Admission troponin T level predicts clinical outcomes, TIMI flow, and myocardial tissue perfusion after primary percutaneous intervention for acute ST-segment elevation myocardial infarction

Risk Factors of Suboptimal Coronary Blood Flow after a Percutaneous Coronary Intervention in Patients with Acute Anterior Wall Myocardial Infarction

BACKGROUND AND AIMS

Primary percutaneous coronary intervention (PCI) is regarded as the most preferred strategy in ST-segment elevation myocardial infarction (STEMI). Thrombolysis in Myocardial Infarction (TIMI) flow grade has been an important and cohesive predictor of outcomes in STEMI patients. We sought to evaluate potential variables associated with the risk of suboptimal TIMI flow after PCI in patients with anterior wall STEMI.

METHODS

We evaluated 107 patients admitted to our hospital between 1 January 2019 and 31 December 2021 with a diagnosis of anterior wall STEMI treated with primary PCI.

RESULTS

Suboptimal TIMI flow grade (≤2) after PCI occurred in 14 (13%) patients while grade 3 was found in 93 (87%) of them presenting with anterior wall STEMI. Failure to achieve optimal TIMI 3 flow grade after PCI was associated with lower TIMI grade prior to PCI (OR 0.5477, 95% CI 0.2589-0.9324, p = 0.02), greater troponin concentration before (OR 1.0001, 95% CI 1-1.0001, p = 0.0028) and after PCI (OR 1.0001, 95% CI 1-1.0001, p = 0.0452) as well as lower mean minimal systolic blood pressure (OR 0.9653, 95% CI 0.9271-0.9985, p = 0.04).

CONCLUSIONS

Among predictors of suboptimal TIMI flow grade after PCI, we noted lower TIMI grade flow pre-PCI, greater serum troponin concentrations in the periprocedural period and lower mean minimal systolic blood pressure.

Peak troponin T in STEMI: a predictor of all-cause mortality and left ventricular function

Background

The clinical significance of peak troponin levels following ST-elevation myocardial infarction (STEMI) has not been definitively established. The purpose of this study was to examine the relationship between peak high-sensitivity cardiac troponin T (hs-cTnT) and all-cause mortality at 30 days and 1 year, and left ventricular ejection fraction (LVEF) in STEMI.

Methods

A single-centre retrospective observational study was conducted of all patients with STEMI between January 2015 and December 2017. Demographics and clinical data were obtained through electronic patient records. Standard Bayesian statistics were employed for analysis.

Results

During the study period, 568 patients presented with STEMI. The mean age was 63.6±12 years and 76.4% were men. Of these, 535 (94.2%) underwent primary percutaneous coronary intervention, 12 (2.1%) underwent urgent coronary artery bypass and 21 (3.7%) were treated medically. Mean peak hs-cTnT levels were significantly higher in those who died within 30 days compared with those who survived (12 238 ng/L vs 4657 ng/L, respectively; p=0.004). Peak hs-cTnT levels were also significantly higher in those who died within 1 year compared with those who survived (10 319 ng/L vs 4622 ng/L, respectively; p=0.003). The left anterior descending artery was associated with the highest hs-cTnT and was the most common culprit in those who died at 1 year. An inverse relationship was demonstrated between peak hs-cTnT and LVEF (Pearson’s R=0.379; p<0.00001).

Conclusions

In STEMI, those who died at 30 days and 1 year had significantly higher peak troponin levels than those who survived. Peak troponin is also inversely proportional to LVEF with higher troponins associated with lower LVEF.

Regulatory Mechanism of LINC00152 on Aggravating Heart Failure through Triggering Fibrosis in an Infarcted Myocardium

OBJECTIVE

To elucidate the role of LINC00152 in the progression of heart failure following myocardial infarction. Patients and Methods. Serum levels of LINC00152 in acute myocardial infarction (AMI) patients were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Receiver operating characteristic (ROC) curves were depicted for assessing the diagnostic value of LINC00152 in AMI. Subsequently, an in vivo AMI model was generated in mice. LINC00152 level in a mouse infarcted myocardium was detected. Echocardiogram was conducted to evaluate the influence of LINC00152 on cardiac function in AMI mice. Primary cardiac fibroblasts were isolated from neonatal mice. After knockdown of LINC00152, proliferative and migratory changes in primary cardiac fibroblasts were assessed by cell counting kit-8 (CCK-8) and transwell assay, respectively. The regulatory effect of LINC00152 on Smad7 level was determined by qRT-PCR. Finally, the involvement of Smad7 in LINC00152-regulated proliferative and migratory abilities in primary cardiac fibroblasts was explored by rescue experiments.

RESULTS

Serum level of LINC00152 was elevated in AMI patients. ROC curves demonstrated the diagnostic potential of LINC00152 in AMI (95% CI: 0.806-0.940, p = 0.034). In myocardial tissues collected from AMI mice, LINC00152 level was higher than those collected from mice of the sham group. LVEF and FS markedly decreased in AMI mice overexpressing LINC00152 on the 4th week of AMI modeling. After knockdown of LINC00152 in primary cardiac fibroblasts, proliferative and migratory abilities were declined, which were abolished by Smad7 intervention.

CONCLUSIONS

By downregulating Smad7, LINC00152 aggravates heart failure following AMI via promoting the proliferative and migratory abilities in cardiac fibroblasts.

Prognostic value of admission high-sensitivity troponin in patients with ST-elevation myocardial infarction

BACKGROUND AND AIM

Although the diagnostic usefulness of high-sensitivity cardiac troponin T (hs-cTnT) is well established in ST-segment elevation myocardial infarction (STEMI), its prognostic relevance in risk stratification of patients with STEMI remains obscure. This study sought to determine the prognostic value of pre-reperfusion (admission) and post-reperfusion (12-hour) hs-cTnT in patients with STEMI treated with primary percutaneous coronary intervention (PPCI).

METHODS

Retrospective observational longitudinal study including consecutive patients with STEMI treated with PPCI at a university hospital in the northeast of England. hs-cTnT was measured at admission to the catheterisation laboratory and 12 hours after PPCI. Clinical, procedural and laboratory data were prospectively collected during patient hospitalisation (June 2010-December 2014). Mortality data were obtained from the UK Office of National Statistics. The study endpoints were in-hospital and overall mortality.

