Small Dense Low-Density Lipoprotein Cholesterol and Cardiovascular Risk in Statin-Treated Patients with Coronary Artery Disease

Impact of Direct Measurement of Small Dense Low-Density Lipoprotein Cholesterol for Long-Term Secondary Prevention in Patients with Stable Coronary Artery Disease

BACKGROUND

This study investigated whether directly measured small dense low-density lipoprotein cholesterol (D-sdLDL-C) can predict long-term coronary artery disease (CAD) events compared with low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), apolipoprotein B (apoB), and estimated small dense low-density lipoprotein cholesterol (E-sdLDL-C) determined by the Sampson equation in patients with stable CAD.

METHODS

D-sdLDL-C measured at Showa University between 2010 and 2022, and E-sdLDL-C were evaluated in 790 male and 244 female patients with stable CAD. CAD events, defined as sudden cardiac death, onset of acute coronary syndrome, and/or need for coronary revascularization, were monitored for 12 years. Cutoff lipid levels were determined by receiver operating characteristic curves.

RESULTS

CAD events were observed in 238 male and 67 female patients. The Kaplan-Meier event-free survival curves showed that patients with D-sdLDL-C ≥32.1 mg/dL (0.83 mmol/L) had an increased risk for CAD events (P = 0.007), whereas risk in patients with E-sdLDL-C ≥36.2 mg/dL (0.94 mmol/L) was not increased. In the group with high D-sdLDL-C, the multivariable-adjusted hazard ratio (HR) was 1.47 (95% CI, 1.15-1.89), and it remained significant after adjustment for LDL-C, non-HDL-C, or apoB and in patients treated with statins. HRs for high LDL-C, non-HDL-C, or apoB were not statistically significant after adjustment for high D-sdLDL-C. Higher D-sdLDL-C was associated with enhanced risk of high LDL-C, non-HDL-C, and apoB (HR 1.73; 95% CI, 1.27-2.37).

CONCLUSIONS

Higher D-sdLDL-C can predict long-term recurrence of CAD in stable CAD patients independently of apoB and non-HDL-C. D-sdLDL-C is an independent risk enhancer for secondary CAD prevention, whereas E-sdLDL-C is not. UMIN-CTR Clinical Trial Number: UMIN000027504.

Role of Small Dense Low-density Lipoprotein Cholesterol in Cardiovascular Events in Patients with Coronary Artery Disease and Type 2 Diabetes Mellitus Receiving Statin Treatment

AIM

There is little information on the relationships of serum small dense low-density lipoprotein cholesterol (sdLDL-C) levels and serum triglyceride (TG) levels with cardiovascular events in patients with coronary artery disease (CAD) and type 2 diabetes mellitus (DM) who are receiving statins. The aim of this study was to evaluate the relationships of serum TG levels and sdLDL-C levels as residual risks for cardiovascular events in patients with CAD and type 2 DM who were being treated with statins.

METHODS

The subjects were divided into four groups based on TG levels and sdLDL-C levels: sdLDL-C of ＜40.0 mg/dL and TG of ＜150 mg/dL, sdLDL-C of ≥ 40.0 mg/dL and TG of ＜150 mg/dL, sdLDL-C of ＜40.0 mg/dL and TG of ≥ 150 mg/dL, and sdLDL-C of ≥ 40.0 mg/dL and TG of ≥ 150 mg/dL. During a median follow-up period of 1419 days, cardiovascular events occurred in 34 patients.

RESULTS

The incidences of cardiovascular events were significantly higher in patients with sdLDL-C of ≥ 40.0 mg/dL and TG of ＜150 mg/dL and in patients with sdLDL-C of ≥ 40.0 mg/dL and TG of ≥ 150 mg/dL, but not in patients with sdLDL-C of ＜40.0 mg/dL and TG of ≥ 150 mg/dL, than in patients with sdLDL-C of ＜40.0 mg/dL and TG of ＜150 mg/dL.

CONCLUSIONS

Under the condition of treatment with statins, patients with CAD and type 2 DM who had sdLDL-C levels of ≥ 40.0 mg/dL had a high risk for cardiovascular events even though serum TG levels were controlled at ＜150 mg/dL.

