Association between baseline LDL-C and prognosis among patients with coronary artery disease and advanced kidney disease

Elevated low-density lipoprotein cholesterol: An inverse marker of morbidity and mortality in patients with myocardial infarction

BACKGROUND

The incidence of atherosclerotic cardiovascular disease increases with levels of low-density lipoprotein cholesterol (LDL-C). Yet, a paradox may exist where lower LDL-C levels at myocardial infarction (MI) are associated with poorer prognoses.

OBJECTIVE

To assess the association between LDL-C levels at MI with risk factor burden and cause-specific outcomes.

METHODS

Statin-naive patients hospitalized for a first MI and registered in SWEDEHEART were included. Data were linked to Swedish registers. Primary outcomes were all-cause mortality and nonfatal MI. Associations between LDL-C and outcomes were assessed using adjusted proportional hazards models.

RESULTS

Among 63,168 patients (median age, 66 years), the median LDL-C level was 3.0 mmol/L (interquartile range 2.4-3.6). Patient age and comorbidities increased as LDL-C decreased. During a median follow-up of 4.5 years, 10,236 patients died, and 4973 had nonfatal MI. Patients with the highest LDL-C had a lower risk of mortality (hazard ratio [HR] 0.75; 95% confidence interval [CI] 0.71-0.80). The risk of hospitalization for pneumonia, hip fracture, chronic obstructive pulmonary disease, and new cancer diagnosis was lower with higher LDL-C (HR range, 0.40-0.81). Patients with the highest LDL-C had a greater risk of recurrent MI (HR 1.16; 95% CI 1.07-1.26).

CONCLUSIONS

Patients with the highest LDL-C levels at MI had the lowest incidence of mortality and morbidity. This seems to reflect lower age at MI, less underlying morbidities, paired with the modifiability of LDL-C. However, supporting the causal association between LDL-C and ischemic heart disease, elevated LDL-C was simultaneously associated with an increased risk of nonfatal MI.

A realistic approach to evaluating the effect of baseline lipid profile in postcoronary artery bypass grafting surgery

BACKGROUND

There are still many uncertainties in the association between lipid profile and postcoronary artery bypass grafting (CABG) outcomes. Although simplifying the association to linear equations makes it understandable but cannot explain many findings.

HYPOTHESIS

There is a nonlinear associatin between lipid profile indices and adverse outcomes after CABG.

METHODS

A total of 17 555 patients who underwent isolated CABG between 2005 and 2016 were evaluated. During the median follow-up of 75.24 months, the Restricted Cubic Splines (RCS) estimated from the Cox regression model adjusted for all possible confounders was applied to show a nonlinear relationship of lipid profile contents with the "ln hazard ratio" of mortality and major cerebro-cardiac events (MACCE).

RESULTS

The relationship between LDL-C and HDL-C with all-cause mortality was nonlinear (nonlinear p were .004 and <.001, respectively). The relationship between remnant cholesterol and all-cause mortality was linear (linearity p = .023). Among men, those in the highest LDL-C level (Q4, LDL-C > 114) and those in the lowest HDL-C level (Q1, HDL-C < 30) showed a significantly higher risk of all-cause mortality compared to other groups (compared with Q3, LDL-C Q4, HR = 1.16, 95% confidence interval [CI]:1.02-1.26, p = .014; HDL-C Q1, HR = 1.14, 95% CI: 1.01-1.31, p = .041). Female patients in the lowest HDL-C level (Q1, HDL-C < 30) showed a significantly higher (compared with Q3, HR = 1.14, 95% CI:1.01-1.31, p = .028) and those in the highest HDL-C level (Q4, HDL-C > 43) showed a significantly lower (compared with Q3, HR = 0.74, 95% CI:0.58-0.98, p = .019) risk of all-cause mortality.

CONCLUSION

Determining a universal cut off for components of lipid profile may be misleading and should better be revised. Extreme values (very low or very high) for HDL-C and LDL-C have different effects on cardiovascular outcomes.

Lipid-Lowering Treatment and the Lipid Goals Attainment in Patients with a Very High Cardiovascular Risk

