Low-density lipoprotein electronegativity and risk of death after acute coronary syndromes: A case-cohort analysis

Evolving concepts of low-density lipoprotein: From structure to function

BACKGROUND

Low-density lipoprotein (LDL) is a central player in atherogenesis and has long been referred to as 'bad cholesterol.' However, emerging evidence indicates that LDL functions in multifaceted ways beyond cholesterol transport that include roles in inflammation, immunity, and cellular signaling. Understanding LDL's structure, metabolism and function is essential for advancing cardiovascular disease research and therapeutic strategies.

METHODS

This narrative review examines the history, structural properties, metabolism and functions of LDL in cardiovascular health and disease. We analyze key milestones in LDL research, from its early identification to recent advancements in molecular biology and omics-based investigations. Structural and functional insights are explored through imaging, proteomic analyses and lipidomic profiling, providing a deeper understanding of LDL heterogeneity.

RESULTS

Low-density lipoprotein metabolism, from biosynthesis to receptor-mediated clearance, plays a crucial role in lipid homeostasis and atherogenesis. Beyond cholesterol transport, LDL contributes to plaque inflammation, modulates adaptive immunity and regulates cellular signaling pathways. Structural studies reveal its heterogeneous composition, which influences its pathogenic potential. Evolving perspectives on LDL redefine its clinical significance, affecting cardiovascular risk assessment and therapeutic interventions.

CONCLUSIONS

A holistic understanding of LDL biology challenges traditional perspectives and underscores its complexity in cardiovascular health. Future research should focus on further elucidating LDL's structural and functional diversity to refine risk prediction models and therapeutic strategies, ultimately improving cardiovascular outcomes.

Alterations in LDL and HDL after an ischemic stroke associated with carotid atherosclerosis are reversed after 1 year

Approximately, 20% of ischemic strokes are attributed to the presence of atherosclerosis. Lipoproteins play a crucial role in the development of atherosclerosis, with LDL promoting atherogenesis and HDL inhibiting it. Therefore, both their concentrations and their biological properties are decisive factors in atherosclerotic processes. In this study, we examined the qualitative properties of lipoproteins in ischemic stroke patients with carotid atherosclerosis. Lipoproteins were isolated from the blood of healthy controls (n = 27) and patients with carotid atherosclerosis (n = 64) at 7 days and 1 year postischemic stroke. Compared to controls, patients' LDL 7 days poststroke showed increased levels of apoC-III, triacylglycerol, and ceramide, along with decreased cholesterol and phospholipid content. LDL from patients induced more inflammation in macrophages than did LDL from controls. HDL isolated from patients 7 days after stroke showed alterations in the apolipoprotein cargo, with reduced levels of apoA-I and increased levels of apoA-II, and apoC-III compared to controls. Patients' HDL also showed a higher electronegative charge than that of controls and partially lost its ability to counteract the modification of LDL and the inflammatory effects of modified LDL. One year after stroke onset, the composition of patients' LDL and HDL resembled those of the controls. In parallel, LDL and HDL gained positive charge, LDL became less prone to oxidation and aggregation, and HDL regained protective properties. In conclusion, LDL and HDL in ischemic stroke patients with carotid atherosclerosis exhibited alterations in composition and function, which were partially reversed 1 year after stroke.

Proenkephalin improves cardio-renal risk prediction in acute coronary syndromes: the KID-ACS score

BACKGROUND AND AIMS

Circulating proenkephalin (PENK) is a stable endogenous polypeptide with fast response to glomerular dysfunction and tubular damage. This study examined the predictive value of PENK for renal outcomes and mortality in patients with acute coronary syndrome (ACS).

METHODS

Proenkephalin was measured in plasma in a prospective multicentre ACS cohort from Switzerland (n = 4787) and in validation cohorts from the UK (n = 1141), Czechia (n = 927), and Germany (n = 220). A biomarker-enhanced risk score (KID-ACS score) for simultaneous prediction of in-hospital acute kidney injury (AKI) and 30-day mortality was derived and externally validated.

