An Evidence-Based Guide to Cholesterol-Lowering Guidelines

Clinical Relevance of Nuclear Magnetic Resonance LipoProfile

Identifying risk factors for cardiovascular diseases in patients is key to reducing their resulting morbidity and mortality. Currently, risk factors are assessed using parameters that include and emphasize the role of the level of cholesterol carried by lipoproteins. Most providers focus on targeting cholesterol levels in patient management. However, recent research shows that lipoprotein particle number is more predictive of cardiovascular risk than cholesterol levels. The Nuclear Magnetic Resonance (NMR) LipoProfile test assesses the number of lipoprotein particles, sizes of lipoproteins, levels of cholesterol, and patient risk categories. Furthermore, it enables the identification of patients with underestimated cardiovascular risks-those with a discordant high number of low-density lipoprotein (LDL) particles (LDL-P) despite low cholesterol levels. While the NMR LipoProfile test requires a higher cost and longer waiting time for results in comparison to the lipid panel test, its advantages cannot be ignored. This review article focuses on exploring the routine use of NMR LipoProfile in clinical practice.

Current Perspectives on the Attainment of Lipid Modification Goals Relating to the Use of Statins and Ezetimibe for the Prevention of Cardiovascular Disease in the United Kingdom

Despite widespread evidence of the effectiveness of lipid modification for the reduction of cardiovascular disease (CVD) risk, lipid modification goals are commonly underachieved in the United Kingdom (UK). In order to understand current UK lipid management guidance and the corresponding attainment of recommended lipid lowering goals relating to treatment with statins and ezetimibe, a literature review was conducted using PubMed focusing on publications between January 2017 and February 2020 in order to capture the most up-to-date literature. Identified publications were reviewed against key clinical guidelines for lipid management in relation to CVD risk from the National Institute for Health and Care Excellence (NICE, CG181), the Scottish Intercollegiate Guidelines Network (SIGN, 149) and European Society of Cardiology (ESC)/European Atherosclerosis Society (EAS). Cholesterol lowering goals are central to current lipid lowering therapy guidance, although specific goals vary depending on the guideline and patients’ individual risk profile. Current guidance by NICE and SIGN specifies that treatment should achieve a greater than 40% reduction in non-high-density lipoprotein cholesterol (non-HDL-C) at 3 months of treatment, while the ESC/EAS place emphasis on the lowering of low-density lipoprotein (LDL-C) and total cholesterol. Yet, despite widespread availability of guidance and consistent messaging that lipid lowering goals should be ambitious, current evidence suggests a significant proportion of UK patients have sub-optimal reductions in cholesterol/non-HDL-C/LDL-C. The reasons for this are reported to be multifactorial, including a lack of compliance with guidelines, particularly regarding high-intensity statin prescribing, patient adherence, statin intolerance and statin reluctance as well as wider genetic factors. A number of possible strategies to improve current lipid management and attainment of lipid-lowering goals were identified, including improving the patient-healthcare professional partnership, conducting audits of local prescribing versus guidance, implementing plans for the refinement of current services and considering alternative options such as cost-effective single pill combinations for improving adherence.

Weight cycling is associated with adverse cardiometabolic markers in a cross-sectional representative US sample

BACKGROUND

Whether weight cycling (repeated weight loss and regain) is associated with cardiometabolic health is unclear. Study objective was to examine whether weight cycling since young adulthood (ie, 25 years of age) was associated with cardiometabolic markers.

METHODS

Data from a nationally representative cross-sectional US sample (National Health and Nutrition Examination Survey, 1999-2014) were used. Weight history was based on self-reported weight at age 25, 10 years prior and 1 year prior to the survey (n=4190, 51% male). Using current self-reported weight as the anchor, participants were classified as (1) stable weight, (2) weight losers, (3) weight gainers and (4) weight cyclers. Cardiometabolic markers included fasting lipids, insulin sensitivity and blood pressure. Multiple linear regressions were used to analyse weight history (reference: stable weight) and adjusted for covariates. Analyses incorporated the sampling design and survey weights and were stratified by sex or weight status.