Hypercholesterolemia is the main cardiovascular (CV) risk factor with a large body of evidence. Our aim was to assess the achievement of the main therapeutic goal of Low-Density Lipoprotein Cholesterol (LDL-C) in patients with a very high CV risk and a high-dose statin therapy. The study group consisted of 1413 consecutive patients hospitalised at the Upper-Silesian Medical Centre in Katowice due to acute myocardial infarction (AMI) treated with atorvastatin ≥ 40 mg or rosuvastatin ≥ 20 mg. The lipid profile was performed on admission and within 12 months after AMI. The main therapeutic goal was defined as LDL-C < 55 mg%. The study group (n = 1413) included 979 males (69.3%) with arterial hypertension (83.3%), diabetes (33.5%), peripheral artery disease (13.6%) and nicotinism (46.2%). In the study group, only 61 patients (4.3%) were additionally taking ezetimibe. During hospitalisation, the primary LDL-C goal was found in only 186 patients (13.2%). Subsequently, a follow-up lipidogram within 12 months was performed in 652 patients (46%), and the therapeutic goal was achieved in 255 patients (39%). There were 258 (18.26%) patients who died within 12 months after myocardial infarction. The lowest mortality rate was found in the subgroup of patients with LDL-C < 55 mg% during follow-up (11.02%). The primary lipid goal attainment among patients with a high-dose statin and a very high CV risk is low and far from the expected rate. Patients hospitalised for AMI should be given a combination of statin and ezetimibe more frequently. Low LDL-C levels measured at follow-up predict a lower risk of death at 12-month follow-up in a large group of patients.

The prognostic role of the low and very low baseline LDL-C level in outcomes of patients with cardiac revascularization; comparative registry-based cohort design

BACKGROUND

Although low-density lipoprotein-cholesterol (LDL-C) level is considered one of the main prognostic factors in patients with coronary artery bypass grafting (CABG), the question about "the lower the better" is still unanswered. We aimed to evaluate and compare the outcomes of patients with CABG and low or very low baseline LDL-C, regardless of statin usage.

METHODS

In this registry-based cohort study, 10,218 patients with low/very low (70-100 and ≤ 70 mg/dL) baseline LDL-C who underwent isolated and the first-time CABG without known previous history of cardio-cerebrovascular events, were included and compared. The median follow-up was 73.33 (72.15-74.51) months. Primary outcomes were all-cause mortality and major adverse cardio-cerebrovascular events (MACCE) (consisted of all-cause mortality, acute coronary syndrome, stroke or transient ischemic attack, and the need for repeat revascularization [percutaneous coronary intervention or redo-CABG]). Cox regression analyses before and after the propensity score matching (PSM) model were applied to evaluate and compare outcomes.

RESULTS

The mean age of the study population was 66.17 ± 9.98 years old and 2506 (24.5%) were women. Diabetes mellitus and a history of cigarette smoking were significantly higher in the very low LDL group (P-value ≤ 0.001). In Cox regression analyses before applying PSM model, both all-cause mortality (14.2% vs. 11.9%, P-value = 0.004 and MACCE (26.0% vs. 23.6%, P-value = 0.006) were significantly higher in the very low LDL group compared to low LDL. However, these results were no longer significant after applying the PSM model (all-cause mortality HR: 1.115 [95% CI: 0.986-1.262], P = 0.083 and MACCE HR: 1.077 [95%CI: 0.984-1.177], P = 0.095). The sensitivity analysis to remove the statin effect demonstrated that very low LDL-C level was correlated to higher risk of all-cause mortality in both unmatched and PSM analyses.

CONCLUSION

Very low serum LDL-C levels (≤ 70 mg/dl) could increase long-term all-cause mortality and cardiovascular events in patients who have undergone isolated CABG.

Novel oxidized LDL-based clinical markers in peritoneal dialysis patients for atherosclerosis risk assessment

Maintenance peritoneal dialysis (PD) is commonly associated with cardiovascular diseases (CVDs), whose risk is assessed via LDL-C. Nonetheless, oxidized LDL (oxLDL), as being a key component of atherosclerotic lesions, could be also associated with atherosclerosis and related CVDs. However, its predictive value for CVDs risk assessment is subject of research studies due to the lack of specific methods to measure oxLDL status from its individual lipid/protein components. In the present study, six novel oxLDL markers, representative of certain oxidative modifications on the LDL protein and lipid components, are measured in atherosclerosis-prone PD patients (39) versus those in chronic kidney disease patients (61) under hemodialysis (HD) and healthy controls (40). LDL from serum of PD, HD and control subjects were isolated and fractionated into cholesteryl esters, triglycerides, free cholesterol, phospholipids and apolipoprotein B100 (apoB100). Subsequently the oxLDL markers cholesteryl ester hydroperoxides (-OOH), triglyceride-OOH, free cholesterol-OOH, phospholipid-OOH, apoB100 malondialdehyde and apoB100 dityrosines were measured. LDL carotenoid levels and LDL particle serum concentration were also measured. The levels of all oxLDL lipid-OOH markers were significantly elevated in PD patients versus control, while the levels of cholesteryl ester-/triglyceride-/free cholesterol-OOH were significantly elevated in PD versus HD patients, regardless of patients' underlying medical conditions, sex, age, PD type, clinical biochemical markers and medication. It should be noted that all fractionated lipid-OOH levels were inversely correlated with LDL-P concentration, while LDL-P concentration was not correlated with LDL-C in PD patients. Moreover, LDL carotenoids were significantly lower in PD patients versus control. The increased levels of oxLDL status specific markers in both PD and HD patients (compared to control), support a potential prognostic value of oxLDL regarding CVD risk assessment in both patient groups. Lastly, the study introduces the oxLDL peroxidation markers free cholesterol-OOH and cholesteryl ester-OOH as complementary to LDL-P number, and as possible alternatives to LDL-C.