Estimated small dense low-density lipoprotein cholesterol and nonalcoholic fatty liver disease in nonobese populations

AIMS/INTRODUCTION

To explore the association between estimated small dense low-density lipoprotein cholesterol (sdLDL-C) and the risk of incident nonalcoholic fatty liver disease (NAFLD) in nonobese populations.

MATERIALS AND METHODS

This study included participants who underwent health checkups in 2014 and were followed up until 2019. We carried out Cox proportional hazards regression analyses to evaluate the association of estimated sdLDL-C with NAFLD. Discordance analyses were carried out to estimate the relative NAFLD risk in estimated sdLDL-C versus low-density lipoprotein cholesterol (LDL-C) discordant/concordant groups. Estimated sdLDL-C was calculated by equations based on LDL-C and triglycerides. The diagnosis of NAFLD was based on the presence of abdominal ultrasonography after excluding other causes of chronic liver disease.

RESULTS

Over a mean follow-up period of 26,694 person-years, 844 incident NAFLD cases were recorded. Compared with the first quartile of estimated sdLDL-C, the fourth quartile was associated with a 2.933-fold increased risk of NAFLD (95% confidence interval 2.095-4.107). With the increase in estimated sdLDL-C, the risk of NAFLD gradually increased both in participants within the normal range of LDL-C (hazard ratio 2.854, 95% confidence interval 1.650-5.617) and beyond the normal range of LDL-C (hazard ratio 2.636, 95% confidence interval 1.263-5.502). In addition, the inconsistent high estimated sdLDL-C/low LDL-C group was associated with an increased risk of NAFLD, but not the low estimated sdLDL-C/high LDL-C group.

CONCLUSIONS

Estimated sdLDL-C was positively associated with the risk of incident NAFLD in a nonobese population, independent of LDL-C.

Association between Intermediate-Density Lipoprotein Particles and the Progression of Carotid Atherosclerosis: A Community-Based Cohort Study

AIM

Experimental studies report that intermediate-density lipoprotein (IDL), the precursor of low-density lipoprotein, promotes atherosclerotic plaque formation. However, whether IDL is involved in the development of atherosclerosis in humans is still unclear. The aim of this community-based study is to examine the association between IDL particle (IDL-P) concentrations and the 5-year progression of carotid atherosclerosis.

METHODS

Baseline IDL-P concentrations were measured using nuclear magnetic resonance spectroscopy in 927 participants aged 45-74 years with no history of cardiovascular disease (CVD) at baseline. To estimate the association between baseline IDL-P concentrations and 5-year progression of carotid atherosclerosis, indicated by atherosclerotic plaque progression and changes in total plaque area (TPA), multivariable-adjusted regression was employed.

RESULTS

During the 5-year follow-up period, 45.8% of participants developed new plaques. Baseline IDL-P concentrations were significantly associated with the progression of carotid atherosclerosis. Participants in the highest quartile of IDL-P concentrations exhibited 1.36-fold (95% confidence interval [CI]: 1.09-1.68) increased progression of carotid plaque and 1.67-fold (95% CI: 1.04-2.69) higher TPA than those in the lowest quartile. These relationships were independent of baseline concentrations of low-density lipoprotein particles and very-low-density lipoprotein particles and their subclasses.

CONCLUSIONS

Elevated IDL-P concentrations were independently associated with the progression of carotid atherosclerosis, suggesting that IDL-P is a novel risk factor for the development of atherosclerosis.

Oxidative Stress, Atherogenic Dyslipidemia, and Cardiovascular Risk

Oxidative stress is the consequence of an overproduction of reactive oxygen species (ROS) that exceeds the antioxidant defense mechanisms. Increased levels of ROS contribute to the development of cardiovascular disorders through oxidative damage to macromolecules, particularly by oxidation of plasma lipoproteins. One of the most prominent features of atherogenic dyslipidemia is plasma accumulation of small dense LDL (sdLDL) particles, characterized by an increased susceptibility to oxidation. Indeed, a considerable and diverse body of evidence from animal models and epidemiological studies was generated supporting oxidative modification of sdLDL particles as the earliest event in atherogenesis. Lipid peroxidation of LDL particles results in the formation of various bioactive species that contribute to the atherosclerotic process through different pathophysiological mechanisms, including foam cell formation, direct detrimental effects, and receptor-mediated activation of pro-inflammatory signaling pathways. In this paper, we will discuss recent data on the pathophysiological role of oxidative stress and atherogenic dyslipidemia and their interplay in the development of atherosclerosis. In addition, a special focus will be placed on the clinical applicability of novel, promising biomarkers of these processes.

