Risk stratification in patients with inferior acute myocardial infarction treated by percutaneous coronary interventions: the role of admission troponin T

Prognostic Implications of the Admission Cardiac Troponin I Levels and Door-to-Balloon Time on Clinical Outcomes in Patients with ST-Segment Elevation Myocardial Infarction Undergoing Percutaneous Coronary Intervention

Background

The prognostic implications of the admission cTnI level and D2B time combined on in-hospital and 1-year heart failure (HF) and mortality in STEMI patients undergoing a primary percutaneous coronary intervention (PCI) are remain uncertain.

Methods and Results

We divided the consecutive 1485 STEMI patients who underwent PCI from January 2015 to October 2019 at our hospital into three groups based on their admission cTnI levels: normal group (<0.1 ng/mL), middle group (0.1 to less than 3 ng/mL), and high group (≥3 ng/mL) and into two groups by their D2B times: >90 min (>90-D2B) and ≤90 min (≤90-D2B). During the in-hospital and 1-year follow-up periods, the incidence of composite clinical events increased significantly with the increase in the admission cTnI level (p < 0.05). In-hospital, the composite rate of death and HF events was significantly higher in the >90-D2B group compared to the ≤90-D2B group (p = 0.006), but its influence disappeared in the 1-year follow-up (p > 0.05). A multivariable logistic analysis revealed that, in the ≤90-D2B group, with the exception of the cTnI ≥3 ng/mL patients, the cTnI level had no effect on in-hospital or 1-year outcomes; in >90-D2B group, cTnI ≥3ng/mL increased outcomes in both periods.

Conclusion

High cTnI levels (≥3 ng/mL) on admission are independent of the D2B time for predicting in-hospital and 1-year cardiac events in STEMI patients undergoing PCI.

Liver parameters as part of a non-invasive model for prediction of all-cause mortality after myocardial infarction

INTRODUCTION

Liver parameters are associated with cardiovascular disease risk and severity of stenosis. It is unclear whether liver parameters could predict the long-term outcome of patients after acute myocardial infarction (AMI). We performed an unbiased analysis of the predictive value of serum parameters for long-term prognosis after AMI.

MATERIAL AND METHODS

In a retrospective, observational, single-center, cohort study, 569 patients after AMI were enrolled and followed up until 6 years for major adverse cardiovascular events, including cardiac death. Patients were classified into non-survivors (n = 156) and survivors (n = 413). Demographic and laboratory data were analyzed using ensemble feature selection (EFS) and logistic regression. Correlations were performed for serum parameters.

RESULTS

Age (73; 64; p < 0.01), alanine aminotransferase (ALT; 93 U/l; 40 U/l; p < 0.01), aspartate aminotransferase (AST; 162 U/l; 66 U/l; p < 0.01), C-reactive protein (CRP; 4.7 U/l; 1.6 U/l; p < 0.01), creatinine (1.6; 1.3; p < 0.01), γ-glutamyltransferase (GGT; 71 U/l; 46 U/l; p < 0.01), urea (29.5; 20.5; p < 0.01), estimated glomerular filtration rate (eGFR; 49.6; 61.4; p < 0.01), troponin (13.3; 7.6; p < 0.01), myoglobin (639; 302; p < 0.01), and cardiovascular risk factors (hypercholesterolemia p < 0.02, family history p < 0.01, and smoking p < 0.01) differed significantly between non-survivors and survivors. Age, AST, CRP, eGFR, myoglobin, sodium, urea, creatinine, and troponin correlated significantly with death (r = -0.29; 0.14; 0.31; -0.27; 0.20; -0.13; 0.33; 0.24; 0.12). A prediction model was built including age, CRP, eGFR, myoglobin, and urea, achieving an AUROC of 77.6% to predict long-term survival after AMI.

CONCLUSIONS

Non-invasive parameters, including liver and renal markers, can predict long-term outcome of patients after AMI.

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.

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.

