Prognostic significance of chronic myocardial injury diagnosed by three different cardiac troponin assays in patients admitted with suspected acute coronary syndrome

OBJECTIVES

Chronic myocardial injury (CMI) is defined as stable concentrations of cardiac troponin T or I (cTnT or cTnI) above the assay-specific 99th percentile upper reference limit (URL) and signals poor outcome. The clinical implications of diagnosing CMI are unclear. We aimed to assess prevalence and association of CMI with long-term prognosis using three different high-sensitivity cTn (hs-cTn) assays.

METHODS

A total of 1,292 hospitalized patients without acute myocardial injury had cTn concentrations quantified by hs-cTn assays by Roche Diagnostics, Abbott Diagnostics and Siemens Healthineers. The median follow-up time was 4.1 years. The prevalence of CMI and hazard ratios for mortality and cardiovascular (CV) events were calculated based on the URL provided by the manufacturers and compared to the prognostic accuracy when lower percentiles of cTn (97.5, 95 or 90), limit of detection or the estimated bioequivalent concentrations between assays were used as cutoff values.

RESULTS

There was no major difference in prognostic accuracy between cTnT and cTnI analyzed as continuous variables. The correlation between cTnT and cTnI was high (r=0.724-0.785), but the cTnT assay diagnosed 3.9-4.5 times more patients with having CMI based on the sex-specific URLs (TnT, n=207; TnI Abbott, n=46, TnI Siemens, n=53) and had higher clinical sensitivity and AUC at the URL.

CONCLUSIONS

The prevalence of CMI is highly assay-dependent. cTnT and cTnI have similar prognostic accuracy for mortality or CV events when measured as continuous variables. However, a CMI diagnosis according to cTnT has higher prognostic accuracy compared to a CMI diagnosis according to cTnI.

Growth Differentiation Factor 15: A Prognostic Marker in Patients with Acute Chest Pain without Acute Myocardial Infarction

BACKGROUND

Acute chest pain is associated with an increased risk of death and cardiovascular events even when acute myocardial infarction (AMI) has been excluded. Growth differentiation factor-15 (GDF-15) is a strong prognostic marker in patients with acute chest pain and AMI, but the prognostic value in patients without AMI is uncertain. This study sought to investigate the ability of GDF-15 to predict long-term prognosis in patients presenting with acute chest pain without AMI.

METHODS

In total, 1320 patients admitted with acute chest pain without AMI were followed for a median of 1523 days (range: 4 to 2208 days). The primary end point was all-cause mortality. Secondary end points included cardiovascular (CV) death, future AMI, heart failure hospitalization, and new-onset atrial fibrillation (AF).

RESULTS

Higher concentrations of GDF-15 were associated with increased risk of death from all causes (median concentration in non-survivors vs survivors: 2124 pg/mL vs 852 pg/mL, P < 0.001), and all secondary end points. By multivariable Cox regression, GDF-15 concentration ≥4th quartile (compared to <4th quartile) remained an independent predictor of all-cause death (adjusted hazard ratio (HR): 2.75; 95% CI, 1.69-4.45, P < 0.001), CV death (adjusted HR: 3.74; 95% CI, 1.31-10.63, P = 0.013), and heart failure hospitalization (adjusted HR: 2.60; 95% CI, 1.11-6.06, P = 0.027). Adding GDF-15 to a model consisting of established risk factors and high-sensitivity cardiac troponin T (hs-cTnT) led to a significant increase in C-statistics for prediction of all-cause mortality.

CONCLUSIONS

Higher concentrations of GDF-15 were associated with increased risk of mortality from all causes and risk of future CV events.

The Effect of Protease-Activated Receptor-1 (PAR-1) Inhibition on Endothelial-Related Biomarkers in Patients with Coronary Artery Disease

BACKGROUND

 Vorapaxar has been shown to reduce cardiovascular mortality in post-myocardial infarction (MI) patients. Pharmacodynamic biomarker research related to protease-activated receptor-1 (PAR-1) inhibition with vorapaxar in humans has short follow-up (FU) duration and is mainly focused on platelets rather than endothelial cells.

AIM

 This article assesses systemic changes in endothelial-related biomarkers during vorapaxar treatment compared with placebo at 30 days' FU and beyond, in patients with coronary heart disease.