RESULTS

A total of 3113 patients were included. Median follow-up was 53 months. Admission hs-cTnT >515 ng/L (fourth quartile) was independently associated with in-hospital mortality (HR=2.53 per highest to lower quartiles; 95% CI: 1.32 to 4.85; p=0.005) after multivariable adjustment for a clinical model of mortality prediction. Likewise, admission hs-cTnT >515 ng/L independently predicted overall mortality (HR=1.27 per highest to lower quartiles; 95% CI: 1.02 to 1.59; p=0.029). Admission hs-cTnT correctly reclassified risk for in-hospital death (net reclassification index (NRI)=0.588, p<0.001) and overall mortality (NRI=0.178, p=0.001). Conversely, 12-hour hs-cTnT was not independently associated with mortality.

CONCLUSION

Admission, but not 12-hour post-reperfusion, hs-cTnT predicts mortality and improves risk stratification in the PPCI era. These results support a prognostic role for admission hs-cTnT while challenge the cost-effectiveness of routine 12-hour hs-cTnT measurements in patients with STEMI.

Preoperative troponin levels and outcomes of coronary surgery following myocardial infarction

BACKGROUND

This study evaluates the impact of peak preoperative troponin level on outcomes of coronary artery bypass grafting (CABG) for non-ST-elevation myocardial infarction (NSTEMI).

METHODS

This was a retrospective review of patients undergoing isolated CABG from 2011 to 2018 with the presentation of NSTEMI. Patients were stratified into low- and high-risk groups based on median preoperative peak troponin (1.95 ng/dl). Major adverse cardiac and cerebrovascular events (MACCE) and mortality were compared. Multivariable analysis was performed to model risk factors for MACCE and mortality.

RESULTS

This study included 1211 patients, 607 low-risk (≤1.95 ng/dl) and 604 high-risk (>1.95 ng/dl). Patients were well-matched with respect to age and comorbidity. High-risk patients had lower median preoperative ejection fraction (46.5% [interquartile range {IQR}: 35.0%-55.0%] vs. 53.0% [IQR: 40.0%-58.0%]) and higher incidence of preoperative intra-aortic balloon pump (15.9% vs. 8.73%). Intensive care unit and hospital length of stay were longer in the high-risk group, but increasing troponin level was not associated with prolonged intensive care or hospital length of stay (>4 and >14 days, respectively) after risk adjustment. Postoperative complications and 30-day, 1- and 5-year rates of both MACCE and survival were similar between groups. Peak troponin greater than 1.95 ng/dl was not associated with increased hazards for MACCE, mortality, or readmission in multivariable modeling. In subanalysis, neither increasing troponin as a continuous variable nor peak troponin greater than 10.00 ng/ml were associated with increased hazards for these outcomes.

CONCLUSIONS

Preoperative troponin levels do not appear to be predictive of short- or long-term outcomes following CABG, and clinical decisions regarding surgical revascularization should not be dictated by these measurements.

MicroRNA-208a: a Good Diagnostic Marker and a Predictor of no-Reflow in STEMI Patients Undergoing Primary Percutaneuos Coronary Intervention

MicroRNA-208a is a cardiac specific oligo-nucleotide. We aimed at investigating the ability of microRNA-208a to diagnose myocardial infarction and predict the outcome of primary percutaneuos coronary angiography (PCI). Patients (n = 75) presented by chest pain were recruited into two groups. Group 1 (n = 40) had ST elevation myocardial infarction (STEMI) and underwent primary PCI: 21 patients had sufficient reperfusion and 19 had no-reflow. Group 2 (n = 35) had negative cardiac troponins (cTns). Plasma microRNA-208a expression was assessed using quantitative polymerase chain reaction and patients were followed for occurrence of in-hospital major adverse cardiac events (MACE). MicroRNA-208a could diagnose of MI (AUC of 0.926). After primary PCI, it was superior to cTnT in prediction of no-reflow (AUC difference of 0.231, P = 0.0233) and MACE (AUC difference of 0.367, P = 0.0053). Accordingly, circulating levels of miR-208a can be used as a diagnostic marker of MI and a predictor of no-reflow and in-hospital MACE. Graphical abstract Receiver operating curve analysis of no-reflow prediction of miRNA208a, CK-MB and hs-Troponin T. MicroRNA-208a shows significantly higher prediction of no-reflow as compared to routine cardiac biomarkers.

Usefulness of High-Sensitivity Troponin I to Predict Outcome in Patients With Newly Detected Atrial Fibrillation

The prognostic role of high-sensitivity cardiac troponin I (hs-TnI) in patients with newly detected atrial fibrillation (AF) is not well established. We investigate the association of elevated hs-TnI with clinical outcomes and explore the utility of hs-TnI for risk assessment in patients with newly detected AF. From August 2014 to December 2016, 2,361 consecutive patients with newly detected AF were enrolled in a retrospective, single-center registry. Of these, 957 patients were selected and classified into 4 groups according to hs-TnI quartiles. The primary outcome was all-cause death during follow-up. The hs-TnI level was 3.6 ng/L or less in the lowest quartile (Q1), more than 3.6 ng/L to 10.1 ng/L or less in the second quartile (Q2), more than 10.1 ng/L to 22.0 ng/L or less in the third quartile (Q3), and more than 22.0 ng/L in the highest quartile (Q4). The median follow-up period was 19.3 months. In multivariable Cox regression model, Q4 has a higher risk of all-cause death (adjusted hazard ratio [HR]: 3.49; 95% confidence interval [CI]: 1.21 to 10.00; p = 0.02), readmission for heart failure (adjusted HR: 1.75; 95% CI: 1.01-3.05; p = 0.04), and readmission for revascularization (adjusted HR: 3.90; 95% CI: 1.25 to 12.17; p = 0.02) compared with Q1. Independent predictors of all-cause death were renal insufficiency (adjusted HR: 1.96; 95% CI: 1.08 to 3.53; p = 0.02), highest hs-TnI quartile (adjusted HR: 3.30; 95% CI: 1.18 to 9.27; p = 0.02) and anticoagulation therapy (adjusted HR: 0.51; 95% CI: 0.27 to 0.93; p = 0.03). Elevated hs-TnI is independently associated with higher mortality in patients with AF and serves as a valuable prognostic biomarker in patients with newly detected AF.

