Prognostic Biomarkers in Acute Coronary Syndromes: Risk Stratification Beyond Cardiac Troponins

Acute Coronary Syndrome Subphenotypes Based on Repeated Biomarker Measurements in Relation to Long-Term Mortality Risk

BACKGROUND

We aimed to identify patients with subphenotypes of postacute coronary syndrome (ACS) using repeated measurements of high-sensitivity cardiac troponin T, N-terminal pro-B-type natriuretic peptide, high-sensitivity C-reactive protein, and growth differentiation factor 15 in the year after the index admission, and to investigate their association with long-term mortality risk.

METHODS AND RESULTS

BIOMArCS (BIOMarker Study to Identify the Acute Risk of a Coronary Syndrome) was an observational study of patients with ACS, who underwent high-frequency blood sampling for 1 year. Biomarkers were measured in a median of 16 repeated samples per individual. Cluster analysis was performed to identify biomarker-based subphenotypes in 723 patients without a repeat ACS in the first year. Patients with a repeat ACS (N=36) were considered a separate cluster. Differences in all-cause death were evaluated using accelerated failure time models (median follow-up, 9.1 years; 141 deaths). Three biomarker-based clusters were identified: cluster 1 showed low and stable biomarker concentrations, cluster 2 had elevated concentrations that subsequently decreased, and cluster 3 showed persistently elevated concentrations. The temporal biomarker patterns of patients in cluster 3 were similar to those with a repeat ACS during the first year. Clusters 1 and 2 had a similar and favorable long-term mortality risk. Cluster 3 had the highest mortality risk. The adjusted survival time ratio was 0.64 (95% CI, 0.44-0.93; P=0.018) compared with cluster 1, and 0.71 (95% CI, 0.39-1.32; P=0.281) compared with patients with a repeat ACS.

CONCLUSIONS

Patients with subphenotypes of post-ACS with different all-cause mortality risks during long-term follow-up can be identified on the basis of repeatedly measured cardiovascular biomarkers. Patients with persistently elevated biomarkers have the worst outcomes, regardless of whether they experienced a repeat ACS in the first year.

RBP4-based Multimarker Score: A Prognostic Tool for Adverse Cardiovascular Events in Acute Coronary Syndrome Patients

CONTEXT

Retinol binding protein 4 (RBP4) has been implicated in the progression of cardiovascular diseases. However, its association with major adverse cardiovascular events (MACEs) in patients with acute coronary syndrome (ACS) remains obscure.

OBJECTIVE

Here, we examined the prognostic value of baseline RBP4 and its derived multimarker score for MACEs in ACS patients.

METHODS

A total of 826 patients with ACS were consecutively recruited from the department of cardiology and prospectively followed up for a median of 1.95 years (interquartile range, 1.02-3.25 years). Plasma RBP4 was measured using enzyme-linked immunosorbent assay. Adjusted associations between RBP4 and its derived multimarker score (1 point was assigned when RBP4 ≥ 38.18μg/mL, left ventricular ejection fraction [LVEF] ≤ 55%, N-terminal pro-B-type natriuretic peptide [NT-proBNP] ≥ 450 ng/L, estimated glomerular filtration rate [eGFR] ≤ 90 mL/min/1.73 m2, and age ≥60) with MACEs were analyzed.

RESULTS

In total, 269 ACS patients (32.57%) experienced MACEs. When patients were grouped by multimarker score (0-1, n = 315; 2-3, n = 406; 4-5, n = 105), there was a significant graded association between RBP4-based multimarker score and risk of MACEs (intermediate score (2-3): HRadj: 1.80; 95% CI, 1.34-2.41; high score (4-5): HRadj: 3.26; 95% CI, 2.21-4.81) and its components (P < .05 for each). Moreover, the prognostic and discriminative value of the RBP4-derived multimarker score remained robust in ACS patients with various high-risk anatomical or clinical characteristics.

CONCLUSION

The RBP4-derived 5-item score serves as a useful risk stratification and decision support for secondary prevention in patients with ACS.

Are the results from a multiplex proteomic assay and a conventional immunoassay for NT-proBNP and GDF-15 comparable?