METHODS

 Local substudy patients in Norway were included consecutively from two randomized controlled trials; post-MI subjects from TRA2P-TIMI 50 and non-ST-segment elevation MI (NSTEMI) patients from TRACER. Aliquots of citrated blood were stored at -80°C. Angiopoietin-2, angiopoietin-like 4, vascular endothelial growth factor, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, von Willebrand factor, thrombomodulin, and plasminogen activator inhibitor-1 and -2 were measured at 1-month FU and at study completion (median 2.3 years for pooled patients).

RESULTS

 A total of 265 consecutive patients (age median 62.0, males 83%) were included. Biomarkers were available at both FUs in 221 subjects. In the total population, angiopoietin-2 increased in patients on vorapaxar as compared with placebo at 1-month FU (p = 0.034). Angiopoietin-like 4 increased (p = 0.028) and plasminogen activator inhibitor-2 decreased (p = 0.025) in favor of vorapaxar at final FU. In post-MI subjects, a short-term increase in E-selectin favoring vorapaxar was observed, p = 0.029. Also, a short-term increase in von Willebrand factor (p = 0.032) favoring vorapaxar was noted in NSTEMI patients.

CONCLUSION

 Significant endothelial biomarker changes during PAR-1 inhibition were observed in post-MI and NSTEMI patients.

Growth differentiation factor 15 at 3 months after an acute chest pain admission is associated with increased risk of death and cardiovascular events

Background

Growth differentiation factor 15 (GDF-15) is related to increased risk of death and cardiovascular events when measured at initial presentation in patients with acute chest pain. Whether follow-up measurements at 3 months provide prognostic information is unknown.

Purpose

This study sought to investigate the ability of GDF-15 to predict long-term prognosis when measured 3 months after an acute chest pain admission.

Methods

GDF-15 was measured at baseline and 3 months after admission in 760 patients admitted with suspected NSTEMI-ACS. NSTEMI-ACS was diagnosed in 228 (30%) patients. Patients were followed for a median of 1480 (17–2118) days. GDF-15 concentration on admission and at 3-months was skewed and therefore compared using the related samples Wilcoxon signed ranked test. A baseline GDF-15 concentration of 1200pg/ml (previously defined as the 90th percentile in a healthy population) was used to divide patients into high and low concentration groups. Kaplan-Meier plots were generated and adjusted hazard ratios were estimated using multiple Cox proportional hazard regression analysis (adjusting for age, sex, hypercholesterolemia, current smoking, diabetes, hypertension, previous myocardial infarction, eGFR &lt;60 ml/min/1.73 m2 and cardiac troponin T). The primary endpoint was all-cause mortality following the 3-month visit and a secondary endpoint included all-cause mortality, future AMI and heart failure hospitalization.

Results

Median GDF-15 concentration on admission was 940 pg/ml (IQR: 678–1464) and similar to the concentration at 3 months: 927 pg/ml (IQR: 652–1431), p=0.183.

In the high-concentration group (n=249) 45 (18%) patients died, and 62 (25%) met the secondary endpoint. In the low-concentration group (n=511) 9 (1.7%) patients died (negative predictive value: 98.2%) and 22 (4%) met the secondary endpoint (negative predictive value: 95.6%).

Patients with persistently elevated GDF-15 at the 3 months follow-up visit carried the highest risk for death and cardiovascular events, followed by patients who developed high concentrations during the 3-month follow-up period. Patients with elevated levels at baseline who return to normal concentrations had similar risk as patients with low levels in both measurements (Figure 1).

The Kaplan-Meier curves demonstrated an increased risk of the primary and secondary endpoint in the high concentration group (Figure 2). GDF-15 concentration &gt;1200 pg/ml at 3 months was an independent predictor of all-cause mortality with an adjusted HR for death of 4.0 (1.7–9.5, p=0.001) and for the secondary endpoint (adjusted HR 2.9, 95% CI: 1.6–5.4, p=0.001).