RESULTS

On multivariable adjustment for established risk factors, circulating PENK remained associated with in-hospital AKI [per log2 increase: adjusted odds ratio 1.53, 95% confidence interval (CI) 1.13-2.09, P = .007] and 30-day mortality (adjusted hazard ratio 2.73, 95% CI 1.85-4.02, P < .001). The KID-ACS score integrates PENK and showed an area under the receiver operating characteristic curve (AUC) of .72 (95% CI .68-.76) for in-hospital AKI and .91 (95% CI .87-.95) for 30-day mortality in the derivation cohort. Upon external validation, KID-ACS achieved similarly high performance for in-hospital AKI (Zurich: AUC .73, 95% CI .70-.77; Czechia: AUC .75, 95% CI .68-.81; Germany: AUC .71, 95% CI .55-.87) and 30-day mortality (UK: AUC .87, 95% CI .83-.91; Czechia: AUC .91, 95% CI .87-.94; Germany: AUC .96, 95% CI .92-1.00), outperforming the contrast-associated AKI score and the Global Registry of Acute Coronary Events 2.0 score, respectively.

CONCLUSIONS

Circulating PENK offers incremental value for predicting in-hospital AKI and mortality in ACS. The simple six-item KID-ACS risk score integrates PENK and provides a novel tool for simultaneous assessment of renal and mortality risk in patients with ACS.

Body temperature, systemic inflammation and risk of adverse events in patients with acute coronary syndromes

BACKGROUND

Inflammatory processes can trigger acute coronary syndromes (ACS) which may increase core body temperature (BT), a widely available low-cost marker of systemic inflammation. Herein, we aimed to delineate baseline characteristics of ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation ACS (NSTE-ACS) patients stratified by initial BT and to assess its predictive utility towards major adverse cardiovascular events (MACE) after the index ACS.

METHODS

From 2012 until 2017, a total of 1044 ACS patients, 517 with STEMI and 527 with NSTE-ACS, were prospectively recruited at the University Hospital Zurich. BT was measured by digital tympanic thermometer along with high-sensitivity C-reactive protein (hs-CRP) and cardiac troponin-T (hs-cTnT) levels prior to coronary angiography. Patients were stratified according to initial BT and uni- and multivariable regression models were fit to assess associations of BT with future MACE risk.

RESULTS

Among patients with STEMI, BT was not predictive of 1-year MACE, but a U-shaped relationship between BT and MACE risk was noted in those with NSTE-ACS (p = .029), translating into a 2.4-fold (HR, 2.44, 95% CI, 1.16-5.16) increased 1-year MACE risk in those with BT >36.8°C (reference: 36.6-36.8°C). Results remained robust in multivariable-adjusted analyses accounting for sex, age, diabetes, renal function and hs-cTnT. However, when introducing hs-CRP, the BT-MACE association did not prevail.

CONCLUSIONS

In prospectively recruited patients with ACS, initial BT shows a U-shaped relationship with 1-year MACE risk among those with NSTE-ACS, but not in those with STEMI. BT is a broadly available low-cost marker to identify ACS patients with high inflammatory burden, at high risk for recurrent ischaemic events, and thus potentially suitable for an anti-inflammatory intervention.

REGISTRATION

ClinicalTrials.gov Identifier: NCT01000701.

Multi-modal transcriptomics: integrating machine learning and convolutional neural networks to identify immune biomarkers in atherosclerosis

BACKGROUND

Atherosclerosis, a complex chronic vascular disorder with multifactorial etiology, stands as the primary culprit behind consequential cardiovascular events, imposing a substantial societal and economic burden. Nevertheless, our current understanding of its pathogenesis remains imprecise. In this investigation, our objective is to establish computational models elucidating molecular-level markers associated with atherosclerosis. This endeavor involves the integration of advanced machine learning techniques and comprehensive bioinformatics analyses.

