Prognostic significance of elevated lipoprotein(a) in coronary artery revascularization patients

Immunologic and inflammatory pathogenesis of chronic coronary syndromes: A review

Chronic coronary syndrome (CCS) is a major cause of progression to acute coronary syndrome. Due to its insidious onset and complex etiology, this condition is often underestimated and insufficiently recognized, and traditional interventions for risk factors do not effectively control the disease progression. Current research suggests that immune and inflammatory pathways contribute to atherosclerosis and its clinical complications, thereby triggering the progression of CCS to acute coronary syndrome. This article primarily reviews the possible mechanisms of immune and inflammatory responses in CCS, with the aim of providing references for the diagnosis, treatment, and prevention of CCS.

Association between Lipoprotein(a) concentration and adverse cardiac events in patients with coronary artery disease: An observational cohort study

This prospective study investigated the association between lipoprotein (a) [Lp(a)] levels and adverse cardiac events in patients undergoing percutaneous coronary intervention (PCI) for coronary artery disease. Among 600 patients, 79.16 % were male. Kaplan Meier analysis revealed significantly higher incidence rates of cardiac death, major adverse cardiac events, myocardial infarction, revascularization and stroke in patients with elevated Lp(a) (≥30 mg/dL). The Cox Regression model identified Lp(a) ≥30 mg/dL as a significant risk factor for adverse events (HR: 4.2920; 95%CI: 2.58-7.120; p < 0.05). Elevated Lp(a) levels were associated with an increased risk of adverse cardiac events in coronary artery disease patients undergoing PCI.

Impact of lipoprotein(a) and fibrinogen on prognosis in patients with coronary artery disease: A retrospective cohort study

BACKGROUND

Despite the considerable progress made in preventative methods, medication, and interventional therapies, it remains evident that cardiovascular events (CVEs) continue to be the primary cause of both death and morbidity among individuals diagnosed with coronary artery disease (CAD).

OBJECTIVE

To compare the connection between lipoprotein a (Lp[a]), fibrinogen (Fib), and both parameters combined with all-cause mortality to detect their value as prognostic biomarkers.

METHODS

This is a retrospective study. Patients diagnosed with CAD between January 2007 and December 2020 at the Guangdong Provincial People's Hospital (China) were involved in the study. 43,367 patients met the eligibility criteria. The Lp(a) and Fib levels were distributed into three tertile groups (low, medium, and high). All of the patients included in the study were followed up for all-cause mortality. Kaplan-Meier and Cox regression were performed to determine the relationship between Lp(a), Fib, and all-cause mortality. A concordance statistics model was developed to detect the impact of Fib and Lp(a) in terms of anticipating poor outcomes in patients with CAD.

RESULTS

Throughout a median follow-up of 67.0 months, 6,883 (15.9%) patients died. Participants with high Lp(a) (above 27.60 mg/dL) levels had a significantly higher risk for all-cause mortality than individuals with low Lp(a) levels (below 11.13 mg/dL; adjusted hazard ratio [aHR] 1.219, 95% confidence interval [CI]: 1.141-1.304, p< 0.001). Similarly, patients with high Fib levels (above 4.32 g/L) had a significantly greater risk of developing all-cause mortality compared with those with reduced Fib levels (below 3.41 g/L; aHR 1.415, 95% CI: 1.323-1.514, p< 0.001). Patients with raised Lp(a) and Fib levels had the maximum risk for all-cause mortality (aHR 1.702; 95% CI: 1.558-1.859, p< 0.001). When considered together, Lp(a) and Fib caused a significant elevation of the concordance statistic by 0.009 (p< 0.05), suggesting a higher value for predicting mortality when combining the two indicators.

CONCLUSION

High Lp(a) and Fib levels could be used as predictive biomarkers for all-cause mortality in individuals with CAD. The prediction accuracy for all-cause mortality improved after combining the two parameters.

