Lipid management in ACS: Should we go lower faster?

Pharmaco-invasive therapy: Early implementation of statins and proprotein convertase subtilisin/kexin type 9 inhibitors after acute coronary syndrome

Elevated LDL-cholesterol (LDL-C) plays a major role in atheroma formation and inflammation. Medical therapy to lower elevated LDL-C is the cornerstone for reducing the progression of atherosclerotic cardiovascular disease. Statin therapy, and more recently, other drugs such as proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, have proven efficacy in long-term lowering of LDL-C and therefore diminish cardiovascular risk. During an acute coronary syndrome (ACS), a systemic inflammatory response can destabilize other non-culprit atherosclerotic plaques. Patients with these vulnerable plaques are at high risk of experiencing recurrent cardiovascular events in the first few years post-ACS. Initiating intensive LDL-C lowering therapy in these patients with statins or PCSK9 inhibitors can be beneficial via several pathways. High-intensity statin therapy can reduce inflammation by directly lowering LDL-C, but also through its pleiotropic effects. PCSK9 inhibitors can directly lower LDL-C to recommended guideline thresholds, and could have additional effects on inflammation and plaque stability. We discuss the potential role of early implementation of statins combined with PCSK9 inhibitors to influence these cascades and to mediate the associated cardiovascular risk, over and above the well-known long-term beneficial effects of chronic LDL-C lowering.

PCSK9 inhibition could be effective for acute myocardial infarction

In this review, we will explore the role of PCSK9 and inhibition of PCSK9 in patients after acute myocardial infarction (MI). Despite the implementation of evidence-based therapies to improve outcomes, mortality at one-year remains at 12-15% and the need to further reduce complications related to MI persists. Mechanistic and epidemiologic studies suggest that the naturally occurring PCSK9 protein increases coronary plaque vulnerability through several pathways, including pro-inflammatory LDL-C oxidation and direct modification of plaque composition. PCSK9 inhibitors are a class of drugs with proven efficacy in patients with recent MI. The latest guidelines recommend the use of PCSK9 in patients with recent MI early in the process of care to reduce LDL-C values and associated morbidity. The use of PCSK9 inhibition could be beneficial for mortality reduction after an acute MI and should be tested in an appropriately powered randomized controlled trial.

Reducing Cardiac Injury during ST-Elevation Myocardial Infarction: A Reasoned Approach to a Multitarget Therapeutic Strategy

The significant reduction in ‘ischemic time’ through capillary diffusion of primary percutaneous intervention (pPCI) has rendered myocardial-ischemia reperfusion injury (MIRI) prevention a major issue in order to improve the prognosis of ST elevation myocardial infarction (STEMI) patients. In fact, while the ischemic damage increases with the severity and the duration of blood flow reduction, reperfusion injury reaches its maximum with a moderate amount of ischemic injury. MIRI leads to the development of post-STEMI left ventricular remodeling (post-STEMI LVR), thereby increasing the risk of arrhythmias and heart failure. Single pharmacological and mechanical interventions have shown some benefits, but have not satisfactorily reduced mortality. Therefore, a multitarget therapeutic strategy is needed, but no univocal indications have come from the clinical trials performed so far. On the basis of the results of the consistent clinical studies analyzed in this review, we try to design a randomized clinical trial aimed at evaluating the effects of a reasoned multitarget therapeutic strategy on the prevention of post-STEMI LVR. In fact, we believe that the correct timing of pharmacological and mechanical intervention application, according to their specific ability to interfere with survival pathways, may significantly reduce the incidence of post-STEMI LVR and thus improve patient prognosis.