MATERIALS AND METHODS

Our analysis incorporated data from three publicly available the Gene Expression Omnibus (GEO) datasets: GSE100927 (104 samples, 30,558 genes), which includes atherosclerotic lesions and control arteries from carotid, femoral, and infra-popliteal arteries of deceased organ donors; GSE43292 (64 samples, 23,307 genes), consisting of paired carotid endarterectomy samples from 32 hypertensive patients, comparing atheroma plaques and intact tissues; and GSE159677 (30,498 single cells, 33,538 genes), examining single-cell transcriptomes of calcified atherosclerotic core plaques and adjacent carotid artery tissues from patients undergoing carotid endarterectomy. Utilizing single-cell sequencing, highly variable atherosclerotic monocyte subpopulations were systematically identified. We analyzed cellular communication patterns with temporal dynamics. The bioinformatics approach Weighted Gene Co-expression Network Analysis (WGCNA) identified key modules, constructing a Protein-Protein Interaction (PPI) network from module-associated genes. Three machine-learning models derived marker genes, formulated through logistic regression and validated via convolutional neural network(CNN) modeling. Subtypes were clustered based on Gene Set Variation Analysis (GSVA) scores, validated through immunoassays.

RESULTS

Three pivotal atherosclerosis-associated genes-CD36, S100A10, CSNK1A1-were unveiled, offering valuable clinical insights. Profiling based on these genes delineated two distinct isoforms: C2 demonstrated potent microbicidal activity, while C1 engaged in inflammation regulation, tissue repair, and immune homeostasis. Molecular docking analyses explored therapeutic potential for Estradiol, Zidovudine, Indinavir, and Dronabinol for clinical applications.

CONCLUSION

This study introduces three signature genes for atherosclerosis, shaping a novel paradigm for investigating clinical immunological medications. It distinguishes the high biocidal C2 subtype from the inflammation-modulating C1 subtype, utilizing identified signature gene as crucial targets.

Sex-specific prediction of cardiogenic shock after acute coronary syndromes: the SEX-SHOCK score

BACKGROUND AND AIMS

Cardiogenic shock (CS) remains the primary cause of in-hospital death after acute coronary syndromes (ACS), with its plateauing mortality rates approaching 50%. To test novel interventions, personalized risk prediction is essential. The ORBI (Observatoire Régional Breton sur l'Infarctus) score represents the first-of-its-kind risk score to predict in-hospital CS in ACS patients undergoing percutaneous coronary intervention (PCI). However, its sex-specific performance remains unknown, and refined risk prediction strategies are warranted.

METHODS

This multinational study included a total of 53 537 ACS patients without CS on admission undergoing PCI. Following sex-specific evaluation of ORBI, regression and machine-learning models were used for variable selection and risk prediction. By combining best-performing models with highest-ranked predictors, SEX-SHOCK was developed, and internally and externally validated.

RESULTS

The ORBI score showed lower discriminative performance for the prediction of CS in females than males in Swiss (area under the receiver operating characteristic curve [95% confidence interval]: 0.78 [0.76-0.81] vs. 0.81 [0.79-0.83]; P =.048) and French ACS patients (0.77 [0.74-0.81] vs. 0.84 [0.81-0.86]; P = .002). The newly developed SEX-SHOCK score, now incorporating ST-segment elevation, creatinine, C-reactive protein, and left ventricular ejection fraction, outperformed ORBI in both sexes (females: 0.81 [0.78-0.83]; males: 0.83 [0.82-0.85]; P < .001), which prevailed following internal and external validation in RICO (females: 0.82 [0.79-0.85]; males: 0.88 [0.86-0.89]; P < .001) and SPUM-ACS (females: 0.83 [0.77-0.90], P = .004; males: 0.83 [0.80-0.87], P = .001).

CONCLUSIONS

The ORBI score showed modest sex-specific performance. The novel SEX-SHOCK score provides superior performance in females and males across the entire spectrum of ACS, thus providing a basis for future interventional trials and contemporary ACS management.