Lp(a), oxidized phospholipids and oxidation-specific epitopes are increased in subjects with keloid formation

BACKGROUND

Keloid formation following trauma or surgery is common among darkly pigmented individuals. Since lipoprotein(a) [Lp(a)] has been postulated to have a putative role in wound healing, and also mediates atherosclerotic cardiovascular disease, it was assessed whether Lp(a), its associated oxidized phospholipids and other oxidation-specific biomarkers were associated with keloid formation.

METHODS

This case-control study included darkly pigmented individuals of African ancestry, 100 with keloid scarring and 100 non-keloid controls. The lipid panel, hsCRP, Lp(a), oxidized phospholipids on apolipoprotein B-100 (OxPL-apoB), IgG and IgM apoB-immune complexes and IgG and IgM autoantibodies to a malondialdehyde mimotope (MDA-mimotope) were measured. Immunohistochemistry of keloid specimens was performed for both Lp(a) and OxPL staining.

RESULTS

Cases and controls were well matched for age, sex and lipid profile. Mean Lp(a) (57.8 vs. 44.2 mg/dL; P = 0.01, OxPL-apoB 17.4 vs. 15.7 nmol/L; P = 0.009) and IgG and IgM apoB-immune complexes and IgG and IgM MDA-mimotope levels were significantly higher in keloid cases. Keloid tissue stained strongly for OxPL.

CONCLUSION

Darkly pigmented individuals of African ancestry with keloids have higher plasma levels of Lp(a), OxPL-apoB and oxidation-specific epitopes. The commonality of excessive wound healing in keloids and chronic complications from coronary revascularization suggests avenues of investigation to define a common mechanism driven by Lp(a) and the innate response to oxidized lipids.

Comparison of apolipoprotein B/A1 ratio, TC/HDL-C, and lipoprotein (a) for predicting outcomes after PCI

BACKGROUND AND AIMS

The Apo B/A1 ratio is a major factor that predicts future cardiovascular outcomes. However, it is unclear whether the apolipoprotein B (Apo B)/apolipoprotein A1 (Apo A1) is a better predictor of future outcome than the total cholesterol (TC)/HDL-C ratio or lipoprotein (a) (Lp (a)) after the percutaneous coronary intervention (PCI). Therefore, we performed this study to evaluate the impact of the Apo B/A1 ratio on the patients who achieved LDL-C below 70 mg/dL one year after PCI.

METHODS

We included 448 PCI patients whose LDL-C levels were below 70 mg/dL at follow-up. The Apo B/A1 ratio, TC/HDL-C ratio, and Lp (a) levels were measured at the time of PCI and follow-up, and decreases in these parameters between baseline and follow-up were assessed as potential markers to predict major cardiovascular adverse events (MACEs).

RESULTS

During a median follow-up period of 38.0 months, 115 MACEs were recorded. The tertile with the lowest decrease in the Apo B/A1 ratio (≤ 0.146) showed a lower MACE survival rate compared to the other tertiles. There were no differences in MACE survival rates for the TC/HDL-C ratio or Lp (a) levels.

CONCLUSIONS

The Apo B/A1 ratio had better predictive accuracy for clinical outcomes compared to the TC/HDL-C ratio and Lp (a) level. A lower decrease in the Apo B/A1 ratio may be a residual risk factor for MACEs in patients who have reached LDL-C levels below 70 mg/dL after PCI.

Recent Updates of Lipoprotein(a) and Cardiovascular Disease

In recent years, epidemiological studies, genome-wide association studies, and Mendelian randomization studies have shown a strong association between increased levels of lipoproteins and increased risks of coronary heart disease and cardiovascular disease (CVD). Although lipoprotein(a) [Lp(a)] was an independent risk factor for ASCVD, the latest international clinical guidelines do not recommend direct reduction of plasma Lp(a) concentrations. The main reason was that there is no effective clinical medicine that directly lowers plasma Lp(a) concentrations. However, recent clinical trials have shown that proprotein convertase subtilisin/kexin-type 9 inhibitors (PCSK9) and second-generation antisense oligonucleotides can effectively reduce plasma Lp(a) levels. This review will present the structure, pathogenicity, prognostic evidences, and recent advances in therapeutic drugs for Lp(a).