BACKGROUND

We aimed to compare absolute plasma concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) and growth differentiation factor 15 (GDF-15) obtained by a conventional immunoassay with the corresponding relative concentrations from a proximity extension assay (PEA) and compare the prognostic impact of the protein levels obtained from these assays.

METHODS

We evaluated 437 patients with peripheral arterial disease (PAD) and a population-based cohort of 643 individuals without PAD. Correlations were calculated using Spearman's rank correlation coefficients (rho). The discriminatory accuracy of the protein levels to predict future cardiovascular events was analyzed with Cox regression and presented as time-dependent areas under the receiver-operator-characteristic curves (tdAUCs).

RESULTS

For NT-proBNP, the two assays correlated with rho 0.93 and 0.93 in the respective cohort. The PEA values leveled off at higher values in both cohorts. The corresponding correlations for GDF-15 were 0.91 and 0.89. At 5 years follow-up, the tdAUCs in the patient cohort were similar for NT-proBNP and GDF-15 regardless of assay used (0.65-0.66). The corresponding tdAUCs in the population-based cohort were between 0.72 and 0.77.

CONCLUSION

Except for the highest levels of NT-proBNP, we suggest that PEA data for NT-proBNP and GDF-15 reliably reflects absolute plasma levels and contains similar prognostic information.

Impact of Baseline Estimated Glomerular Filtration Rate Using CKD-EPI Equation on Long-term Prognosis of STEMI Patients: A Matter of Small Increments!

BACKGROUND

Baseline biomarkers including glomerular filtration rate (GFR) guide the management of patients with ST-segment elevation myocardial infarction (STEMI). GFR is a tool for prediction of adverse outcomes in these patients.

OBJECTIVES

We aimed to determine the prognostic utility of estimated GFR using Chronic Kidney Disease Epidemiology Collaboration in a cohort of STEMI patients.

METHODS

A retrospective cohort was designed among 5953 patients with STEMI. Primary endpoint of the study was major adverse cardiovascular events. GFR was classified into 3 categories delineated as C1 (<60 mL/min), C2 (60-90), and C3 (≥ 90).

RESULTS

Mean age of the patients was 60.38 ± 5.54 years and men constituted 78.8% of the study participants. After a median of 22 months, Multivariate Cox-regression demonstrated that hazards of major averse cardiovascular event, all-cause mortality, cardiovascular mortality, and nonfatal myocardial infarction were significantly lower for subjects in C3 as compared with those in C1. Corresponding hazard ratios (HRs) for mentioned outcomes regarding C3 versus C1 were (95% confidence interval) were (HR = 0.852 [0.656-0.975]; P = 0.035), (HR = 0.425 [0.250-0.725]; P = 0.002), (HR = 0.425 [0.242-0.749]; P = 0.003), and (0.885 [0.742-0.949]; P = 0.003), respectively. Normal GFR was also associated with declined in-hospital mortality with HR of C3 versus C1: 0.299 (0.178-0.504; P < 0.0001).

CONCLUSIONS

Baseline GFR via Chronic Kidney Disease Epidemiology Collaboration is associated with long-term cardiovascular outcomes following STEMI.

Effects of early myocardial reperfusion and perfusion on myocardial necrosis/dysfunction and inflammation in patients with ST-segment and non-ST-segment elevation acute coronary syndrome: results from the PLATelet inhibition and patients Outcomes (PLATO) trial

AIMS

Restoration of myocardial blood flow and perfusion during percutaneous coronary intervention (PCI) measured using Thrombolysis in Myocardial Infarction (TIMI) flow grade (TFG) and perfusion grade (TMPG) is associated with improved outcomes in acute coronary syndrome (ACS). Associations between TFG/TMPG and changes in biomarkers reflecting myocardial damage/dysfunction and inflammation is unknown.