Biomarker-enhanced cardiovascular risk prediction in patients with cancer: a prospective cohort study

BACKGROUND

Continuously improving cancer-specific survival puts a growing proportion of cancer patients at risk of major adverse cardiovascular events (MACE), but tailored tools for cardiovascular risk prediction remain unavailable.

OBJECTIVES

To assess a broad panel of cardiovascular biomarkers and risk factors for the prediction of MACE and cardiovascular death in cancer patients.

METHODS

In total, 2192 patients with newly diagnosed or recurrent cancer were followed prospectively for the occurrence of 2-year MACE and 5-year cardiovascular death. Univariable and multivariable risk models were fit to assess independent associations of cardiovascular risk factors and biomarkers with adverse outcomes, and a risk score was developed.

RESULTS

Traditional cardiovascular risk factors and selected cancer types were linked to higher MACE risk. While levels of Lp(a), CRP, and GDF-15 did not associate with MACE, levels of ICAM-1, P-/E-/L-selectins, and NT-proBNP were independently linked to 2-year MACE risk. A clinical risk score was derived, assigning +1 point for male sex, smoking, and age of ≥60 years and +2 points for atherosclerotic disease, yielding a bootstrapped C-statistic of 0.76 (95% CI: 0.71-0.81) for the prediction of 2-year MACE. Implementation of biomarker data conferred improved performance (0.83, 95% CI: 0.78-0.88), with a simplified model showing similar performance (0.80, 95% CI: 0.74-0.86). The biomarker-enhanced and simplified prediction models achieved a C-statistic of 0.82 (95% CI: 0.71-0.93) and 0.74 (95% CI: 0.64-0.83) for the prediction of 5-year cardiovascular death.

CONCLUSION

Biomarker-enhanced risk prediction strategies allow the identification of cancer patients at high risk of MACE and cardiovascular death. While external validation studies are ongoing, this first-of-its-kind risk score may provide the basis for personalized cardiovascular risk assessment across cancer entities.

Safety and effectiveness of glycoprotein IIb/IIIa inhibitors in acute coronary syndromes: insights from the SPUM-ACS study

AIMS

Data on glycoprotein IIb/IIIa inhibitor (GPI) use in real-world acute coronary syndrome (ACS) patients following the introduction of potent P2Y12 inhibitors and newer-generation stents are scant. Here, we aimed to assess the utilization, effectiveness, and safety of GPI in a large prospective multicentre cohort of contemporary ACS patients.

METHODS AND RESULTS

SPUM-ACS prospectively recruited patients presenting with ACS between 2009 and 2017. The primary endpoint of the present study was major adverse cardiovascular events (MACE), a composite of all-cause death, non-fatal myocardial infarction, and non-fatal stroke at 1 year. Secondary endpoints were defined as any bleeding events, Bleeding Academic Research Consortium (BARC) 3-5 bleeding, and net adverse cardiovascular events (NACE). A total of 4395 ACS patients were included in the analysis. GPI-treated patients had more total coronary artery occlusion (56% vs. 35%, P < 0.001) and thrombus (60% vs. 35%, P < 0.001) at angiography. Among the propensity score-matched (PSM) population (1992 patients equally split into two groups), GPI-treated patients showed lower risk of MACE [PSM adjusted hazard ratio (HR) 0.70, 95% CI 0.49-0.99], but a higher risk of any (PSM adjusted HR 1.46, 95% CI 1.06-1.99) and major bleedings (PSM adjusted HR 1.73, 95% CI 1.09-2.76), resulting in a neutral effect on NACE (PSM adjusted HR 0.87, 95% CI 0.65-1.17). These results remained consistent across all subgroups.

CONCLUSIONS

In patients with ACS undergoing percutaneous coronary intervention and receiving potent P2Y12 inhibitors, we observed a reduced risk of MACE and an increased risk of major bleedings at 1 year in patients treated with GPI. Although the routine use of GPI is currently not recommended, they might be considered in selected patients following a personalized balancing between ischaemic and bleeding risks.