Staged cardiovascular magnetic resonance for differential diagnosis of troponin T positive patients with low likelihood for acute coronary syndrome

BACKGROUND

Cardiac troponin-T (cTnT) is a cardio-specific indicator of myocardial necrosis due to ischemic or non-ischemic events. Considering the multiple causes of myocardial injury and treatment consequences there is great clinical need to clarify the underlying reason for cTnT release. We sought to implement acute CMR as a non-invasive imaging method for differential diagnosis of elevated cTnT in chest-pain unit (CPU) patients with non-conclusive symptoms and ECG-changes and a low to intermediate probability for coronary artery disease (CAD).

RESULTS

CPU patients (n = 29) who had positive cTnT were scanned at 1.5T with a new step-by-step CMR algorithm including cine-, perfusion-, T2-, angiography-and late gadolinium enhancement (LGE) imaging. For comparison patients also underwent echocardiography and coronary angiography if necessary. CMR was conducted successfully in all patients and detected 93% of cTnT releases of unknown cause, without adverse hemodynamic or arrhythmic events. Acute myocardial infarction was detected in 11, pulmonary embolism in 6, myocarditis in 5, renal disease and cardiomyopathy in 2, storage disorder in 1 patient. In 2 patients CMR was unable to reveal the cause of cTnT elevations. Mean CMR scan-time was 35 ± 8 min. In 4 patients, CMR led to immediate coronary angiography with correct prediction of the infarct related artery.

CONCLUSIONS

We implemented a novel CMR algorithm to show the clinical value and practical feasibility of acute CMR in a non-conclusive patient cohort with unclear cTnT elevation. Since this pilot study has shown the feasibility of CMR in CPU patients, further prospective studies are warranted to compare CMR with other imaging modalities.

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.

Use and Misuse of Cardiac Troponins in Clinical Practice

Cardiac troponins are very sensitive and specific markers of myocardial injury. Elevated troponin levels in the setting of acute coronary syndrome are diagnostic of acute myocardial infarction and provide guidance to clinicians with regard to appropriate use of intensive medical and revascularization therapies. However, elevated troponin levels are commonly seen in several noncoronary ischemia presentations and create considerable confusion among clinicians in these settings. In this review article, we discuss the utility of troponins in various clinical settings and present a "common sense" approach to interpreting troponin elevation outside the setting of acute coronary syndrome.

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.

Prognostic value of C-reactive protein and cardiac troponin I in primary percutaneous interventions for ST-elevation myocardial infarction

BACKGROUND

The rise in cardiac troponin I after ST-elevation myocardial infarction treated by primary percutaneous coronary interventions (PCIs) is predictive of infarct size and left ventricular ejection fraction (LVEF). However, the comparative value of C-reactive protein (CRP) and troponin I for infarct size evaluation and the respective relationships between these biomarkers and mortality have not been investigated.

METHODS

We studied 87 patients who underwent primary PCI for ST-elevation myocardial infarction. Concentrations of troponin I and CRP were measured before and for 72 hours after PCI. Infarct size was measured by the cumulative release of alpha-hydroxybutyrate deshydrogenase during the 72 hours after PCI (QHBDH72) and by delayed radionuclide LVEF (at 4.6 +/- 1.7 weeks).

RESULTS

Concentrations of CRP at peak and at 24, 48 and 72 hours, and of troponin I at 6 and 72 hours, correlated with QHBDH72 and LVEF. In single variable analysis, at a mean follow-up of 42 +/- 8 months, Killip score of 3 to 4, CRP at baseline and at 48 hours, and troponin I at 6 and 72 hours were related to mortality. By multiple variable analysis, Killip score (OR 9.9, CI 1.6-58.8) and troponin I at 72 hours (OR 9.43, CI 2.1-43.5) were the only independent predictors of mortality.

CONCLUSIONS

Plasma concentrations of CRP and troponin I after PCI were related to infarct size and mortality. However, Killip class and troponin I at 72 hours were the only independent predictors of mortality at long-term follow-up.

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.