Relationship Between Troponin on Presentation and In-Hospital Mortality in Patients With ST-Segment-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Background Troponin release in ST-segment-elevation myocardial infarction (STEMI) has predictable kinetics with early levels reflective of ischemia duration. Little research has examined the value of admission troponin levels in STEMI patients undergoing primary percutaneous coronary intervention. We investigated the relationship between troponin on presentation and mortality in a large, real-world cohort of STEMI patients undergoing primary percutaneous coronary intervention. Methods and Results We used multivariable adaptive regression modeling to examine the association between admission troponin levels and in-hospital mortality for patients who underwent primary percutaneous coronary intervention for STEMI. We adjusted for known clinical risk factors using a validated mortality risk model derived from the NCDR (National Cardiovascular Data Registry) CathPCI database, and this same model was used to calculate patients' predicted mortality based on clinical and demographic factors. Patients were then stratified by troponin groups to compare predicted versus observed mortality. Of the 14 061 patients included in the cohort, 47.2% had initial troponin levels that were undetectable or within the reference range. Admission troponin was an independent predictor of in-hospital mortality, and any value above the reference range was associated with increased mortality (1.8% versus 5.1%, [standardized difference, 18.2%]). Patients with the highest predicted risk for mortality (13% predicted) in the highest admission troponin grouping experienced an observed mortality of 19.5%. Patients in low troponin groupings consistently demonstrated lower than predicted mortality based on their clinical and demographic risk profile. Conclusions Nearly half of patients undergoing primary percutaneous coronary intervention had normal troponin on presentation and had a relatively good outcome. Mortality increases with elevated admission troponin levels, regardless of baseline clinical risk. The substantial number of patients who present with markedly elevated troponin and their relatively worse outcomes highlights the need for continued improvement in prehospital STEMI detection and care.

High-sensitivity cardiac troponin T and prognosis in patients with ST-segment elevation myocardial infarction

BACKGROUND

Evidence on the use of high-sensitivity cardiac troponins (hs-cTn) to risk-stratify patients with ST-segment elevation myocardial infarction (STEMI) is limited.

METHODS

We assessed the prognostic value of preprocedural (admission) and peak postprocedural hs-cTnT in 818 patients with STEMI treated with primary percutaneous coronary intervention (PPCI). Preprocedural and peak postprocedural hs-cTnT was measured. The primary outcome was 3-year all-cause mortality.

RESULTS

The median values of preprocedural and peak postprocedural hs-cTnT were 153ng/L and 1980ng/L. Overall, 134 patients died during the follow-up. There were 85 deaths in patients with preprocedural hs-cTnT >median value and 49 deaths in patients with preprocedural hs-cTnT ≤median value [Kaplan-Meier estimates of mortality, 22.2% and 13.5%; unadjusted hazard ratio (HR)=1.88, 95% confidence interval (CI) 1.32-2.67, p<0.001]. According to peak postprocedural hs-cTnT, there were 84 deaths in patients with postprocedural hs-cTnT >median value and 50 deaths in patients with postprocedural hs-cTnT ≤median value [Kaplan-Meier estimates of mortality, 22.3% and 13.4%; unadjusted HR=1.82 (1.28-2.59), p<0.001]. After adjustment, preprocedural [adjusted HR=1.08 (1.03-1.12), p<0.001] and peak postprocedural hs-cTnT value [adjusted HR=1.06 (1.04-1.08), p<0.001] were independently associated with 3-year mortality (with risk estimates calculated per 70×99th upper reference limit of hs-cTnT). The C statistic of multivariable model increased from 0.868 (0.841-0.895) to 0.872 (0.845-0.898) after incorporation of preprocedural hs-cTnT (p=0.050) and to 0.874 (0.846-0.899) after incorporation of the postprocedural hs-cTnT into the model (p=0.035).

CONCLUSIONS

In conclusion, admission or peak postprocedural hs-cTnT is independently associated with the risk for 3-year mortality in patients with STEMI undergoing PPCI.

Does Preoperative Troponin Level Impact Outcomes After Coronary Artery Bypass Grafting?

BACKGROUND

As a marker of myocardial injury, troponin level correlates with adverse outcomes after myocardial infarction (MI). We hypothesized that patients with a higher preoperative troponin level would have increased morbidity and mortality after coronary artery bypass grafting (CABG).

METHODS

Preoperative troponin measurements were available for 1,272 patients who underwent urgent or emergent isolated CABG at our institution from 2002 to 2016. Logistic regression assessed the risk-adjusted effect of peak troponin level on morbidity and mortality. Long-term survival analysis was performed with Kaplan-Meier and Cox proportional hazards models.

RESULTS

Preoperative troponin was positive in 835 patients (65.6%). The median peak troponin for this group was 3.2 ng/mL (interquartile range, 0.6 to 11.9 ng/mL), with a median time from peak troponin to the operation of 3 days (interquartile range, 1 to 4 days). Positive troponin was associated with more significant comorbid conditions and more extensive coronary artery disease. Operative mortality (3.7% versus 1.1%, p = 0.009), major morbidity (11.7% versus 3.9%, p < 0.001), and long-term mortality (median survival 12.5 years versus 13.6 years, p = 0.01) were increased in the positive troponin group. After risk adjustment, positive troponin was not independently associated with increased operative mortality (odds ratio, 2.61; p = 0.053). Adjusted and unadjusted analysis showed the peak preoperative troponin level did not independently predict death at any time point (all odds ratios, 1.0; p > 0.05).

CONCLUSIONS

A positive preoperative troponin correlates with worse outcomes after CABG, but risk adjustment eliminates much of the short-term predictive value of this biomarker. Peak troponin level does not influence outcomes after CABG and is a poor predictor of events when The Society of Thoracic Surgeons predictive models are used.

Prognostic Value of New-Generation Troponins in ST-Segment-Elevation Myocardial Infarction in the Modern Era: The RUTI-STEMI Study

Background

In ST‐segment–elevation myocardial infarction (STEMI), troponins are not needed for diagnosis: symptoms and ECG data are sufficient to activate percutaneous coronary intervention. This study explored the prognostic value of new‐generation troponins in a real‐life cohort contemporarily treated for STEMI.