Non-HDL cholesterol and residual cardiovascular risk in statin-treated patients with and without diabetes: the Western Denmark Heart Registry

AIMS

Assessment of residual cardiovascular risk in statin-treated patients with atherosclerotic cardiovascular disease (ASCVD) is pivotal for optimizing secondary preventive therapies. This study investigates if non-high-density lipoprotein cholesterol (non-HDL-C) is associated with residual ASCVD risk in statin-treated ischaemic heart disease (IHD) patients with and without diabetes.

METHODS AND RESULTS

Using the Western Denmark Heart Registry, we identified statin-treated patients with IHD examined by coronary angiography (CAG) from 2011 to 2020. Non-HDL-C was assessed within 1 year after CAG. Outcomes were ASCVD (myocardial infarction, ischaemic stroke, and cardiovascular death) and all-cause death. Cox regression analyses obtained hazard ratios (HRs) adjusted for age, sex, smoking, and hypertension. A total of 42 057 patients were included: 8196 patients with diabetes and 33 861 without diabetes. During the median 4.6 years of follow-up, event rates per 1000 person-years of ASCVD were 28.8 (27.1-30.5) and 17.2 (16.5-17.8) among patients with and without diabetes. In patients with diabetes, the adjusted HRs of ASCVD as compared with non-HDL-C < 25th percentile were 1.0 (0.9-1.2), 1.3 (1.1-1.6), and 1.6 (1.2-2.1) for patients in the 25th-74th, 75th-94th, and ≥95th percentiles. In patients without diabetes, the corresponding adjusted HRs were 1.1 (0.9-1.1), 1.2 (1.1-1.4), and 1.7 (1.4-2.0). Results were consistent across sex, age, clinical presentation, and low-density lipoprotein cholesterol strata.

CONCLUSION

In statin-treated IHD patients with and without diabetes, non-HDL-C, especially above the 75th percentile, is associated with residual cardiovascular risk. These results have implications for secondary prevention, targeting patients who may benefit most from intensified preventive therapy.

Prognostic value of elevated lipoprotein (a) in patients with acute coronary syndromes: a systematic review and meta-analysis

Background

Elevated lipoprotein (a) level was recognized as an independent risk factor for significant adverse cardiovascular events in acute coronary syndrome (ACS) patients. Despite this recognition, the consensus in the literature regarding the prognostic significance of elevated lipoprotein (a) in ACS was also limited. Consequently, we conducted a thorough systematic review and meta-analysis to evaluate the prognostic relevance of elevated lipoprotein (a) level in individuals diagnosed with ACS.

Methods and results

A thorough literature review was conducted by systematically searching PubMed, Embase, and Cochrane databases until September 2023. This review specifically examined cohort studies exploring the prognostic implications of elevated lipoprotein (a) level in relation to major adverse cardiovascular events (MACE), including death, stroke, non-fatal myocardial infarction (MI), and coronary revascularization, in patients with ACS. The meta-analysis utilized aggregated multivariable hazard ratios (HR) and their respective 95% confidence intervals (CI) to evaluate prognostic implications between high and low lipoprotein (a) levels [the cut-off of high lipoprotein (a) level varies from 12.5 to 60 mg/dl]. Among 18,168 patients in the identified studies, elevated lipoprotein (a) was independently associated with increased MACE risk (HR 1.26; 95% CI: 1.17-1.35, P < 0.00001) and all-cause mortality (HR 1.36; 95% CI: 1.05-1.76, P = 0.02) in ACS patients. In summary, elevated lipoprotein (a) levels independently forecast MACE and all-cause mortality in ACS patients. Assessing lipoprotein (a) levels appears promising for risk stratification in ACS, offering valuable insights for tailoring secondary prevention strategies.

Systematic Review Registration

PROSPERO (CRD42023476543).

