Relation between troponin T and the risk of subsequent cardiac events in unstable coronary artery disease. The FRISC study group

Troponin dependent 30-day mortality in patients with acute pulmonary embolism

BACKGROUND

Troponin concentrations above upper reference are associated with increased mortality in patients with pulmonary embolism (PE). We aimed to assess whether risk of 30-day mortality increases in a dose-response relationship with concentration of troponin.

METHODS

Using Danish national registries, we identified patients ≥ 18 years of age hospitalized with first-time PE between 2013 and 2018 and available troponin measurements - 1/+1 day from admission. Patients were stratified into quintiles by increasing troponin concentration. Risk of 30-day mortality was assessed performing cumulative mortality curves and Cox regression model comparing the troponin quintiles.

RESULTS

We identified 5,639 PE patients of which 3,278 (58%) had a troponin concentration above upper reference. These patients were older (74 years), 50% male and with heavier comorbidity compared to patients with non-elevated troponin. We found increasing 30-day mortality with increasing troponin concentration (1% in 1st quintile (95% CI 0.5-1.5%), 2% in 2nd quintile (95% CI 1-2.5%), 8% in 3rd quintile (95% CI 5-9%), 11% in 4th quintile (95% CI 9-13%) and 15% in 5th quintile (95% CI 13-16%), confirmed in a Cox model comparing 1st quintile with 2nd quintile (HR 1.09; 95% CI 0.58-2.02), 3rd quintile (HR 3.68; 95% CI 2.20-6.15), 4th quintile (HR 5.51; 95% CI 3.34-9.10) and 5th quintile (HR 8.09; 95% CI 4.95-13.23).

CONCLUSION

30-day mortality was strongly associated with troponin concentration useful for improving risk stratification, treatment strategies and outcomes in PE patients.

Increased levels of NT-proBNP and troponin T 2 years after coronary artery bypass grafting complicated by mediastinitis

Background

Mediastinitis after coronary bypass grafting (CABG) increases the risk of the internal mammary artery (IMA) graft obstruction, and has a detrimental effect on long-term survival. The pathogenesis for this increased mortality is poorly understood. In the present study, we aimed to investigate the relationship between mediastinitis and persistently elevated cardiac-specific biomarkers [troponin T (TnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP)] and C-reactive protein (CRP) at mid-term follow-up following CABG.

Material and methods

The epidemiologic design was of an exposed (mediastinitis, n = 41) vs. randomly selected non-exposed (non-mediastinitis) controls (n = 41) cohort. Serum samples for measurements of NT-proBNP, TnT, and CRP were obtained at a median follow up time of 2.7 (range 0.5-5.2) years after CABG surgery.

Results

NT-proBNP (mean 65.0 pg/ml vs. 34.8 pg/ml, p = 0.007) and TnT levels (mean 14.7 ng/L vs. 11.2 ng/L, p = 0.004) were significantly higher in the mediastinitis group than in the control group. Patients with mediastinitis had also higher body mass index (BMI) and were more likely to have diabetes and previous myocardial infarction. There was no difference in serum CRP level between the groups. After controlling for potential confounders (previous myocardial infarction, age, and BMI), the presence of mediastinitis was associated with higher levels of log NT-proBNP (p = 0.02) and log TnT (p = 0.04).

Conclusion

Mediastinitis increases the concentrations of cardiac-specific biomarkers NT-proBNP and TnT at mid-term follow-up, representing persistent myocardial injury and impaired cardiac function.

Association between high-sensitivity cardiac troponin T levels and incident stroke in the elderly Japanese population: Results from the Tohoku Medical Megabank Community-based Cohort Study

Elevated levels of circulating high-sensitivity cardiac troponin T (hs-cTnT) are associated with cardiovascular disease. This study aimed to examine whether hs-cTnT levels are associated with incident stroke in the elderly population. The Iwate Tohoku Medical Megabank Organization pooled participant data for a community-based cohort study (n = 15,063, 69.6 ± 3.4 years), with a mean follow-up period of 5.23 years for all-cause death and incident stroke. The follow-up revealed 316 incident strokes, including atherothrombotic (n = 98), cardioembolic (n = 54), lacunar (n = 63), hemorrhagic (n = 101), and 178 all-cause deaths. Participants were classified into quartiles according to hs-cTnT levels (Q1 ≦ 4 ng/L, Q2: 5-6 ng/L, Q3: 7-9 ng/L, and Q4 > 9 ng/L). After adjusting for sex, age, smoking, drinking, systolic blood pressure, estimated glomerular filtration rate, N-terminal pro-brain natriuretic peptide, hemoglobin A1c, and lipid profile, a Cox proportional hazard model showed that higher hs-cTnT levels were associated with ischemic stroke (Q1 vs. Q4, hazard ratio [HR] = 2.24, 95 % confidence interval [CI] = 1.12-4.51, p = 0.023). The incident of total stroke was not associated with hs-cTnT levels (Q1 vs. Q4, HR 1.39, 95 % CI = 0.89-1.74, p = 0.145). Numerical differences were highest regarding incident lacunar stroke subtypes; however, this association was not statistically significant. Higher hs-cTnT concentrations were associated with ischemic stroke in the elderly Japanese population.

