Usefulness of lipoprotein changes during acute coronary syndromes for predicting postdischarge lipoprotein levels

Pharmacological rationale for the very early treatment of acute coronary syndrome with monoclonal antibodies anti-PCSK9

Immediate and aggressive lipid lowering therapies after acute coronary syndromes (ACS) and percutaneous coronary interventions (PCI) are supported by the ESC/EAS dyslipidemia guidelines, recommending the initiation of high-intensity statin therapy within the first 1-4 days of hospitalization. However, whether non statin lipid-lowering agents, added to statin treatment, could produce a further reduction in the risk of major adverse cardiovascular events (MACE) is still unknown. Thus, the efficacy of early treatment post-ACS with monoclonal antibodies (mAbs) anti PCSK9, evolocumab and alirocumab, is under investigation. The rationale to explore the rapid and aggressive pharmacological intervention with PCSK9 mAbs is supported by at least five confirmatory data in ACS: 1) circulating PCSK9 levels are raised during ACS 2) PCSK9 may stimulate platelet reactivity, this last being pivotal in the recurrence of ischemic events; 3) PCSK9 is associated with intraplaque inflammation, macrophage activation and endothelial dysfunction; 4) PCSK9 concentrations are associated with inflammation in the acute phase of ACS; and 5) statins raise PCSK9 levels promptly and, at times, dramatically. In this scenario, appropriate pharmacodynamic characteristics of anti PCSK9 therapies are a prerequisite for an effective response. Monoclonal antibodies act on circulating PCSK9 with a direct and rapid binding by blocking the interaction with the low-density lipoprotein receptor (LDLR). Evolocumab and alirocumab show a very rapid (within 4 h) and effective suppression of circulating unbound PCSK9 (- 95 % ÷ - 97 %). This inhibition results in a significant reduction of LDL-cholesterol (LDL-C) after 48 h (- 35 %) post injection with a full effect after 7-10 days (55-75 %). The complete and swift inhibitory action by evolocumab and alirocumab could have a potential clinical impact in ACS patients, also considering their potential inhibition of PCSK9 within the atherosclerotic plaque. Thus, administration of evolocumab or alirocumab is effective in lowering LDL-C levels in ACS, although the efficacy to prevent further cardiovascular (CV) events is still undetermined. The answer to this question will be provided by the ongoing clinical trials with evolocumab and alirocumab in ACS. In the present review we will discuss the pharmacological and biological rationale supporting the potential use of PCSK9 mAbs in ACS patients and the emerging evidence of evolocumab and alirocumab treatment in this clinical setting.

The triglyceride paradox in the mortality of coronary artery disease

Background

The role of triglyceride (TG) in secondary prevention of patients with coronary artery disease (CAD) was debated. In the present study, we assessed the association between admission TG levels and long-term mortality risk in CAD patients.

Methods

A retrospective analysis was conducted from a single registered database. 3061 consecutive patients with CAD confirmed by coronary angiography were enrolled and were grouped into 3 categories by the tertiles of admission serum TG levels. The primary end point in this study was all-cause mortality and the secondary end point was cardiovascular mortality.

Results

The mean follow-up time was 26.9 ± 13.6 months and death events occurred in 258 cases and cardiovascular death events occurred in 146 cases. Cumulative survival curves indicated that the risk of all-cause death decreased with increasing TG level (Tertile 1 vs. Tertile 2 vs. Tertile 3 = 10.3% vs. 8.6% vs. 6.3%, log rank test for overall p = 0.001). Cox regression analysis showed an independent correlation between TG level and risk of all-cause mortality [hazard ratio (HR) 0.71, 95% confidence interval (CI) 0.58–0.86] and cardiovascular mortality (HR 0.67, 95% CI 0.51–0.89) in total patients with CAD. Subgroup analysis found the similar results in patients with acute coronary syndrome and acute myocardial infarction.

Conclusions

This study found an inverse association between TG levels and mortality risk in CAD patients, which suggests that the “TG paradox” may exist in CAD patients.

Trial registration

ChiCTR, ChiCTR-OOC-17010433. Registered 17 February 2017 - Retrospectively registered.

Lipid Biomarkers for Risk Assessment in Acute Coronary Syndromes

PURPOSE OF REVIEW

The objective of this review was to summarize evidence gathered for the prognostic value of routine and novel blood lipids and lipoproteins measured in patients with acute coronary syndromes (ACS).

