Background: Small dense LDL-cholesterol is an established risk factor for atherosclerosis but is not routinely measured in daily practice. The association between small dense LDL-cholesterol and triglyceride, which in turn is routinely measured, in patients with acute coronary syndrome remains unknown. Methods: Consecutive patients with acute coronary syndrome who were admitted to our institute were prospectively included, and serum samples were obtained on admission. The association between small dense LDL-cholesterol and triglyceride was investigated. Results: Among 55 patients (median 71 years old, 64% men), median (interquartile range) small dense LDL-cholesterol was 23.6 (17.0, 36.0) and triglyceride was 101 (60, 134) mg/dL. Triglyceride level correlated with small dense LDL-cholesterol (r = 0.67, p < 0.001) and was an independent determinant of small dense LDL-cholesterol together with body mass index (p = 0.010 and p = 0.008, respectively). Those with high triglyceride and high body mass index had a 3-fold level of small dense LDL-cholesterol compared with those with low triglyceride and low body mass index (45.8 [35.0, 54.0] mg/dL versus 15.0 [11.6, 23.7] mg/dL, p = 0.001). Conclusions: Triglyceride level was a major determinant of small dense LDL-cholesterol in patients with acute coronary syndrome. Triglyceride level might be a useful and practical biomarker for risk stratification for patients with acute coronary syndrome together with body mass index.

Triglyceride and Small Dense LDL-Cholesterol in Patients with Acute Coronary Syndrome.

Title of the article: Analysis and correlation of small dense low-density lipoprotein-cholesterol (sdLDL-C) with various lipoproteins and cardiac markers in acute coronary syndrome patients associated with normal Low-density lipoprotein-cholesterol (LDL-C) level: A cross-sectional study. Aim: To analyze the levels of sdLDL cholesterol in acute coronary syndrome patients (ACS) with normal LDL cholesterol (LDL-C) and correlate with various lipoproteins and cardiac markers. Methodology: The present study included 100 patients diagnosed with ACS with normal LDL-C. Demographic details and cardiac markers were correlated with sdLDL levels. A detailed history was elicited from the patients and the details of clinical examination and laboratory findings such as cardiac Troponin, C- reactive protein, and CK-MB were obtained from patient case files. Results: The results are expressed in mean±sd. The mean age of study participants was 39.5±10.5yrs. The majority of the participants were men (69%) between the age group of 31-40 years. Mean values of total cholesterol, VLDL, sdLDL, Trop-I, CRP, and CKMB are at higher levels in men when compared to women. Whereas, mean values of triglycerides, LDL, and HDL are higher in women when compared to men. The majority of participants were having unstable angina (42%) followed by STEMI (33%) and NSTEMI (25%). Correlation between sdLDL and other parameters was carried out using Mann–Whitney–Wilcoxon test. The result showed a statistically significant correlation between sdLDL and VLDL, Trop-I, and CRP with p <0.05. Patients with sdLDL of > 25mg/dl had a higher incidence of unstable angina and STEMI. Conclusion: Our study result suggests that ACS with normolipidemic patients has a positive correlation with sdLDL levels and sdLDL can be a new diagnostic marker along with cardiac troponins in ACS.

Analysis and correlation of small dense low-density lipoprotein-cholesterol (sdLDL-C) with various lipoproteins and cardiac markers in acute coronary syndrome patients associated with normal Low-density lipoprotein-cholesterol (LDL-C) level: A cross sectional study.

Atherogenesis is a highly complex and silent condition that develops over years. In the past, it was thought that only the accumulation of lipids in the tunica intima was involved in this process. However, today it is also known that a series of environmental, inflammatory, immunological, and genetic factors are strongly implicated in its pathophysiology. One of the main triggers of atherosclerotic cardiovascular disease (ASCVD) is lifetime exposure to high cholesterol levels, especially low-density lipoprotein cholesterol (LDL-C). This, in turn, accumulated in the subendothelial space, becomes susceptible to changes, such as oxidation, giving rise to endothelial dysfunction, a wide cascade of pro-inflammatory processes and atherosclerotic plaque formation. Finally, there may be luminal narrowing, thrombus formation, and ischemia. This chapter reviews the importance of lipoproteins in atherogenesis and discusses some of the major molecular mechanisms involved in the pathophysiology of ASCVD. 

Blood lipids and molecular pathways of atherogenesis

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Prognostic Implication of Small Dense LDL-Cholesterol Levels following Acute Coronary Syndrome

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.

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

Residual risk remained significant despite effective low density lipoprotein cholesterol (LDL-C) lowering treatment. Small dense low density lipoprotein cholesterol (sdLDL-C) as part of LDL-C has been found to be predictor of coronary heart disease (CHD) and cardiovascular (CV) events in patients with stable CHD independently of LDL-C. However, to date, few studies have explored the role of sdLDL-C in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI). Accordingly, this study aimed to evaluate the association of sdLDL-C with CV events in patients with ACS undergoing PCI. Patients hospitalized with ACS undergoing PCI were enrolled and followed up for 18 months. The risk of sdLDL-C for CV events was compared according to sdLDL-C quartiles. The primary outcome was major cardiovascular and cerebrovascular adverse events (MACCE), which was the composite of all cause of death, nonfatal myocardial infarction (MI), nonfatal stroke or unplanned repeat revascularization. A Cox proportional hazards regression model was performed to estimate the risk of CV events. Subgroup analysis according to diabetes status and LDL-C were performed separately for MACCE. A total of 6092 patients were included in the analysis (age: 60.2 ± 10.13 years, male: 75.3%, BMI: 25.9 ± 3.33 kg/m2, dyslipidemia: 74.1% and diabetes: 44.5%). During 18 months of follow-up, 320 (5.2%) incident CV events occurred. Compared to the lowest sdLDL-C quartile group, patients in the highest quartile had a greater risk of CV events after multivariable adjustment (HR 1.92; 95% CI 1.37–2.70). In addition, it was mainly due to the increase of unplanned repeat revascularization. In the subgroup analyses, significant association was observed regardless of level of LDL-C and diabetes status. Patients with elevated sdLDL-C have a higher risk of CV events in Chinese patients with ACS undergoing PCI, providing additional value for better risk assessment.

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Relationship between small dense low density lipoprotein and cardiovascular events in patients with acute coronary syndrome undergoing percutaneous coronary intervention

Lingjie He

Papers

Relationship between small dense low density lipoprotein and cardiovascular events in patients with acute coronary syndrome undergoing percutaneous coronary intervention