Differential prediction of high-sensitivity cardiac troponin-I, but not N-terminal pro-brain natriuretic peptide, in different pitavastatin doses on cardiovascular events in stable coronary artery disease

BACKGROUND

This study aimed to examine whether high-sensitivity cardiac troponin-I (hsTnI) and N-terminal pro-brain natriuretic peptide (NT-proBNP) could predict future major adverse cardiovascular events (MACE) in stable coronary artery disease (CAD) patients with high- or low-dose of pitavastatin.

METHODS

This was a case-cohort analysis of the REAL-CAD study, a randomized trial of high- or low-dose (4 or 1 mg/day) pitavastatin therapy in patients with stable CAD. We examined the MACE risk according to the quartile of hsTnI and NT-proBNP at baseline.

RESULTS

A total of 1336 and 1396 patients including 582 MACE cases were randomly examined into the hsTnI and NT-proBNP cohort, respectively. Both higher levels of hsTnI and NT-proBNP at baseline were significantly associated with increased risk of MACE (p < 0.001, respectively). When separately analyzed in statin dose, the higher marker levels were significantly associated with higher MACE risk in all cohorts (p < 0.001 in all cohorts). After multivariable adjustment, hsTnI levels were significantly associated with MACE risk in low-dose statin group (HR 2.54, p = 0.0001); however, in high-dose pitavastatin therapy, a significant association was diminished in MACE risk among the quartiles of baseline hsTnI levels (p = 0.154). Conversely in the NT-proBNP cohort, the association between NT-proBNP levels and MACE risk was constantly observed regardless of pitavastatin dose even after multivariable adjustment (both p < 0.0001).

CONCLUSIONS

Patients with high hsTnI levels had high risk of MACE in low-dose statin group, but not in high-dose, suggesting that high-dose statin treatment might decrease MACE risk in stable CAD patients with high hsTnI levels.

CYP2C19 metabolizer phenotypes may affect the efficacy of statins on lowering small dense low-density lipoprotein cholesterol of patients with coronary artery disease

Background

Dyslipidemia is a major cause of arteriosclerotic cardiovascular disease (ASCVD), and low-density lipoprotein cholesterol (LDL-C) is the profile to be reduced to prevent disease progression. Small dense low-density lipoprotein cholesterol (sdLDL-C) has been proven to be a more effective biomarker than LDL-C for ASCVD primary and secondary prevention. CYP2C19 is an important drug metabolism gene. This study aimed to investigate the relationship between sdLDL-C and coronary artery disease (CAD) risk factors and explore the influence of CYP2C19 metabolizer phenotypes on the sdLDL-C lowering efficacy of statins.

Methods

This study recruited 182 patients with CAD and 200 non-CAD controls. Baseline laboratory indices of fasting blood were detected, including blood lipids, glucose, and creatinine. In addition, LDL-C subfractions were separated and quantified. Gene polymorphisms of SLCO1B1 and CYP2C19 were detected in patients with CAD. The LDL-C subfractions levels of patients with CAD were followed up after statin drug treatment.

Results

Total cholesterol, LDL-C, LDLC-2, LDLC-3, LDLC-4, LDLC-5, LDLC-6, LDLC-7, and sdLDL-C levels of patients with CAD were significantly higher than those in non-CAD controls. Meanwhile, sdLDL-C (AUC = 0.838) and LDLC-4 (AUC = 0.835) performed outstandingly in distinguishing patients with CAD from controls. Based on CYP2C19 metabolizer phenotypes, 113 patients with CAD were divided into the extensive metabolizer (EM, n = 49), intermediate metabolizer (IM, n = 52), and poor metabolizer (PM, n = 12) groups. The patients with IM and PM metabolizer phenotypes had better sdLDL-C lowering efficacy after taking statin drugs than patients with EM phenotype (P = 0.0268, FDR = 0.0536). The SLCO1B1 genotype had no significant impact on the efficacy of statins (P = 0.1611, FDR = 0.1611).