METHODS AND RESULTS

Among 2606 patients included, TFG was evaluated in 2198 and TMPG in 1874 with ST-segment elevation myocardial infarction (STEMI) or non-ST-segment ACS (NSTE-ACS). Biomarkers reflecting myocardial necrosis [troponin T (TnT)], myocardial dysfunction [N-terminal prohormone brain natriuretic peptide (NT-proBNP)], inflammation [interleukin-6 (IL-6) and C-reactive protein (CRP)], and oxidative stress/ageing/inflammation [growth differentiation factor-15 (GDF-15)] were measured at baseline, discharge, and 1- and 6-month post-randomization. Associations between TFG/TMPG and changes in biomarker levels were evaluated using the Mann-Whitney-Wilcoxon signed test. In total, 1423 (54.6%) patients had STEMI and 1183 (45.4%) NSTE-ACS. Complete reperfusion after PCI with TFG = 3 was achieved in 1110 (85.3%) with STEMI and in 793 (88.5%) with NSTE-ACS. Normal myocardial perfusion with TMPG = 3 was achieved in 475 (41.6%) with STEMI and in 396 (54.0%) with NSTE-ACS. Levels of TnT, NT-proBNP, IL-6, CRP, and GDF-15 were substantially lower at discharge in patients with complete vs. incomplete TFG and STEMI (P < 0.01). This pattern was not observed for patients with NSTE-ACS. Patients with normal vs. abnormal TMPG and NSTE-ACS had lower levels of NT-proBNP at discharge (P = 0.01).

CONCLUSIONS

Successful restoration of epicardial blood flow in STEMI was associated with less myocardial necrosis/dysfunction and inflammation. Attainment of normal myocardial perfusion was associated with less myocardial dysfunction in NSTE-ACS.

Glycosylated apolipoprotein J in cardiac ischaemia: molecular processing and circulating levels in patients with acute ischaemic events

AIM

Using proteomics, we previously found that serum levels of glycosylated (Glyc) forms of apolipoprotein J (ApoJ), a cytoprotective and anti-oxidant protein, decrease in the early phase of acute myocardial infarction (AMI). We aimed to investigate: (i) ApoJ-Glyc intracellular distribution and secretion during ischaemia; (ii) the early changes in circulating ApoJ-Glyc during AMI; and (iii) associations between ApoJ-Glyc and residual ischaemic risk post-AMI.

METHODS AND RESULTS

Glycosylated apolipoprotein J was investigated in: (i) cells from different organ/tissue origin; (ii) a pig model of AMI; (iii) de novo AMI patients (n = 38) at admission within the first 6 h of chest pain onset and without troponin T elevation at presentation (early AMI); (iv) ST-elevation myocardial infarction patients (n = 212) who were followed up for 6 months; and (v) a control group without any overt cardiovascular disease (n = 144). Inducing simulated ischaemia in isolated cardiac cells resulted in an increased intracellular accumulation of non-glycosylated ApoJ forms. A significant decrease in ApoJ-Glyc circulating levels was seen 15 min after ischaemia onset in pigs. Glycosylated apolipoprotein J levels showed a 45% decrease in early AMI patients compared with non-ischaemic patients (P < 0.0001), discriminating the presence of the ischaemic event (area under the curve: 0.934; P < 0.0001). ST-elevation myocardial infarction patients with lower ApoJ-Glyc levels at admission showed a higher rate of recurrent ischaemic events and mortality after 6-month follow-up (P = 0.008).

CONCLUSIONS

These results indicate that ischaemia induces an intracellular accumulation of non-glycosylated ApoJ and a reduction in ApoJ-Glyc secretion. Glycosylated apolipoprotein J circulating levels are reduced very early after ischaemia onset. Its continuous decrease indicates a worsening in the evolution of the cardiac event, likely identifying patients with sustained ischaemia after AMI.

Differences in biomarker concentrations and predictions of long-term outcome in patients with ST-elevation and non-ST-elevation myocardial infarction

BACKGROUND

Differences in biomarkers reflective of pathobiology and prognosis between ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI) are incompletely understood and may offer insights for tailoring of treatment.

METHODS

This registry-based study included 538 STEMI and 544 NSTEMI patients admitted 2008-2014. Blood samples were collected day 1-3 after admission and 175 biomarkers were analyzed using Proximity Extension Assay and Multiple Reaction Monitoring mass spectrometry. Adjusted Lasso analysis (penalized logistic regression model) was used to select biomarkers that discriminated STEMI from NSTEMI patients. Biomarkers identified by the Lasso analysis were then evaluated in adjusted Cox regressions for associations with death or major adverse cardiovascular events.