Poor outcome among patients undergoing myocardial perfusion imaging with intermediate-zone troponin

BACKGROUND

Intermediate zone troponin elevation is defined as one to five times the upper limit of normal. Approximately half the patients presenting with chest pain to the emergency department have initial intermediate zone troponin.

OBJECTIVES

We aimed to investigate the long-term outcome of patients hospitalized with chest pain and intermediate zone troponin elevation.

METHODS

We investigated 8269 patients hospitalized in a tertiary center with chest pain. All patients had serial measurements of troponin during hospitalization. Patients were divided into three groups based on their initial troponin levels: negative troponin (N = 6112), intermediate zone troponin (N = 1329) and positive troponin (N = 828). All patients underwent myocardial perfusion imaging (MPI) as part of the initial evaluation.

RESULTS

Mean age of the study population was 68 ± 11, of whom 36% were women. Patients with an intermediate zone troponin were older, more likely to be males, and with significantly more cardiovascular co-morbidities. Multivariate analysis adjusted for age, gender, cardiovascular risk factors, and abnormal MPI result found that patients with intermediate zone troponin had a 70% increased risk of re-hospitalization at 1 year (HR 1.70, 95%CI 1.48-1.96, p-value < 0.001) and 5.3 times higher risk of total mortality at 1-year (HR 5.33, 95%CI 3.65-7.78, p-value < 0.001). sub-group analysis found that among the intermediate zone troponin group, patients with double intermediate zone troponin had the poorest outcome.

CONCLUSIONS

Intermediate zone troponin elevation is an independent risk factor associated with adverse outcomes and therefore patients with an initial value in this range should be closely monitored and aggressively managed.

Carbon Monoxide Releasing Molecule A1 Reduces Myocardial Damage After Acute Myocardial Infarction in a Porcine Model

ABSTRACT

Infarct size is a major determinant of outcomes after acute myocardial infarction (AMI). Carbon monoxide-releasing molecules (CORMs), which deliver nanomolar concentrations of carbon monoxide to tissues, have been shown to reduce infarct size in rodents. We evaluated efficacy and safety of CORM-A1 to reduce infarct size in a clinically relevant porcine model of AMI. We induced AMI in Yorkshire White pigs by inflating a coronary angioplasty balloon to completely occlude the left anterior descending artery for 60 minutes, followed by deflation of the balloon to mimic reperfusion. Fifteen minutes after balloon occlusion, animals were given an infusion of 4.27 mM CORM-A1 (n = 7) or sodium borate control (n = 6) over 60 minutes. Infarct size, cardiac biomarkers, ejection fraction, and hepatic and renal function were compared amongst the groups. Immunohistochemical analyses were performed to compare inflammation, cell proliferation, and apoptosis between the groups. CORM-A1-treated animals had significant reduction in absolute infarct area (158 ± 16 vs. 510 ± 91 mm2, P < 0.001) and infarct area corrected for area at risk (24.8% ± 2.6% vs. 45.2% ± 4.0%, P < 0.0001). Biochemical markers of myocardial injury also tended to be lower and left ventricular function tended to recover better in the CORM-A1 treated group. There was no evidence of hepatic or renal toxicity with the doses used. The cardioprotective effects of CORM-A1 were associated with a significant reduction in cell proliferation and inflammation. CORM-A1 reduces infarct size and improves left ventricular remodeling and function in a porcine model of reperfused MI by a reduction in inflammation. These potential cardioprotective effects of CORMs warrant further translational investigations.