RESULTS

Compared with females with stable weight, female weight cyclers had worse lipids and homeostasis model assessment for insulin resistance (HOMA-IR) (all ps<0.05). Compared with males with stable weight, male weight cyclers had worse high-density lipoprotein cholesterol (HDL) and HOMA-IR (ps<0.05). Weight cyclers with normal weight had worse HDL and low-density lipoprotein cholesterol (ps<0.05), and weight cyclers with overweight or obesity had worse HOMA-IR (p=0.05). Blood pressure was not associated.

CONCLUSION

Weight cycling is adversely associated with cardiometabolic markers but associations differ by sex and weight status. While weight cycling is consistently associated with worse cardiometabolic markers among females, results are mixed among males. Weight cycling is associated with worse lipid measures for normal weight persons, and marginally worse insulin sensitivity for those with overweight/obesity.

Targeted profiling of amino acid metabolome in serum by a liquid chromatography-mass spectrometry method: application to identify potential markers for diet-induced hyperlipidemia

To better understand the mechanism of hyperlipidemia and discover potential biomarkers, we have used targeted metabolomics to analyze eight amino acid profiles of control and hyperlipidemia rats by a liquid chromatography-mass spectrometry method. With high fat diet, the concentrations of serum of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C) and apolipoprotein B (ApoB) were increased by 666.7%, 99.0%, 61.7% and 51.0%, whereas the concentrations of high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (ApoA-I) were decreased by 46.3% and 58.9%. The concentrations of alanine, arginine, lysine, methionine, serine, tyrosine and valine in hyperlipidemia rats were significantly decreased by 21.8%, 19.72%, 26.5%, 19.6%, 48.7%, 19.8% and 24.91%, while there was no striking change in threonine. Combined with experimental results and previous literature, we inferred that alanine and serine were gradually disordered and subsequently generated abundant acetyl-CoA through pyruvate, which resulted in energy metabolism deficiency. Furthermore, Spearman correlation analysis shows that TC was negatively associated with methionine (r = -0.640, p < 0.05), suggesting that the lowered level of methionine caused by the homocysteine pathway enhances absorption and synthesis of TC. Meanwhile, the reduction of tyrosine demonstrated that rapid metabolism of cholesterol in vivo was caused by high levels of exogenous cholesterol. Furthermore, the observed ApoB and lysine changes indicated that lysine was largely incorporated into ApoB particles during the disease process. In addition, the levels of arginine, SOD and MDA reflected the behavior of oxidative stress. Finally, the metabolism fluctuation of valine demonstrated that abnormal lipid metabolism could cause abnormal glucose metabolism. In general, disordered energy metabolism, lipid metabolism, glucose metabolism and elevated oxidative stress were important characteristics of metabolic perturbations in hyperlipidemia. Herein, the discovery of biomarkers and the biological explanations mentioned above could be used to analyze the pathogenesis of hyperlipidemia through metabolic pathways, and these results could play an important role in assisting the clinical diagnosis of hyperlipidemia.

Low-density lipoprotein cholesterol goal attainment rates in high-risk patients with cardiovascular diseases and diabetes mellitus in Korea: a retrospective cohort study

BACKGROUND

Real-world evidence of low-density lipoprotein cholesterol (LDL-C) goal attainment rates for Asian patients is deficient. The objective of this study was to assess the status of dyslipidemia management, especially in high-risk patients with cardiovascular disease (CVD) including stroke and acute coronary syndrome (ACS).

METHODS

This was a retrospective cohort study of 514,866 subjects from the National Health Insurance Service-National Health Screening Cohort database in Korea. Participants were followed up from 2002 to 2015. Subjects with a high-risk of CVD prior to LDL-C measurement and subjects who were newly-diagnosed for high-risk of CVD following LDL-C measurement were defined as known high-risk patients (n = 224,837) and newly defined high-risk patients (n = 127,559), respectively. Data were analyzed by disease status: stroke, ACS, coronary heart disease (CHD), peripheral artery disease (PAD), diabetes mellitus (DM) and atherosclerotic artery disease (AAD).

RESULTS

Overall, less than 50% of patients in each disease category achieved LDL-C goals (LDL-C < 70 mg/dL in patients with stroke, ACS, CHD and PAD; and LDL-C < 100 mg/dL in patients with DM and AAD). Statin use was observed in relatively low proportions of subjects (21.5% [known high-risk], 34.4% [newly defined high-risk]). LDL-C goal attainment from 2009 to 2015 steadily increased but the goal-achiever proportion of newly defined high-risk patients with ACS remained reasonably constant (38.7% in 2009; 38.1% in 2015).