RESULTS

Biomarkers strongly discriminated STEMI and NSTEMI when considered simultaneously in adjusted Lasso analysis (c-statistic 0.764). Eleven biomarkers independently discriminated STEMI and NSTEMI; seven showing higher concentrations in STEMI: myoglobin, N-terminal pro-B-type natriuretic peptide, serum amyloid A-1 and A-2 protein, ST2 protein, interleukin-6 and chitinase-3-like protein 1; and four showing higher concentrations in NSTEMI: fibroblast growth factor 23, membrane-bound aminopeptidase P, tumor necrosis factor-related activation-induced cytokine and apolipoprotein C-I. During up to 6.6 years of prognostic follow-up, none of these biomarkers exhibited different associations with adverse outcome between STEMI and NSTEMI.

CONCLUSIONS

In the acute setting, biomarkers indicated greater myocardial dysfunction and inflammation in STEMI, whereas they displayed a more diverse pathophysiologic pattern in NSTEMI patients. These biomarkers were similarly prognostic in STEMI and NSTEMI patients. The results do not support treating STEMI and NSTEMI patients differently based on the concentrations of these biomarkers.

Efficacy and Safety of Colchicine in Post-acute Myocardial Infarction Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Inflammation plays a key role in atherosclerotic plaque destabilization and adverse cardiac remodeling. Recent evidence has shown a promising role of colchicine in patients with coronary artery disease. We evaluated the efficacy and safety of colchicine in post–acute myocardial infarction (MI) patients.

Methods: We searched five electronic databases from inception to January 18, 2021, for randomized controlled trials (RCTs) evaluating colchicine in post–acute MI patients. Primary outcomes were cardiovascular mortality and recurrent MI. Secondary outcomes were all-cause mortality, stroke, urgent coronary revascularization, levels of follow-up high-sensitivity C-reactive protein (hs-CRP), and drug-related adverse events. All meta-analyses used inverse-variance random-effects models.

Results: Six RCTs involving 6,005 patients were included. Colchicine did not significantly reduce cardiovascular mortality [risk ratio (RR), 0.91; 95% confidence interval (95% CI), 0.52–1.61; p = 0.64], recurrent MI (RR, 0.87; 95% CI, 0.62–1.22; p = 0.28), all-cause mortality (RR, 1.06; 95% CI, 0.61–1.85; p = 0.78), stroke (RR, 0.28; 95% CI, 0.07–1.09; p = 0.05), urgent coronary revascularization (RR, 0.46; 95% CI, 0.02–8.89; p = 0.19), or decreased levels of follow-up hs-CRP (mean difference, −1.95 mg/L; 95% CI, −12.88 to 8.98; p = 0.61) compared to the control group. There was no increase in any adverse events (RR, 0.97; 95% CI, 0.89–1.07; p = 0.34) or gastrointestinal adverse events (RR, 2.49; 95% CI, 0.48–12.99; p = 0.20). Subgroup analyses by colchicine dose (0.5 vs. 1 mg/day), time of follow-up (<1 vs. ≥1 year), and treatment duration (≤30 vs. >30 days) showed no changes in the overall findings.

Conclusion: In post–acute MI patients, colchicine does not reduce cardiovascular or all-cause mortality, recurrent MI, or other cardiovascular outcomes. Also, colchicine did not increase drug-related adverse events.

Growth differentiation factor-15 is a biomarker for all-cause mortality but less evident for cardiovascular outcomes: A prospective study

BACKGROUND

Previous studies have proposed growth differentiation factor-15 (GDF-15) as a predictor of adverse cardiovascular outcomes and mortality. The present study aimed to determine if such associations remain after accounting for death as a competing risk, and if GDF-15 provides superior prediction performance than other biomarkers.