Long-Term Prognostic Significance of High-Sensitive Troponin I Increase during Hospital Stay in Patients with Acute Myocardial Infarction and Non-Obstructive Coronary Arteries

Background and Objectives: A topic already widely investigated is the negative prognostic value regarding the extent of high sensitive troponin I (hs-TnI) increases among patients with myocardial infarction (MI) and obstructive coronary atherosclerosis compared to a group of patients with MI and non-obstructive coronary atherosclerosis (MINOCA). Thus, the aim of this study was to evaluate the prognostic value concerning the extent of hs-TnI increase on clinical outcomes among patients with a MINOCA working diagnosis. Materials and Methods: We selected 337 consecutive patients admitted to hospital with a working diagnosis of MINOCA. The patients were divided in three groups according to the extent of hs-TnI increase during hospitalization (increase ≤5-times above the limit of the upper norm, >5 and ≤20-times, and >20-times). The study endpoints included all-cause mortality and major adverse cardiac and cerebrovascular events (MACCE; cerebral stroke and transient ischemic attacks, MI, coronary artery revascularization, either percutaneous coronary intervention or coronary artery bypass grafting and all-cause mortality). Results: During the mean follow-up period of 516.1 ± 239.8 days, using Kaplan-Meier survival curve analysis, significantly higher mortality rates were demonstrated among patients from the group with the greatest hs-TnI increase compared to the remaining groups (p = 0.01) and borderline values for MACCE (p = 0.053). Multivariable cox regression analysis did not confirm hs-TnI among factors related to increased MACCE or all-cause mortality rates. Conclusion: While a relationship between clinical outcomes and the extent of the hs-TnI increase among patients with a MINOCA working diagnosis remains, it does not seem to be not as strong as it is in patients with obstructive coronary atherosclerosis.

Cardiac biomarkers by point-of-care testing – back to the future?

The measurement of the cardiac troponins (cTn), cardiac troponin T (cTnT) and cardiac troponin I (cTnI) are integral to the management of patients with suspected acute coronary syndromes (ACS). Patients without clear electrocardiographic evidence of myocardial infarction require measurement of cTnT or cTnI. It therefore follows that a rapid turnaround time (TAT) combined with the immediacy of results return which is achieved by point-of-care testing (POCT) offers a substantial clinical benefit. Rapid results return plus immediate decision-making should translate into improved patient flow and improved therapeutic decision-making. The development of high sensitivity troponin assays offer significant clinical advantages. Diagnostic algorithms have been devised utilising very low cut-offs at first presentation and rapid sequential measurements based on admission and 3 h sampling, most recently with admission and 1 h sampling. Such troponin algorithms would be even more ideally suited to point-of-care testing as the TAT achieved by the diagnostic laboratory of typically 60 min corresponds to the sampling interval required by the clinician using the algorithm. However, the limits of detection and analytical imprecision required to utilise these algorithms is not yet met by any easy-to-use POCT systems.

Association between high-sensitivity cardiac troponin T and future cardiovascular incidence in a general Japanese population: results from the Tohoku medical megabank project

Purpose: Elevation of high-sensitivity cardiac troponin T (hs-cTnT) is associated with an increased risk of cardiovascular disease (CVD). This study determined whether hs-cTnT was detectable with N-terminal pro-b-type natriuretic peptide (NT-proBNP) and related to CV risk factors in a general Japanese population. Materials and methods: The Tohoku Medical Megabank Organization pooled individual participant data for a population-based cohort study in the Iwate prefecture (n = 30,193, age = 60.2 ± 11.5 year). Results: Hs-cTnT levels were higher in participants with hypertension, diabetes mellitus than in participants without these conditions (all ps < 0.001). Logistic regression analysis demonstrated that NT-proBNP was strongly associated with elevation of hs-cTnT (OR = 3.35, 95% CI = 2.90-3.89, p < 0.001). The receiver operating characteristic curve analysis showed that hs-cTnT was one of useful biomarker for the differentiation of high risk for CVD (the Suita score ≥ 56) from a general population. Logistic regression analysis demonstrated hs-cTnT levels were related to the CVD high risk group (OR = 2.67, 95% CI = 2.28-3.14, p < 0.001). Conclusions: Hs-cTnT levels are associated with elevation of NT-proBNP and high Suita score, which suggests that elevated hs-cTnT is related to subclinical myocardial damage and indicates CV risk.