Methods and Results

We studied 1260 consecutive patients with primary STEMI treated with percutaneous coronary intervention between February 22, 2011, and August 31, 2015. We collected data on clinical characteristics and major adverse cardiovascular and cerebrovascular events (MACCEs) at 30 days and 1 year. Peak high‐sensitivity troponin T and sensitive‐contemporary troponin I levels were recorded. MACCEs occurred in 75 patients (6.1%) by day 30 and in 124 patients (10.8%) between day 31 and 1 year. A short‐term (0–30 days) multivariable Cox regression analysis revealed that age, Killip‐Kimball class, and left ventricular ejection fraction were independent predictors of MACCEs. In adjusted analysis, peak high‐sensitivity troponin T and sensitive‐contemporary troponin I were not significant (hazard ratio, 1.23 [95% confidence interval, 0.98–1.54] [P=0.071]; and hazard ratio, 1.15 [95% confidence interval, 0.93–1.43] [P=0.200], respectively). A long‐term (31 days–1 year) multivariable Cox regression analysis revealed that age, female sex, diabetes mellitus, prior coronary artery disease, Killip‐Kimball class, and left ventricular ejection fraction were statistically significantly associated with MACCEs. However, peak high‐sensitivity troponin T and peak sensitive‐contemporary troponin I were not significantly associated with MACCEs (hazard ratio, 1.03 [95% confidence interval, 0.88–1.20] [P=0.715]; and hazard ratio, 0.99 [95% confidence interval, 0.85–1.15] [P=0.856], respectively).

Conclusions

In the modern era, new‐generation troponins do not provide significant prognostic information for predicting clinical events in STEMI. We should reconsider the value of serial troponin measurements for risk stratification in STEMI.

Use of Admission Troponin in Critically Ill Medical Patients

Serum troponin I (TnI) is a sensitive marker of cardiac injury. A relation between elevated TnI and mortality has been suggested. In this retrospective chart review of 221 patients admitted to the medical intensive care unit (MICU) during a 6-month period, the authors studied the use of admission TnI levels in predicting mortality in MICU-admitted patients. Data retrieved included demographics, admission diagnosis, troponin, electrocardiogram, Acute Physiology and Chronic Health Evaluation (APACHE) II score, echocardiogram, requirements for mechanical ventilation and vasopressor support, development of multiorgan failure, mortality, and discharge disposition. There were 132 patients for whom TnI level was sent within 24 hours of admission; these patients comprised the study group. The median age was 70 years; 59% were female. The mean APACHE II score was 22. Troponin I was positive in 31% of patients (median level, 0.4 Ug/L; range 0-358 Ug/L). The hospital mortality was 39%. Positive TnI showed a weak association with intensive care unit (ICU) mortality ( P= .049) but not with overall mortality. There was no significant correlation between admission TnI concentration and APACHE II score ( P= .33), administration of vasopressor medications ( P= .115), or development of multiorgan failure ( P= .64). The authors concluded that there is no benefit in obtaining a routine admission troponin level in MICU patients when an acute coronary event is not suspected.

Cardiac troponin elevation pattern in patients undergoing a primary percutaneous coronary intervention for ST-segment elevation myocardial infarction: characterization and relationship with cardiovascular events during hospitalization

HYPOTHESIS

We aimed to describe the kinetics and associated prognostic implications of the cardiac troponin release curve after a primary percutaneous coronary intervention (PPCI) in patients presenting with ST-segment elevation myocardial infarction (STEMI).

PATIENTS AND METHODS

We prospectively determined, in a prespecified timely manner, serial cardiac troponin I levels and obtained clinical, ECG, and echocardiographic data from 175 consecutive patients hospitalized with STEMI who underwent PPCI. The median peak troponin levels and time until troponin peaking were determined.

RESULTS

The troponin elevation curve following PPCI was single peaked, with a median value measuring 715 times the upper normal limit and a median peaking time of 8 h. Later-peaking troponin levels were associated with a TIMI flow grade of 0/1 at the initiation of angiography and with lack of at least 70% regression in the ST-elevation on the first post-PPCI ECG. Higher peak values were similarly associated with these two parameters as well as with a lower blush score and with distal embolization during PPCI. Both higher peak values and later peaking of troponin were associated independently with higher occurrence of the combined adverse cardiovascular event outcomes consisting of death, congestive heart failure, and recurrent infarction.

CONCLUSION

The cardiac troponin elevation curve following PPCI for STEMI shows a single peak and is affected by the adequacy of myocardial reperfusion. This method can serve as a simple surrogate for risk stratification of patients with STEMI who undergo PPCI.

Different Prognostic Significance of Cardiac Troponin at Presentation and Peak Cardiac Troponin in Patients with Non-ST Segment Elevation Myocardial Infarction

OBJECTIVES

Non-ST elevation myocardial infarction (NSTEMI) is one of the most common manifestations of acute coronary syndromes (ACS). We evaluated the prognostic role of cardiac troponin I (cTnI) at presentation and peak cardiac troponin I in patients with NSTEMI.

METHODS

We consecutively enrolled 215 subjects presenting with NSTEMI. Subjects were followed up for 1 year. cTnI at presentation and the peak value of cTnI were measured. The primary end point was defined as cardiovascular death, readmission to hospital with heart failure and new ACS.

RESULTS

The subjects who presented the primary end point (49 subjects) had significantly increased values of peak cTnI compared to subjects free of cardiovascular events [7.19 (2.97-21.32) vs. 4.09 (1.18-11.85) ng/l; p = 0.002]. Nevertheless, cTnI at presentation did not differ between subjects who presented the primary end point and those free of events (p = 0.39). Multivariate Cox regression analysis after adjustment for confounders revealed by the univariate analysis showed that for an increase in peak cTnI from 1 to 10 ng/l, there is a 60% anticipated increase in the relative risk to present the primary end point (p = 0.04).

CONCLUSION

These findings documented the different prognostic significance of cTnI at presentation and peak cTnI in patients presenting with NSTEMI, and highlighted the importance of monitoring the levels of cTnI in this high-risk population.

Q10 supplementation effects on cardiac enzyme CK-MB and troponin in patients undergoing coronary artery bypass graft: a randomized, double-blinded, placebo-controlled clinical trial

INTRODUCTION

Coronary artery bypass surgery (CABG) is associated with ischemia-reperfusion injury and tissue damage. CoQ10 as an antioxidant has an important role and may have cardio-protective effects after myocardial dysfunction and CABG. We aimed to evaluate whether CoQ10 has a myocardial cardio protective impact on cardiac biomarkers after CABG.

METHODS

In this double-blind study, 80 patients with coronary artery disease (CAD) who underwent CABG surgery were divided into intervention and control groups and received Q10 supplement or placebo, respectively. The surgical characteristics of the patients in the two groups were similar. The intervention group received 150 mg of Q10 supplement per day for 7 days before the surgery. The control group received placebo capsule. After operation the inter- and intra-group blood levels of CK-MB and troponin, before and after supplementation and 12 hours after the CABG, and postoperative outcomes such as intensive care unit (ICU) stay and hospital stay were compared.