METHODS

Plasma GDF-15 levels and cardiovascular risk factors were measured in individuals without cardiovascular diseases (n = 4,143, aged 57.4 ± 5.96 years, 38.6 % men) from Malmö Diet and Cancer-Cardiovascular Cohort and were followed up for more than 20 years. Incidence of coronary events, ischemic stroke, cardiovascular mortality, and all-cause mortality was studied in relation to GDF-15 using Cox proportional hazards regression, with adjustment for potential confounders. Confounding from death as competing risk was carefully checked using the Fine and Gray subdistribution hazard model. Predictive capabilities were further evaluated using C-statistics, continuous net reclassification improvement, and integrated discrimination improvement.

RESULTS

During follow-up, 424 coronary events, 327 ischemic stroke, 368 cardiovascular deaths, and 1,308 all-cause deaths occurred. After controlling for death from other causes as competing events, only all-cause mortality remained significantly related to GDF-15. The addition of GDF-15 significantly improved prediction for all-cause mortality in addition to the traditional risk factors, high-sensitive C-reactive protein and N-terminal prohormone of brain natriuretic peptide. Only N-terminal prohormone of brain natriuretic peptide improved prediction for CVD mortality.

CONCLUSIONS

GDF-15 is a robust biomarker for all-cause mortality but less reliable for coronary event, ischemic stroke or cardiovascular mortality. Competing risk from death is an important consideration when interpreting the results.

Oxidized Low-Density Lipoprotein Associates with Ventricular Stress in Young Adults and Triggers Intracellular Ca2+ Alterations in Adult Ventricular Cardiomyocytes

Oxidized low-density lipoprotein (oxLDL) is associated with cardiac damage and causes injury to multiple cell types. We aimed to investigate the role of oxLDL in ventricular stress. We first examined the association between circulating oxLDL and N-terminal pro-brain natriuretic peptide (NT-proBNP), a marker of myocardial stress, in young subjects (30-50 years) with or without stable coronary artery disease (SCAD). oxLDL and NT-proBNP were significantly higher in subjects at high cardiovascular risk (CVR) than in subjects at low CVR and were associated independently of traditional CVR factors and C-reactive protein. Furthermore, the levels of oxLDL and NT-proBNP were significantly lower in subjects with SCAD than in peers at high CVR. To determine the intracellular mechanisms involved in the cardiac effects of oxLDL, we analyzed the in vitro effect of oxLDL on intracellular Ca²⁺ handling in adult rat ventricular cardiomyocytes using confocal microscopy. Acute challenge of adult ventricular cardiomyocytes to oxLDL reduced systolic Ca²⁺ transients and sarcoplasmic reticulum Ca²⁺ load. Moreover, diastolic spontaneous Ca²⁺ leak increased significantly after acute exposure to oxLDL. Thus, we demonstrate that oxLDL associates with NT-proBNP in young subjects, and can directly induce Ca²⁺ mishandling in adult ventricular cardiomyoyctes, predisposing cardiomyocytes to cardiac dysfunction and arrhythmogenicity.

Targeting Inflammation After Myocardial Infarction

PURPOSE OF REVIEW

Inflammation plays a key role in clearing cellular debris and recovery after acute myocardial infarction (AMI). Dysregulation of or prolonged inflammation may result in adverse cardiac remodeling and major adverse clinical events (MACE). Several pre-clinical studies and moderate sized clinical trials have investigated the role of immunomodulation in improving clinical outcomes in patients with AMI.

RECENT FINDINGS

Clinical data from the Canakinumab Atherothrombosis Outcome (CANTOS) and Colchicine Cardiovascular Outcomes Trial (COLCOT) have provided encouraging results among patients with AMI. Several other clinical and pre-clinical trials have brought about the prospect of modulating inflammation at various junctures of the inflammatory cascade including inhibition of complement cascade, interleukins, and matrix metalloproteinases. In patients with AMI, modulation of residual inflammation via various inflammatory pathways and mediators may hold promise for further reducing MACE. Learning from current data and understanding the nuances of immunomodulation in AMI are key for future trials and before widespread dissemination of such therapies.