Uppsala Clinical Research Center-development of a platform to promote national and international clinical science

Uppsala Clinical Research Center (UCR) is a non-profit organization that provides service for clinical research aiming for development and improvement of health care in Sweden and worldwide. UCR was started in 2001 with the ambition to shift the focus of clinical research from new medications or devices launched by the industry to problem-based research on issues identified in clinical reality, for example through the national quality registries. In order to accomplish these goals, UCR has established services in: 1) clinical trials of new and old methods in health care; 2) quality development of the health care system supported by internet-based national quality registries; 3) biostatistics, epidemiology, and data management; 4) biobanking of biological materials (Uppsala Biobank); 5) high-throughput biochemical analyses (UCR laboratory); and 6) academic leadership by the members of the UCR research faculty. The UCR clinical trials group provides services for investigator-driven projects in all areas of health care, for global mega-trials on new pharmaceutical treatments and devices, for biobanking including biomarker and genetics analyses, and for clinical events adjudication in national as well as global mega-trials. During the last few years, UCR has been a pioneer in establishing the registry-based randomized clinical trial (R-RCT), which today is an international model on how to perform cost-effective pragmatic randomized trials in the real-world environment. In 2002, UCR started the first national competence center for national quality registries, which pioneered the development of the current internet-based technologies for registering, reporting, and supporting continuous systematic improvement of health care. UCR is currently harboring around 20 national quality registries in all areas of health care. Today, UCR is the leading European center for registry-based quality development and evaluation of new medical treatments in cardiovascular care and has started to support other European countries in implementing the UCR registry platform in order to improve quality of care in the European Union.

Safety and efficacy of rivaroxaban for the secondary prevention following acute coronary syndromes among biomarker-positive patients: Insights from the ATLAS ACS 2-TIMI 51 trial

BACKGROUND:

Despite dual antiplatelet therapy, persistent thrombin generation and thrombin-mediated platelet activation account in part for the residual risk of atherothrombotic disease among patients with prior acute coronary syndrome (ACS). Inhibition of thrombin generation among high-risk ACS patients (biomarker-positive ACS) with the factor Xa inhibitor rivaroxaban may limit ongoing thrombus formation and myocardial necrosis and thereby improve clinical outcomes.

OBJECTIVES AND METHODS:

ATLAS ACS 2-TIMI 51 was a double-blind, placebo-controlled clinical trial that randomized ACS patients to either rivaroxaban 2.5 mg b.i.d., rivaroxaban 5 mg b.i.d., or placebo plus standard-of-care antiplatelet therapy for a mean of 13.1 months and up to 31 months ( N=15,526). This post-hoc analysis evaluates the safety and efficacy of rivaroxaban among biomarker-positive ACS patients with and without a history of prior stroke of transient ischemic attack in the ATLAS ACS 2-TIMI 51 trial.

RESULTS:

A total of 12,626 biomarker-positive ACS patients were included in this analysis. Among biomarker-positive patients without a prior history of stroke or transient ischemic attack, rivaroxaban 2.5 b.i.d. was associated with a reduction in the primary efficacy endpoint (composite of cardiovascular death, myocardial infarction, or stroke) as compared with placebo (hazard ratio=0.80, 95% confidence interval (0.68-0.94), p=0.007) at the expense of an increase in non-coronary-artery-bypass-graft-related Thrombolysis in Myocardial Infarction major bleeding (1.9% vs. 0.7%, p<0.0001), but not a significant increase in either intracranial hemorrhage (0.4% vs. 0.2%, p=0.11) or fatal bleeding (0.1% vs. 0.3%, p=0.16).

CONCLUSION:

Rivaroxaban 2.5 mg b.i.d. was associated with a significant reduction in the composite of cardiovascular death, myocardial infarction, or stroke with no increase in fatal bleeding. Biomarker-positive patients with no prior history of stroke or transient ischemic attack may be a optimal target population to receive "dual pathway" therapy with rivaroxaban plus dual antiplatelet therapy for secondary prevention following ACS.

The role of biomarkers in the diagnosis and risk stratification of acute coronary syndrome

Coronary artery disease is a growing concern. Although traditional biomarkers, such as troponins and creatine kinase, play a central role in the diagnosis, risk stratification and management of coronary artery disease, they are unable to detect myocardial ischemia in the absence of necrosis. Therefore, early detection of ischemia in patients presenting with acute coronary syndrome still remains a burning question. High-sensitivity troponin is evolving as a reliable biomarker in this regard and has been absorbed into clinical practice. Biomarkers are currently the focus of immense interest as it not only helps with diagnosis and management but also helps to understand the pathophysiology of the disease process. In addition, analysis using a multimarker strategy has also proven to be a very useful tool in risk stratification. This review will focus on the biomarkers and its application in the diagnosis and risk stratification of acute coronary syndrome.