Low-density lipoprotein cholesterol to apolipoprotein B ratio predicts mortality and cardiovascular events in peritoneal dialysis patients

PURPOSE

The ratio of low-density lipoprotein cholesterol (LDL-C)/apolipoprotein B (apo B) is associated with all-cause mortality and cardiovascular events in chronic kidney disease patients. The aim of this study was to investigate the association between the LDL-C/apo B ratio (LAR) and all-cause mortality and cardiovascular events in peritoneal dialysis (PD) patients.

METHODS

A total of 1199 incident PD patients were enrolled from November 1, 2005 to August 31, 2019. The LAR was used to divide the patients into two groups by X-Tile software and restricted cubic splines using 1.04 as the cutoff. The incidence of all-cause mortality and cardiovascular events at follow-up was compared according to LAR.

RESULTS

Of the 1199 patients, 58.0% were men, the mean age was 49.3 ± 14.5 years, 225 patients had a history of diabetes, and 117 patients had prior cardiovascular disease. During the follow-up period, 326 patients died, and 178 patients experienced cardiovascular events. After full adjustment, a low LAR was significantly associated with HRs for all-cause mortality of 1.37 (95% CI 1.02-1.84, P = 0.034) and for cardiovascular events of 1.61 (95% CI 1.10-2.36, P = 0.014).

CONCLUSION

This study suggests that a low LAR is an independent risk factor for all-cause mortality and cardiovascular events in PD patients, indicating that the LAR may provide significant information when assessing all-cause mortality and cardiovascular risks.

Methods on LDL particle isolation, characterization, and component fractionation for the development of novel specific oxidized LDL status markers for atherosclerotic disease risk assessment

The present study uses simple, innovative methods to isolate, characterize and fractionate LDL in its main components for the study of specific oxidations on them that characterize oxidized low-density lipoprotein (oxLDL) status, as it causatively relates to atherosclerosis-associated cardiovascular disease (CVD) risk assessment. These methods are: (a) A simple, relatively time-short, low cost protocol for LDL isolation, to avoid shortcomings of the currently employed ultracentrifugation and affinity chromatography methodologies. (b) LDL purity verification by apoB100 SDS-PAGE analysis and by LDL particle size determination; the latter and its serum concentration are determined in the present study by a simple method more clinically feasible as marker of CVD risk assessment than nuclear magnetic resonance. (c) A protocol for LDL fractionation, for the first time, into its main protein/lipid components (apoB100, phospholipids, triglycerides, free cholesterol, and cholesteryl esters), as well as into LDL carotenoid/tocopherol content. (d) Protocols for the measurement, for the first time, of indicative specific LDL component oxidative modifications (cholesteryl ester-OOH, triglyceride-OOH, free cholesterol-OOH, phospholipid-OOH, apoB100-MDA, and apoB100-DiTyr) out of the many (known/unknown/under development) that collectively define oxLDL status, which contrasts with the current non-specific oxLDL status evaluation methods. The indicative oxLDL status markers, selected in the present study on the basis of expressing early oxidative stress-induced oxidative effects on LDL, are studied for the first time on patients with end stage kidney disease on maintenance hemodialysis, selected as an indicative model for atherosclerosis associated diseases. Isolating LDL and fractionating its protein and main lipid components, as well as its antioxidant arsenal comprised of carotenoids and tocopherols, paves the way for future studies to investigate all possible oxidative modifications responsible for turning LDL to oxLDL in association to their possible escaping from LDL's internal antioxidant defense. This can lead to studies to identify those oxidative modifications of oxLDL (after their artificial generation on LDL), which are recognized by macrophages and convert them to foam cells, known to be responsible for the formation of atherosclerotic plaques that lead to the various CVDs.

Effects of Serum LDL-C, CysC, and D-D in Patients with Coronary Atherosclerotic Heart Disease

Objective

To investigate the effects of low-density lipoprotein cholesterol (LDL-C) and serum cystatin C (CysC) combined with D-dimer (D-D) on patients with coronary atherosclerotic heart disease (CHD).

Methods

90 patients with CHD who were admitted to our hospital and diagnosed by coronary angiography (CAG) from February 2020 to June 2021 were selected as the study subjects. 90 patients were grouped according to different types and branches of coronary lesions, and 30 patients with outpatient health check-ups at the same period were selected as the control group, and the differences in serum LDL-C, CysC, and D-D levels between the groups were compared. The logistic regression model was built to explore risk factors affecting the occurrence of CHD. Also, receiver operating characteristic (ROC) curves were drawn to analyze the diagnostic value of LDL-C, CysC, and D-D in CHD.