Conclusion

Elevated GDF-15 three months after admission due to suspected NSTEMI-ACS independently predicts long-term mortality and cardiovascular events, irrespective of GDF-15 values during admission.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Western Norway Regional Health Authority

Adding stress biomarkers to high-sensitivity cardiac troponin for rapid non-ST-elevation myocardial infarction rule-out protocols

AIMS

This study tested the hypothesis that combining stress-induced biomarkers (copeptin or glucose) with high-sensitivity cardiac troponin (hs-cTn) increases diagnostic accuracy for non-ST-elevation myocardial infarction (NSTEMI) in patients presenting to the emergency department.

METHODS AND RESULTS

The ability to rule-out NSTEMI for combinations of baseline hs-cTnT or hs-cTnI with copeptin or glucose was compared with the European Society of Cardiology (ESC) hs-cTnT/I-only rule-out algorithms in two independent (one Norwegian and one international multicentre) diagnostic studies. Among 959 patients (median age 64 years, 60.5% male) with suspected NSTEMI in the Norwegian cohort, 13% had NSTEMI. Adding copeptin or glucose to hs-cTnT/I as a continuous variable did not improve discrimination as quantified by the area under the curve {e.g. hs-cTnT/copeptin 0.91 [95% confidence interval (CI) 0.89-0.93] vs. hs-cTnT alone 0.91 (95% CI 0.89-0.93); hs-cTnI/copeptin 0.85 (95% CI 0.82-0.87) vs. hs-cTnI alone 0.93 (95% CI 0.91-0.95)}, nor did adding copeptin <9 mmol/L or glucose <5.6 mmol/L increase the sensitivity of the rule-out provided by hs-cTnT <5 ng/L or hs-cTnI <4 ng/L in patients presenting more than 3 h after chest pain onset (target population in the ESC-0 h-algorithm). The combination decreased rule-out efficacy significantly (both P < 0.01). These findings were confirmed among 1272 patients (median age 62 years, 69.3% male) with suspected NSTEMI in the international validation cohort, of which 20.7% had NSTEMI. A trend towards increased sensitivity for the hs-cTnT/I/copeptin combinations (97-100% vs. 91-97% for the ESC-0 h-rule-out cut-offs) was observed in the Norwegian cohort.

CONCLUSION

Adding copeptin or glucose to hs-cTnT/I did not increase diagnostic performance when compared with current ESC guideline hs-cTnT/I-only 0 h-algorithms.

Diagnostic Performance of Novel Troponin Algorithms for the Rule-Out of Non-ST-Elevation Acute Coronary Syndrome

BACKGROUND

The European Society of Cardiology (ESC) rule-out algorithms use cutoffs optimized for exclusion of non-ST elevation myocardial infarction (NSTEMI). We investigated these and several novel algorithms for the rule-out of non-ST elevation acute coronary syndrome (NSTE-ACS) including less urgent coronary ischemia.

METHOD

A total of 1504 unselected patients with suspected NSTE-ACS were included and divided into a derivation cohort (n = 988) and validation cohort (n = 516). The primary endpoint was the diagnostic performance to rule-out NSTEMI and unstable angina pectoris during index hospitalization. The secondary endpoint was combined MI, all-cause mortality (within 30 days) and urgent (24 h) revascularization. The ESC algorithms for high-sensitivity cardiac troponin T (hs-cTnT) and I (hs-cTnI) were compared to different novel low-baseline (limit of detection), low-delta (based on the assay analytical and biological variation), and 0-1-h and 0-3-h algorithms.

RESULTS

The prevalence of NSTE-ACS was 24.8%, 60.0% had noncardiac chest pain, and 15.2% other diseases. The 0-1/0-3-h algorithms had superior clinical sensitivity for the primary endpoint compared to the ESC algorithm (validation cohort); hs-cTnT: 95% vs 63%, and hs-cTnI: 87% vs 64%, respectively. Regarding the secondary endpoint, the algorithms had similar clinical sensitivity (100% vs 94%-96%) but lower clinical specificity (41%-19%) compared to the ESC algorithms (77%-74%). The rule-out rates decreased by a factor of 2-4.

CONCLUSION

Low concentration/low-delta troponin algorithms improve the clinical sensitivity for a combined endpoint of NSTEMI and unstable angina pectoris, with the cost of a substantial reduction in total rule-out rate. There was no clear benefit compared to ESC for diagnosing high-risk events.

