and physiology with a focus on available data from racially diverse cohorts. There is a need to perform studies in diverse populations to understand if they are at higher risk than whites are.