Cardiovascular diseases are a common group of diseases that affect a large population and account for a significant number of deaths worldwide. Acute coronary syndrome (ACS) is a growing public health concern, where inadequate blood flow to the heart muscle results in reversible or irreversible damage to the cardiomyocyte. Early detection of ACS is crucial to deliver appropriate timely therapy to prevent myocardial necrosis and heart failure. Biomarkers are measurable and quantifiable biological substances that are used as indicators in the early diagnosis and management of patients with ACS. This article provides an overview of this topic and provides suggestions for the future.

Effect of Pentoxifylline in Ameliorating Myocardial Injury in Patients With Myocardial Infarction Undergoing Thrombolytic Therapy: A Pilot Randomized Clinical Trial

Cell death following acute myocardial infarction (MI) is the hallmark pathology of cardiovascular disease, leading to considerable mortality and morbidity. Platelet and neutrophil activation and inflammatory cytokines, prominently TNF-α, play an important role in the development of cell death. Because pentoxifylline inhibits platelet and neutrophil activation and reduces TNF-α, this study was performed to assess the potential benefit of pentoxifylline in the reduction of myocardial injury following acute MI. In this randomized clinical trial, 98 patients with acute MI were randomly divided into 2 groups. The intervention group received an oral dose of 1200 mg of pentoxifylline immediately before thrombolytic therapy (TLT). All patients received the same standard protocol for treatment of MI. Cardiac enzymes were checked over 48 hours. ST resolution was measured over 90 minutes. Then all patients were followed up for a 1-month period to assess major adverse cardiac effects (MACEs). There were no significant differences in peak levels of CPK (P = .18) and CK-MB (P = .33) between the 2 groups, whereas peak level of troponin I was significantly lower in the pentoxifylline group (16.8 ± 10.4 vs 21.3 ± 11.6; P = .048). No significant change between the groups was observed in biomarkers levels, ST segment resolution, cardiac ejection fraction, and MACEs. The results showed that pentoxifylline significantly reduced the peak value of troponin I in patients with acute MI receiving TLT. No significant change was observed in the other studied parameters. Further outcome-based studies are needed to show the clinical relevance of differences between the groups in troponin peak.

Relationship Between Peak Troponin Values and Long-Term Ischemic Events Among Medically Managed Patients With Acute Coronary Syndromes

BACKGROUND

The relationship between troponin level and outcomes among patients with non-ST-segment elevation ACS is established, but the relationship of troponin level with long-term outcomes among medically managed non-ST-segment elevation ACS patients receiving contemporary antiplatelet therapy is inadequately defined.

METHODS AND RESULTS

In 6763 medically managed non-ST-segment elevation ACS patients randomized in TRILOGY ACS (Targeted Platelet Inhibition to Clarify the Optimal Strategy to Medically Manage Acute Coronary Syndromes) (prasugrel versus clopidogrel), we examined relationships between categories of peak troponin/upper limit of normal (ULN) ratio within 48 hours of the index ACS event (≈4.5 days before randomization) and 30-month outcomes (cardiovascular death, myocardial infarction, or stroke; cardiovascular death or myocardial infarction; and all-cause death). Patients with peak troponin levels <1×ULN were younger, were more often women, and had lower GRACE risk scores than those in other troponin groups. Those with ratios ≥5×ULN were more frequently smokers but less often had prior myocardial infarction or percutaneous coronary intervention. Diabetes mellitus prevalence, body mass index, serum creatinine, and hemoglobin were similar across groups. For all end points, statistically significant differences in 30-month event rates were observed between peak troponin categories. The relationship was linear for 30-month mortality (<1×ULN, n=1849 [6.2%]; 1 to <3×ULN, n=1203 [9.6%]; 3 to <5×ULN, n=581 [10.8%]; and ≥5×ULN, n=3405 [12.8%]) but plateaued for composite end points beyond peak troponin values ≥3×ULN. There was no statistically significant heterogeneity in treatment effect by peak troponin ratio for any end point.

CONCLUSIONS

Among medically managed non-ST-segment elevation ACS patients selected for medical management, there was a graded relationship between increasing peak troponin and long-term ischemic events but no heterogeneity of treatment effect for prasugrel versus clopidogrel according to peak troponin.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00699998.