Cardiac Phenotype-Genotype Associations in DMD/BMD: A Meta-Analysis and Systematic Review

Cardiac involvement of Duchenne and Becker muscular dystrophies (DMD/BMD) is the most common cause of fatal outcomes. It is still unclear whether some DMD/BMD gene mutations might be predictive of cardiac involvement. In this study, we provide a comprehensive overview on genotypes of cardiac disease in DMD/BMD. We systematically searched the PubMed/Medline, EMBASE and Cochrane electronic databases. Search results were filtered to include only human studies, English language and all dates up to August 2019. We summarized and extensively reviewed all studies that passed the selection criteria and performed a meta-analysis on key genotype parameters of cardiac disease in DMD/BMD. Of 3450 articles scanned, we included 18 studies from 9 regions in the meta-analysis. The pooled studies included 2661 DMD/BMD patients and 1324 DMD/BMD patients with cardiac disease. The most common mutation type was exon deletion, with a pooled frequency of 90% (P < 0.01). In DMD/BMD patients with cardiac dysfunction, a higher frequency of involvement of exons 45 and 46 was found in DMD/BMD patients with cardiac dysfunction. This might be predictive of cardiac involvement in patients with DMD/BMD.

Elevated Lipoprotein A in South Asians and the Associated Risk of Cardiovascular Disease: A Systematic Review

BACKGROUND

South Asians have a premature risk of cardiovascular disease and increased lipoprotein A which enhances their risk.

METHODS

This systematic review evaluates the role of elevated lipoprotein A in cardiovascular disease risk for South Asians. It discusses the pathophysiology, clinical studies, and treatment of elevated lipoprotein A using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses method.

RESULTS

A total of 72 articles was incorporated which consisted of clinical studies, case-control and cohort studies, meta-analysis, reviews, and editorials. Cardiovascular disease and myocardial infarction occurs prematurely in South Asians, which is further enhanced with an elevated lipoprotein A.

CONCLUSIONS

South Asians with an elevated lipoprotein A have an increased risk of coronary artery disease so they should have early enactment of lifestyle modification and aggressive medical management.

Serum Lipoprotein (a) levels in acute coronary syndrome; Comparison of younger and elderly patients with healthy controls

Objective:

To compare and see the association of serum Lipoprotein (a) levels in younger and older patients suffering from acute coronary syndrome compared to healthy controls

Methods:

This case control study was conducted in department of cardiology, King Edward Medical University, Lahore from January to December 2015. Total 180 subjects (90 cases and 90 healthy controls, subdivided in 45 young and old in each group ≤/>45 years of age) were included in the study by non-probability purposive sampling. Patients presenting with acute coronary event and angiographically proven coronary vascular disease were considered cases while those with normal coronaries served as controls. Lp(a) was measured after ten hours fasting. Lp(a) >30 nmol/l) were considered as high. Data were entered and analyzed in SPSS 17. Independent sample t-test was used to compare the mean lipoprotein (a) in cases and controls.

Results:

The mean age of cases and controls was 48.02 ± 10.90 & 45.89±10.09 years respectively. Lipid profile was similar in both cases and controls except triglycerides that were higher in controls (p=0.024). The mean lipoprotein (a) in cases was 47.03 ± 45.47 and in controls was 29.69±23.10 (p-value 0.001). Mean Lp(a) level was significantly high in cases vs controls in young subjects, (50.15±55.62 vs 25.75±15.84, p= 0.006), while in old ones, difference was not statistically significant (43.92±32.69 vs 33.64±28.22, p= 0.114). The frequency of desirable, borderline high, high, and very high Lp(a) levels in cases was 23(25.6%), 12(13.3%), 27(30.0%) and 28(31.1%), while in controls, it was 26(28.9%), 31(34.4%), 17(18.9%) and 16(17.8%), (p-value 0.003). Chi-Square test showed significant association of high Lp(a) with coronary artery disease in younger cases vs controls (P=0.004) with OR 3.65 but not in older (p-value 0.358).