Myocardial infarction drives trained immunity of monocytes, accelerating atherosclerosis

BACKGROUND AND AIMS

Survivors of acute coronary syndromes face an elevated risk of recurrent atherosclerosis-related vascular events despite advanced medical treatments. The underlying causes remain unclear. This study aims to investigate whether myocardial infarction (MI)-induced trained immunity in monocytes could sustain proatherogenic traits and expedite atherosclerosis.

METHODS

Apolipoprotein-E deficient (ApoE-/-) mice and adoptive bone marrow transfer chimeric mice underwent MI or myocardial ischaemia-reperfusion (IR). A subsequent 12-week high-fat diet (HFD) regimen was implemented to elucidate the mechanism behind monocyte trained immunity. In addition, classical monocytes were analysed by flow cytometry in the blood of enrolled patients.

RESULTS

In MI and IR mice, blood monocytes and bone marrow-derived macrophages exhibited elevated spleen tyrosine kinase (SYK), lysine methyltransferase 5A (KMT5A), and CCHC-type zinc finger nucleic acid-binding protein (CNBP) expression upon exposure to a HFD or oxidized LDL (oxLDL) stimulation. MI-induced trained immunity was transmissible by transplantation of bone marrow to accelerate atherosclerosis in naive recipients. KMT5A specifically recruited monomethylation of Lys20 of histone H4 (H4K20me) to the gene body of SYK and synergistically transactivated SYK with CNBP. In vivo small interfering RNA (siRNA) inhibition of KMT5A or CNBP potentially slowed post-MI atherosclerosis. Sympathetic denervation with 6-hydroxydopamine reduced atherosclerosis and inflammation after MI. Classical monocytes from ST-elevation MI (STEMI) patients with advanced coronary lesions expressed higher SYK and KMT5A gene levels.

CONCLUSIONS

The findings underscore the crucial role of monocyte trained immunity in accelerated atherosclerosis after MI, implying that SYK in blood classical monocytes may serve as a predictive factor for the progression of atherosclerosis in STEMI patients.

Circulating GDF11 exacerbates myocardial injury in mice and associates with increased infarct size in humans

AIMS

The heart rejuvenating effects of circulating growth differentiation factor 11 (GDF11), a transforming growth factor-β superfamily member that shares 90% homology with myostatin (MSTN), remains controversial. Here, we aimed to probe the role of GDF11 in acute myocardial infarction (MI), a frequent cause of heart failure and premature death during ageing.

METHODS AND RESULTS

In contrast to endogenous Mstn, myocardial Gdf11 declined during the course of ageing and was particularly reduced following ischaemia/reperfusion (I/R) injury, suggesting a therapeutic potential of GDF11 signalling in MI. Unexpectedly, boosting systemic Gdf11 by recombinant GDF11 delivery (0.1 mg/kg body weight over 30 days) prior to myocardial I/R augmented myocardial infarct size in C57BL/6 mice irrespective of their age, predominantly by accelerating pro-apoptotic signalling. While intrinsic cardioprotective signalling pathways remained unaffected by high circulating GDF11, targeted transcriptomics and immunomapping studies focusing on GDF11-associated downstream targets revealed attenuated Nkx2-5 expression confined to CD105-expressing cells, with pro-apoptotic activity, as assessed by caspase-3 levels, being particularly pronounced in adjacent cells, suggesting an indirect effect. By harnessing a highly specific and validated liquid chromatography-tandem mass spectrometry-based assay, we show that in prospectively recruited patients with MI circulating GDF11 but not MSTN levels incline with age. Moreover, GDF11 levels were particularly elevated in those at high risk for adverse outcomes following the acute event, with circulating GDF11 emerging as an independent predictor of myocardial infarct size, as estimated by standardized peak creatine kinase-MB levels.