Interaction between BDNF val66met polymorphism and personality on long-term cardiac outcomes in patients with acute coronary syndrome

Background

The prognostic role of BDNF val66met polymorphism on long-term cardiac outcomes in acute coronary syndrome (ACS) has been unclear. Environmental factors may modify the association, but these have not been investigated to date. This study aimed to investigate the potential interactive effects of BDNF val66met polymorphism and personality traits, one of the main environmental prognostic factors of ACS, on major adverse cardiac events (MACEs) in patients with ACS.

Methods

A total of 611 patients with recent ACS were recruited at a university hospital in Korea. Baseline evaluations from 2007 to 2012 assessed BDNF val66met polymorphism and personality using the Big Five Inventory, which yielded two personality clusters (resilient and vulnerable) and five dimensions (extraversion, agreeableness, conscientiousness, neuroticism, and openness). Over a 5~12 year follow-up after the index ACS, times to MACE were investigated using Cox regression models after adjustment for a range of covariates.

Results

The BDNF val66met polymorphism modified the associations between vulnerable personality type and worse long-term cardiac outcomes in ACS patients with significant interaction terms, in that the associations were statistically significant in the presence met allele. Similar findings were observed for the individual personality dimensions of agreeableness and neuroticism.

Conclusions

Gene (BDNF val66met polymorphism) x environment (personality traits) interactions on long-term cardiac outcomes were found in ACS.

Prognostic value of HbA1c for in-hospital and short-term mortality in patients with acute coronary syndrome: a systematic review and meta-analysis

Background

HbA1c, the most commonly used indicator of chronic glucose metabolism, is closely associated with cardiovascular disease. However, the relationship between HbA1c and the mortality of acute coronary syndrome (ACS) patients has not been elucidated yet. Here, we aim to conduct a systematic review assessing the effect of HbA1c on in-hospital and short-term mortality in ACS patients.

Methods

Relevant studies reported before July 2019 were retrieved from databases including PubMed, Embase, and Central. Pooled relative risks (RRs) and the corresponding 95% confidence interval (CI) were calculated to evaluate the predictive value of HbA1c for the in-hospital mortality and short-term mortality.

Results

Data from 25 studies involving 304,253 ACS patients was included in systematic review. The pooled RR of in-hospital mortality was 1.246 (95% CI 1.113–1.396, p: 0.000, I² = 48.6%, n = 14) after sensitivity analysis in studies reporting HbA1c as categorial valuable. The pooled RR was 1.042 (95% CI 0.904–1.202, p: 0.57, I² = 82.7%, n = 4) in random-effects model for studies reporting it as continuous valuable. Subgroup analysis by diabetic status showed that elevated HbA1c is associated increased short-term mortality in ACS patients without diabetes mellitus (DM) history and without DM (RR: 2.31, 95% CI (1.81–2.94), p = 0.000, I² = 0.0%, n = 5; RR: 2.56, 95% CI 1.38–4.74, p = 0.003, I² = 0.0%, n = 2, respectively), which was not the case for patients with DM and patients from studies incorporating DM and non-DM individuals (RR: 1.16, 95% CI 0.79–1.69, p = 0.451, I² = 31.9%, n = 3; RR: 1.10, 95% CI 0.51–2.38), p = 0.809, I² = 47.4%, n = 4, respectively).

Conclusions

Higher HbA1c is a potential indicator for in-hospital death in ACS patients as well as a predictor for short-term mortality in ACS patients without known DM and without DM.

Association of GDF-15 and Syntax Score in Patient with Acute Myocardial Infarction

Aims

GDF-15 is considered to be an important biomarker for cardiovascular events, but the differences in serum GDF-15 levels between acute myocardial infarction (AMI) patients and non-AMI patients warrant further investigation.

Methods

A cohort of 409 subjects was enrolled in the current study. The Syntax score was calculated from the baseline coronary angiography results by using online methods. Blood samples were obtained at the start of the study for an assessment of GDF-15 by using ELISA methods.

Results

Patients with AMI had significantly higher levels of serum GDF-15 (Wilcox test, P < 0.001), Syntax scores (Wilcox test, P = 0.006), and left ventricular ejection fractions (LEVF, Wilcox test, P< 0.001). However, no significant differences were present among the other clinical characteristics. The logistical regression analysis indicated that serum GDF-15 levels (P=0.01534) were independent predictors of non-AMI and AMI after adjusting for age, sex, smoking status, and LVEF.