CONCLUSIONS

LDL-C goal attainment rates in high-risk patients with CVD and DM in Korea demonstrate unmet medical needs. Proactive management is necessary to bridge the gap between the recommendations of clinical guidelines and actual clinical practice.

HIV infection and coronary heart disease: mechanisms and management

Antiretroviral therapy has largely transformed HIV infection into a chronic disease condition. As such, physicians and other providers caring for individuals living with HIV infection need to be aware of the potential cardiovascular complications of HIV infection and the nuances of how HIV infection increases the risk of cardiovascular diseases, including acute myocardial infarction, stroke, peripheral artery disease, heart failure and sudden cardiac death, as well as how to select available therapies to reduce this risk. In this Review, we discuss the epidemiology and clinical features of cardiovascular disease, with a focus on coronary heart disease, in the setting of HIV infection, which includes a substantially increased risk of myocardial infarction even when the HIV infection is well controlled. We also discuss the mechanisms underlying HIV-associated atherosclerotic cardiovascular disease, such as the high rates of traditional cardiovascular risk factors in patients with HIV infection and HIV-related factors, including the use of antiretroviral therapy and chronic inflammation in the setting of effectively treated HIV infection. Finally, we highlight available therapeutic strategies, as well as approaches under investigation, to reduce the risk of cardiovascular disease and lower inflammation in patients with HIV infection.

Relation between baseline LDL-cholesterol and cardiovascular outcomes in high cardiovascular risk hypertensive patients: A post-hoc SPRINT data analysis

BACKGROUND

Patients at increased cardiovascular (CV) risk, noticeably hypertensive patients, have multiple CV risk factors which may be treatment targets. LDL-cholesterol is one of such targets. Using the SPRINT cohort, studying the cardiovascular outcomes of hypertensive patients at increased CV risk, this post-hoc study aimed to assess the association of LDL-C with CV outcomes.

METHODS

Clinical outcomes were those defined in SPRINT: a composite of various CV outcomes, all-cause mortality, and CV mortality. Association between LDL-C and the primary outcome was analyzed using survival regression adjusted on confounding factors (age, sex, body-mass index, active smoking status, eGFR-estimated kidney function, history of CV disease, Framingham risk score, SPRINT treatment arm (intensive or control), baseline high-density-lipoprotein-bound cholesterol, and co-treatments by aspirin and statins).

RESULTS

LDL-C was not associated with the primary outcome in the overall cohort (n = 9631). Among patients in secondary prevention (i.e. with a previous history of CV disease) (n = 1562), LDL-C was marginally associated with the incidence of the primary outcome (adjusted hazard-ratio 1.005 (95% CI = 1.002-1.009), p = 0.005 (per 1 mg/dl increase)) however, discrimination was poor with a ROC AUC of 0.54, p = 0.087. There was no association between LDL-C and the primary outcome in other subgroup analyses (those under statin or not, and those in primary prevention).

CONCLUSION

This post-hoc analysis of SPRINT indicates that LDL-C levels do not influence cardiovascular events over a period of 3 years in a large cohort of hypertensive patients at increased risk of cardiovascular events but without previous history of clinical cardiovascular disease other than stroke.

Lipid Abnormalities in Persons Living With HIV Infection

Lipid abnormalities are prevalent among persons living with HIV infection and contribute to increasing the risk of cardiovascular events. Antiretroviral therapy (ART) is associated with lipid abnormalities, most commonly hypertriglyceridemia, but also increases in low-density lipoprotein cholesterol and total cholesterol. Different classes of ART, and different drugs within classes, have differing effects on lipid levels, but in general newer drugs have more favourable effects compared with older ones. Low-level inflammation and chronic immune activation act on lipids through a variety of mechanisms to make them more atherogenic. As a consequence, risk is higher than would be expected for any given cholesterol level. Clinical outcome trials of cholesterol-lowering therapies have not yet been completed in people living with HIV, so that treatment decisions depend on extrapolation from studies in uninfected populations. Traditional risk assessment tools underestimate cardiovascular risk in individuals with HIV. Statins are the mainstay of lipid-lowering drug treatment; however, drug-drug interactions with ART must be considered. Simvastatin and lovastatin are contraindicated in patients taking protease inhibitors, and the dose of atorvastatin and rosuvastatin should be limited to 40 mg and 10 mg/d with some ART combinations. Switching from older forms of ART to lipid-friendly newer ones is a useful strategy as long as virologic suppression is maintained, but adding a statin lowers low-density lipoprotein cholesterol more effectively. Studies indicate that lipid abnormalities are not treated as aggressively in individuals living with HIV as they are in uninfected people, making this an opportunity to improve care.