Conclusion:

Serum lipoprotein(a) is strongly associated with coronary vascular disease especially in patients younger than 45 years of age despite comparable LDL and HDL between cases and controls, making Lp(a) likely independent risk factor for coronary vascular disease.

Prognostic value of lipoprotein (a) level in patients with coronary artery disease: a meta-analysis

Background

Elevated lipoprotein (a) is recognized as a risk factor for incident cardiovascular events in the general population and established cardiovascular disease patients. However, there are conflicting findings on the prognostic utility of elevated lipoprotein (a) level in patients with coronary artery disease (CAD).Thus, we performed a meta-analysis to evaluate the prognostic value of elevated lipoprotein (a) level in CAD patients.

Methods and results

A systematic literature search of PubMed and Embase databases was conducted until April 16, 2019. Observational studies reporting the prognostic value of elevated lipoprotein (a) level for cardiac events (cardiac death and acute coronary syndrome), cardiovascular events (death, stroke, acute coronary syndrome or coronary revascularisation), cardiovascular death, and all-cause mortality in CAD patients were included. Pooled multivariable adjusted risk ratio (RR) and 95% confidence interval (CI) for the highest vs. the lowest lipoprotein (a) level were utilized to calculate the prognostic value. Seventeen studies enrolling 283,328 patients were identified. Meta-analysis indicated that elevated lipoprotein (a) level was independently associated with an increased risk of cardiac events (RR 1.78; 95% CI 1.31–2.42) and cardiovascular events (RR 1.29; 95% CI 1.17–1.42) in CAD patients. However, elevated lipoprotein (a) level was not significantly associated with an increased risk of cardiovascular mortality (RR 1.43; 95% CI 0.94–2.18) and all-cause mortality (RR 1.35; 95% CI 0.93–1.95).

Conclusions

Elevated lipoprotein (a) level is an independent predictor of cardiac and cardiovascular events in CAD patients. Measurement of lipoprotein (a) level has potential to improve the risk stratification among patients with CAD.

Electronic supplementary material

The online version of this article (10.1186/s12944-019-1092-6) contains supplementary material, which is available to authorized users.

Impact of Lipoprotein(a) on Long-term Outcomes in Patients With Diabetes Mellitus Who Underwent Percutaneous Coronary Intervention

Patients with diabetes mellitus (DM) are at twofold to fourfold higher cardiovascular risk than those without DM. Serum levels of lipoprotein(a) (Lp(a)) can be risk factors for adverse events. However, the clinical implications of Lp(a) in patients with DM who underwent percutaneous coronary intervention (PCI) is unknown. The aim of the study was to determine the role of Lp(a) in patients with DM who underwent PCI. A total of 3,508 patients were treated by PCI from 1997 to 2011 at our institution. Among them, we analyzed consecutive 1,546 patients with DM. Eligible 1,136 patients were divided into 2 groups (high Lp(a) [n = 575] and low Lp(a) [n = 561]) by the median of Lp(a) levels. The number of chronic kidney disease, multivessel disease, and the level of LDL-C were higher in the group with high Lp(a) than with low Lp(a). The median follow-up period was 4.7 years. Event rate of all-cause death was same between the 2 groups (p = 0.37). However, cumulative incidence of cardiac death and acute coronary syndrome was significantly higher in the high Lp(a) than in the low Lp(a) group (p = 0.03). Multivariable analysis selected a high Lp(a) level as an independent predictor of cardiac death and acute coronary syndrome (hazard ratio 1.20; 95% confidence interval 1.00 to 1.42; p = 0.04). In conclusion, a high Lp(a) value could be associated with advanced cardiac events after PCI for patients with DM.

