Association between interleukin-6 and the risk of cardiac events measured by coronary computed tomography angiography

Cardiac biomarkers and CT coronary angiography for the assessment of coronary heart disease

Over the last 30 years, the widespread use of cardiac biomarkers has transformed the diagnostic evaluation of patients with coronary heart disease. Cardiac troponin is integral to the definition of acute myocardial infarction. High-sensitivity cardiac troponin (hs-cTn) assays can improve risk stratification to facilitate both the rapid rule out of myocardial infarction and prediction of future cardiovascular events. Numerous circulating biomarkers representing different pathological pathways improve prediction of atherosclerotic cardiovascular disease (ACVD) and coronary artery disease (CAD). In parallel, coronary computed tomography angiography (CCTA) has become the most widely used imaging modality for the evaluation of patients with possible angina. CCTA now allows for the quantification of coronary calcification, atherosclerotic plaque volume and different plaque characteristics, enabling the identification high-risk features and inflammation. In the future, the use of CCTA is likely to extend to risk stratification for the prevention of ACVD. As such, how to integrate these diagnostic and prognostic circulating and imaging biomarkers is a topic of considerable interest. This review aims to describe current status and future possibilities for the integration of CCTA and cardiac biomarker testing to improve the identification and treatment of individuals with coronary heart disease and heightened cardiovascular risk.

Platelet-Leukocyte Aggregate and Interleukin-6: An Emerging Perspective on a New Diagnostic and Therapeutic Clue for Acute Coronary Syndrome, A Case-Control Study

Background and Aims

Acute coronary syndrome (ACS) is one of the most important cardiovascular diseases. The rupture of atherosclerotic plaques in coronary arteries is considered the underlying pathophysiology of ACS. The interaction between cytokines and leukocytes in the presence of platelets results in platelet-leukocyte aggregate (PLA). Monocytes, neutrophils, and cytokines are prime factors that promote PLA formation, which leads to atherosclerotic plaque progression and subsequent ACS development. This study aimed to investigate PLA (PMA and PNA) formation and cytokine (IL-6 and TNF-α) levels as well as the correlation between them in ACS patient samples to identify diagnostic markers.

Methods

A total of 30 patients with ACS and 24 healthy controls participated in this study. Flow cytometry analysis was performed to evaluate PLA formation, and the serum levels of cytokines were assessed by ELISA. The Pearson's correlation coefficient and ROC curve were calculated to investigate the correlation between the parameters and their diagnostic value, respectively.

Results

The results showed that PMA, PNA, and IL-6 levels were significantly higher in ACS patients than in healthy controls. Additionally, TNF-α levels were not significantly increased in the patient group. In addition, the Pearson's correlation coefficient results revealed a direct linear and statistically significant relationship between PMA-IL-6 and PNA-IL-6 as well as a direct linear but statistically nonsignificant relationship between IL-6-TNF-α and PMA-PNA, whereas a convers linear but nonsignificant correlation was shown between PMA and TNF-α and no correlation was detected between PNA and TNF-α. Finally, ROC curve analysis revealed that the PMA, PNA, and IL-6 can have diagnostic value.

Conclusion

In conclusion, the PMA, PNA, and IL-6 can be used as powerful diagnostic markers in ACS patients. Therefore, disrupting PMA and PNA formation and inhibiting cytokine production may be new strategies for the treatment of ACS. However, further investigations are required to explore these parameters in the clinical diagnosis of ACS.

Relationship between serum interleukin-6 levels and severity of coronary artery disease undergoing percutaneous coronary intervention

BACKGROUND

Cytokines play a potential role in atherosclerosis pathogenesis and progression. We investigated the association of interleukin-6 (IL-6) with the angiographic severity of coronary artery disease (CAD).

METHODS

Three hundred ten angiografically diagnosed CAD patients and 210 controls were enrolled in this study. CAD patients were stratified according to IL-6 cut-off value into high levels IL-6 group (≥ 9.5 pg/mL) and low levels IL-6 group (< 9.5 pg/mL). The severity of CAD was assessed according to Gensini score (GS), artery stenosis degree and the number of vessels involved. The mean age was 60.3 ± 11.0 years.