RECENT FINDINGS

Data supports clear association with risk and actionable value for non-high-density lipoprotein (Non-HDL) cholesterol and plasma ceramides in a setting of ACS. The prognostic value and clinical actionability of apolipoprotein B (apoB) and lipoprotein(a) [Lp(a)] in ACS have not been thoroughly tested, while the data for omega-3 fatty acids and oxidized low-density lipoprotein (Ox-LDL) are either untested or more varied. Measuring basic lipids, which should include Non-HDL cholesterol, at the time of presentation for ACS is guideline mandated. Plasma ceramides also provide useful information to guide both treatment decisions and follow-up. Additional studies targeting ACS patients are necessary for apoB, Lp(a), omega-3 fatty acids, and Ox-LDL.

[Prevalence of metabolic syndrome and its components in patients with acute coronary syndrome]

INTRODUCTION AND OBJECTIVES

A large proportion of patients with coronary disease have metabolic syndrome, although the frequency and association of its different components are not well understood. The aim of this study was to determine the prevalence of metabolic syndrome and the combination of its components in a Spanish cohort of patients with acute coronary syndrome.

METHODS

Clinical histories of 574 inpatients with acute coronary syndrome in 6 tertiary hospitals were reviewed and the presence of metabolic syndrome and its components determined by applying Adult Treatment Panel III criteria. In a second step, the components of the metabolic syndrome were analyzed, excluding those patients with diabetes mellitus.

RESULTS

The metabolic syndrome was present in 50.9% of patients and was more frequent in women than in men (66.3% vs. 47.3%; P<.001). The most prevalent component was carbohydrate metabolism disorder (85.3%), followed by low high-density lipoprotein cholesterol (HDLc) levels (80.5%). In nondiabetic patients, 34.6% had metabolic syndrome and the most prevalent component was low HDLc levels (86%), followed by high blood pressure and hypertriglyceridemia and, in fourth place, impaired fasting serum glucose levels.

CONCLUSIONS

The metabolic syndrome has a high prevalence in patients with an acute coronary syndrome, especially in women. The most frequent components are hyperglycemia and low HDLc levels. After excluding diabetic patients, the most prevalent diagnostic criterion of metabolic syndrome was low HDLc levels. Full English text available from: www.revespcardiol.org.

Change in serum lipids after acute coronary syndromes: secondary analysis of SPACE ROCKET study data and a comparative literature review

BACKGROUND

It has long been an accepted belief that serum cholesterol significantly falls after myocardial infarction and that a return to pre-event levels takes approximately 3 months. The magnitude and clinical significance of this fall has recently been challenged.

METHODS

In the Secondary Prevention of Acute Coronary Events-Reduction Of Cholesterol to Key European Targets (SPACE ROCKET) trial, we measured serum lipids of individuals on day 1 and between days 2 and 4 after acute myocardial infarction (AMI). Second, we performed a thorough literature review and compared all studies reporting data on absolute changes in lipids immediately after AMI, using weighted means.

RESULTS

Of 1263 SPACE ROCKET participants, 128 had paired lipid measurements where both samples had been measured using identical methods at baseline and on days 2-4 after AMI. The mean lowering in total cholesterol between day 1 and day 2-4 was 0.71 mmol/L (95% CI 0.58-0.84; P < 0.0001) and in triglycerides was 0.10 mmol/L (-0.14-0.33; P = 0.405). A total of 25 papers showing absolute lipid changes post-AMI were identified. The combined data demonstrated a mean fall in total cholesterol of 9% to 11% from baseline over days 3-14 post-AMI, whereas for triglycerides, there was a rise of 18% from baseline to between day 9 and 12 weeks.

CONCLUSIONS

After a secondary analysis of SPACE ROCKET data and a comparison of previously published data, we report a 10% fall in total cholesterol after AMI-a difference that is of high clinical significance. Consequently, measurement of serum lipids in patients with AMI should be performed within the first hours after presentation.

Impact of the metabolic syndrome on high-sensitivity C reactive protein levels in patients with acute coronary syndrome

OBJECTIVE

Underlying predisposition for a heightened inflammatory response is postulated as one of the mechanisms for elevated high-sensitivity C reactive protein (hs-CRP) levels in patients with acute coronary syndrome (ACS). It is unclear whether metabolic syndrome (MetS) may cause a predisposition for heightened hs-CRP response in patients with ACS. The aim of this study is to investigate the interaction between hs-CRP levels and presence of MetS in patients with and without ACS.

METHODS

Two hundred and seventy-three consecutive patients presenting with a first ACS event and 261 MetS patients without any ACS event were included to the study. The study participants were divided into three groups as MetS (+) ACS (-) [n=261], MetS (-) ACS (+) [n=110], and MetS (+) ACS (+) [n=163]. Median levels of hs-CRP were compared between and within the three groups.

