Role of Cardiac Biomarkers in Epidemiology and Risk Outcomes

Prognostic Value of Cardiovascular Biomarkers in the Population

Importance

Identification of individuals at high risk for atherosclerotic cardiovascular disease within the population is important to inform primary prevention strategies.

Objective

To evaluate the prognostic value of routinely available cardiovascular biomarkers when added to established risk factors.

Design, Setting, and Participants

Individual-level analysis including data on cardiovascular biomarkers from 28 general population-based cohorts from 12 countries and 4 continents with assessments by participant age. The median follow-up was 11.8 years.

Exposure

Measurement of high-sensitivity cardiac troponin I, high-sensitivity cardiac troponin T, N-terminal pro-B-type natriuretic peptide, B-type natriuretic peptide, or high-sensitivity C-reactive protein.

Main Outcomes and Measures

The primary outcome was incident atherosclerotic cardiovascular disease, which included all fatal and nonfatal events. The secondary outcomes were all-cause mortality, heart failure, ischemic stroke, and myocardial infarction. Subdistribution hazard ratios (HRs) for the association of biomarkers and outcomes were calculated after adjustment for established risk factors. The additional predictive value of the biomarkers was assessed using the C statistic and reclassification analyses.

Results

The analyses included 164 054 individuals (median age, 53.1 years [IQR, 42.7-62.9 years] and 52.4% were women). There were 17 211 incident atherosclerotic cardiovascular disease events. All biomarkers were significantly associated with incident atherosclerotic cardiovascular disease (subdistribution HR per 1-SD change, 1.13 [95% CI, 1.11-1.16] for high-sensitivity cardiac troponin I; 1.18 [95% CI, 1.12-1.23] for high-sensitivity cardiac troponin T; 1.21 [95% CI, 1.18-1.24] for N-terminal pro-B-type natriuretic peptide; 1.14 [95% CI, 1.08-1.22] for B-type natriuretic peptide; and 1.14 [95% CI, 1.12-1.16] for high-sensitivity C-reactive protein) and all secondary outcomes. The addition of each single biomarker to a model that included established risk factors improved the C statistic. For 10-year incident atherosclerotic cardiovascular disease in younger people (aged <65 years), the combination of high-sensitivity cardiac troponin I, N-terminal pro-B-type natriuretic peptide, and high-sensitivity C-reactive protein resulted in a C statistic improvement from 0.812 (95% CI, 0.8021-0.8208) to 0.8194 (95% CI, 0.8089-0.8277). The combination of these biomarkers also improved reclassification compared with the conventional model. Improvements in risk prediction were most pronounced for the secondary outcomes of heart failure and all-cause mortality. The incremental value of biomarkers was greater in people aged 65 years or older vs younger people.

Conclusions and Relevance

Cardiovascular biomarkers were strongly associated with fatal and nonfatal cardiovascular events and mortality. The addition of biomarkers to established risk factors led to only a small improvement in risk prediction metrics for atherosclerotic cardiovascular disease, but was more favorable for heart failure and mortality.

Biomarker-based prediction of fatal and non-fatal cardiovascular outcomes in individuals with diabetes mellitus

AIMS

The role of biomarkers in predicting cardiovascular outcomes in high-risk individuals is not well established. We aimed to investigate benefits of adding biomarkers to cardiovascular risk assessment in individuals with and without diabetes.

METHODS AND RESULTS

We used individual-level data of 95 292 individuals of the European population harmonized in the Biomarker for Cardiovascular Risk Assessment across Europe consortium and investigated the prognostic ability of high-sensitivity cardiac troponin I (hs-cTnI), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and high-sensitivity C-reactive protein (hs-CRP). Cox-regression models were used to determine adjusted hazard ratios of diabetes and log-transformed biomarkers for fatal and non-fatal cardiovascular events. Models were compared using the likelihood ratio test. Stratification by specific biomarker cut-offs was performed for crude time-to-event analysis using Kaplan-Meier plots. Overall, 6090 (6.4%) individuals had diabetes at baseline, median follow-up was 9.9 years. Adjusting for classical risk factors and biomarkers, diabetes [HR 2.11 (95% CI 1.92, 2.32)], and all biomarkers (HR per interquartile range hs-cTnI 1.08 [95% CI 1.04, 1.12]; NT-proBNP 1.44 [95% CI 1.37, 1.53]; hs-CRP 1.27 [95% CI 1.21, 1.33]) were independently associated with cardiovascular events. Specific cut-offs for each biomarker identified a high-risk group of individuals with diabetes losing a median of 15.5 years of life compared to diabetics without elevated biomarkers. Addition of biomarkers to the Cox-model significantly improved the prediction of outcomes (likelihood ratio test for nested models P < 0.001), accompanied by an increase in the c-index (increase to 0.81).