Risk of Incident Atherosclerotic Cardiovascular DiseaseEvents by Achieved Atherogenic Lipid Levels Among62,428 Statin-Treated Individuals With Diabetes Mellitus

The relevance of low-density lipoprotein cholesterol (LDL-C) or non-high-density lipoprotein cholesterol (non-HDL-C) goals for primary prevention of atherosclerotic cardiovascular disease (ASCVD) among patients with diabetes was assessed. This retrospective cohort study included patients with type 2 diabetes, age 21 to 90years, taking statins, with no history of ASCVD as of January 1, 2006, in Kaiser Permanente Northern California, an integrated healthcare delivery system. Multivariate cox models were utilized to estimate hazard ratios (HRs) for incident ASCVD events by achieved LDL-C and non-HDL-C levels with adjustment for potential confounders. Incident ASCVD events were defined as a composite of myocardial infarction, ischemic stroke, or coronary heart disease death. A cohort of 62,428 patients, with mean age of 64.1years, 46.9% women, and mean follow-up of 6.0 years, was identified. After adjustment, the risk of incident ASCVD for these statin-treated patients was monotonically lower with decreasing achieved LDL-C levels (p<0.0001 for trend) and non-HDL-C levels (p <0.0001 for trend). Relative to achieved LDL-C ≥130 mg/dl, LDL-C <50 mg/dl had HR = 0.58 (95% confidence interval 0.49 to 0.69). Relative to achieved non-HDL-C ≥160mg/dl, non-HDL-C <80 mg/dl had HR = 0.59 (95% confidence interval 0.51 to 0.68). In a large cohort of statin-treated diabetic patients without ASCVD, a monotonically lower risk of incident ASCVD events was associated with lower achieved lipid levels. These findings support the use of LDL-C ornon-HDL-C treatment goals for ASCVD primary prevention in diabetic patients.

Cholesterol Lowering Guidelines: From Whence We Came and Where We Are Now

Treatment guidelines have proliferated in cardiology, although most guideline recommendations are not supported by clinical trial evidence. What is considered to be a normal cholesterol level has progressively declined over the past 50 years, with the increasing realization that "normal" is far from optimal and that lower is better. The first important United States and Canadian cholesterol guidelines were published in 1988, and recommended diet for 6 months to be followed by consideration of bile acid sequestrants or nicotinic acid. Over the ensuing 25 years guidelines have changed rapidly and dramatically in response to a large number of definitive clinical trials, usually with statins. Low-density lipoprotein cholesterol targets have moved progressively lower, and in some guidelines, have been abandoned entirely. The concept of selecting patients for treatment according to the absolute risk reduction expected from treatment on the basis of clinical trial data seems to be a rational approach. For secondary prevention, some patients are still untreated or undertreated, presenting an opportunity for improving outcomes.

Targeting LDL Cholesterol: Beyond Absolute Goals Toward Personalized Risk

PURPOSE OF REVIEW

The aim of this study was to review and assess the evidence for low-density lipoprotein cholesterol (LDL-C) treatment goals as presented in current guidelines for primary and secondary prevention of cardiovascular disease.

RECENT FINDINGS

Different sets of guidelines and clinical studies for secondary prevention have centered on lower absolute LDL-C targets [<70 mg/dL (<1.8 mmol/L)], greater percent reductions of LDL-C (≥50%), or more intense treatment to achieve greater reductions in cardiovascular risk. Population-based risk models serve as the basis for statin initiation in primary prevention. Reviews of current population risk models for primary prevention show moderate ability to discriminate [with c-statistics ranging from 0.67 to 0.77 (95% CIs from 0.62 to 0.83) for men and women] with poor calibration and overestimation of risk. Individual clinical trial data are not compelling to support specific LDL-C targets and percent reductions in secondary prevention. Increasing utilization of electronic health records and data analytics will enable the development of individualized treatment goals in both primary and secondary prevention.