Troponin in Cardiovascular Disease Prevention: Updates and Future Direction

Cardiac troponin has been well described as the preferred biomarker for diagnosis of myocardial infarction due to the high sensitivity and specificity for myocardial injury. Numerous other conditions apart from acute coronary syndrome can also lead to small elevations in troponin levels. However, the use of cTn as prognostic biomarker for the primary assessment of cardiovascular risk in asymptomatic patient has only recently been described. And with the development of newer generations of high-sensitivity cardiac troponin assays that can detect 10-fold lower concentrations of troponin, the potential value cTn in the prevention and management of asymptomatic cardiovascular disease has come to the fore. This review provides an overview of the transition of cardiac troponin as a marker of acute myocardial injury to one that detects sub-clinical injury. Evidence continues to show that high-sensitivity troponin is emerging as one of the most powerful prognostic biomarkers for the assessment of cardiovascular risk in the general population.

Bleeding following Coronary Surgery after Preoperative Low-Molecular-Weight Heparin

Low-molecular-weight heparin and acetyl salicylic acid have become an established treatment for unstable angina. A retrospective study on our database of one year was carried out to see what impact preoperative low-molecular-weight heparin versus none had on the postoperative course of 473 patients having coronary surgery exclusively. Apart from the fact that the low-molecular-weight heparin patients had a higher New York Heart Association classification and marginally more grafts, longer bypass and cross-clamp time, the preoperative characteristics and surgery of the two groups were similar. The low-molecular-weight heparin group had twice as many (9.7% versus 4.7%) re-operations for bleeding, 46% versus 26% had blood transfusion and 22.3% versus 12.6% plasma transfusion. The postoperative outcome was otherwise similar. Preoperative treatment of unstable angina with low-molecular-weight heparin carries a definite risk of postoperative bleeding. Although this study did not reveal any serious consequences, bleeding, transfusions and re-operations are associated with infections, wound healing problems and death. The indications and length of treatment with low-molecular-weight heparin in unstable angina patients have to be appropriate and the perioperative management of these patients has to address the bleeding tendency.

Routine invasive strategies versus selective invasive strategies for unstable angina and non-ST elevation myocardial infarction in the stent era

BACKGROUND

People with unstable angina and non-ST elevation myocardial infarction (UA/NSTEMI) are managed with a combination of medical therapy, invasive angiography and revascularisation. Specifically, two approaches have evolved: either a 'routine invasive' strategy whereby all patients undergo coronary angiography shortly after admission and, if indicated, coronary revascularisation; or a 'selective invasive' (also referred to as 'conservative') strategy in which medical therapy alone is used initially, with a selection of patients for angiography based upon evidence of persistent myocardial ischaemia. Uncertainty exists as to which strategy provides the best outcomes for these patients. This Cochrane review is an update of a Cochrane review originally published in 2006, to provide a robust comparison of these two strategies in the early management of patients with UA/NSTEMI.

OBJECTIVES

To determine the benefits and harms associated with the following.1. A routine invasive versus a conservative or 'selective invasive' strategy for the management of UA/NSTEMI in the stent era.2. A routine invasive strategy with and without glycoprotein IIb/IIIa receptor antagonists versus a conservative strategy for the management of UA/NSTEMI in the stent era.

SEARCH METHODS

We searched the following databases and additional resources up to 25 August 2015: the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library, MEDLINE and EMBASE, with no language restrictions.

SELECTION CRITERIA

We included prospective randomised controlled trials (RCTs) that compared invasive with conservative or 'selective invasive' strategies in participants with acute UA/NSTEMI.

DATA COLLECTION AND ANALYSIS

Two review authors screened the records and extracted data in duplicate. Using intention-to-treat analysis with random-effects models, we calculated summary estimates of the risk ratio (RR) with 95% confidence intervals (CIs) for the primary endpoints of all-cause death, fatal and non-fatal myocardial infarction (MI), combined all-cause death or non-fatal MI, refractory angina and re-hospitalisation. We performed further analysis of included studies based on whether glycoprotein IIb/IIIa receptor antagonists were used routinely. We assessed the heterogeneity of included trials using Pearson χ² (Chi² test) and variance (I² statistic) analysis. Using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, we assessed the quality of the evidence and the GRADE profiler (GRADEPRO) was used to import data from Review Manager 5.3 (Review Manager) to create Summary of findings (SoF) tables.