CONCLUSION

Biomarkers improve cardiovascular risk prediction in individuals with and without diabetes and facilitate the identification of individuals with diabetes at highest risk for cardiovascular events.

The Effects of Statins on Cardiovascular and Inflammatory Biomarkers in Primary Prevention: A Systematic Review and Meta-Analysis

BACKGROUND

Statins are well-established for their treatment of cardiovascular disease (CVD) due to their cholesterol-lowering effects and potential anti-inflammatory properties. Although previous systematic reviews demonstrate that statins reduce inflammatory biomarkers in the secondary prevention of CVD, none examine their effects on cardiac and inflammatory biomarkers in a primary prevention setting.

METHODS

We conducted a systematic review and meta-analysis to examine the effects of statins on cardiovascular and inflammatory biomarkers among individuals without established CVD. The biomarkers included are: cardiac troponin, N-terminal pro B-type natriuretic peptide (NT-proBNP), C-reactive protein (CRP), tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), soluble vascular cell adhesion molecule (sVCAM), soluble intercellular adhesion molecule (sICAM), soluble E-selectin (sE-selectin) and endothelin-1 (ET-1). A literature search was performed through Ovid MEDLINE, Embase and CINAHL Plus for randomised controlled trials (RCTs) published up to June 2021.

RESULTS

Overall, 35 RCTs with 26,521 participants were included in our meta-analysis. Data was pooled using random effects models presented as standardised mean differences (SMD) with 95% confidence intervals (CI). Combining 36 effect sizes from 29 RCTs, statin use resulted in a significant reduction in CRP levels (SMD -0.61; 95% CI -0.91, -0.32; P<0.001). This reduction was observed for both hydrophilic (SMD -0.39; 95% CI -0.62, -0.16; P<0.001) and lipophilic statins (SMD -0.65; 95% CI -1.01, -0.29; P<0.001). There were no significant changes in serum concentrations of cardiac troponin, NT-proBNP, TNF-α, IL-6, sVCAM, sICAM, sE-selectin and ET-1.

CONCLUSION

This meta-analysis demonstrates that statin use reduces serum CRP levels in a primary prevention setting for CVD, with no clear effect on the other eight biomarkers studied.

Inflammageing and Cardiovascular System: Focus on Cardiokines and Cardiac-Specific Biomarkers

The term "inflammageing" was introduced in 2000, with the aim of describing the chronic inflammatory state typical of elderly individuals, which is characterized by a combination of elevated levels of inflammatory biomarkers, a high burden of comorbidities, an elevated risk of disability, frailty, and premature death. Inflammageing is a hallmark of various cardiovascular diseases, including atherosclerosis, hypertension, and rapid progression to heart failure. The great experimental and clinical evidence accumulated in recent years has clearly demonstrated that early detection and counteraction of inflammageing is a promising strategy not only to prevent cardiovascular disease, but also to slow down the progressive decline of health that occurs with ageing. It is conceivable that beneficial effects of counteracting inflammageing should be most effective if implemented in the early stages, when the compensatory capacity of the organism is not completely exhausted. Early interventions and treatments require early diagnosis using reliable and cost-effective biomarkers. Indeed, recent clinical studies have demonstrated that cardiac-specific biomarkers (i.e., cardiac natriuretic peptides and cardiac troponins) are able to identify, even in the general population, the individuals at highest risk of progression to heart failure. However, further clinical studies are needed to better understand the usefulness and cost/benefit ratio of cardiac-specific biomarkers as potential targets in preventive and therapeutic strategies for early detection and counteraction of inflammageing mechanisms and in this way slowing the progressive decline of health that occurs with ageing.

Prognostic value of soluble ST2, high-sensitivity cardiac troponin, and NT-proBNP in type 2 diabetes: a 15-year retrospective study

Background

Patients with type 2 diabetes (T2DM) present an increased risk of cardiovascular (CV) disease and excess CV-related mortality. Beyond the established role of brain natriuretic peptide (BNP) and cardiac troponins (cTn), other non-cardiac-specific biomarkers are emerging as predictors of CV outcomes in T2DM.