Growth differentiation factor 15 – a strong prognostic marker in patients presenting with acute chest pain without acute myocardial infarction

Background

Patients who present with acute chest pain who are not diagnosed with acute myocardial infarction (AMI) may still carry an increased cardiovascular risk. Growth differentiation factor-15 (GDF-15) has earlier been shown to be a strong prognostic marker in the general population and after AMI. However, the prognostic value in the chest pain population without AMI is unknown.

Purpose

The objective of this study was to investigate the prognostic power of GDF-15 in patients presenting with acute chest pain without myocardial infarction.

Methods

A total of 984 patients admitted with suspected NSTE-ACS were included. After excluding patients with AMI the remaining 849 patients were followed for median 722 days (range 1 to 1112 days). The primary endpoint was all-cause mortality. The secondary endpoint was all-cause mortality or AMI. GDF-15 was measured in biobanked admission samples, and patients were divided into two groups based on GDF-15 levels (1: ≤1800 pg/ml, 2: &gt;1800 pg/ml). Kaplan-Meier survival curves according to GDF-15 concentrations ≤1800 pg/ml or &gt;1800 pg/ml were generated. Cox proportional hazards regression analysis was used to estimate unadjusted and adjusted hazard ratios, the latter using age, sex, hypercholesterolemia, current smoking, diabetes, hypertension, BMI, previous myocardial infarction and eGFR &lt;60ml/min/1.73m2 as covariates. The incremental prognostic value of adding GDF-15 to cardiac troponin T was estimated.

Results

GDF-15 concentrations were strongly associated with outcome. GDF-15 concentration were higher in non-survivors than survivors (median 2572 pg/ml vs. 910 pg/ml, p&lt;0,001). In the category with GDF-15 &gt;1800 pg/ml, 28 (17.9%) died, and 49 (31.4%) patients met the secondary endpoint, whereas in the category with GDF-15 levels &lt;1800 pg/ml, only 12/693 (1.7%) died and 25 (3.6%) reached the secondary endpoint, respectively. GDF-15 &gt;1800 pg/ml was associated with an increased risk of death with an unadjusted hazard ratio (HR) of 10.9 (95% CI: 5.6 – 21.5, p: 0.001) and an adjusted HR of 5.2 (95% CI: 1.4 – 19.4, p: 0.014). The risk of death or AMI in patients with GDF-15 &gt;1800 pg/ml was also increased with an unadjusted HR of 9.5 (95% CI 5.9 – 17.7 p: 0.001) and an adjusted hazard ratio of 4.6 (95% CI: 1.7–12.27, p: 0.002). Adding GDF-15 to troponin T led to an increase in C-statistic from: 0.80 (95% CI: 0.73- 0.88) to 0.86 (95% CI 0.79 – 0.91) in predicting all-cause mortality. The optimal cut-off value for predicting the primary endpoint was estimated to be 1818 pg/ml, resulting in a Youden Index of 0.55 with a specificity of 85% and sensitivity of 70%.

Conclusion

GDF-15 is a strong prognostic marker in patients presenting with acute chest pain without AMI and may aid identifying those patients with high cardiovascular risk who require further diagnostics and treatment.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Western Norway Regional Health Authority

Patients with NSTEMI have fewer symptoms and higher quality of life three months after admission for acute chest pain

Background

A substantial proportion of patients admitted for possible non-ST elevation acute coronary syndrome (NSTE-ACS) who are not diagnosed with non-ST elevation myocardial infarction (NSTEMI) suffer from conditions (e.g. chronic myocardial injury [CMI]) that may imply serious cardiac risk and impaired quality of life. It is unknown what predicts quality of life and recurrence of symptoms in chest pain patients.

Purpose

To investigate which demographic and clinical characteristics, including discharge diagnosis, that predict recurrent symptoms and quality of life three months after hospitalization for acute chest pain.

Methods

A total of 1506 patients ≥18 years admitted with suspected NSTE-ACS at Haukeland University Hospital, Bergen, Norway, were included in the WESTCOR study. The final diagnosis was adjudicated by two independent cardiologists based on all clinical data including routine cTnT (5th gen, Roche Diagnostics). Three months after discharge patients received questionnaires assessing general health (SF-12v1), angina-related health (SAQ-7) and dyspnea (Rose Dyspnea Scale). In all, 774 (51.3%) patients responded and were included in the analyses. Univariable and multivariable regression models were applied to identify predictors of symptoms and quality of life scores after adjusting for a subset of candidate predictors. A subgroup analysis was undertaken in patients with stable troponin concentrations (N=658).