RESULTS

In this study, 40 subjects were located in each group. The participation rate was 97.5% and men and women accounted for 52.5% and 47.5% respectively. The mean age of the subjects was 58.17 ± 8.55. The two groups were not significantly different in terms of basic variables. Within-group comparison showed a significant increase in the level of troponin enzymes over time (P < 0.001) and CK-MB (P < 0.001). However, between-group comparison showed no significant difference between the two groups in terms of CK-MB (P = 0.384) and troponin (P = 0.115). In the end, no interaction was observed between the intervention and time on CK-MB (P = 0.095) and troponin (P = 0.198) variables.

CONCLUSION

Q10 supplementation 7 days before surgery was not effective in reducing CK-MB and troponin after CABG.

Discordant cardiac biomarker levels independently predict outcome in ST-segment elevation myocardial infarction

AIMS

To investigate the prognostic relevance of elevated Troponin T (cTnT) levels in patients with ST-segment elevation myocardial infarction (STEMI) without significant creatine kinase (CK) elevation on admission.

METHODS AND RESULTS

From January 1, 2002 to December 31, 2006 patients with STEMI without significant CK elevation (<2-fold) on admission treated with percutaneous coronary intervention (PCI) were included and stratified according to cTnT plasma levels. Univariate and multivariate regression analyses were used to find independent predictors for mortality. During the 5-year period 514 patients with STEMI and normal CK plasma levels were included. 308 (59.9 %) patients had cTnT levels <0.1 μg/l and 206 (40.1 %) patients had cTnT levels ≥0.1 μg/l. Multivariate logistic regression analysis identified cTnT levels ≥0.1 μg/l and 3-vessel disease as positive, and hemoglobin levels as negative independent predictors for long-term mortality. Discordantly elevated cTnT plasma levels independently predicted higher mortality rates in the first year (HR 3.9, 95 % CI 1.7-9.1, p = 0.002) and during 5 years (HR 2.3, 95 % CI 1.4-3.9, p = 0.002) after PCI for STEMI.

CONCLUSIONS

Discordant elevation of cTnT in the presence of normal CK plasma levels on admission is associated with increased mortality in STEMI patients undergoing primary PCI. This may be due to preceding microembolization.

Subclinical elevation of high-sensitive troponin T levels at the convalescent stage is associated with increased 5-year mortality after ST-elevation myocardial infarction

BACKGROUND

It is unclear whether serum high-sensitive troponin T (hs-TnT) levels at the convalescent stage of ST-elevation myocardial infarction (STEMI) are associated with long-term mortality.

METHODS

This study enrolled a total of 2944 consecutive STEMI patients who were registered in the Osaka Acute Coronary Insufficiency Study between 2000 and 2009, and whose hs-TnT levels were evaluated at the convalescent stage. Patients were divided into four hs-TnT category groups according to the results of survival classification and regression tree (CART) analysis. The impact of hs-TnT levels on 5-year mortality was evaluated using multivariate Cox regression analysis.

RESULTS

Only one patient had hs-TnT level below the detection limit of the assay (<0.003ng/mL). The median hs-TnT level was 0.025 (quartile 0.011-0.083)ng/mL. During the median follow-up period of 1782 days, 188 patients died. Survival CART analysis revealed that the 1st, 2nd, and 3rd discriminating hs-TnT levels to discern 5-year mortality were 0.028, 0.008, and 1.340ng/mL, respectively. The adjusted hazard ratios for the medium-low (0.009-0.028ng/mL), medium-high (0.029-1.340ng/mL), and high-risk (≥1.341ng/mL) groups were 3.03 (95% confidence interval 1.18-7.77, p=0.021), 4.29 (1.63-11.28, p=0.003), and 8.68 (2.20-34.27, p=0.002), respectively. Integrated discrimination improvement (IDI) analysis revealed that incorporation of this hs-TnT classification scheme with other clinical variables statistically improved the discriminatory accuracy for 5-year mortality, with a time-dependent IDI of 0.0076 (p=0.033).

CONCLUSIONS

hs-TnT levels at the convalescent stage were associated with long-term mortality in STEMI patients. Even subclinical elevation of hs-TnT levels was associated with increased 5-year mortality.

Biomarkers for risk stratification of patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention: Insights from the Platelet Inhibition and Patient Outcomes trial

BACKGROUND

The incremental prognostic value of admission measurements of biomarkers beyond clinical characteristics and extent of coronary artery disease (CAD) in patients treated with primary percutaneous coronary intervention (PPCI) for ST-elevation myocardial infarction (STEMI) is unclear.

METHODS

Centrally analyzed plasma for biomarker measurements was available in 5,385 of the STEMI patients treated with PPCI in the PLATO trial. Extent of CAD was graded by operators in association with PPCI. We evaluated the prognostic value of high-sensitivity cardiac troponin T, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and growth differentiation factor 15 (GDF-15) beyond clinical characteristics and extent of CAD using Cox proportional hazards analyses, C-index, and net reclassification improvement (NRI). Outcomes were cardiovascular death (CVD) and spontaneous myocardial infarction (MI).

RESULTS

Angiographic data on extent of CAD improved the prediction of CVD compared to clinical risk factors alone, increasing the C-index from 0.760 to 0.778, total NRI of 0.31. Biomarker information provided additional prognostic value for CVD beyond clinical risk factors and extent of CAD, C-indices ranging from 0.792 to 0.795 for all biomarkers, but with a higher NRI for NT-proBNP. Extent of CAD and high-sensitivity cardiac troponin T were not associated with spontaneous MI. The prediction of spontaneous MI beyond clinical characteristics and extent of CAD (C-index 0.647) was improved by both NT-proBNP (C-index 0.663, NRI 0.22) and GDF-15 (C-index 0.652, NRI 0.05).

CONCLUSIONS

Biomarker measurement on admission is feasible and provides incremental risk stratification in patients with STEMI treated with PPCI, with NT-proBNP and GDF-15 being most valuable due to the association with both CVD and spontaneous MI.