Elevated lipoprotein(a) levels predict cardiovascular disease in type 2 diabetes mellitus: a 10-year prospective cohort study

BACKGROUND/AIMS

Elevated lipoprotein(a) (Lp[a]) level is known to be a risk factor for cardiovascular disease (CVD). However, the data that has been reported on the association between the Lp(a) level and CVD in type 2 diabetes has been limited and incoherent. The aim of this study was to investigate the relationship between the Lp(a) concentration and new onset CVD in type 2 diabetes.

METHODS

From March 2003 to December 2004, patients with type 2 diabetes without a prior history of CVD were consecutively enrolled. CVD was defined as the occurrence of coronary artery disease or ischemic stroke. Cox proportional hazards models were used to identify the associations between the Lp(a) and CVD after adjusting for confounding variables.

RESULTS

Of the 1,183 patients who were enrolled, 833 participants were evaluated with a median follow-up time of 11.1 years. A total of 202 participants were diagnosed with CVD (24.2%). The median Lp(a) level for 1st and 4th quartile group was 5.4 (3.5 to 7.1) and 55.7 mg/dL (43.1 to 75.3). Compared with patients without CVD, those with CVD were older, had a longer duration of diabetes and hypertension, and used more insulin and angiotensin converting enzyme inhibitors/angiotensin receptor blockers at baseline. A Cox hazard regression analysis revealed that the development of CVD was significantly associated with serum Lp(a) level (hazard ratio, 1.92; 95% confidence interval [CI], 1.26 to 2.92; p < 0.001, comparing the 4th vs. 1st quartile of Lp[a]).

CONCLUSIONS

Elevated Lp(a) level was an independent predictable risk factor for CVD in type 2 diabetes. Other cardiovascular risk factors should be treated more intensively in type 2 diabetic patients with high Lp(a) levels.

Prognostic Value of Elevated Homocysteine Levels in Korean Patients with Coronary Artery Disease: A Propensity Score Matched Analysis

BACKGROUND AND OBJECTIVES

We sought to determine whether an elevated homocysteine (Hcy) level is associated with a worse prognosis in Korean patients with coronary artery disease (CAD).

SUBJECTS AND METHODS

A total of 5839 patients (60.4% male, mean age 61.3±11.2 years) with CAD were enrolled from 2000 to 2010 at Gangnam Severance Hospital. CAD was diagnosed by invasive coronary angiography. Laboratory values including Hcy level were obtained on the day of coronary angiography and analyses were performed shortly after sampling. Patients were divided into two groups according to their Hcy levels. Baseline risk factors, coronary angiographic findings, length of follow-up, and composite endpoints including cardiac death (CD) and non-fatal myocardial infarction (NFMI) were recorded. 1:1 propensity score matched analysis was also performed.

RESULTS

Over a mean follow-up period of 4.4±2.5 years, there were 132 composite endpoints (75 CD and 57 NFMI) with an event rate of 2.3%. Mean Hcy level was 9.9±4.3 µmol/L (normal Hcy 7.9±1.5 µmol/L and elevated Hcy 13.9±5.1 µmol/L). Kaplan-Meier survival analysis showed an association of elevated Hcy level with worse prognosis (p<0.0001). In addition, a multivariate Cox regression analysis showed an association of elevated Hcy level with worse prognosis for both the entire cohort (hazard ratio [HR] 2.077, 95% confidence interval [CI] 1.467-2.941, p<0.0001) and the propensity score matched cohort (HR 1.982, 95% CI 1.305-3.009, p=0.001).

CONCLUSION

Elevated Hcy level is associated with worse outcomes in Korean patients with CAD.