RESULTS

Hs-CRP levels were lowest in MetS (+) ACS (-) subjects and highest in MetS (+) ACS (+) patients. Factors associated with hs-CRP levels were troponin elevation, presence of ACS, body mass index (BMI), and presence of MetS (R(2)=0.26, p<0.01). Predictors of elevated hs-CRP levels (>0.3mg/dl) were the presence of ACS (OR=3.6, 95% CI=1.9-6.5, p<0.01), presence of MetS (OR=2.1, 95% CI=1.0-4.0, p=0.02), troponin elevation (OR=5.7, 95% CI=2.8-11.5, p<0.01) and BMI (OR=1.1, 95% CI=1.0-1.1, p<0.01).

CONCLUSIONS

The presence of MetS had an impact on the increase in hs-CRP levels observed with an ACS event in the study population. These findings suggested that a heightened baseline inflammatory status of MetS may predispose ACS patients to an augmented hs-CRP response.

Prevalence of metabolic syndrome in patients < or =45 years of age with acute myocardial infarction having percutaneous coronary intervention

The prevalence of metabolic syndrome (MS) was determined in patients aged < or =45 years who presented with acute myocardial infarction and underwent primary percutaneous coronary intervention. Two hundred twenty-three consecutive patients aged 18 to 45 years who underwent cardiac catheterization for acute myocardial infarction from June 2001 to December 2004 were reviewed. MS was diagnosed by National Cholesterol Education Program Adult Treatment Panel III guidelines (modified by substituting body mass index > or =28.8 kg/m2 for waist circumference). One hundred sixty-one patients met all 5 criteria for MS available for evaluation. Seventy-six of these patients (47%) met > or =3 of the 5 criteria for MS. Sixteen patients with MS (21%) and 5 patients without MS (6%) had diabetes mellitus. The prevalence of each criterion was significantly higher (p <0.05) in the MS group. Average Framingham risk scores were 7.0 and 4.5 for patients with and without MS, respectively. The prevalence of smoking, male gender, and family history of premature coronary artery disease were the same for the 2 groups. In conclusion, MS was highly prevalent in this population of young patients with acute myocardial infarction.

Co-administration of ezetimibe and simvastatin in acute myocardial infarction

BACKGROUND

Recent trials in acute myocardial infarction indicate that intensive and early statin therapy that lowers low-density lipoprotein cholesterol (LDL-C) to < or = 70 mg dL(-1) is beneficial. The combination of statins with ezetimibe, a newly developed cholesterol-absorption inhibitor, can lead to a further reduction in LDL-C of up to 26%. In this study, we examined the rapidity and intensity of the lipid-lowering effect of ezetimibe co-administered with simvastatin immediately after myocardial infarction.

MATERIALS AND METHODS

Sixty patients admitted for acute myocardial infarction were randomized to receive either simvastatin 40 mg (SIMVA), a combination of simvastatin 40 mg and ezetimibe 10 mg (EZE/SIMVA), or no lipid-lowering drugs (NLLD) and had their lipid levels assessed 2, 4 and 7 days later.

RESULTS

At baseline, cardiovascular risk factors were similar in all three groups [mean (SD) LDL-C of 141 (36) mg dL(-1)]. At days 2 , 4 and 7 there was no significant change in mean LDL-C levels in the NLLD group (-10%, -6%, and -9%, all P > 0.09), while there were significant reductions with SIMVA (-15%, -27%, and -25%, respectively, all P < 0.001 vs. day 0) and even greater reductions with co-administration of EZE/SIMVA (-27%, -41%, and -51%, respectively, all P < 0.001 vs. day 0). The percentages of patients achieving LDL-C below 70 mg dL(-1) at days 4 and 7 were substantially greater with EZE/SIMVA (45% and 55%, respectively) than with SIMVA (5% and 10%, respectively), while no NLLD patient reached this goal. Triglyceride levels showed a progressive increase in the NLLD group (+45% at day 7, P < 0.05 vs. day 0), no change in the SIMVA group, but a decrease in the EZE/SIMVA group (-17% at day 7, P < 0.05 vs. day 0). No significant difference in HDL-C levels, tolerability, or clinical events was observed between the three groups.

CONCLUSIONS

The co-administration of ezetimibe 10 mg with simvastatin 40 mg, by inhibiting cholesterol absorption and production, allowed more patients with acute myocardial infarction to reach LDL-C < or = 70 mg dL(-1) as early as the fourth day of treatment. The effects of such rapid and intense reduction in LDL-C on cardiovascular morbidity and mortality need to be evaluated in future clinical endpoint studies.