RESULTS

The level of IL-6 in patients was increased compared to controls and ranged from 1.5 to 3640.0 pg/mL. High levels of IL-6 were significantly associated with high levels of GS (> 40) but not with stenosis degree and vessel score. GS levels were significantly more elevated in patients with high levels of IL-6 group than in low IL6 levels patients (60.6 ± 39.5 vs 46.7 ± 37.2; p = 0.027). The analysis of the ROC curve performed in myocardial infarction patients showed that IL-6 (AUC: 0.941 (CI 95% 0.886, 0.997; p < 0.001) could be a powerful predictor marker in evaluating the infarct size after myocardial infarction when compared to myonecrosis biomarkers.

CONCLUSIONS

IL-6 levels were associated with the severity of CAD assessed by the GS. Based on the highest levels of IL-6 measured in patients with STEMI, our study strongly suggests that IL-6 could be a powerful marker in evaluating the myocardial necrosis.

TRIAL REGISTRATION

ClinicalTrials.gov Number: NCT03075566 (09/03/2017).

Novel Biomarkers for Atherosclerotic Disease: Advances in Cardiovascular Risk Assessment

Atherosclerosis is a significant health concern with a growing incidence worldwide. It is directly linked to an increased cardiovascular risk and to major adverse cardiovascular events, such as acute coronary syndromes. In this review, we try to assess the potential diagnostic role of biomarkers in the early identification of patients susceptible to the development of atherosclerosis and other adverse cardiovascular events. We have collected publications concerning already established parameters, such as low-density lipoprotein cholesterol (LDL-C), as well as newer markers, e.g., apolipoprotein B (apoB) and the ratio between apoB and apoA. Additionally, given the inflammatory nature of the development of atherosclerosis, high-sensitivity c-reactive protein (hs-CRP) or interleukin-6 (IL-6) are also discussed. Additionally, newer publications on other emerging components linked to atherosclerosis were considered in the context of patient evaluation. Apart from the already in-use markers (e.g., LDL-C), emerging research highlights the potential of newer molecules in optimizing the diagnosis of atherosclerotic disease in earlier stages. After further studies, they might be fully implemented in the screening protocols.

Coronary Atherosclerosis, Cardiac Troponin, and Interleukin-6 in Patients With Chest Pain

BACKGROUND

Increased inflammation and myocardial injury can be observed in the absence of myocardial infarction or obstructive coronary artery disease (CAD).

OBJECTIVES

The authors determined whether biomarkers of inflammation and myocardial injury-interleukin (IL)-6 and high-sensitivity cardiac troponin (hs-cTn)-were associated with the presence and extent of CAD and were independent predictors of major adverse cardiovascular events (MACEs) in stable chest pain.

METHODS

Using participants from the PROMISE trial, the authors measured hs-cTn I and IL-6 concentrations and analyzed computed tomography angiography (CTA) images in the core laboratory for CAD characteristics: significant stenosis (≥70%), high-risk plaque (HRP), Coronary Artery Disease Reporting and Data System (CAD-RADS) categories, segment involvement score (SIS), and coronary artery calcium (CAC) score. The primary endpoint was a composite MACE (death, myocardial infarction, or unstable angina).

RESULTS

The authors included 1,796 participants (age 60.2 ± 8.0 years; 47.5% men, median follow-up 25 months). In multivariable linear regression adjusted for atherosclerotic cardiovascular disease (ASCVD) risk, hs-cTn was associated with HRP, stenosis, CAD-RADS, and SIS. IL-6 was only associated with stenosis and CAD-RADS. hs-cTn above median (1.5 ng/L) was associated with MACEs in univariable analysis (HR: 2.1 [95% CI: 1.3-3.6]; P = 0.006), but not in multivariable analysis adjusted for ASCVD and CAD. IL-6 above median (1.8 ng/L) was associated with MACEs in multivariable analysis adjusted for ASCVD and HRP (HR: 1.9 [95% CI: 1.1-3.3]; P = 0.03), CAC (HR: 1.9 [95% CI: 1.0-3.4]; P = 0.04), and SIS (HR: 1.8 [95% CI: 1.0-3.2]; P = 0.04), but not for stenosis or CAD-RADS. In participants with nonobstructive CAD (stenosis 1%-69%), the presence of both hs-cTn and IL-6 above median was strongly associated with MACEs (HR: 2.5-2.7 after adjustment for CAD characteristics).

