Lipoprotein(a) screening in young and middle-aged patients presenting with acute coronary syndrome

Association between lipoprotein(a) and premature atherosclerotic cardiovascular disease: a systematic review and meta-analysis

Aims

High lipoprotein(a) [Lp(a)] level has been demonstrated as an important risk factor for atherosclerotic cardiovascular diseases (ASCVD) amongst the older populations, whereas its effects in the younger population remain unclear. This study evaluated the associations between Lp(a) and the risk of premature ASCVD.

Method and results

PubMed and Embase were searched for related studies until 12 November 2023. Fifty-one studies including 100 540 participants were included. Mean age of patients ranged from 35.3 to 62.3 years. The proportion of male participants ranged from 0% to 100%. The mean follow-up was provided in five studies ranging from 1 year to 40 years. The definition of elevated Lp(a) varied among studies, such as >30 mg/dL, >50 mg/dL, the top tertiles, the top quartiles, the top quintiles, and so on. Higher Lp(a) was significantly associated with the composite ASCVD [odds ratio (OR): 2.15, 95% confidence interval (95% CI): 1.53-3.02, P < 0.001], especially for coronary artery disease (OR: 2.44, 95% CI: 2.06-2.90, P < 0.001) and peripheral arterial disease (OR: 2.56, 95% CI: 1.56-4.21, P < 0.001). This association remained significant in familial hypercholesterolaemia (FH) (OR: 3.11, 95% CI: 1.63-5.96, P < 0.001) and type 2 diabetes mellitus (T2DM) patients (OR: 2.23; 95% CI: 1.54-3.23, P < 0.001).Significant results were observed in South Asians (OR: 3.71, 95% CI: 2.31-5.96, P < 0.001), Caucasians (OR: 3.17, 95% CI: 2.22-4.52, P < 0.001), and patients with baseline low-density lipoprotein cholesterol (LDL-c) level ≥ 2.6 mmol/L.

Conclusion

Elevated Lp(a) predicts the risk of the composite or individual ASCVD in young, regardless of study design, gender, population characteristics (community or hospitalized), different premature definitions, and various Lp(a) measurement approaches. This association was important in South Asians, Caucasians, FH patients, T2DM patients, and patients with baseline LDL-c level ≥ 2.6 mmol/L.

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.

Low-density lipoprotein cholesterol goal attainment in patients with clinical evidence of familial hypercholesterolemia and elevated Lp(a)

BACKGROUND

Although potent lipid-lowering therapies are available, patients commonly fall short of recommended low-density lipoprotein cholesterol (LDL-C) levels. The aim of this study was to examine the relationship between familial hypercholesterolemia (FH) and elevated lipoprotein(a) [Lp(a)] and LDL-C goal attainment, as well as the prevalence and severity of coronary artery disease (CAD). Moreover, we characterized patients failing to meet recommended LDL-C goals.

METHODS

We performed a cross-sectional analysis in a cohort of patients undergoing cardiac catheterization. Clinical FH was determined by the Dutch Clinical Lipid Network Score, and Lp(a) ≥ 50 mg/dL (≈ 107 nmol/L) was considered elevated.

RESULTS

A total of 838 participants were included. Overall, the prevalence of CAD was 72%, and 62% received lipid-lowering treatment. The prevalence of clinical FH (probable and definite FH) was 4%, and 19% had elevated Lp(a) levels. With 35%, LDL-C goal attainment was generally poor. Among the participants with clinical FH, none reached their LDL-C target. Among patients with elevated Lp(a), LDL-C target achievement was only 28%. The prevalence and severity of CAD were higher in participants with clinical FH (86% prevalence) and elevated Lp(a) (80% prevalence).

CONCLUSION

Most participants failed to meet their individual LDL-C goals according to the ESC 2016 and 2019 guidelines. In particular, high-risk patients with clinical FH or elevated Lp(a) rarely met their target for LDL-C. The identification of these patients and more intense treatment approaches are crucial for the improvement of CAD primary and secondary prevention.

Causes, Angiographic Characteristics, and Management of Premature Myocardial Infarction: JACC State-of-the-Art Review

Among patients presenting with acute myocardial infarction (AMI), the proportion of young individuals has increased in recent years. Although coronary atherosclerosis is less extensive in young patients with AMI, with higher prevalence of single-vessel disease and rare left main involvement, the long-term prognosis is not benign. Young patients with AMI with obstructive coronary artery disease have similar risk factors as older patients except for higher prevalence of smoking, lipid disorders, and family history of premature coronary artery disease, and lower prevalence of diabetes mellitus and hypertension. Smoking cessation is by far the most effective secondary preventive measure. Myocardial infarction with nonobstructive coronary arteries is a relatively common clinical entity (10%-20%) among young patients with AMI, with intravascular and cardiac magnetic resonance imaging being key for diagnosis and potentially treatment. Spontaneous coronary artery dissection is a frequent pathogenetic mechanism of AMI among young women, requiring a high degree of suspicion, especially in the peripartum period.