CONCLUSION

Our data challenge the initially reported heart rejuvenating effects of circulating GDF11 and suggest that high levels of systemic GDF11 exacerbate myocardial injury in mice and humans alike. Persistently high GDF11 levels during ageing may contribute to the age-dependent loss of cardioprotective mechanisms and thus poor outcomes of elderly patients following acute MI.

Short and medium chain acylcarnitines as markers of outcome in diabetic and non-diabetic subjects with acute coronary syndromes

BACKGROUND

Carnitine metabolism produces numerous molecular species of short-, medium-, and long-chain acylcarnitines, which play important roles in energy homeostasis and fatty acid transport in the myocardium. Given that disturbances in the carnitine metabolism are linked to cardiometabolic disease, we studied the relationship of circulating acylcarnitines with outcomes in patients with acute coronary syndromes (ACS) and evaluated differences in circulating levels of these metabolites between diabetic and non-diabetic patients.

METHODS

Harnessing a prospective multicentre cohort study (SPUM-ACS; NCT01000701), we measured plasma levels of acylcarnitines, carnitine, and carnitine metabolites to assess their relationship with adjudicated major adverse cardiac events (MACE), defined as composite of myocardial infarction, stroke, clinically indicated revascularization, or death of any cause. The SPUM-ACS study enrolled patients presenting with ACS to Swiss University Hospitals between 2009 and 2012. Acetylcarnitine, octanoylcarnitine, proprionylcarnitine, butyrylcarnitine, pentanoylcarnitine, hexanoylcarnitine, carnitine, γ-butyrobetaine, and trimethylamine N-oxide were measured in plasma using stable isotope dilution high-performance liquid chromatography with online electrospray ionization tandem mass spectrometry.

RESULTS

A total of 1683 patients with ACS were included in the study. All measured metabolites except γ-butyrobetaine and carnitine were higher in diabetic subject (n = 294) than in non-diabetic subjects (n = 1389). On univariate analysis, all metabolites, apart from octenoylcarnitine, were significantly associated with MACE at 1 year. After multivariable adjustment for established risk factors, acetylcarnitine remained an independent predictor of MACE at 1-year (quartile 4 vs. quartile 1, adjusted hazard ratio 2.06; 95% confidence interval 1.12-3.80, P = 0.020).

CONCLUSION

Circulating levels of acetylcarnitine independently predict residual cardiovascular risk in patients with ACS.

TCA cycle metabolites associated with adverse outcomes after acute coronary syndrome: mediating effect of renal function

Aims

To examine relationships of tricarboxylic acid (TCA) cycle metabolites with risk of cardiovascular events and mortality after acute coronary syndrome (ACS), and evaluate the mediating role of renal function in these associations.

Methods

This is a prospective study performed among 309 ACS patients who were followed for a mean of 6.7 years. During this period 131 patients developed major adverse cardiovascular events (MACE), defined as the composite of myocardial infarction, hospitalization for heart failure, and all-cause mortality, and 90 deaths were recorded. Plasma concentrations of citrate, aconitate, isocitrate, succinate, malate, fumarate, α-ketoglutarate and d/l-2-hydroxyglutarate were quantified using LC-tandem MS. Multivariable Cox regression models were used to estimate hazard ratios, and a counterfactual-based mediation analysis was performed to test the mediating role of estimated glomerular filtration rate (eGFR).

Results

After adjustment for traditional cardiovascular risk factors and medications, positive associations were found between isocitrate and MACE (HR per 1 SD, 1.25; 95% CI: 1.03, 1.50), and between aconitate, isocitrate, d/l-2-hydroxyglutarate and all-cause mortality (HR per 1 SD, 1.41; 95% CI: 1.07, 1.84; 1.58; 95% CI: 1.23, 2.02; 1.38; 95% CI: 1.14, 1.68). However, these associations were no longer significant after additional adjustment for eGFR. Mediation analyses demonstrated that eGFR is a strong mediator of these associations.

Conclusion

These findings underscore the importance of TCA metabolites and renal function as conjunctive targets in the prevention of ACS complications.