MAIN RESULTS

Eight RCTs with a total of 8915 participants (4545 invasive strategies, 4370 conservative strategies) were eligible for inclusion. We included three new studies and 1099 additional participants in this review update. In the all-study analysis, evidence did not show appreciable risk reductions in all-cause mortality (RR 0.87, 95% CI 0.64 to 1.18; eight studies, 8915 participants; low quality evidence) and death or non-fatal MI (RR 0.93, 95% CI 0.71 to 1.2; seven studies, 7715 participants; low quality evidence) with invasive strategies compared to conservative (selective invasive) strategies at six to 12 months follow-up. There was appreciable risk reduction in MI (RR 0.79, 95% CI 0.63 to 1.00; eight studies, 8915 participants; moderate quality evidence), refractory angina (RR 0.64, 95% CI 0.52 to 0.79; five studies, 8287 participants; moderate quality evidence) and re-hospitalisation (RR 0.77, 95% CI 0.63 to 0.94; six studies, 6921 participants; moderate quality evidence) with routine invasive strategies compared to conservative (selective invasive) strategies also at six to 12 months follow-up.Evidence also showed increased risks in bleeding (RR 1.73, 95% CI 1.30 to 2.31; six studies, 7584 participants; moderate quality evidence) and procedure-related MI (RR 1.87, 95% CI 1.47 to 2.37; five studies, 6380 participants; moderate quality evidence) with routine invasive strategies compared to conservative (selective invasive) strategies.The low quality evidence were as a result of serious risk of bias and imprecision in the estimate of effect while moderate quality evidence was only due to serious risk of bias.

AUTHORS' CONCLUSIONS

In the all-study analysis, the evidence failed to show appreciable benefit with routine invasive strategies for unstable angina and non-ST elevation MI compared to conservative strategies in all-cause mortality and death or non-fatal MI at six to 12 months. There was evidence of risk reduction in MI, refractory angina and re-hospitalisation with routine invasive strategies compared to conservative (selective invasive) strategies at six to 12 months follow-up. However, routine invasive strategies were associated with a relatively high risk (almost double the risk) of procedure-related MI, and increased risk of bleeding complications. This systematic analysis of published RCTs supports the conclusion that, in patients with UA/NSTEMI, a selectively invasive (conservative) strategy based on clinical risk for recurrent events is the preferred management strategy.

Type 2 myocardial infarction: the chimaera of cardiology?

The term type 2 myocardial infarction first appeared as part of the universal definition of myocardial infarction. It was introduced to cover a group of patients who had elevation of cardiac troponin but did not meet the traditional criteria for acute myocardial infarction although they were considered to have an underlying ischaemic aetiology for the myocardial damage observed. Since first inception, the term type 2 myocardial infarction has always been vague. Although attempts have been made to produce a systematic definition of what constitutes a type 2 myocardial infarction, it has been more often characterised by what it is not rather than what it is. Clinical studies that have used type 2 myocardial infarction as a diagnostic criterion have produced disparate incidence figures. The range of associated clinical conditions differs from study to study. Additionally, there are no agreed or evidence-based treatment strategies for type 2 myocardial infarction. The authors believe that the term type 2 myocardial infarction is confusing and not evidence-based. They consider that there is good reason to stop using this term and consider instead the concept of secondary myocardial injury that relates to the underlying pathophysiology of the primary clinical condition.

High sensitivity cardiac troponin assays in the clinical laboratories

Immunoassays measuring cardiac troponins I or T have become firmly established as critical tools for diagnosing acute myocardial infarction. While most contemporary assays provide adequate diagnostic performance, the increased sensitivity and precision of the new, high sensitivity assays that have already been introduced into clinical practice, provide the potential to further shorten intervals between blood draws or the time needed to detect the first significant troponin elevation. In addition to the relatively modest benefits at the diagnostic end, the high sensitivity assays and the investigational ultrasensitive cardiac troponin assays offer improvements for predicting major adverse cardiovascular events, development of heart failure or transition to end-stage kidney disease. These novel high sensitivity assays can measure troponin concentrations in 50%–100% of healthy individuals and therefore allow for the distribution of troponin values within a healthy cohort to be measured, patient’s baseline troponin levels to be monitored, and clinicians to be alerted of deteriorating cardiorenal conditions. We envisage that the high sensitivity assays will become important tools for predicting each patient’s risk of future adverse events and for guiding and monitoring corresponding adjustments of preventative therapeutic interventions.