Use of biomarkers in the emergency department and chest pain unit

The use of biomarkers of cardiac injury in the emergency department (ED) and observation unit settings has several nuances that are different and, therefore, worthy of its own set of use guidelines. The markers that are used, however, are the same. The primary marker of choice continues to be cardiac troponin (Tn). Other markers that have been used because of the need in the ED for rapid triage have been myoglobin and fatty acid binding protein. In addition, some centers still prefer less sensitive and less specific markers such as creatine kinase myocardial band (CK-MB). More recently, a push has occurred to develop markers of ischemia, such as ischemia modified albumin (IMA),to determine which patients have ischemia, even in the absence of cardiac injury. As troponin assays become more sensitive and method for use becomes better understood, the use of these other markers are being relegated to lesser and lesser roles. Markers of ischemia are useful, but at present, despite some enthusiasm, are not ready for routine use. Before describing the recommendations for clinical use of biomarkers in the ED, a basic understanding of some of the science and measurement issues related to these analytes is helpful.

Point-of-Care Testing and Cardiac Biomarkers: The Standard of Care and Vision for Chest Pain Centers

Point-of-care testing (POCT) is defined as testing at or near the site of patient care. POCTdecreases therapeutic turnaround time (TTAT), increases clinical efficiency, and improves medical and economic outcomes. TTAT represents the time from test ordering to patient treatment. POC technologies have become ubiquitous in the United States, and, therefore,so has the potential for speed, convenience, and satisfaction, strong advantages for physicians, nurses, and patients in chest pain centers. POCT is applied most beneficially through the collaborative teamwork of clinicians and laboratorians who use integrative strategies, performance maps, clinical algorithms, and care paths (critical pathways). For example, clinical investigators have shown that on-site integration of testing for cardiac injury markers (myoglobin, creatinine kinase myocardial band [CKMB],and cardiac troponin I [cTnI]) in accelerated diagnostic algorithms produces effective screening, less hospitalization, and substantial savings. Chest pain centers, which now total over 150 accredited in the United States, incorporate similar types of protocol-driven performance enhancements. This optimization allows chest pain centers to improve patient evaluation, treatment, survival, and discharge. This article focuses on cardiac biomarker POCT for chest pain centers and emergency medicine.

Admission N-terminal pro-brain natriuretic peptide and its interaction with admission troponin T and ST segment resolution for early risk stratification in ST elevation myocardial infarction

OBJECTIVE

To assess the long term prognostic value of N-terminal pro-brain natriuretic peptide (NT-proBNP) on admission and its prognostic interaction with both admission troponin T (TnT) concentrations and resolution of ST segment elevation in fibrinolytic treated ST elevation myocardial infarction (STEMI).

DESIGN AND SETTING

Substudy of the ASSENT (assessment of the safety and efficacy of a new thrombolytic) -2 and ASSENT-PLUS trials.

PATIENTS

NT-proBNP and TnT concentrations were determined on admission in 782 patients. According to NT-proBNP concentrations, patients were divided into three groups: normal concentration (for patients < or = 65 years, < or = 184 ng/l and < or = 268 ng/l and for those > 65 years, < or = 269 ng/l and < or = 391 ng/l in men and women, respectively); higher than normal but less than the median concentration (742 ng/l); and above the median concentration. For TnT, a cut off of 0.1 microg/l was used. Of the 782 patients, 456 had ST segment resolution (< 50% or > or = 50%) at 60 minutes calculated from ST monitoring.

MAIN OUTCOME MEASURES

All cause one year mortality.

RESULTS

One year mortality increased stepwise according to increasing concentrations of NT-proBNP (3.4%, 6.5%, and 23.5%, respectively, p < 0.001). In receiver operating characteristic analysis, NT-proBNP strongly trended to be associated more with mortality than TnT and time to 50% ST resolution (area under the curve 0.81, 95% confidence interval (CI) 0.72 to 0.9, 0.67, 95% CI 0.56 to 0.79, and 0.66, 95% CI 0.56 to 0.77, respectively). In a multivariable analysis adjusted for baseline risk factors and TnT, both raised NT-proBNP and ST resolution < 50% were independently associated with higher one year mortality, whereas raised TnT contributed independently only before information on ST resolution was added to the model.