PCSK9 Biology and Its Role in Atherothrombosis

It is now about 20 years since the first case of a gain-of-function mutation involving the as-yet-unknown actor in cholesterol homeostasis, proprotein convertase subtilisin/kexin type 9 (PCSK9), was described. It was soon clear that this protein would have been of huge scientific and clinical value as a therapeutic strategy for dyslipidemia and atherosclerosis-associated cardiovascular disease (CVD) management. Indeed, PCSK9 is a serine protease belonging to the proprotein convertase family, mainly produced by the liver, and essential for metabolism of LDL particles by inhibiting LDL receptor (LDLR) recirculation to the cell surface with the consequent upregulation of LDLR-dependent LDL-C levels. Beyond its effects on LDL metabolism, several studies revealed the existence of additional roles of PCSK9 in different stages of atherosclerosis, also for its ability to target other members of the LDLR family. PCSK9 from plasma and vascular cells can contribute to the development of atherosclerotic plaque and thrombosis by promoting platelet activation, leukocyte recruitment and clot formation, also through mechanisms not related to systemic lipid changes. These results further supported the value for the potential cardiovascular benefits of therapies based on PCSK9 inhibition. Actually, the passive immunization with anti-PCSK9 antibodies, evolocumab and alirocumab, is shown to be effective in dramatically reducing the LDL-C levels and attenuating CVD. While monoclonal antibodies sequester circulating PCSK9, inclisiran, a small interfering RNA, is a new drug that inhibits PCSK9 synthesis with the important advantage, compared with PCSK9 mAbs, to preserve its pharmacodynamic effects when administrated every 6 months. Here, we will focus on the major understandings related to PCSK9, from its discovery to its role in lipoprotein metabolism, involvement in atherothrombosis and a brief excursus on approved current therapies used to inhibit its action.

Inhibitors of Protein Convertase Subtilisin/Kexin 9 (PCSK9) and Acute Coronary Syndrome (ACS): The State-of-the-Art

Acute Coronary Syndrome (ACS) remains one of the most frequent causes of morbidity and mortality in the world. Although the age- and gender-adjusted incidence of ACS is decreasing, the mortality associated with this condition remains high, especially 1-year after the acute event. Several studies demonstrated that PCSK9 inhibitors therapy determine a significant reduction of major adverse cardiovascular events (MACE) in post-ACS patients, through a process of plaque modification, by intervening in lipid metabolism and platelet aggregation and finally determining an improvement in endothelial function. In the EVACS (Evolocumab in Acute Coronary Syndrome) study, evolocumab allows >90% of patients to achieve LDL-C < 55 mg/dL according to ESC/EAS guidelines compared to 11% of patients who only receive statins. In the EVOPACS (EVOlocumab for Early Reduction of low-density lipoprotein (LDL)-cholesterol Levels in Patients With Acute Coronary Syndromes) study, evolocumab determined LDL levels reduction of 40.7% (95% CI: 45.2 to 36.2; p < 0.001) and allowed 95.7% of patients to achieve LDL levels <55 mg/dL. In ODYSSEY Outcome trial, alirocumab reduced the overall risk of MACE by 15% (HR = 0.85; CI: 0.78-0.93; p = 0.0003), with a reduced risk of all-cause mortality (HR = 0.85; CI: 0.73-0.98: nominal p = 0026), and fewer deaths for coronary heart disease (CHD) compared to the control group (HR = 0.92; CI: 0.76-1.11; p = 0.38). The present review aimed at describing the beneficial effect of PCSK9 inhibitors therapy early after ACS in reducing LDL circulating levels (LDL-C) and the risk of major adverse cardiovascular events, which was very high in the first year and persists higher later after the acute event.

Role of Lipid-Lowering Therapy in Low-Density Lipoprotein Cholesterol Goal Attainment: Focus on Patients With Acute Coronary Syndrome

Dyslipidemia is a major risk factor for cardiovascular (CV) disease, which is the leading cause of death globally. Acute coronary syndrome (ACS) is a common cause of death, accounting for nearly half of the global burden of CV mortality. Epidemiologic studies have identified low-density lipoprotein cholesterol (LDL-C) as an independent CV risk factor, and this is now the primary target for initiating and adjusting lipid-lowering therapies in most current guidelines. Evidence from pivotal studies supports the use of high-intensity statin therapy and a lower level for optimal LDL-C in secondary prevention of atherosclerotic CV disease, especially in patients with ACS undergoing percutaneous coronary intervention. However, current research has identified a gap between the target LDL-C goal attainment and target LDL-C levels recommended by the guidelines. Statins have proven benefits in the management of CV disease and are the cornerstone of lipid-lowering management in patients with ACS. Recent randomized controlled trials have also demonstrated the benefits of cholesterol absorption inhibitors and proprotein convertase subtilisin/kexin type 9 inhibitors. This review summarizes the current evidence for LDL-lowering therapy in patients with ACS, with an emphasis on the importance of LDL-C goal attainment, rapid LDL-C lowering, and duration of LDL-C-lowering therapy.