A review of troponins in ischemic heart disease and other conditions

Measuring cardiac troponin (cTn) I and T levels is currently considered to be a cornerstone for making the diagnosis of acute coronary syndrome (ACS).Based on current literature, cTnI and cTnT are known to be very sensitive and specific for myocardial damage, regardless of the underlying cause. Lately, it has been found that cTns can be elevated and reflect worse prognoses in many situations where ACS is excluded. Such information can affect the validity of cTns as markers for ACS without classic symptoms. This may call for a revision of the troponin cutoff values to make a diagnosis of ACS. Furthermore, it opens a new field of study to determine appropriate management of patients with elevated cTn levels in whom ACS has been excluded.

Established and novel biomarkers in ST-elevation myocardial infarction

Cardiac biomarkers assist in the diagnosis of and risk stratification in acute coronary syndromes. In ST-elevation myocardial infarction (STEMI), rapid diagnosis and initiation of reperfusion via primary percutaneous coronary intervention or fibrinolysis is often based on the clinical history and presenting ECG, but measurement of biomarkers in the early and/or late phases of STEMI may allow the selection of patients who are at increased or decreased risk of subsequent complications. Although the measurement of only three biomarkers (troponin, natriuretic peptides and C-reactive protein) are currently included in practice guidelines, more than 20 other novel cardiac biomarkers have been proposed to provide improved risk stratification after a STEMI.

Early dynamic risk stratification with baseline troponin levels and 90-minute ST-segment resolution to predict 30-day cardiovascular mortality in ST-segment elevation myocardial infarction: analysis from CLopidogrel as Adjunctive ReperfusIon TherapY (CLARITY)-Thrombolysis in Myocardial Infarction (TIMI) 28

BACKGROUND

Troponin is the preferred biomarker for risk stratification in non-ST elevation ACS. The incremental prognostic use of the initial magnitude of troponin elevation and its value in conjunction with ST-segment resolution (STRes) in ST elevation myocardial infarction (STEMI) is less well defined.

METHODS

Troponin T (TnT) was measured in 1,250 patients at presentation undergoing fibrinolysis for STEMI in CLARITY-TIMI 28. ST-segment resolution was measured at 90 minutes. Multivariable logistic regression was used to examine the independent association between TnT levels, STRes, and 30-day cardiovascular (CV) mortality.

RESULTS

Patients were classified into undetectable TnT at baseline (n = 594), detectable but below the median of 0.12 ng/mL (n = 330), and above the median (n = 326). Rates of 30-day CV death were 1.5%, 4.5%, and 9.5%, respectively (P < .0001). Compared with those with undetectable levels and adjusting for baseline factors, the odds ratios for 30-day CV death were 4.56 (1.72-12.08, P = .002) and 5.81 (2.29-14.73, P = .0002) for those below and above the median, respectively. When combined with STRes, there was a significant gradient of risk, and in a multivariable model both baseline TnT (P = .004) and STRes (P = .003) were significant predictors of 30-day CV death. The addition of TnT and STRes to clinical risk factors significantly improved the C-statistic (from 0.86 to 0.90, P = .02) and the integrated discriminative improvement (7.1% increase) (P = .0009).

CONCLUSIONS

Baseline TnT and 90-minute STRes are independent predictors of 30-day CV death in patients with STEMI. Use of these 2 simple, readily available tools can aid clinicians in early risk stratification.

Predicting the no-reflow phenomenon following successful percutaneous coronary intervention

In the setting of acute myocardial infarction, early and adequate reopening of an infarct-related artery is not necessarily followed by a complete restoration of myocardial perfusion. This condition is usually defined as ‘no-reflow’. The pathophysiology of no-reflow is multifactorial since extravascular compression, microvascular vasoconstriction, embolization during percutaneous coronary intervention, and platelet and neutrophil aggregates are involved. In the clinical arena, angiographic findings and easily available clinical parameters can predict the risk of no-reflow. More recently, several studies have demonstrated that biomarkers, especially those related to the pathogenetic components of no-reflow, could also have a prognostic role in the prediction and in the full understanding of the multiple mechanisms of this phenomenon. Thus, in this article, we investigate the role of several biomarkers on admission in predicting the occurrence of no-reflow following successful percutaneous coronary intervention.

Predictive value of inflammation and myocardial necrosis markers in acute coronary syndrome

Introduction. Biochemical cardiac markers play an important role in diagnosing and treatment of patients with acute coronary syndrome. Markers of myocytes necrosis, troponins, have been recommended for diagnosing and treatment of myocardial infarction with ST segment elevation, myocardial infarction without ST segment elevation and unstable angina pectoris. Two more groups of cardiac markers have been gaining in importance: inflammation markers and cardiac function markers. The objective of this study was the risk stratification and identification of patients with coronary syndrome, who could take advantage from evolutionary changes of serum cardiac markers. Material and Methods. The method of the analysis sums up the results of independently published studies and literature and data base review, such as MEDLINE, PubMed and KOBSON. Inflammation markers. Systemic and localized inflammation plays an important role in the development of acute coronary syndrome. The following inflammation markers are available: C-reactive protein. IL-2, sedimentation of erythrocytes and fibrinogen; as well as myocardial necrosis markers: creatine kinase MB, myoglobin and cardiac troponins. Conclusion. Tropinins are ideal markers which enable early detection of patients with acute coronary syndrome, whereas inflammation markers are helpful in diagnosing and assessing the severity of inflammation.

Organ protection by volatile anesthetics in non-coronary artery bypass grafting surgery

The cardioprotective properties of volatile anesthetics have been widely demonstrated by numerous randomized studies and meta-analyses in the setting of cardiac surgery, above of all during coronary artery bypass grafting procedures. Recently, conflicting results have been presented in cardiac non-coronary artery bypass grafting surgery. Unfortunately, despite the existence of a great number of studies comparing a total intravenous anesthetic regimen with an inhalational regimen, at present there are no randomized studies presenting data regarding mortality and important outcomes, such as myocardial infarction, in non-cardiac surgery. In this review we analyze and present the results of the most recent and important studies regarding anesthetic preconditioning in cardiac and in noncardiac surgery. Furthermore, we focus on the emerging data from animal experiments, discussing in particular the molecular mechanisms underlying anesthetic preconditioning.