CONCLUSION

Admission NT-proBNP is a strong independent predictor of mortality and gives, together with 50% ST resolution at 60 minutes, important prognostic information even after adjustment for TnT and baseline characteristics in STEMI.

[Acute coronary syndrome: unstable angina and myocardial infarction]

The acute coronary syndrome comprises unstable angina, non-ST-segment elevation myocardial infarction, and ST-segment elevation myocardial infarction. A successful and stable revascularisation of the infarct related vessel, and the prevention of the loss of myocardium are the main therapeutic targets, as cardiovascular mortality and long term quality of life are essentially determined by left ventricular function. The clinical diagnosis comprises clinical symptoms, ECG-changes, and cardiac troponins. Early percutaneous coronary intervention (PCI) has become the most common method of coronary revascularisation. If PCI is not available, systemic thrombolysis is an alternative after exclusion of contraindications. Parenteral anticoagulation with intravenous or subcutaneous heparines, antithrombotic therapy and HMG-CoA reductase inhibitors are the common secondary drug therapy. Moreover, to prevent left ventricular remodelling ACE-inhibitors, angiotension 2-receptor antagonists, and beta-blocker are indicated.

Clinical significance of a single measurement of troponin-I and C-reactive protein at admission in 1773 consecutive patients with acute coronary syndromes

BACKGROUND

The clinical significance of biochemical markers of myocardial damage or inflammation has not been prospectively established in populations representing the whole spectrum of acute coronary syndromes. We investigated whether the elevation of these biomarkers at admission has a prognostic value that is independent and incremental to baseline clinical variables and quantitative electrocardiographic ischemia.

METHODS

We measured blood levels of cardiac troponin I (cTnI) and C-reactive protein (CRP) in 1773 consecutive patients admitted to 31 Italian coronary care units within 12 hours from an episode of acute coronary syndrome. Primary and secondary outcomes were (1) 30-day incidence of death or nonfatal (re)infarction and (2) death alone.

RESULTS

In a multivariate model, cTnI was independently associated with the risk of death or (re)infarction (OR, 1.8; 95% CI, 1.2 to 2.6; P =.002) and death (OR, 2.2; 95% CI, 1.4 to 3.4; P <.001), whereas CRP was of borderline significance for the primary outcome but was associated with death (OR, 1.4; 95% CI, 1.0 to 2.1; P =.06, and OR, 1.7; 95% CI, 1.1 to 2.6; P =.01, respectively). However, the inclusion of the biomarkers did not increase the prognostic capacity of the clinical risk model (C-index of both models with and without biomarkers was 0.73 for the primary outcome measures and 0.80 for the secondary outcome measures). CRP further stratified cTnI-negative patients. The prognostic significance of the biomarkers was similar in patients with and in those without persistent ST-segment elevation.

CONCLUSIONS

In acute coronary syndromes, the elevation of cTnI and CRP at admission has an independent prognostic value that is not incremental to baseline clinical variables and quantitative electrocardiographic ischemia.

Troponin I concentrations following primary percutaneous coronary intervention predict large infarct size and left ventricular dysfunction in patients with ST-segment elevation acute myocardial infarction

The aim of this study was to investigate the ability of troponin I (cTnI) levels to predict myocardial infarction size in patients with ST-segment elevation acute myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). In 87 patients with STEMI undergoing primary PCI, serial plasma concentrations of cTnI and alpha-hydroxybutyrate deshydrogenase (HBDH) were measured before PCI and over the following 72 h. Enzymatic infarct size was estimated by the cumulative release of HBDH during the 72 h following PCI (QHBDH72). Delayed radionuclide left ventricular ejection fraction (LVEF) was measured in 63 patients. While cTnI concentrations at admission did not correlate with QHBDH72 or with LVEF, from the 3rd to the 72nd h following PCI, they did correlated with QHBDH72 (P<0.001; R: 0.76-0.86) and with LVEF (P<0.001; R: -0.42 to -0.50). Receiver-operator characteristic (ROC) curve analysis showed that admission concentrations of cTnI could not predict either a large infarct size (i.e., QHBDH72>10 g-eq l(-1)) or a low LVEF (i.e., LVEF<40%). However, 6 h and up until 72 h after PTCA, cTnI concentrations were predictive of large enzymatic infarct size (sensitivity: 91 and 95%, specificity: 90 and 87%, respectively) and of LVEF under 40% (sensitivity: 75 and 77%, specificity: 90 and 78%, respectively). Thus, our study suggests that in contrast with admission cTnI concentration, cTnI levels following primary PCI represent a reliable tool for predicting large enzymatic infarct size and may help in selecting patients with a high risk of low LVEF at 1 month.