CONCLUSIONS

Concentrations of hs-cTn and IL-6 were associated with CAD characteristics and MACEs, indicating that myocardial injury and inflammation may each contribute to pathways in CAD pathophysiology. This association was most pronounced among participants with nonobstructive CAD representing an opportunity to tailor treatment in this at-risk group. (PROspective Multicenter Imaging Study for Evaluation of Chest Pain [PROMISE]; NCT01174550).

Acute Changes in Interleukin-6 Level During Four Days of Long-Distance Walking

Background

Interleukin 6 (IL-6) has an inflammatory effect, and its concentration in serum increases during exercise. However, no studies have assessed acute changes in IL-6 concentration after consecutive days of extreme and long-term exercise.

Objective

This study aimed to assess acute changes in serum IL-6 concentration during four days of long-distance walking.

Methods

This prospective observational study assessed 25 athletes (aged 44.8 ± 9.1 years), who covered a total of 251 km in four days. Blood samples were collected daily to assess serum IL-6 concentrations. Repeated-measures analysis of variance (with Bonferroni’s post hoc test) and the Kruskal–Wallis H-test (with Dunn’s post hoc test) were used to investigate the differences between the measures.

Results

The serum IL-6 concentrations were higher on the four days of walking (1st day: 26.8 ± 14.8; 2nd day: 14 ± 7.4; 3rd day: 9.4 ± 10.8; 4th day: 4.5 ± 0.2 pg/mL) when compared to pre-walk values (pre-walk: 2.2 ± 2.1 pg/mL; p < 0.001). On the first day, there was a tenfold increase compared to the pre-walk value.

Conclusion

The inflammatory response increased the serum concentration of IL-6 after four days of exercise. With the passing of days, there were reductions but not to baseline values.

Sudden Cardiac Death (SCD) - risk stratification and prediction with molecular biomarkers

Sudden cardiac death (SCD) is a sudden, unexpected death that is caused by the loss of heart function. While SCD affects many patients suffering from coronary artery diseases (CAD) and heart failure (HF), a considerable number of SCD events occur in asymptomatic individuals. Certain risk factors for SCD have been identified and incorporated in different clinical scores, however, risk stratification using such algorithms is only useful for health management rather than for early detection and prediction of future SCD events in high-risk individuals. In this review, we discuss different molecular biomarkers that are used for early detection of SCD. This includes genetic biomarkers, where the majority of them are genomic variants for genes that encode for ion channels. Meanwhile, protein biomarkers often denote proteins that play roles in pathophysiological processes that lead to CAD and HF, notably (i) atherosclerosis that involves oxidative stress and inflammation, as well as (ii) cardiac tissue damage that involves neurohormonal and hemodynamic regulation and myocardial stress. Finally, we outline existing challenges and future directions including the use of OMICS strategy for biomarker discovery and the multimarker panels.

Clinical utility of circulating interleukin-6 concentrations in the detection of functionally relevant coronary artery disease

BACKGROUND

Inflammation plays a major role in the pathogenesis of coronary artery disease (CAD).

METHODS

We hypothesized, that quantifying inflammation by measuring circulating interleukin-6 concentrations help in the diagnosis and/or prediction of functionally relevant CAD. Among consecutive patients with symptoms suggestive of CAD, functionally relevant CAD was adjudicated in two domains: first, diagnosis according to myocardial perfusion single photon emission tomography (MPI-SPECT) and coronary angiography; second, cardiovascular death and all-cause death during 2-years follow-up. Adjudication was done blinded to the interleukin-6 concentrations.

