Admission Low-Density Lipoprotein Cholesterol Stratified by Circulating CD14++CD16+ Monocytes and Risk for Recurrent Cardiovascular Events Following ST Elevation Myocardial Infarction: Lipid Paradox Revised

Outcomes of Patients with Normal LDL-Cholesterol at Admission for Acute Coronary Syndromes: Lower Is Not Always Better

BACKGROUND AND AIM

There are few prospective data on the prognostic value of normal admission low-density lipoprotein cholesterol (LDL-C) in statin-naïve patients with acute coronary syndromes (ACS) who are treated with a preemptive invasive strategy. We aimed to analyze the proportion of patients with normal LDL-C at admission for ACS in our practice, and their characteristics and clinical outcomes in comparison to patients with high admission LDL-C.

PATIENTS AND METHODS

Two institutions' prospective registries of patients with confirmed ACS from Jan 2017 to Jan 2023 were used to identify 1579 statin-naïve patients with no history of prior coronary artery disease (CAD), and with available LDL-C admission results, relevant clinical and procedural data, and short- and long-term follow-up data. Normal LDL-C at admission was defined as lower than 2.6 mmol/L. All demographic, clinical, procedural, and follow-up data were compared between patients with normal LDL-C and patients with a high LDL-C level (≥2.6 mmol/L) at admission.

RESULTS

There were 242 (15%) patients with normal LDL-C at admission. In comparison to patients with high LDL-cholesterol at admission, they were significantly older (median 67 vs. 62 years) with worse renal function, had significantly more cases of diabetes mellitus (DM) (26% vs. 17%), peripheral artery disease (PAD) (14% vs. 9%), chronic obstructive pulmonary disease (COPD) (8% vs. 2%), and psychological disorders requiring medical attention (19% vs. 10%). There were no significant differences in clinical type of ACS. Complexity of CAD estimated by coronary angiography was similar between the two groups (median Syntax score 12 for both groups). There were no significant differences in rates of complete revascularization (67% vs. 72%). Patients with normal LDL-C had significantly lower left ventricular ejection fraction (LVEF) at discharge (median LVEF 52% vs. 55%). Patients with normal LDL-C at admission had both significantly higher in-hospital mortality (5% vs. 2%, RR 2.07, 95% CI 1.08-3.96) and overall mortality during a median follow-up of 43 months (27% vs. 14%, RR 1.86, 95% CI 1.45-2.37). After adjusting for age, renal function, presence of diabetes mellitus, PAD, COPD, psychological disorders, BMI, and LVEF at discharge in a multivariate Cox regression analysis, normal LDL-C at admission remained significantly and independently associated with higher long-term mortality during follow-up (RR 1.48, 95% CI 1.05-2.09).

CONCLUSIONS

A spontaneously normal LDL-C level at admission for ACS in statin-naïve patients was not rare and it was an independent risk factor for both substantially higher in-hospital mortality and mortality during long-term follow-up. Patients with normal LDL-C and otherwise high total cardiovascular risk scores should be detected early and treated with optimal medical therapy. However, additional research is needed to reveal all the missing pieces in their survival puzzle after ACS-beyond coronary anatomy, PCI optimization, numerical LDL-C levels, and statin therapy.

Patterns of Circulating Microbiota during the Acute Phase Following ST-Segment Elevation Myocardial Infarction Predict Long-Term Cardiovascular Events

Limited information exists regarding whether circulating microbiota could predict long-term clinical outcomes following ST-segment elevation myocardial infarction (STEMI). A total of 244 consecutive patients with STEMI were followed for 2.8 years, and 64 first major adverse cardiovascular events (MACEs) were recorded. Both microbiota abundance [Corynebacterium tuberculostearicum (HR, 1.28; 95% CI, 1.03-1.58) and Staphylococcus aureus (S. aureus) (HR, 1.16; 95% CI, 1.02-1.33) ] and microbiota clusters (Cluster 2 versus Cluster 1: HR, 1.84; 95% CI, 1.04-3.27) could independently predict MACE. Furthermore, a model based on established independent predictors alone was significantly improved by the addition of different microbiota patterns. In addition, CD14⁺⁺CD16⁺ monocytes (Mon2) had a significant mediation effect on the microbiota patterns → MACE association. The present study demonstrated that the abundance and clusters of circulating microbiota are associated with future adverse cardiovascular events independent of traditional risk factors, which were partially mediated by an increase in Mon2.