Methods

Serum levels of soluble suppression of tumorigenesis 2 (sST2), high-sensitivity (hs)-cTnI, and N-terminal (NT)-proBNP were assessed in 568 patients with T2DM and 115 healthy controls (CTR). Their association with all-cause mortality and the development of diabetic complications was tested in T2DM patients over a median follow-up of 16.8 years using Cox models and logistic regressions.

Results

sST2 followed an increasing trend from CTR to uncomplicated T2DM patients (T2DM-NC) to patients with at least one complication (T2DM-C), while hs-cTnI was significantly higher in T2DM-C compared to CTR but not to T2DM-NC. A graded association was found between sST2 (HR 2.76 [95% CI 1.20–6.33] for ≥ 32.0 ng/mL and 2.00 [1.02–3.94] for 16.5–32.0 ng/mL compared to < 16.5 ng/mL, C-statistic = 0.729), NT-proBNP (HR 2.04 [1.90–4.55] for ≥ 337 ng/L and 1.48 [1.05–2.10] for 89–337 ng/L compared to < 89 ng/L, C-statistic = 0.741), and 15-year mortality in T2DM, whereas increased mortality was observed in patients with hs-cTnI ≥ 7.8 ng/L (HR 1.63 [1.01–2.62]). A ‘cardiac score’ based on the combination of sST2, hs-cTnI, and NT-proBNP was significantly associated with all-cause mortality (HR 1.35 [1.19–1.53], C-statistic = 0.739) and development of CV events.

Conclusions

sST2, hs-cTnI, and NT-proBNP are associated with 15-year mortality and onset of CV events in T2DM. The long-term prognostic value of sST2 and its ability to track variables related to insulin resistance and associated metabolic disorders support its implementation into routine clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01616-3.

Association of Dipstick Proteinuria with Long-Term Mortality among Patients with Hypertensive Crisis in the Emergency Department

Proteinuria, frequently observed in hypertensive crisis, is a risk factor for cardiovascular and all-cause mortality in patients with hypertension. Here we investigated the association between proteinuria and all-cause mortality in patients with a hypertensive crisis in the emergency department (ED). This retrospective study included patients admitted to the ED of a tertiary referral center between 2016 and 2019 with hypertensive crisis (systolic blood pressure ≥ 180 mmHg or diastolic blood pressure ≥ 110 mmHg); 3599 patients with an assay for proteinuria were included in this study. Proteinuria was defined as a trace or more protein on a urine dipstick test. Proteinuria was present in 1964 (54.6%) of 3599 patients. At 3 years, crude all-cause mortality rates were 10.8% for patients with negative proteinuria, 21.7% for those with trace proteinuria, 29.0% for those with proteinuria (1+), 32.0% for those with proteinuria (2+), and 35.4% for those with proteinuria (≥3+). After adjusting for age, sex, blood pressure, and comorbid conditions, the hazard ratio (95% confidence interval) for dipstick proteinuria was 1.91 (1.53–2.37) for those with trace proteinuria, 2.32 (1.85–2.91) for those with proteinuria (1+), 2.40 (1.86–3.10) for those with proteinuria (2+), and 2.40 (1.78–3.24) for those with proteinuria (≥3+) compared to the reference of negative proteinuria. In patients with hypertensive crisis, dipstick proteinuria was a significant predictor of all-cause mortality, and the risk of all-cause mortality increased in a dose-dependent manner according to its degree. Moreover, even trace proteinuria was associated with an increased risk of mortality. The dipstick urine test could be used as a simple and useful method for risk assessment of all-cause mortality in patients with hypertensive crisis.

Impact of the estimated glomerular filtration rate on long-term mortality in patients with hypertensive crisis visiting the emergency department

Background

The association between renal function and all-cause mortality in patients with hypertensive crisis remains unclear. We aimed to identify the impact of estimated glomerular filtration rate (eGFR) on all-cause mortality in patients with hypertensive crisis visiting the emergency department (ED).

Methods

This retrospective study included patients aged ≥18 years admitted to the ED between 2016 and 2019 for hypertensive crisis (systolic blood pressure ≥180 mmHg and/or diastolic blood pressure ≥110 mmHg). They were classified into four groups according to the eGFR at admission to the ED: ≥90, 60–89, 30–59, and <30 mL/min/1.73 m².