RESULTS

Among 1553 patients, symptoms were adjudicated to be causally related to CAD in 43% (665/1553). Interleukin-6 concentrations were higher in patients with functionally relevant CAD as compared to those without (1.56 pg/mL versus 1.30 pg/mL, p < 0.001), but overall had only low-to-modest diagnostic accuracy (area under the curve [AUC]: 0.57, 95%CI 0.55-0.61) and were no independent predictor of functionally relevant CAD after multivariable adjustment (p = 0.068). Interleukin-6 concentrations had moderate-to-high accuracy in the prediction of cardiovascular death (AUC 0.75, 95%CI 0.69-0.82) and all-cause death (AUC 0.72, 95%CI 0.66-0.78) at 2-years, and remained a significant predictor after multivariable adjustment (p < 0.001). Compared to patients with interleukin-6 concentrations below the median (1.41 pg/mL), patients with concentrations above the median had a significantly higher cumulative incidence of cardiovascular death (1% vs. 4%, log-rank p < 0.001) and all-cause death (2% vs. 8%, log-rank p < 0.001) at 2 years.

CONCLUSION

Interleukin-6 concentrations are strong and independent predictors of cardiovascular death and all-cause death.

Increased glycoprotein acetylation is associated with high cardiac event rates: Analysis using coronary computed tomography angiography

Objective:

Glycoprotein acetylation (GlycA), an emerging inflammatory biomarker, has been used as an indicator of cardiovascular disease. Our research aimed to evaluate the correlation between GlycA and coronary artery disease (CAD) using coronary computed tomography angiography (CCTA).

Methods:

In the present study, a total of 342 patients were enrolled, and each of them underwent CCTA. The correlation between GlycA and major adverse cardiac events (MACE) was detected via Cox’s proportional hazards models. Based on differences in the GlycA level, patients were categorized into three groups (T1, T2, and T3).

Results:

Compared with the group with the lowest GlycA level (T1), the group with the highest GlycA level (T3) exhibited stronger atherosclerotic pressure involving the extent of atherosclerotic plaque and risk of obstructive CAD. In addition, the patients in the T3 group had a greater chance of experiencing MACE and higher all-cause mortality than those in the T1 group. Among patients without CAD who underwent CCTA, those with high GlycA levels experienced elevated atherosclerotic stress and heightened risk of MACE compared with those with low GlycA levels.

Conclusion:

These results suggest that serum GlycA is significantly associated with the long-term clinical results of patients with no known CAD undergoing CCTA. The risks of death and experiencing MACE increase among patients with high GlycA levels.

Coronary computed tomography angiography detection of short- and long-term outcomes after heart valve surgery with high risk cardiovascular patients

Coronary computed tomography angiography (CCTA) is a promising alternative technique to detect significant coronary artery lesions in high-risk cardiovascular patients with left ventricular dysfunction (left ventricular ejection fractions < 40%) referred for elective valve surgery, while little research about the use of CCTA to detect the outcomes of heart valve surgery was performed. Forty-six consecutive high-risk cardiovascular patients with the New York Heart Association (NYHA) classification were retrospectively studied. Immediate, 10-week, 20-week, and 40-week outcomes after heart valve surgery were assessed with CCTA. Patients' average age at the time of surgery was 73 years, with the majority being male (54.35%). Among the CCTA parameters detected after 10, 20, and 40 weeks after heart valve surgery, only segment involvement score (SIS) did reach statistical significance when compared with baseline levels. The cumulative mortality rate at 10, 20, and 40 weeks were 19.56%, 30.43%, and 39.13% respectively. It can be seen that the early death is mainly due to complications, and with the time-lapse of surgery, the impact of complications on death is gradually eliminated. CCTA might be a useful tool to detect the outcomes of short- and long-term outcomes after heart valve surgery with high risk cardiovascular patients, and SIS level is associated with the short- and long-term outcomes.