The usefulness of arylesterase in predicting contrast-induced nephropathy in ST-segment elevation myocardial infarction patients undergoing percutaneous coronary intervention

Aim: Oxidative stress is one of the causes of contrast-induced nephropathy (CIN). Paraoxonase1 (PON1), is one of the oxidative stress markers. The most sensitive method that has been in use to measure PON1 enzyme activity is the measurement of arylesterase (AREase) activity. To explore relationship between AREase activity and CIN development. Material and Method: A total of 58 STEMI patients were included in our study. The patients were divided into two groups as CIN (+) and CIN (-). The success of AREase activity level in predicting the development of CIN was also examined by using ROC analysis. Results: Out of the study patients, 13 were CIN (+) and 45 were CIN (-). AREase activity was found to be statistically significantly lower in the CIN (+) group (875 U/L vs 819 U/L, p= 0.004). In the regression analysis, diabetes mellitus, contrast volume and AREase activity were determined as independent risk factors in the development of CIN. As a result of the ROC analysis, we concluded that the AREase activity level

Synergistic role of circulating CD14++CD16+ monocytes and fibrinogen in predicting the cardiovascular events after myocardial infarction

BACKGROUND

Monocytes and fibrinogen (FIB) play important roles in driving acute and reparative inflammatory pathways after myocardial infarction (MI). In humans, there are three subsets of monocytes, namely, CD14++CD16- (Mon1), CD14++CD16+ (Mon2), and CD14+CD16++ (Mon3). During the inflammatory response, monocyte subsets express high levels of integrin α_M β₂ and protease-activated receptors 1 and 3 to interact with FIB.

HYPOTHESIS

However, whether there is a synergistic role of FIB combined with Mon2 counts in prioritizing patients at high risk of future major adverse cardiovascular events (MACEs) after MI remains unknown.

METHODS

The MI patients who treated with primary percutaneous coronary intervention were enrolled. MI patients were categorized into four groups, that is, low FIB/low Mon2, low FIB/high Mon2, high FIB/low Mon2, and high FIB/high Mon2, according to cutoff values of 3.28 g/L for FIB and 32.20 cells/μL for Mon2. Kaplan-Meier survival analysis and Cox proportional hazards models were used to estimate the risk of MACEs of MI patients during a median follow-up of 2.7 years. Mediating effects of high FIB levels and MACEs associated with high monocyte subsets were calculated by mediation analysis.

RESULTS

High FIB/high Mon2 group had the highest risk of MACEs during a median follow-up of 2.7 years. Moreover, mediation analysis showed that a high FIB level could explain 24.9% (p < .05) of the increased risk of MACEs associated with Mon2.

CONCLUSION

This work provides evidence indicating the translational potential of a synergistic role of FIB combined with Mon2 in prioritizing patients at high risk of future MACEs after MI.

Integrin-linked kinase (ILK): the known vs. the unknown and perspectives

Integrin-linked kinase (ILK) is a multifunctional molecular actor in cell-matrix interactions, cell adhesion, and anchorage-dependent cell growth. It combines functions of a signal transductor and a scaffold protein through its interaction with integrins, then facilitating further protein recruitment within the ILK-PINCH-Parvin complex. ILK is involved in crucial cellular processes including proliferation, survival, differentiation, migration, invasion, and angiogenesis, which reflects on systemic changes in the kidney, heart, muscle, skin, and vascular system, also during the embryonal development. Dysfunction of ILK underlies the pathogenesis of various diseases, including the pro-oncogenic activity in tumorigenesis. ILK localizes mostly to the cell membrane and remains an important component of focal adhesion. We do know much about ILK but a lot still remains either uncovered or unclear. Although it was initially classified as a serine/threonine-protein kinase, its catalytical activity is now questioned due to structural and functional issues, leaving the exact molecular mechanism of signal transduction by ILK unsolved. While it is known that the three isoforms of ILK vary in length, the presence of crucial domains, and modification sites, most of the research tends to focus on the main isoform of this protein while the issue of functional differences of ILK2 and ILK3 still awaits clarification. The activity of ILK is regulated on the transcriptional, protein, and post-transcriptional levels. The crucial role of phosphorylation and ubiquitylation has been investigated, but the functions of the vast majority of modifications are still unknown. In the light of all those open issues, here we present an extensive literature survey covering a wide spectrum of latest findings as well as a past-to-present view on controversies regarding ILK, finishing with pointing out some open questions to be resolved by further research.