Plasma lipoprotein(a) predicts major cardiovascular events in patients with chronic kidney disease who undergo percutaneous coronary intervention

BACKGROUND

Chronic kidney disease (CKD) is associated with increased risk for cardiovascular disease. The predictive power of traditional risk factors for cardiovascular disease is diminished in patients with CKD. The serum level of lipoprotein(a) [Lp(a)] can be a risk factor for adverse events, but the clinical implications of Lp(a) in patients with CKD who have been treated by percutaneous coronary intervention (PCI) remain uncertain. We aimed to determine the role of Lp(a) on long-term outcomes in patients with CKD after PCI.

METHODS

We analyzed data from 904 patients with CKD among 3508 patients who underwent a first PCI between 1997 and 2011 at our institution. We divided patients into 2 groups [high (n=454) or low (n=450)] according to median levels of Lp(a). The primary outcome was a composite of all-cause death and acute coronary syndrome (ACS).

RESULTS

The baseline characteristics of the groups were similar and the median follow-up period was 4.7 years. Cumulative event-free survival was significantly worse for the group with high, than low Lp(a) (P=0.01). Multivariable analysis indicated a high Lp(a) level as an independent predictor of primary outcomes (hazard ratio, 1.35; 95% CI, 1.01-1.82; P=0.04).

CONCLUSIONS

A high Lp(a) value is associated with a poor prognosis after PCI for patients with CKD.

Endogenous Fibrinolysis: An Important Mediator of Thrombus Formation and Cardiovascular Risk

Most acute cardiovascular events are attributable to arterial thrombosis. Plaque rupture or erosion stimulates platelet activation, aggregation, and thrombosis, whilst simultaneously activating enzymatic processes that mediate endogenous fibrinolysis to physiologically maintain vessel patency. Interplay between these pathways determines clinical outcome. If proaggregatory factors predominate, the thrombus may propagate, leading to vessel occlusion. However, if balanced by a healthy fibrinolytic system, thrombosis may not occur or cause lasting occlusion. Despite abundant evidence for the fibrinolytic system regulating thrombosis, it has been overlooked compared with platelet reactivity, partly due to a lack of techniques to measure it. We evaluate evidence for endogenous fibrinolysis in arterial thrombosis and review techniques to assess it, including biomarkers and global assays, such as thromboelastography and the Global Thrombosis Test. Global assays, simultaneously assessing proaggregatory and fibrinolytic pathways, could play a role in risk stratification and in identifying impaired fibrinolysis as a potential target for pharmacological modulation.

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.

Lipoprotein(a) is associated with necrotic core progression of non-culprit coronary lesions in statin-treated patients with angina pectoris

Background

Statin therapy results in regression and stabilization of coronary artery plaques, and reduces the incidence of coronary artery disease. However, statin therapy does not effectively halt the accumulation of necrotic core in all patients. The purpose of the present study was to identify the predictors associated with necrotic core progression during statin therapy.

Methods

Coronary atherosclerosis in non-culprit lesions was evaluated using virtual histology intravascular ultrasound at baseline and 8 months after statin therapy. One hundred nineteen patients were divided into 2 groups based on necrotic core progression or regression during an 8-month follow-up period.

Results

Patients with necrotic core progression had higher serum lipoprotein(a) [Lp(a)] levels than patients with regression at baseline (16 mg/dL vs. 12 mg/dL, p = 0.02) and at the 8-month follow-up (17 mg/dL vs. 10 mg/dL, p = 0.006). Patients with necrotic core progression had a higher fibro-fatty plaque volume (1.28 mm³/mm vs. 0.73 mm³/mm, p = 0.002), and less necrotic core (0.56 mm³/mm vs. 1.04 mm³/mm, p < 0.0001) and dense calcium (0.35 mm³/mm vs. 0.56 mm³/mm, p = 0.006) plaque volumes at baseline than patients with regression. Multivariate logistic regression analysis showed that Lp(a) was a significant independent predictor associated with necrotic core progression during statin therapy (odds ratio [OR]: 3.514; 95% confidence interval [CI]: 1.338-9.228; p = 0.01).

Conclusions

Serum Lp(a) is independently associated with necrotic core progression in statin-treated patients with angina pectoris.