Cardiac troponins and autoimmunity: their role in the pathogenesis of myocarditis and of heart failure

Despite the widespread use of cardiac troponins as biomarkers for the diagnosis and quantitation of cardiac injury, the effect of troponin release and a possible autoimmune response to the troponins is unknown. Other investigators reported that programmed cell death-1 (PD-1)-receptor deficient mice developed severe cardiomyopathy with autoantibodies to troponin I. We found that immunization of genetically susceptible mice with troponin I but not troponin T induced a robust autoimmune response leading to marked inflammation and fibrosis in the myocardium. At later times, antibodies to cardiac myosin were detected in troponin-immunized mice. The severity of inflammation correlated with expression of chemokines RANTES, MIP-2, IP-10 and MCP-1 in the myocardium. Prior immunization with troponin I increased the severity of experimental infarctions, indicating that an autoimmune response to troponin I aggravates acute cardiac damage. Cardiac inflammation, fibrosis and functional impairment were transferred from immunized to naive recipients by CD4+ T cells, and the cytokine profile suggested both Th2 and Th17 profiles in A/J mice. Finally we identified an 18-mer of troponin I containing an immuno-dominant epitope.

Prognostic value of megatroponinemia after myocardial infarction

PURPOSE

The purpose of this study is to investigate the prognostic value of megatroponinemia (troponins >100 ng/mL), as a predictor of major adverse cardiac events such as recurrent angina, myocardial infarction, and death in patients presenting with acute myocardial infarction.

METHODS

Over a period of 2 years, we identified 27 patients admitted with acute myocardial infarction and troponin I values >100 ng/mL. These patients were followed-up for the short term during their hospitalization as well as for an intermediate term of 18+/-14 months after their initial presentation with acute myocardial infarction for major adverse cardiac events including recurrent angina, myocardial infarction, and death.

RESULTS

Of the 27 patients, one died 5 days after myocardial infarction and 26 were discharged home in stable condition, with few requiring timely intervention. Six patients were lost to follow-up. Five patients died during follow-up, 4 from recurrent myocardial infarction and 1 died from metastatic renal cell carcinoma. Twelve patients had non-fatal myocardial infarction, with 10 being acute ST elevation; 3 patients had recurrent angina.

CONCLUSION

Patients presenting with an acute myocardial infarction and troponins >100 ng/mL have continued incremental risk of excessive major adverse cardiac events during short and intermediate follow-up period.

Usefulness of peak troponin-T to predict infarct size and long-term outcome in patients with first acute myocardial infarction after primary percutaneous coronary intervention

In acute myocardial infarction cardiac troponin-T (cTnT) is the preferred biomarker to detect myocardial necrosis. Our aim was to investigate the prognostic value of peak plasma cTnT in patients with ST-elevation myocardial infarction treated by primary percutaneous coronary intervention (PCI). Patients were eligible if ST-elevation myocardial infarction symptoms started <9 hours before the primary PCI. During the first 48 hours after primary PCI, cTnT and creatine kinase were measured repeatedly. Main outcome measures were left ventricular ejection fraction assessed by myocardial scintigraphy at 90 days, and clinical outcomes through 1-year follow-up after primary PCI in a dedicated outpatient clinic; 168 consecutive patients (79% men) with first ST-elevation myocardial infarction were studied. Mean age +/- SD was 59 +/- 12 years. Peak cTnT values were reached within 24 hours after primary PCI in all patients. The enzymatic infarct size, measured by cumulative 48-hours creatine kinase release, correlated positively with peak cTnT (r = 0.73, p <0.001). Left ventricular ejection fraction at 3 months was negatively correlated with peak cTnT (r = -0.52, p <0.001). A peak plasma cTnT > or = 6.5 microg/L predicted a left ventricular ejection fraction < or = 40% at follow-up with 86% sensitivity and 74% specificity. Multivariable Cox regression analysis identified peak cTnT as an independent predictor of major adverse cardiac events (hazard ratio 1.07, 95% confidence limits 1.01 to 1.12) and heart failure (hazard ratio 1.12, 95% confidence limits 1.05 to 1.20) during follow-up. In conclusion, peak cTnT after primary PCI for ST-elevation myocardial infarction offers a good estimation of infarct size and is a prognostic indicator in patients with first acute myocardial infarction.

Differential impact of admission C-reactive protein levels on 28-day mortality risk in patients with ST-elevation versus non-ST-elevation myocardial infarction (from the Monitoring Trends and Determinants on Cardiovascular Diseases [MONICA]/Cooperative Health Research in the Region of Augsburg [KORA] Augsburg Myocardial Infarction Registry)

The present study investigated the association between C-reactive protein (CRP) on admission independently and in combination with troponin and short-term prognosis in an unselected sample of patients with acute myocardial infarction (AMI) from the community. The study population consisted of 1,646 patients aged 25 to 74 years who were consecutively hospitalized with AMI within 12 hours after symptom onset. They were divided into the 2 groups of CRP positive (n = 919) or CRP negative (n = 727) with respect to admission CRP (cutoff < or =0.3 mg/dl). CRP-positive patients had significantly more in-hospital complications and a higher 28-day case-fatality rate (9.6% vs 3.4%; p <0.0001). Troponin at admission (n = 1,419) also correlated with 28-day case-fatality rate (troponin-negative 3.4% vs troponin-positive patients 8.0%; p <0.002). Multivariable analysis showed that both troponin positivity and CRP positivity were associated with a 2-fold (adjusted odds ratio 1.99, 95% confidence interval 1.15 to 3.44; adjusted odds ratio 2.05, 95% confidence interval 1.09 to 3.84, respectively) increased risk of dying within 28 days after the acute event for all patients with AMI. Stratifying by AMI type showed that in patients with ST-elevation myocardial infarction (STEMI), troponin positivity, but not CRP positivity, independently predicted 28-day case fatality. In patients with non-STEMI, CRP positivity, but not troponin positivity, predicted outcome. In conclusion, admission CRP was a powerful parameter for risk stratification of patients with AMI. Stratification by AMI type and troponin showed that CRP was a better short-term risk predictor for patients with non-STEMI, and troponin was, for patients with STEMI.

Biomarkers and Bioassays for Cardiovascular Diseases: Present and Future

Stratification of cardiac patients arriving at the emergency department is now being made according to the levels of acute cardiac biomarkers (i.e. cardiac troponin (cTn) or creatine kinase myocardial band (CK-MB)). Ongoing efforts are undertaken in an attempt to identify and validate additional cardiac biomarkers, for example, interleukin-6, soluble CD40L, and C-reactive protein, in order to further risk stratify patients with acute coronary syndrome. Several studies have also now shown an association of platelet transcriptome and genomic single nucleotide polymorphisms with myocardial infarction by using advanced genomic tools. A number of markers, such as myeloid-related protein 14 (MRP-14), cyclooxygenase-1 (COX-1), 5-lipoxygenase activating protein (FLAP), leukotriene A4 hydrolase (LTA4H) and myocyte enhancing factor 2A (MEF2A), have been linked to acute coronary syndromes, including myocardial infarction. In the future, these novel markers may pave the way toward personalized disease-prevention programs based on a person's genomic, thrombotic and cardiovascular profiles. Current and future biomarkers and bioassays for identifying at-risk patients will be discussed in this review.