Revisiting the lipid paradox in ST-elevation myocardial infarction in the Chinese population: findings from the CCC-ACS project

AIMS

Previous observations revealed a negative association between low-density lipoprotein cholesterol (LDL-C) and clinical outcomes following myocardial infarction, i.e., the lower level the higher mortality, which was referred to as lipid paradox. We sought to re-evaluate this association in ST-elevation myocardial infarction (STEMI) in contemporary practice.

METHODS AND RESULTS

We examined the association between admission LDL-C and in-hospital mortality among 44 563 STEMI patients enrolled from 2014 to 2019 in a nationwide registry in China. A total of 43 covariates, which were temporally classified into the following three domains were used for adjustment: (i) pre-admission characteristics; (ii) percutaneous coronary intervention (PCI)-related variables; and (iii) other in-hospital medications. In-hospital mortality was 2.01% (897/44 563). When no covariate adjustment was performed, an inversely 'J-shaped' curve was observed between admission LDL-C levels and in-hospital mortality by restricted cubic spline in logistic regression, with a threshold value of <75 mg/dL that associated with increased risk for in-hospital mortality. However, a gradual attenuation for this association was noted when step-wise adjustments were performed, with the threshold values for LDL-C decreasing from 75 mg/dL to 70 mg/dL after accounting for pre-admission characteristics, further to 65 mg/dL after accounting for PCI-related variables, and finally to no statistical association after further adjustment for other in-hospital medications.

CONCLUSIONS

In a nationwide registry in China, our findings do not support the lipid paradox in terms of in-hospital mortality in STEMI patients in contemporary practice. Previous findings in this scenario are possibly due to inadequate control for confounders.

An Allosteric Shift in CD11c Affinity Activates a Proatherogenic State in Arrested Intermediate Monocytes

Intermediate monocytes (iMo; CD14⁺CD16⁺) increase in number in the circulation of patients with unstable coronary artery disease (CAD), and their recruitment to inflamed arteries is implicated in events leading to mortality following MI. Monocyte recruitment to inflamed coronary arteries is initiated by high affinity β2-integrin (CD11c/CD18) that activates β1-integrin (VLA-4) to bind endothelial VCAM-1. How integrin binding under shear stress mechanosignals a functional shift in iMo toward an inflammatory phenotype associated with CAD progression is unknown. Whole blood samples from patients treated for symptomatic CAD including non-ST elevation MI, along with healthy age-matched subjects, were collected to assess chemokine and integrin receptor levels on monocytes. Recruitment on inflamed human aortic endothelium or rVCAM-1 under fluid shear stress was assessed using a microfluidic-based artery on a chip (A-Chip). Membrane upregulation of high affinity CD11c correlated with concomitant activation of VLA-4 within focal adhesive contacts was required for arrest and diapedesis across inflamed arterial endothelium to a greater extent in non-ST elevation MI compared with stable CAD patients. The subsequent conversion of CD11c from a high to low affinity state under fluid shear activated phospho-Syk- and ADAM17-mediated proteolytic cleavage of CD16. This marked the conversion of iMo to an inflammatory phenotype associated with nuclear translocation of NF-κB and production of IL-1β⁺ We conclude that CD11c functions as a mechanoregulator that activates an inflammatory state preferentially in a majority of iMo from cardiac patients but not healthy patients.