The role of C-reactive protein on the long-term clinical outcome after primary or rescue percutaneous coronary intervention

BACKGROUND

We examined the clinical and angiographic outcomes, success rate of the percutaneous coronary intervention (PCI) and long-term survival rate after primary or rescue PCI in patients with acute myocardial infarction (AMI) according to the level of the C-Reactive Protein (CRP) on admission.

METHODS

Two hundred and eight consecutive patients with AMI who underwent primary or rescue PCI between 1997 and 1999 at Chonnam National University Hospital were divided into two groups: Group I (n = 86, 59.9 +/- 9.3 years, male 74.4%) with a normal CRP (< 1.0 mg/dL, mean value = 0.43 +/- 0.14 mg/dL) on admission and Group II (n = 122, 59.1 +/- 10.4 years, male 83.6%) with an elevated CRP (> or = 1.0 mg/dL, mean value = 3.50 +/- 0.93 mg/dL) on admission.

RESULTS

There were no significant differences in teh baseline characteristics noted between the two groups. The incidence of cardiogenic shock was higher in Group II than in Group I (Group I; 3/86, 3.5% vs. Group II; 15/122, 12.3%, p = 0.026). The coronary angiographic findings did not differ between the two groups. The ejection fraction and Thrombolysis In Myocardial Infarction flow grade improved after PCI in both groups. The primary success rate of PCI was 94.2% (81/86) in Group I and 95.1% (116/122) in Group II (p = 0.776). The survival rates for Group I were 97.7%, 97.7% and 96.5%, and those for Group II were 91.8%, 91.0% and 86.9% at 1, 6 and 12 months, respectively (p = 0.043 at 1 month, p = 0.040 at 6 months, p = 0.018 at 12 months).

CONCLUSION

A high incidence of cardiogenic shock and worse long-term survival after PCI are observed in AMI patients with an elevated CRP.

Prognostic significance of admission cardiac troponin T in patients treated successfully with direct percutaneous interventions for acute ST-segment elevation myocardial infarction

BACKGROUND

Cardiac troponin T (cTnT) elevations at admission indicate a high-risk subgroup of patients with acute ST-segment elevation myocardial infarction, possibly due to a higher failure rate of reperfusion therapies.

OBJECTIVE

We sought to determine the predictive role of admission cTnT in patients with ST-segment elevation myocardial infarction undergoing successful direct percutaneous coronary intervention.

METHODS

A total of 218 consecutive patients with ST-segment elevation myocardial infarction were enrolled. Patients were stratified according to admission cTnT and infarct location. They were followed prospectively for short-term and long-term outcomes. RESULTS A positive cTnT (47.7%) was associated with higher mortality rates at 30 days (14.4% vs. 3.5%, p = .003) and 12 months (17.3% vs. 4.4%, p =.007). cTnT allowed discrimination of patients at high and low risk for cardiac death at 30 days and 12 months among anterior (19.2% vs. 7.9%, p = .19, and 25% vs. 13.2%, p = .22, respectively) and, more impressively, among nonanterior acute myocardial infarction (9.6% vs. 1.3%, p = .04, and 11.5% vs. 1.3%, p = .017, respectively). In multivariate analysis, older age, anterior infarct location, and depressed left ventricular function were the most potent independent predictors of future risk. Among clinical variables available at admission, cTnT indicated independently a higher risk of cardiac death (odds ratio, 3.1 [1.07-9.01], p =.038). This increased risk associated with a positive cTnT was almost independent of time delays from onset of symptoms to admission (3.8 vs. 2.3 hrs in cTnT-positive vs. cTnT-negative patients, p <.001).