Results

Among the 4,821 patients, 46.7% and 5.8% had an eGFR of ≥90 and <30 mL/min/1.73 m², respectively. Patients with lower eGFR were older and more likely to have comorbidities. The 3-year all-cause mortality rates were 7.7% and 41.9% in those with an eGFR ≥90 and <30 mL/min/1.73 m², respectively. After adjusting for confounding variables, those with an eGFR of 30–59 (hazard ratio [HR], 1.93; 95% confidence interval [CI], 1.47–2.54) and <30 mL/min/1.73 m² (HR, 2.35; 95% CI, 1.71–3.24) had significantly higher 3-year all-cause mortality risks than those with an eGFR of ≥90 mL/min/1.73 m². Patients with an eGFR of 60–89 mL/min/1.73 m² had a higher mortality (21.1%) than those with an eGFR of ≥90 mL/min/1.73 m² (7.7%); however, the difference was not significant (HR, 1.21; 95% CI, 0.94–1.56).

Conclusions

Renal impairment is common in patients with hypertensive crisis who visit the ED. A strong independent association was observed between decreased eGFR and all-cause mortality in these patients. eGFR provides useful prognostic information and permits the early identification of patients with hypertensive crisis with an increased mortality risk. Intensive treatment and follow-up strategies are needed for patients with a decreased eGFR who visit the ED.

A fresh look at coronary microembolization

Mechanical stress from haemodynamic perturbations or interventional manipulation of epicardial coronary atherosclerotic plaques with inflammatory destabilization can release particulate debris, thrombotic material and soluble substances into the coronary circulation. The physical material obstructs the coronary microcirculation, whereas the soluble substances induce endothelial dysfunction and facilitate vasoconstriction. Coronary microvascular obstruction and dysfunction result in patchy microinfarcts accompanied by an inflammatory reaction, both of which contribute to progressive myocardial contractile dysfunction. In clinical studies, the benefit of protection devices to retrieve atherothrombotic debris during percutaneous coronary interventions has been modest, and the treatment of microembolization has mostly relied on antiplatelet and vasodilator agents. The past 25 years have witnessed a relative proportional increase in non-ST-segment elevation myocardial infarction in the presentation of acute coronary syndromes. An associated increase in the incidence of plaque erosion rather than rupture has also been recognized as a key mechanism in the past decade. We propose that coronary microembolization is a decisive link between plaque erosion at the culprit lesion and the manifestation of non-ST-segment elevation myocardial infarction. In this Review, we characterize the features and mechanisms of coronary microembolization and discuss the clinical trials of drugs and devices for prevention and treatment.

A Biomarker Model to Distinguish Types of Myocardial Infarction and Injury

BACKGROUND

Discrimination among patients with type 1 myocardial infarction (T1MI), type 2 myocardial infarction (T2MI), and myocardial injury is difficult.

OBJECTIVES

The aim of this study was to investigate the discriminative value of a 29-biomarker panel in an emergency department setting.

METHODS

Patients presenting with suspected myocardial infarction (MI) were recruited. The final diagnosis in all patients was adjudicated on the basis of the fourth universal definition of MI. A panel of 29 biomarkers was measured, and multivariable logistic regression analysis was used to evaluate the associations of these biomarkers with the diagnosis of MI or myocardial injury. Biomarkers were chosen using backward selection. The model was internally validated using bootstrapping.

RESULTS

Overall, 748 patients were recruited (median age 64 years), of whom 138 had MI (107 T1MI and 31 T2MI) and 221 had myocardial injury. In the multivariable model, 4 biomarkers (apolipoprotein A-II, N-terminal prohormone of brain natriuretic peptide, copeptin, and high-sensitivity cardiac troponin I) remained significant discriminators between T1MI and T2MI. Internal validation of the model showed an area under the curve of 0.82. For discrimination between MI and myocardial injury, 6 biomarkers (adiponectin, N-terminal prohormone of brain natriuretic peptide, pulmonary and activation-regulated chemokine, transthyretin, copeptin, and high-sensitivity troponin I) were selected. Internal validation showed an area under the curve of 0.84.

CONCLUSIONS

Among 29 biomarkers, 7 were identified to be the most relevant discriminators between subtypes of MI or myocardial injury. Regression models based on these biomarkers allowed good discrimination. (Biomarkers in Acute Cardiac Care [BACC]; NCT02355457).