Impact of the metabolic syndrome on the clinical outcomes of non-clinically diagnosed diabetic patients with acute coronary syndrome

The aim of this study is to explore the impact of metabolic syndrome (MS) on the outcome of patients with non-clinically diagnosed diabetes with acute coronary syndrome (ACS) based on a comprehensive nationwide registry during a 1-year follow-up. In the ACS Israeli Survey, 1,060 consecutive patients with non-clinically diagnosed diabetes were admitted due to ACS; 359 patients with MS features on admission were compared with 701 subjects without MS. A modified National Cholesterol Education Program Adult Treatment Panel III definition of MS was used in patients who presented with > or =3 of the 5 components: (1) hyperglycemia, defined as occasional blood glucose on admission >140 mg/dl; (2) preexisting hypertension; (3) body mass index >28 kg/m(2); (4) high-density lipoprotein cholesterol < or =40 mg/dl (men) or < or =50 mg/dl (women); and (5) triglycerides > or =150 mg/dl. Patients with MS were more frequently women (27% vs 12%, p = 0.001), were in Killip > or =II on admission (19% vs 14%, p = 0.03), and had higher 30-day (5.0% vs 1.7%, p = 0.002) and 1-year (8.9% vs 4.6%, p = 0.005) crude mortality rates. Patients with hyperglycemia (glucose >140 mg/dl) and MS had higher 30-day mortality rates compared with patients with hyperglycemia without MS (8.3% vs 2.5%, p <0.05). Multivariate analysis identified MS as a strong independent predictor of 30-day and 1-year mortality with hazard ratios of 2.54 (95% confidence interval 1.22 to 5.31) and 1.96 (95% confidence interval 1.18 to 3.24), respectively. In conclusion, MS defined early at admission is a strong independent predictor of mortality and morbidity in patients with non-clinically diagnosed diabetes with ACS.

Emerging risk factors and early atherosclerosis indices in subjects with impaired glucose tolerance

AIM

To evaluate the response to an oral lipid overload, inflammatory markers and carotid intima-media thickness in subjects with impaired glucose tolerance.

METHODS

54 subjects, both sexes, 58 y-old average were submitted to 1) Clinical evaluation 2) Glucose tolerance test with 75 g glucose; classified as normal (2 h plasma glucose<140 mg/dl, n=37) or IGT (2 h G 140-200 mg/dl, n=17), 3) 12 h fasting sample (plasma glucose, lipids, C-reactive protein, fibrinogen and HOMA-IR calculation); 4 and 6 h after the oral lipid overload (1000 kcal, lipids 65 g) glycemia, fibrinogen and triglycerides were reevaluated. Intima-media thickness was calculated by the average of 6 measurements (3 highest of each carotid) evaluated by ultrasonography (7 MHZ transducer).

RESULTS

The IGT group had higher (P<0.001) fasting plasma glucose (89.4 +/- 13 vs 104.4 +/- 8 mg/dl), HOMA-IR (1.69 +/- 1.2 vs 2.93 +/- 2.2) and waist (91 +/- 14 vs 101 +/- 9 cm), similar fasting lipids, intima-media thickness (P=0.58) and post-oral lipid overload triglycerides (P=0.74), but higher fibrinogen (284.3 +/- 6 and 305 +/- 10 mg/dl, P=0.05) and C-reactive protein (2.11 +/- 0.33 and 4.19 +/- 0.65 mg/l, P=0.003). C-reactive protein was positively correlated with HOMA-IR (r=0.45, P=0.001), fasting plasma glucose (r=0.43, P=0.002) and waist (r=0.45, P=0.0006), but not with postprandial lipids.

CONCLUSION

A higher C-reactive protein in IGT, and its positive correlation with insulin resistance indices, but not with postprandial lipaemia, suggests that the clustering of these factors, characteristic of the metabolic syndrome, occurs earlier than postprandial lipid abnormalities.

The evaluation and management of dyslipidemia and impaired glucose metabolism during acute coronary syndromes

Dyslipidemia and hyperglycemia are common among patients presenting with acute coronary syndromes (ACS), and patients with ACS and metabolic disorders are at increased risk for worse outcomes. Although guidelines for the diagnosis and management of dyslipidemia, diabetes, and the metabolic syndrome have been published, these guidelines have not specifically focused on the ACS patient population. Recent observational registries and clinical trials have advanced the appreciation of these disorders in ACS populations and data from these studies support aggressive efforts to diagnose and treat dyslipidemia and hyperglycemia in patients admitted for ACS.