Cardiovascular events in patients with familial hypercholesterolemia and hyperlipoproteinaemia (a): Indications for lipoprotein apheresis in Poland

BACKGROUND

Lipoprotein apheresis (LA) is a safe method of reducing atherogenic lipoproteins and improving cardiovascular (CV) outcomes. We aimed to assess the reductions in low-density lipoprotein cholesterol (LDL-C) and lipoprotein (a) [Lp(a)] levels in patients undergoing regular LA therapy and to evaluate its influence on the incidence rate of adverse cardiac and vascular events (ACVE) and major adverse cardiac events (MACE).

METHODS

A longitudinal study in Poland evaluated the prospective and retrospective observational data of 23 patients with hyperlipoproteinaemia (a) [hyper-Lp(a)] and familial hypercholesterolemia (FH), undergoing 1014 LA sessions between 2013 and 2020. Their pre- and post-apheresis LDL-C and Lp(a) levels were assessed to calculate the acute percent reductions. The time period used to evaluate annual rates of ACVE and MACE before and after initiation of LA was matched in each patient.

RESULTS

The pre-apheresis LDL-C and Lp(a) concentrations were 155 (107-228) (mg/dL) (median and interquartile range) and 0.56 (0.14-1.37) (g/L), respectively. LA therapy resulted in a reduction of LDL-C to 50 (30-73.5) (mg/dL) and of Lp(a) to 0.13 (0.05-0.34) (g/L), representing a percent reduction of 70.0% and 72.7% for LDL-C and Lp(a), respectively. We found a significant reduction in the annual rate of ACVE (0.365[0.0-0.585] vs (0.0[0.0-0.265]; P = .047) and MACE (0.365[0.0-0.585] vs 0.0[0.0-0.265]; P = .031).

CONCLUSIONS

The findings of our study indicate that LA treatment in patients with hyperlipoproteinaemia (a) and FH on maximally tolerated lipid lowering therapies leads to a substantial reduction in LDL-C and Lp(a) concentrations and lowers CV event rates in Polish patients.

Lipoprotein(a) as a predictor for the presence and severity of premature coronary artery disease: a cross-sectional analysis of 2433 patients

BACKGROUND

Lipoprotein(a) [Lp(a)] has been emerged as a risk factor for coronary artery disease (CAD), but there is currently insufficient data on the relationship between Lp(a) and premature CAD (PCAD). Thus, this study aimed to examine the association between Lp(a) and PCAD in a Chinese cohort.

METHODS

Data on 2433 individuals (male <55 years old and female <65 years old) who underwent coronary angiography from March 2016 to February 2019 were included in this study and were divided into the PCAD group (n = 1751) and non-CAD group (n = 682) according to the angiography results. Their clinical and laboratory parameters were collected, and plasma Lp(a) level was measured by immunoturbidimetry. The severity of CAD was evaluated using Gensini score (GS) and divided into three subgroups. The relationship between plasma Lp(a) levels and the presence and severity of PCAD was analyzed.

RESULTS

The level of plasma Lp(a) in the PCAD group was significantly higher than that in the non-CAD group (P < 0.001). The plasma Lp(a) concentration in the highest GS group was significantly higher than that in the lowest GS group (P < 0.001). Multivariate linear regression analysis showed that elevated plasma Lp(a) levels were correlated with higher GS (b = 0.41, P < 0.001). Multivariate logistic regression showed that elevated plasma Lp(a) levels were independently associated with PCAD (odds ratio = 2.91, P < 0.001). Moreover, elevated plasma Lp(a) levels correlated with higher GS (b = 0.41, P < 0.001).

CONCLUSION

In this study, Lp(a) concentration was associated with the presence and severity of PCAD, suggesting that Lp(a) may be a marker or target for patients with PCAD.

Risk factors for coronary artery disease in young patients with stable angina pectoris

Background/aim

We aimed to investigate the relationship between risk factors and the presence of coronary artery disease (CAD) in a young population with stable angina pectoris (SAP).

Materials and methods

A total of571 individuals younger than 60 years old, admitted to the outpatient clinic with chest pain and referred for coronary angiography between January 2015 and December 2017, were included in the study. All clinical and biochemical parameters were documented in the hospital records. Coronary angiography of patients was monitored from records. The individuals were divided into two groups. The patient group consisted of 363 individuals with at least one-vessel stenosis of ≥70%, and the control group consisted of 208 individuals with normal coronary angiography. We compared the traditional and nontraditional risk factors of these two groups in terms of the presence of CAD.

Results

Prevalence of male sex and smoking were higher in the patient group, and the prevalence of hypertension and diabetes were similar in the two groups. In the patient group, mean age, blood cholesterols, serum gamma-glutamyltransferase, hemoglobin, and white blood cell and lymphocyte levels were higher, while estimated glomerular filtration rate (eGFR), high-density lipoprotein cholesterol (HDL-C), platelets, and neutrophil/lymphocyte and platelet/lymphocyte ratios were lower. Low eGFR and HDL-C levels, older age, male sex, smoking, and high levels of low-density lipoprotein cholesterol and lymphocytes were independent risk factors for the presence of CAD in young patients.

Conclusion

Contrary to studies performed in the elderly, traditional and nontraditional risk factors could not exactly predict the presence of CAD in a young population with SAP.

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

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