Conclusion

sdLDL-C and LDLC-4 outperformed other blood lipids such as LDL-C for CAD risk screening. CYP2C19 metabolizer phenotypes had the potential to predict the efficacy of statins in lowering sdLDL-C.

Small dense low-density lipoprotein cholesterol compared to other lipoprotein biomarkers for predicting coronary heart disease among individuals with normal fasting glucose: The Multi-Ethnic Study of Atherosclerosis

Objective

This study compared small dense low-density lipoprotein cholesterol (sdLDL-C) with apolipoprotein B (apo B), and low-density lipoprotein particles (LDL-P) in predicting CHD risk in generally healthy adults with normal fasting glucose (NFG).

Methods

This study was conducted among participants with NFG in the Multi-Ethnic Study of Atherosclerosis (MESA) prospective cohort with measurements of sdLDL-C, LDL-P, and apo B available at baseline (2000-2002) and follow-up CHD data (through 2015) (N = 3,258). Biomarkers were evaluated as quartiles, and in categories using clinically and 75th percentile-defined cut-points. Discordance/concordance of sdLDL-C relative to other biomarkers was calculated using 75th percentile cut-points and linear regression residuals. Associations between individual biomarkers, sdLDL-C discordance and CHD incidence were evaluated using Cox proportional hazards regression.

Results

There were 241 incident CHD events in this population through 2015. Higher sdLDL-C, apo B, LDL-P were similarly associated with increased CHD in individuals with NFG. Discordance of sdLDL-C with apo B or LDL-P by 75th percentiles was not significantly associated with CHD. Residuals discordantly higher/lower sdLDL-C relative to apo B (discordant high HR=1.26, 95% CI: 0.89, 1.78; discordant low HR=0.94, 95% CI: 0.68, 1.29) and LDL-P (discordant high HR=1.25, 95% CI: 0.88, 1.75; discordant low HR=0.84, 95% CI:0.60, 1.16), compared to those with concordant measures, had non-statistically significant higher/lower risk of CHD.

Conclusions

Results suggest sdLDL-C, apo B and LDL-P are generally comparable for predicting CHD events in normoglycemic individuals. Larger studies are needed to confirm findings and to investigate whether measurement of sdLDL-C may be beneficial to evaluate as an additional risk-enhancing factor.

Lipid Profile and Small Dense Low-Density Lipoprotein in Acute Coronary Syndrome Patients: Relationships to Demographic, Clinical, Angiographic, and Therapeutic Variables

Background: Several lines of evidence have supported small dense low-density lipoproteins (sd-LDL) as a marker of cardiovascular disease. The present study assessed the relationship between lipid profile and sd-LDL levels with demographic, clinical, angiographic, and therapeutic variables in acute coronary syndrome (ACS) patients. Methods: This was a single-centre, prospective, cross-sectional study conducted from September 2014 to September 2015. Patients with a diagnosis of ACS were included in this study. High-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were determined by direct homogenous assay and sd-LDL levels were calculated using an earlier described equation by Srisawadi et al. Results: A total of 200 patients with a diagnosis of ACS were studied. Males constituted 78% of the population cohort and almost 45% of participants were aged <45 years. Patients aged ≤45 years displayed higher mean sd-LDL levels of 30.40 ± 14.18 mg/dL versus patients aged >45 years with mean sd-LDL levels of 28.01 ± 11.58 mg/dL, but the difference was not statistically significant (p = 0.19). Females also displayed higher mean sd-LDL levels, but the difference also failed to achieve statistical significance (30.95 ± 13.44 mg/dL and 28.54 ± 12.64, respectively; p = 0.185). Diabetics had higher mean sd-LDL levels (33.64 ± 13.01 mg/dL and 28.07 ± 12.60 mg/dL; p = 0.273) whilst smokers had lower mean levels (27.21 ± 12.12 mg/dL and 30.51 ± 13.21 mg/dL, respectively; p = 0.071). However, the ratio of sd-LDL/lb-LDL (large buoyant LDL) was significantly higher in diabetics (0.48 vs. 0.39; p = 0.023). In the angiography cohort (n = 88), single-vessel disease was the most predominant overall while among patients aged >45 years, triple-vessel disease was significantly higher (p = 0.005). Similarly, the sd-LDL levels were 33.12 ± 11.13 mg/dL, 27.68 ± 9.80 mg/dL, and 31.65 ± 15.26 mg/dL among patients with single, double, and triple-vessel disease and did not differ significantly (p = 0.262). Prior statin users had significantly lower mean sd-LDL levels of 24.79 ± 12.23 mg/dL compared to statin-naïve patients with a mean sd-LDL of 30.01 ± 12.79 mg/dL (p = 0.027). Non-HDL levels were also significantly lower in prior statin users (112.83 mg/dL vs. 128.9 mg/dL; p = 0.017). Conclusion: In this cohort of ACS patients, age, sex, diabetes, smoking, and the angiographic severity of coronary artery disease had no significant impact on sd-LDL levels, while prior statin usage led to significantly lower sd-LDL levels. Diabetic patients, however, did have significantly higher sd-LDL/lb-LDL ratios.