Comparison of Atorvastatin and Rosuvastatin in Reduction of Inflammatory Markers in Acute Coronary Syndrome

Introduction: Patients suffering from acute coronary syndrome (ACS) are found to have elevated levels of inflammatory markers such as high sensitivity C-reactive protein (hsCRP) and erythrocyte sedimentation rate (ESR) in their blood. These elevated inflammatory markers can lead to complications in ACS. Statins such as atorvastatin and rosuvastatin are known to reduce inflammatory markers. Our aim is to compare the efficacy of atorvastatin and rosuvastatin in reducing inflammatory markers.

Methods: This prospective, open-label, randomized trial was conducted in the cardiovascular department of tertiary care in a rural area of Pakistan. There were 128 patients diagnosed with ACS who were enrolled in the study. They were randomized into two groups, i.e. group A in which patients received 40 mg rosuvastatin daily and group B in which patients received 20 mg atorvastatin daily. hsCRP and ESR were recorded for all the patients at baseline (before starting therapy) and then again after four weeks. The results were compared between both groups.

Result: Out of 128 patients, 113 (88.2%) patients completed the study. According to this study, at the end of four weeks, rosuvastatin reduced hsCRP (p value: < 0.0001) and ESR (p value: 0.015) values significantly more when compared with atorvastatin.

Conclusion: In this study, rosuvastatin was significantly superior to atorvastatin in reducing inflammatory markers such as ESR and hsCRP in patients suffering from ACS. Cardiologists should consider using rosuvastatin rather than atorvastatin in management of patients suffering from ACS with elevated inflammatory biomarkers. 

Cardiovascular and Metabolic Protection by Vitamin E: A Matter of Treatment Strategy?

Cardiovascular diseases (CVD) cause about 1/3 of global deaths. Therefore, new strategies for the prevention and treatment of cardiovascular events are highly sought-after. Vitamin E is known for significant antioxidative and anti-inflammatory properties, and has been studied in the prevention of CVD, supported by findings that vitamin E deficiency is associated with increased risk of cardiovascular events. However, randomized controlled trials in humans reveal conflicting and ultimately disappointing results regarding the reduction of cardiovascular events with vitamin E supplementation. As we discuss in detail, this outcome is strongly affected by study design, cohort selection, co-morbidities, genetic variations, age, and gender. For effective chronic primary and secondary prevention by vitamin E, oxidative and inflammatory status might not have been sufficiently antagonized. In contrast, acute administration of vitamin E may be more translatable into positive clinical outcomes. In patients with myocardial infarction (MI), which is associated with severe oxidative and inflammatory reactions, decreased plasma levels of vitamin E have been found. The offsetting of this acute vitamin E deficiency via short-term treatment in MI has shown promising results, and, thus, acute medication, rather than chronic supplementation, with vitamin E might revitalize vitamin E therapy and even provide positive clinical outcomes.

Impact of Lowering Low-Density Lipoprotein Cholesterol with Contemporary Lipid-Lowering Medicines on Cognitive Function: A Systematic Review and Meta-Analysis

PURPOSE

To evaluate the potential association between the lowering of low-density lipoprotein cholesterol (LDL-C) with contemporary lipid-lowering medicines and cognitive function.

METHODS

Randomized controlled trials (RCTs) in databases including PubMed, Embase, and the Web of Science and all databases in the Cochrane Library and ClinicalTrials.gov were collected from inception to January 1, 2020. The cognitive function of patients receiving proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, statins and ezetimibe was evaluated using meta-analysis.