The use of biomarkers for the evaluation and treatment of patients with acute coronary syndromes

The advent of inexpensive, highly accurate, and predictive markers of myocardial injury, inflammation, and hemodynamic stability has revolutionized the evaluation and treatment of patients who have acute coronary syndromes (ACSs). These blood biomarkers require small sample volumes, can be run expeditiously, and provide important information concerning the diagnosis, risk stratification, and treatment of these patients. To understand the use of these markers, one must have some knowledge about what elevations in these markers imply, how they have to be collected and measured to provide reliable information, when to suspect analytic confounds, and what the key values are that impart the diagnostic, prognostic, and therapeutic information. This article discusses these issues, emphasizing what clinicians must know for optimal test use, and then addresses the practical use of these markers in patients who have ACS.

The effects of facilitated primary PCI by guide wire on procedural and clinical outcomes in acute ST-segment elevation myocardial infarction

BACKGROUND

Reperfusion of the infarct related artery (IRA) prior to PCI is prognostically important in patients with acute ST segment elevation myocardial infarction (STEMI). Reperfusion is either achieved spontaneously, facilitated by GP IIb/ IIIa inhibitors, or mechanically by crossing the guide wire beyond the lesion. In order to test the hypothesis that a visible coronary anatomy is independently associated with procedural and clinical outcomes, we evaluated the frequency and prognostic impact of guide wire facilitated reperfusion of the IRA before primary PCI.

METHODS AND RESULTS

We enrolled 311 consecutive patients with successful primary PCI for STEMI (TIMI grade > or =2 flow) within 12 h after onset of symptoms. Among these, 90 patients (28.9%) had a spontaneously reperfused IRA on initial angiogram, 56 patients (18.0%) achieved reperfusion after crossing of the guide wire, and 165 patients (53.1%) successful reperfusion only after PCI. Variables associated with successful guide wire facilitated reperfusion were younger age, no history of arterial hypertension, active smoking status, negative cardiac troponin T on admission, and an infarct in the territory of the right coronary artery. Patients with spontaneous reperfusion or reperfusion after crossing of the guide wire required less fluoroscopic time and less contrast material during angiography and had higher procedural success rates (TIMI grade 3 flow 91.1 vs 79.4%, p=0.048) than patients without initial reperfusion. In addition, patients with reperfusion after crossing the lesion with the guide wire had lower mortality rates at 30 days (3.6 vs 9.1%) and after a median of 16 months (3.6 vs 13.9%, p=0.03) than those with reperfusion after PCI.

CONCLUSIONS

Reperfusion of an occluded IRA by crossing the guide wire is associated with higher procedural success rates and better outcomes. Better roadmapping and device selection represent potential reasons but the exact mechanism for these benefits is still illusive.

Modulation of ventricular repolarization in patients with transient left ventricular apical ballooning: a case control study

OBJECTIVE

Even though diffuse T wave inversion and prolongation of the QT interval in the surface electrocardiogram (ECG) have been consistently reported in patients with transient stress-induced left ventricular apical ballooning (AB), ventricular repolarization has not yet been systematically investigated in this clinical entity.

BACKGROUND

AB, an emerging syndrome that mimics acute ST-segment elevation myocardial infarction (MI), is characterized by reversible left ventricular wall motion abnormalities in the absence of obstructive coronary heart disease and significant QT interval prolongation.

METHODS

We prospectively enrolled 22 consecutive patients (21 women, median age 65 years) with transient left ventricular AB. A total of 22 age-, gender-, body-mass-index-, and left-ventricular-function-matched patients with acute anterior ST-segment elevation MI undergoing successful direct percutaneous coronary intervention for a proximal occlusion of the LAD, as well as 22 healthy volunteers served as control groups. Beat-to-beat QT interval and QT interval dynamicity were determined from 24-hour Holter ECGs, recorded on the third day after hospital admission.

RESULTS

There were no significant differences in baseline clinical characteristics, except higher peak enzyme release in MI patients. Compared with MI patients, AB patients exhibited significantly prolonged mean QT intervals and rate-corrected QT intervals (QT: 418 +/- 37 vs 384 +/- 33 msec, P < 0.01; QTcBazett: 446 +/- 40 vs 424 +/- 35 msec, P < 0.05; QTcFridericia: 437 +/- 35 vs 412 +/- 31 msec, P < 0.05). Mean RR intervals tended to be higher in AB patients, without reaching statistical significance (877 +/- 96 vs 831 +/- 102 msec, P = NS). The linear regression slope of QT intervals plotted against RR intervals was significantly flatter in AB patients at both day- and nighttime (QT/RR slopeday: 0.18 +/- 0.04 vs 0.22 +/- 0.06, P < 0.01; QT/RR slopenight: 0.12 +/- 0.03 vs 0.17 +/- 0.05, P < 0.01).

CONCLUSION

The present study is the first to demonstrate significant differences of QT interval modulation in patients with transient left ventricular AB and acute ST-segment elevation MI. Even though transient AB is associated with a significant QT interval prolongation, rate adaptation of ventricular repolarization (i.e., QT dynamicity) is not significantly altered, suggesting a differential effect of autonomic nervous activity on the ventricular myocardium in transient AB and in acute MI.

Biomarkers in acute cardiac disease: the present and the future

The use of biomarkers to aid diagnosis and treatment is increasing rapidly as genomics and proteomics help us expand the number of markers we can use and as an improved understanding of the pathophysiology of cardiac disease guides their use. However, as with all rapidly expanding fields, there is the risk of excessive enthusiasm unless we are circumspect about the data that guide the clinical use of these new tools. This review focuses first on how to use troponin, which at present is the best validated of the new markers, and will hopefully provide insight into how to use this biomarker more productively by distinguishing subsets of patients and by providing an understanding of the meaning of elevations in various clinical situations. The review then discusses the use as well as the knowledge gaps associated with emerging biomarkers such as B-type natriuretic peptide and C-reactive protein, which are increasingly moving toward more productive clinical use. Finally, it reflects on some of the large number of markers that are still in development.