Results

In the comparison of LDL-C, CysC, and D-D levels, CHD group > control group (P < 0.05); stable angina (SAP) group > unstable angina (UAP) group > acute myocardial infarction (AMI) group (P < 0.05); three-branch group > two-branch group > single-branch group (P < 0.05). The logistic regression model showed that high expression levels of LDL-C, CysC, and D-D, male gender, and combined hypertension were risk factors for CHD. The area under the curve (AUC) of the combination of LDL-C, CysC, and D-D was 0.868, and the sensitivity and specificity were 88.89% and 73.33%, respectively, which are higher than those in single diagnosis (P < 0.05).

Conclusions

LDL-C, CysC, and D-D are highly expressed in CHD samples, and the combination of the three is beneficial to enhance the diagnostic accuracy of clinical CHD.

C Deletion at the re74650330 Locus of the SLC39A8 Gene (rs74650330) Increases the Risk of Coronary Artery Disease in Individuals with Low-Density Lipoprotein Cholesterol Levels

Background: Genetic variants of the SLC39A8 gene are associated with several cardiovascular disease risk factors, including body mass index, systolic blood pressure (SBP), diastolic blood pressure (DBP), N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-density lipoprotein cholesterol (HDL-C) levels. The present study aimed to investigate the association between the SLC39A8 SNPs rs13107325 and rs74650330 and CAD in the Han population in Jiangsu (China). Methods: Genotyping of these SNPs was performed in 258 patients with CAD and 170 healthy controls using the base-quenched probe technique. The association between the alleles of the rs74650330 locus and blood lipid and glucose profiles was investigated. Receiver operating characteristic (ROC) curve analysis was used to quantify the optimal thresholds for lipid and FBG levels and the risk factors for CAD were estimated by logistic regression analysis. Results: The rs13107325 polymorphism was not found in the 428 Chinese individuals enrolled in the current study. For rs74650330, individuals harboring the C allele had significantly higher HDL levels than those without this allele in the control group (p = 0.039), while the opposite was true for low-density lipoprotein cholesterol (LDL-C) levels (p = 0.046). Further analysis indicated that when LDL-C levels were lower than 2.365 mmol/L, subjects with C/del and del/del had a 7.293-fold increased risk of CAD compared with that of controls without the mutation (odds ratio: 7.293; 95% confidence interval: 0.953-55.79). Conclusions: The susceptibility of SLC39A8 polymorphisms to CAD were studied and revealed a possible role for the deletion variant of rs74650330 in increasing the risk of CAD among the Chinese Han population.

Low density lipoprotein cholesterol and all-cause mortality rate: findings from a study on Japanese community-dwelling persons

Background

Low-density lipoprotein cholesterol (LDL-C) independently impacts aging-related health outcomes and plays a critical role in cardiovascular diseases (CVDs). However, there are limited predictive data on all-cause mortality, especially for the Japanese community population. In this study, it was examined whether LDL-C is related to survival prognosis based on 7 or 10 years of follow-up.

Methods

Participants included 1610 men (63 ± 14 years old) and 2074 women (65 ± 12 years old) who participated in the Nomura cohort study conducted in 2002 (first cohort) and 2014 (second cohort) and who continued throughout the follow-up periods (follow-up rates: 94.8 and 98.0%). Adjusted relative risk estimates were obtained for all-cause mortality using a basic resident register. The data were analyzed by a Cox regression with the time variable defined as the length between the age at the time of recruitment and that at the end of the study (the age of death or censoring), and risk factors including gender, age, body mass index (BMI), presence of diabetes, lipid levels, renal function, serum uric acid levels, blood pressure, and history of smoking, drinking, and CVD.

Results

Of the 3684 participants, 326 (8.8%) were confirmed to be deceased. Of these, 180 were men (11.2% of all men) and 146 were women (7.0% of all women). Lower LDL-C levels, gender (male), older age, BMI under 18.5 kg/m², and the presence of diabetes were significant predictors for all-cause mortality. Compared with individuals with LDL-C levels of 144 mg/dL or higher, the multivariable-adjusted Hazard ratio (and 95% confidence interval) for all-cause mortality was 2.54 (1.58–4.07) for those with LDL-C levels below 70 mg/dL, 1.71 (1.15–2.54) for those with LDL-C levels between 70 mg/dL and 92 mg/dL, and 1.21 (0.87–1.68) for those with LDL-C levels between 93 mg/dL and 143 mg/dL. This association was particularly significant among participants who were male (P for interaction = 0.039) and had CKD (P for interaction = 0.015).

Conclusions

There is an inverse relationship between LDL-C levels and the risk of all-cause mortality, and this association is statistically significant.