Conclusions

Elevated serum levels of GDF-15 are independently associated with the risk of MI, and GDF-15 may serve as a protective factor for MI in the cardiovascular system.

Growth Differentiation Factor-15 Levels at Admission Provide Incremental Prognostic Information on All-Cause Long-term Mortality in ST-Segment Elevation Myocardial Infarction Patients Treated with Primary Percutaneous Coronary Intervention

INTRODUCTION

To investigate the additive prognostic value of growth differentiation factor (GDF-15) levels in ST-segment elevation myocardial infarction (STEMI) patients treated with primary percutaneously coronary intervention (pPCI) with 10-year mortality on top of clinical characteristics and known cardiac biomarkers.

METHODS

Baseline serum GDF-15 levels were measured in 290 STEMI patients treated with pPCI in the MISSION! intervention trial conducted from February 1, 2004 through October 31, 2006. The incremental prognostic value of GDF-15 and NTproBNP levels was evaluated on top of clinical characteristics using Cox proportional hazards analysis, Chi-square models and C-index. Outcome was 10-year all-cause mortality.

RESULTS

Mean age was 59.0 ± 11.5 years and 65 (22.4) patients were female. A total of 37 patients died during a follow-up of 9.4 (IQR 8.8-10.0) years. Multivariable Cox regression revealed GDF-15 and NTproBNP levels above median to be independently associated with 10-year all-cause mortality [HR GDF-15, 2.453 (95% CI 1.064-5.658), P = 0.04; HR NTproBNP, 2.413 (95% CI 1.043-5.564), P = 0.04] after correction for other clinical variables. Stratified by median GDF-15 (37.78 pmol/L) and NTproBNP (11.74 pmol/L) levels, Kaplan-Meier curves showed significant better survival for patients with GDF-15 and NTproBNP levels below the median versus above the median. The likelihood ratio test showed a significant incremental value of GDF-15 (P = 0.03) as compared with a model with clinically important variables and NTproBNP. The C-statistics for this model improved from 0.82 to 0.84 when adding GDF-15.

CONCLUSION

GDF-15 levels at admission in STEMI patients are independently associated with 10-year all-cause mortality rates and could improve risk stratification on top of clinical variables and other cardiac biomarkers.

Routinely measured hematological parameters and prediction of recurrent vascular events in patients with clinically manifest vascular disease

Background and aims

The predictive value of traditional risk factors for vascular events in patients with manifest vascular disease is limited, underscoring the need for novel biomarkers to improve risk stratification. Since hematological parameters are routinely assessed in clinical practice, they are readily available candidates.

Methods

We used data from 3,922 vascular patients, who participated in the Second Manifestations of ARTerial Disease (SMART) study. We first investigated associations between recurrent vascular events and 22 hematological parameters, obtained from the Utrecht Patient Oriented Database (UPOD), and then assessed whether parameters associated with outcome improved risk prediction.

Results

After adjustment for all SMART risk score (SRS) variables, lymphocyte %, neutrophil count, neutrophil % and red cell distribution width (RDW) were significantly associated with vascular events. When individually added to the SRS, lymphocyte % improved prediction of recurrent vascular events with a continuous net reclassification improvement (cNRI) of 17.4% [95% CI: 2.1, 32.1%] and an increase in c-statistic of 0.011 [0.000, 0.022]. The combination of lymphocyte % and neutrophil count resulted in a cNRI of 22.2% [3.2, 33.4%] and improved c-statistic by 0.011 [95% CI: 0.000, 0.022]. Lymphocyte % and RDW yielded a cNRI of 18.7% [3.3, 31.9%] and improved c-statistic by 0.016 [0.004, 0.028]. However, the addition of hematological parameters only modestly increased risk estimates for patients with an event during follow-up.

Conclusions

Several hematological parameters were independently associated with recurrent vascular events. Lymphocyte % alone and in combination with other parameters enhanced discrimination and reclassification. However, the incremental value for patients with a recurrent event was limited.