Familial Hypercholesterolemia and Its Current Diagnostics and Treatment Possibilities: A Literature Analysis

Familial hypercholesterolemia (FH) is a common, inherited disorder of cholesterol metabolism. This pathology is usually an autosomal dominant disorder and is caused by inherited mutations in the APOB, LDLR, and PCSK9 genes. Patients can have a homozygous or a heterozygous genotype, which determines the severity of the disease and the onset age of cardiovascular disease (CVD) manifestations. The incidence of heterozygous FH is 1: 200-250, whereas that of homozygous FH is 1: 100.000-160.000. Unfortunately, FH is often diagnosed too late and after the occurrence of a major coronary event. FH may be suspected in patients with elevated blood low-density lipoprotein cholesterol (LDL-C) levels. Moreover, there are other criteria that help to diagnose FH. For instance, the Dutch Lipid Clinical Criteria are a helpful diagnostic tool that is used to diagnose FH. FH often leads to the development of early cardiovascular disease and increases the risk of sudden cardiac death. Therefore, early diagnosis and treatment of this disease is very important. Statins, ezetimibe, bile acid sequestrants, niacin, PCSK9 inhibitors (evolocumab and alirocumab), small-interfering-RNA-based therapeutics (inclisiran), lomitapide, mipomersen, and LDL apheresis are several of the available treatment possibilities that lower LDL-C levels. It is important to say that the timeous lowering of LDL-C levels can reduce the risk of cardiovascular events and mortality in patients with FH. Therefore, it is essential to increase awareness of FH in order to reduce the burden of acute coronary syndrome (ACS).

Small dense low-density lipoprotein particles: clinically relevant?

PURPOSE OF REVIEW

Levels of small, dense low-density lipoprotein (LDL) (sdLDL) particles determined by several analytic procedures have been associated with risk of atherosclerotic cardiovascular disease (ASCVD). This review focuses on the clinical significance of sdLDL measurement.

RECENT FINDINGS

Results of multiple prospective studies have supported earlier evidence that higher levels of sdLDL are significantly associated with greater ASCVD risk, in many cases independent of other lipid and ASCVD risk factors as well as levels of larger LDL particles. A number of properties of sdLDL vs. larger LDL, including reduced LDL receptor affinity and prolonged plasma residence time as well as greater oxidative susceptibility and affinity for arterial proteoglycans, are consistent with their heightened atherogenic potential. Nevertheless, determination of the extent to which sdLDL can preferentially impact ASCVD risk compared with other apoprotein B-containing lipoproteins has been confounded by their metabolic interrelationships and statistical collinearity, as well as differences in analytic procedures and definitions of sdLDL.

SUMMARY

A growing body of data points to sdLDL concentration as a significant determinant of ASCVD risk. Although future studies should be aimed at determining the clinical benefit of reducing sdLDL levels, there is sufficient evidence to warrant consideration of sdLDL measurement in assessing and managing risk of cardiovascular disease.

VIDEO ABSTRACT

https://www.dropbox.com/s/lioohr2ead7yx2p/zoom_0.mp4?dl=0.