Results

Based on the discharge diagnosis the patients were grouped as NSTEMI (14.2%), unstable angina pectoris (UAP) (16.9%), non-coronary cardiac disease (6.6%), non-cardiac disease (6.3%) and non-cardiac chest pain (NCCP) (56.0%). After three months the NSTEMI patients had the highest quality of life scores and the lowest prevalence of symptoms (angina and dyspnea), while the inverse was true for the UAP patients (Fig 1). Revascularized patients had a better quality of life compared to those treated conservatively (P&lt;0.001). Adjusted multivariable analysis also demonstrated that revascularization (β=0.19, P=0.002) and a diagnosis of UAP (β=−0.18, P=0.007) succeeded to predict angina frequency. Additionally, current smoking and hypertension were also associated with worse quality of life outcomes (Table 1). NCCP patients had high median prevalence of symptoms after three months, with 50% of the group reporting chest pain in the last four weeks, and 33% reporting dyspnea. In the subgroup analysis, current smoking predicted worse quality of life in all domains (all P&lt;0.05) except SAQ7-Angina frequency.

Conclusions

Three months after hospitalization for chest pain revascularized patients had better quality of life and less symptoms compared to other patient groups. A diagnosis of UAP predicted recurrent symptoms and impaired quality of life in patients, suggesting that closer monitoring should be considered in order to minimize re-hospitalization.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The study is funded by grants from the Western Norway Regional Health Authority, Haukeland and Stavanger University hospitals. Figure 1Table 1

Cardiac Troponin Assays With Improved Analytical Quality: A Trade-Off Between Enhanced Diagnostic Performance and Reduced Long-Term Prognostic Value

Background

Cardiac troponin (cTn) permits early rule‐out/rule‐in of patients admitted with possible non–ST‐segment–elevation myocardial infarction. In this study, we developed an admission and a 0/1 hour rule‐out/rule‐in algorithm for a troponin assay with measurable results in >99% of healthy individuals. We then compared its diagnostic and long‐term prognostic properties with other protocols.

Methods and Results

Blood samples were collected at 0, 1, 3, and 8 to 12 hours from patients admitted with possible non–ST‐segment–elevation myocardial infarction. cTnT (Roche Diagnostics), cTnI_(Abbott) (Abbott Diagnostics), and cTnI_(sgx) (Singulex Clarity System) were measured in 971 admission and 465 1‐hour samples. An admission and a 0/1 hour rule‐out/rule‐in algorithm were developed for the cTnI_(sgx) assay and its diagnostic properties were compared with cTnT_ESC (European Society of Cardiology), cTnI_(Abbott)ESC, and 2 earlier cTnI_(sgx) algorithms. The prognostic composite end point was all‐cause mortality and future nonfatal myocardial infarction during a median follow‐up of 723 days. non–ST‐segment–elevation myocardial infarction prevalence was 13%. The novel cTnI_(sgx) algorithms showed similar performance regardless of time from symptom onset, and area under the curve was significantly better than comparators. The cTnI_{(sgx)0/1 hour} algorithm classified 92% of patients to rule‐in or rule‐out compared with ≤78% of comparators. Patients allocated to rule‐out by the prior published 0/1 hour algorithms had significantly fewer long‐term events compared with the rule‐in and observation groups. The novel cTnI_{(sgx)0/1 hour} algorithm used a higher troponin baseline concentration for rule‐out and did not allow for prognostication.

Conclusions

Increasingly sensitive troponin assays may improve identification of non–ST‐segment–elevation myocardial infarction but could rule‐out patients with subclinical chronic myocardial injury. Separate protocols for diagnosis and risk prediction seem appropriate.

Clinical risk scores identify more patients at risk for cardiovascular events within 30 days as compared to standard ACS risk criteria: the WESTCOR study

AIMS

Troponin-based algorithms are made to identify myocardial infarctions (MIs) but adding either standard acute coronary syndrome (ACS) risk criteria or a clinical risk score may identify more patients eligible for early discharge and patients in need of urgent revascularization.