Intense lipid peroxidation in premature clinical coronary atherosclerosis is associated with metabolic abnormalities

Increased oxidative stress is associated with rapid progression of atherosclerosis. In this study we sought to determine whether premature onset of clinical coronary atherosclerosis is associated with increased levels of lipid peroxidation. We measured plasma levels of malondialdehyde (MDA), using high-pressure liquid chromatography, in 42 male patients with early- (<56 years) or late-onset (>64 years) unstable angina and in 2 age-matched control groups (n=20). Plasma MDA levels were higher in the patients with unstable angina than in the control groups (1.57 +/- 0.07 vs 1.14 +/- 0.03 nmol/mL; P<.001). Patients with early-onset angina showed higher MDA levels than those in late-onset patients (1.75 +/- 0.11 vs 1.44 +/- 0.097 nmol/mL; P<.05), despite a similar prevalence of risk factors for atherothrombosis. The inflammatory component, measured with the use of a high-sensitivity enzyme-linked immunosorbent assay for C-reactive protein, and platelet activity, measured as prothrombin fragment 1+2, failed to predict MDA level. Fasting glucose (P<.05) was the best predictor of MDA level in patients with early-onset unstable angina; uric acid (P=.09) and body-mass index (P=.15) showed trends toward significant correlation with MDA level in the same group of patients. Metabolic abnormalities related to insulin resistance in patients with premature coronary atherosclerosis appear to be important mediators of major plasma oxidative damage.

Clinical practice guidelines for managing dyslipidemias in kidney transplant patients: a report from the Managing Dyslipidemias in Chronic Kidney Disease Work Group of the National Kidney Foundation Kidney Disease Outcomes Quality Initiative

The incidence of cardiovascular disease (CVD) is very high in patients with chronic kidney (CKD) disease and in kidney transplant recipients. Indeed, available evidence for these patients suggests that the 10-year cumulative risk of coronary heart disease is at least 20%, or roughly equivalent to the risk seen in patients with previous CVD. Recently, the National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (K/DOQI) published guidelines for the diagnosis and treatment of dyslipidemias in patients with CKD, including transplant patients. It was the conclusion of this Work Group that the National Cholesterol Education Program Guidelines are generally applicable to patients with CKD, but that there are significant differences in the approach and treatment of dyslipidemias in patients with CKD compared with the general population. In the present document we present the guidelines generated by this workgroup as they apply to kidney transplant recipients. Evidence from the general population indicates that treatment of dyslipidemias reduces CVD, and evidence in kidney transplant patients suggests that judicious treatment can be safe and effective in improving dyslipidemias. Dyslipidemias are very common in CKD and in transplant patients. However, until recently there have been no adequately powered, randomized, controlled trials examining the effects of dyslipidemia treatment on CVD in patients with CKD. Since completion of the K/DOQI guidelines on dyslipidemia in CKD, the results of the Assessment of Lescol in Renal Transplantation (ALERT) Study have been presented and published. Based on information from randomized trials conducted in the general population and the single study conducted in kidney transplant patients, these guidelines, which are a modified version of the K/DOQI dyslipidemia guidelines, were developed to aid clinicians in the management of dyslipidemias in kidney transplant patients. These guidelines are divided into four sections. The first section (Introduction) provides the rationale for the guidelines, and describes the target population, scope, intended users, and methods. The second section presents guidelines on the assessment of dyslipidemias (guidelines 1-3), while the third section offers guidelines for the treatment of dyslipidemias (guidelines 4-5). The key guideline statements are supported mainly by data from studies in the general population, but there is an urgent need for additional studies in CKD and in transplant patients. Therefore, the last section outlines recommendations for research.

Lipid-lowering therapies in the management of acute coronary syndromes

Despite the significant advances made in the treatment of acute coronary syndromes (ACS) with antiplatelet and antithrombotic therapy, the risk of serious complications remains high, especially in the first few months following an acute coronary event. Although lipid-lowering therapy in patients with significant risk factors (primary prevention) or stable coronary disease (secondary prevention) is known to improve long-term survival, patients with a recent ACS were specifically excluded from the early statin trials. However, the use of lipid-lowering agents (principally statins) during hospitalization or in the period immediately following an acute coronary event has recently been studied. Statin therapy in this setting has been shown to reduce angina, rehospitalization, and mortality. Improved outcomes associated with lipid-lowering therapy in ACS may be mediated through beneficial effects on plaque stabilization, endothelial function, inflammation, and thrombus formation. This paper reviews the evidence supporting the potential benefits and mechanisms of statin therapy in the management of ACS. Clinical guidelines to achieve optimal lipid management are also discussed.