RESULTS

A total of 2910 studies were obtained from databases and other sources. Thirty-three studies were selected by screening, including 11 studies on alirocumab, 9 studies on evolocumab, 11 studies on statins and 2 studies on ezetimibe. In our study, a total of 128,691 patients with no cognitive impairment were divided into an intervention group (66,330 patients) and a control group (62,361 patients). The data were subjected to a random-effects model or a fixed-effects model for meta-analysis. The contemporary lipid-lowering medicines significantly reduced LDL-C in terms of both percentage (WMD: -45.06%, 95% CI -50.12% to -40.00%, P < 0.001) and absolute value (WMD: -64.01 mg/dL, 95% CI -72.25 to -55.78, P < 0.001). Compared with the control group, patients receiving treatment with contemporary lipid-lowering medicines did not show a significant difference in the rate of neurocognitive disorder (RR: 1.02, 95% CI 0.90 to 1.16, I² = 0.0%, p = 0.696). Subgroup analysis was performed according to the intervention and LDL-C stratification. The result of this subgroup analysis was consistent with the main findings. Regarding global cognitive performance, no difference in major cognition was found among the pooled data (SMD: 0.02, 95% CI -0.01 to 0.04, P = 0.002), except for psychomotor speed (SMD: 0.09, 95% CI 0.02 to 0.16, P = 0.0024).

CONCLUSIONS

Contemporary lipid-lowering medicines were not associated with cognitive impairment in RCTs. A low LDL-C level did not influence the incidence of cognitive disorder or global cognitive performance.

Efficacy of Evolocumab on Cardiovascular Outcomes in Patients With Recent Myocardial Infarction: A Prespecified Secondary Analysis From the FOURIER Trial

Importance

The 2018 American Heart Association/American College of Cardiology Multisociety Guideline on the Management of Blood Cholesterol identified patients with recent (past 12 months) myocardial infarction (MI) as very high risk, in whom a PCSK9 inhibitor is reasonable to add to maximally tolerated statin combined with ezetimibe if their low-density lipoprotein cholesterol level is 70 mg/dL or greater or non-high-density lipoprotein cholesterol level is 100 mg/dL or greater.

Objective

To examine the clinical efficacy of evolocumab in patients with recent MI.

Design, Setting, and Participants

This was a prespecified secondary analysis of the Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk (FOURIER) trial, in which 27 564 patients with atherosclerotic cardiovascular disease treated with a statin were randomized to evolocumab vs placebo. Patients with prior MI with a known date (n = 22 320) were stratified as having a recent MI (within 12 months of randomization) or a remote MI (more than 12 months prior to randomization). Per protocol, patients with MI within 4 weeks prior to randomization were excluded from the FOURIER trial. Data were collected from February 2013 to November 2016, and data were analyzed from May 2019 to February 2020.

Main Outcomes and Measures

The primary composite end point was cardiovascular death, MI, stroke, hospitalization for unstable angina, or coronary revascularization. The key secondary composite end point was cardiovascular death, MI, or stroke.

Results

Of 22 320 included patients, 17 516 (78.5%) were male, and the mean (SD) age was 62.2 (9.0) years. Compared with 16 609 patients with a remote MI, 5711 patients with a recent MI were younger and more likely to be treated with high-intensity statin (77.3% [4415] vs 69.3% [11 506]). In the placebo arm, the 3-year Kaplan-Meier rate for the primary end point was 17.2% in patients with recent MI compared with 14.4% in those with remote MI (adjusted HR, 1.45; 95% CI, 1.29-1.64; P < .001). Similarly, the 3-year Kaplan-Meier rates for the key secondary end point was also higher in those with recent MI (10.9% vs 9.5%; adjusted HR, 1.45; 95% CI, 1.24-1.69; P < .001). In patients with a recent MI, evolocumab reduced the risk of the primary and key secondary end points by 19% (hazard ratio [HR], 0.81; 95% CI, 0.70-0.93) and 25% (HR, 0.75; 95% CI, 0.62-0.91), respectively. In patients with a remote MI, evolocumab reduced the risk of the primary and key secondary end points by 8% (HR, 0.92; 95% CI, 0.84-1.01; P for interaction = .13) and 15% (HR, 0.85; 95% CI, 0.76-0.96; P for interaction = .24), respectively. Given the higher event rates in patients with a recent MI, the absolute risk reductions over 3 years with evolocumab were 3.7% in those with recent MI vs 1.1% in those with remote MI for the primary end point and 3.2% vs 1.3%, respectively, for the key secondary end point.