METHODS AND RESULTS

Post-hoc analysis of the WESTCOR study including 932 patients (mean 63 years, 61% male) with suspected NSTE-ACS. Serum samples were collected at 0, 3, and 8-12 h and high-sensitivity cTnT (Roche Diagnostics) and cTnI (Abbott Diagnostics) were analysed. The primary endpoint was MI, all-cause mortality, and unplanned revascularizations within 30 days. Secondary endpoint was non-ST-elevation myocardial infarction (NSTEMI) during index hospitalization. Two combinations were compared: troponin-based algorithms (ESC 0/3 h and the High-STEACS algorithm) and either ACS risk criteria recommended in the ESC guidelines, or one of eleven clinical risk scores, HEART, mHEART, CARE, GRACE, T-MACS, sT-MACS, TIMI, EDACS, sEDACS, Goldman, and Geleijnse-Sanchis. The prevalence of primary events was 21%. Patients ruled out for NSTEMI and regarded low risk of ACS according to ESC guidelines had 3.8-4.9% risk of an event, primarily unplanned revascularizations. Using HEART score instead of ACS risk criteria reduced the number of events to 2.2-2.7%, with maintained efficacy. The secondary endpoint was met by 13%. The troponin-based algorithms without evaluation of ACS risk missed three-index NSTEMIs with a negative predictive value (NPV) of 99.5% and 99.6%.

CONCLUSION

Combining ESC 0/3 h or the High-STEACS algorithm with standardized clinical risk scores instead of ACS risk criteria halved the prevalence of rule-out patients in need of revascularization, with maintained efficacy.

Arterial Stiffness: A Prognostic Marker in Coronary Heart Disease. Available Methods and Clinical Application

Multiple biomarkers may predict short and long-term prognosis in patients with coronary heart disease, but their impact is limited when used in addition to established risk factors such blood pressure, cholesterol levels, diabetes mellitus, smoking as well as age and sex. Arteries are an integral part of the cardiovascular (CV) system. Arterial stiffness has been shown to be a predictor of cardiovascular events and mortality independent of traditional risk factors. It has also been shown that increased arterial stiffness may predict cardiovascular events in asymptomatic individuals without overt cardiovascular disease. Measuring arterial stiffness may, therefore, identify patients at risk at an early stage. Antihypertensive treatment has been shown to reduce arterial stiffness beyond its antihypertensive effect. Arterial stiffness could, therefore, be a surrogate marker of treatment that relates to prognosis. Arterial stiffness has mostly been used in research protocols, and its use as a prognostic indicator in clinical practice is still uncommon. Several methods exist that can determine parameters related to arterial stiffness, both local and in specific artery beds such as the aorta. In this brief review we present methods to evaluate arterial stiffness, their clinical utility, limitations and the advantages of a novel method, the Cardio-Ankle Vascular Index. Easier and more reproducible methods to evaluate arterial stiffness may increase the use of parameter as a risk factor for coronary heart disease in common clinical practice.

Sex-based short- and long-term survival in patients following complicated myocardial infarction

AIMS

Mortality in women following an acute myocardial infarction (AMI) is higher than in men, in that women are older and have more co-morbidity at the time of AMI. We evaluated short- and long-term sex-related differences in management and prognosis among high-risk patients following AMI.

METHODS AND RESULTS

A total of 1575 women and 3902 men with AMI and heart failure, left ventricular dysfunction, or anterior Q waves, were recruited for participation in the OPTIMAAL trial and followed for 2.7+/-0.9 years in seven European countries. Symptomatic heart failure was more common in women when compared with men. Women were older, with more hypertension and diabetes mellitus. Fewer women were treated with thrombolytics (P<0.001 in all cases). Women had a 1.37-fold higher risks of death (P<0.001) during follow-up, but no differences were observed after adjusting for age. However, in-hospital mortality was significantly higher in women (4.89 vs. 2.54%; P<0.001) and a 1.57-fold higher risk of in-hospital death (P=0.006) persisted after adjusting for age and co-morbidities.

CONCLUSION

Among high-risk patients with AMI, age-adjusted long-term survival was similar between sexes. However, adjusted in-hospital mortality was significantly higher in women. Higher short-term risk may warrant more rapid and appropriate management of women with AMI.