CONCLUSIONS

Admission cTnT is a strong predictor of future cardiac risk in patients with ST-segment elevation myocardial infarction, despite successful restoration of Thrombolysis in Myocardial Infarction grade 3 coronary flow by direct percutaneous coronary intervention.

Acute coronary syndrome: biochemical strategies in the troponin era

New biomarkers, such as cardiac troponins, have a major role to play for cost-effective management of individuals with acute chest pain and suspected coronary syndrome, and the laboratory is now poised to assume a vital role in assessing damage and determining prognosis. The redefined biochemical criterion proposed to classify acute coronary syndrome patients presenting with ischemic symptoms as patients with myocardial infarction is heavily predicated on an increased troponin concentration in blood. In an era of evidence-based medicine, we can no longer overlook the diagnostic and prognostic benefits provided by the measurement of these highly sensitive and specific proteins.

Nicorandil-induced preconditioning as evidenced by troponin T measurements after coronary angioplasty in patients with stable angina pectoris

Nicorandil has been reported to have a preconditioning effect which suppresses the ST-segment shift or lactate production during coronary angioplasty in patients with stable angina pectoris. The present study investigated whether the preconditioning effect of nicorandil affects troponin T (TnT) levels after coronary angioplasty. Twenty-four patients with stable angina pectoris were randomized to receive a 1-minute intravenous infusion of nicorandil (100 microg/kg) or normal saline. Five minutes later they underwent three 2-minute balloon inflations 5 minutes apart. The sum of ST-segment elevation in all leads (Sum-ST) was determined at the end of each balloon inflation. Serum levels of TnT were measured 6 and 18 hours after the procedure, and the higher value of the two measurements was compared between the groups. SumST decreased progressively during the three sequential balloon inflations in both groups and was less in the nicorandil group than in the control group. The TnT level after the procedure was significantly lower in the nicorandil group than in the control group (0.05+/-0.05 vs 0.11+/-0.10 ng/mL). In conclusion, pretreatment with intravenous nicorandil suppresses TnT release after coronary angioplasty as well as ST-segment elevation during coronary angioplasty, suggesting pharmacological preconditioning by nicorandil.

Relation of troponin T release kinetics to long-term clinical outcome in patients with acute ST segment elevation myocardial infarction treated with a percutaneous intervention

The purpose of this study was to determine the relation of troponin T release kinetics to long-term clinical outcome in patients with an acute ST segment elevation myocardial infarction treated with a primary percutaneous intervention. One hundred and four patients with typical ischemic chest pain and > 1.5 mm ST segment elevation in > 2 contiguous leads underwent primary stenting (n = 60) or primary percutaneous transluminal coronary angioplasty (n = 44). Serum troponin T concentrations were obtained prior to and serially postintervention for 72 hr. Mean time to peak serum troponin T concentration was significantly longer in patients with cardiac death (P = 0.02), reinfarction (P = 0.007), target lesion reintervention (P = 0.03), and the composite of these events (13.2 +/- 5.3 vs. 9.3 +/- 4.0 hr; P < 0.0005). Multivariate analysis identified age, Killip class > 2, and time to peak serum troponin T concentration as independent predictors of long-term cardiac event-free survival. Thus, time to peak serum troponin T concentration independently predicts long-term cardiac event-free survival in patients with acute ST segment elevation myocardial infarction treated with a primary percutaneous intervention.

Detection of myocardial damage - are the troponins the ultimate solution?

Biochemical markers of myocardial damage are together with the clinical history, the physical examination and the 12-lead ECG key elements in the clinical evaluation of patients presenting with symptoms suggestive of an acute coronary syndrome (ACS). In this situation the detection of myocardial damage, even very minor, is of importance, not only for diagnosis, but also for risk assessment and selection of treatment. The new markers of myocardial damage. troponin T and I, have been shown to offer some advantages over the conventional markers in ACS and there is also an increasing interest for troponins in other clinical situations, e.g. after surgery and percutaneous coronary intervention. This paper will discuss the role of troponins in these different clinical situations.