Conclusions and Relevance

Patients with a recent MI were at higher risk of cardiovascular events and tended to experience greater absolute risk reductions with evolocumab than those with remote MIs. These findings support the concept in US and European guidelines to aggressively lower low-density lipoprotein cholesterol levels in very high-risk patients, such as those with a recent MI.

Trial Registration

ClinicalTrials.gov Identifier: NCT01764633.

The Prevalence and Diagnostic Ratio of Familial Hypercholesterolemia (FH) and Proportion of Acute Coronary Syndrome in Japanese FH Patients in a Healthcare Record Database Study

Background

Familial hypercholesterolemia (FH) is a genetic disorder characterized by high levels of low-density lipoprotein cholesterol (LDL-C). Because of underdiagnosis, acute coronary syndrome (ACS) is often the first clinical manifestation of FH. In Japan, there are few reports on the prevalence and diagnostic ratios of FH and the proportion of ACS among FH patients in clinical settings.

Methods

This retrospective, observational study used anonymized data from electronic healthcare databases between April 2001 and March 2015 of patients who had ≥2 LDL-C measurements recorded after April 2009. The index date was defined as the date of the first LDL-C measurement after April 2009. The primary endpoint was the prevalence of definite or suspected FH; secondary endpoints included the proportion of FH patients hospitalized for ACS, the proportion of patients using lipid-lowering drugs (LLDs), and LDL-C levels.

Results

Of the 187,781 patients screened, 1547 had definite or suspected FH (0.8%) based on data from the entire period; 832 patients with definite (n = 299, 0.16%) or suspected FH (n = 533, 0.28%) before the index date were identified in the main analysis cohort. LLDs were used in 214 definite FH patients (71.6%) and 137 suspected FH patients (25.7%). Among definite or suspected FH patients with ACS (n = 84) and without ACS (n = 748), 32.1% and 30.1% with definite FH and 3.2% and 2.4% with suspected FH had LDL-C levels < 2.6 mmol/L (<100 mg/dL), respectively. Sixty patients (7.2%) were hospitalized due to ACS at the index date.

Conclusions

The prevalence of FH in this Japanese cohort of patients with ≥2 LDL-C measurements at hospitals was 0.8%, which is higher than that currently reported in epidemiological studies (0.2-0.5%). Patients with suspected FH, with or without ACS, had poorly controlled LDL-C levels and were undertreated. The proportion of FH patients who were hospitalized due to ACS was 7.2%.

PCSK9 inhibition and inflammation: A narrative review

Atherosclerotic cardiovascular disease (ASCVD) remains a leading cause of morbidity and mortality despite excellent pharmacological and revascularization approaches. Low-density lipoproteins (LDL) are undoubtedly the most significant biochemical variables associated with atheroma, however, compelling data identify inflammation as critical for the maintenance of the atherosclerotic process, underlying some of the most feared vascular complications. Although its causal role is questionable, high-sensitivity C-reactive protein (hs-CRP) represents a major biomarker of inflammation and associated risk in CVD. While statin-associated reduced risk may be related to the lowering of both LDL-C and hs-CRP, PCSK9 inhibitors leading to dramatic LDL-C reductions do no alter hs-CRP levels. On the other hand, hs-CRP levels identify groups of patients with a high risk of CV disease achieving better ASCVD prevention in response to PCSK9 inhibition. In the FOURIER study, even in patients with extremely low levels of LDL-C, there was a stepwise risk increment according to the values of hs-CRP: +9% (<1 mg/L), +10.8% (1-3 mg/L) and +13.1% (>3 mg/L). Likewise, in the SPIRE-1 and -2 studies, bococizumab patients with hs-CRP> 3 mg/L had a 60% greater risk of future CV events. Most of the patients enrolled in the PCSK9 trials were on maximally tolerated statin therapy at baseline, and an elevated hs-CRP may reflect residual inflammatory risk after standard LDL-C lowering therapy. Moreover, data on changes in inflammation markers in carriers of PCSK9 loss-of-function mutations are scanty and not conclusive, thus, evidence from the effects of anti-inflammatory molecules on PCSK9 levels might help unravel this hitherto complex tangle.