Decision limits and the reporting of cardiac troponin: Meeting the needs of both the cardiologist and the ED physician

Cardiac troponin is the preferred biomarker for defining the acute coronary syndrome and acute myocardial infarction. Currently, the only decision limit formally endorsed with regard to the cardiac troponins is the 99th percentile. This is a "rule-in" criterion, intended to ensure that only persons with the acute coronary syndrome are reviewed. The 99th percentile is an arbitrary cut point and there are many problems associated with its application, including defining a truly healthy population, the difficulty of standardisation of cardiac troponin assays, especially but not only cardiac troponin I, and the effects of age and sex on this parameter. The Emergency Department (ED) screens many more persons for possible acute coronary syndromes than actually have the condition and their needs are best met by a "rule-out" test that enables them to clear their busy departments of the many persons who do not actually have the condition. The needs of the ED are not optimally met using the 99th percentile. The index of individuality for the cardiac troponins is small and significant changes consistent with an acute coronary syndrome can occur without the 99th percentile being exceeded. It appears that the ED may be better served by use of delta troponin changes rather than the 99th percentile, but there are problems with this approach, particularly in persons who present late when troponin release has plateaued. In addition, there are many non-acute coronary syndrome causes for cardiac troponin release. The needs of the cardiologist and the ED physician are so different that it may be inappropriate for both groups to use the same diagnostic criteria for cardiac troponin, and it is of great importance that cardiac troponin measurement be used as only one part of the assessment of the person presenting with possible acute coronary syndrome.

Incremental Prognostic Value of Biomarkers beyond the GRACE (Global Registry of Acute Coronary Events) Score and High-Sensitivity Cardiac Troponin T in Non-ST-Elevation Acute Coronary Syndrome

BACKGROUND

Guidelines recommend the use of validated risk scores and a high-sensitivity cardiac troponin assay for risk assessment in non-ST-elevation acute coronary syndrome (NSTE-ACS). The incremental prognostic value of biomarkers in this context is unknown.

METHODS

We calculated the Global Registry of Acute Coronary Events (GRACE) score and measured the circulating concentrations of high-sensitivity cardiac troponin T (hs-cTnT) and 8 selected cardiac biomarkers on admission in 1146 patients with NSTE-ACS. We used an hs-cTnT threshold at the 99th percentile of a reference population to define increased cardiac marker in the score. The magnitude of the increase in model performance when individual biomarkers were added to GRACE was assessed by the change (Δ) in the area under the receiver-operating characteristic curve (AUC), integrated discrimination improvement (IDI), and category-free net reclassification improvement [NRI(&gt;0)].

RESULTS

Seventy-eight patients reached the combined end point of 6-month all-cause mortality or nonfatal myocardial infarction. The GRACE score alone had an AUC of 0.749. All biomarkers were associated with the risk of the combined end point and offered statistically significant improvement in model performance when added to GRACE (likelihood ratio test P ≤ 0.015). Growth differentiation factor 15 [ΔAUC 0.039, IDI 0.049, NRI(&gt;0) 0.554] and N-terminal pro–B-type natriuretic peptide [ΔAUC 0.024, IDI 0.027, NRI(&gt;0) 0.438] emerged as the 2 most promising biomarkers. Improvements in model performance upon addition of a second biomarker were small in magnitude.

CONCLUSIONS

Biomarkers can add prognostic information to the GRACE score even in the current era of high-sensitivity cardiac troponin assays. The incremental information offered by individual biomarkers varies considerably, however.

Role of imaging for acute chest pain syndromes

Acute chest pain suggestive of ischemic cardiac origin, with a normal or nondiagnostic electrocardiogram and negative initial cardiac markers for myocardial necrosis represent a significant diagnostic dilemma for clinicians. Multiple imaging modalities play a pivotal role in early diagnosis and safe discharge of these patients. In this review, we compare the current imaging modalities available for these patients including their diagnostic accuracy, feasibility, and cost effectiveness. Acute rest myocardial perfusion imaging significantly improves the clinical outcome in these patients and reduces the overall cost when incorporated into the decision making pathway. The choice of imaging modality recommended should be based on local institutional expertise and the overall clinical presentation. The imaging modality with high diagnostic accuracy and negative predictive value will provide for precise risk stratification which is important to clinical decision making, including patients who require admission to the hospital and those who can be safely discharged.

Use of high-sensitivity troponin assays predicts mortality in patients with normal conventional troponin assays on admission-insights from a meta-analysis

BACKGROUND

Use of high-sensitivity troponin (hs-Tn) assays can detect small levels of myocardial damage previously undetectable with conventional troponin (c-Tn) assays. However, prognostic utility of these hs-Tn assays in prediction of mortality remains unclear in the presence of nonelevated c-Tn levels on admission. A systematic review and meta-analysis was performed to assess mortality risk of patients with hs-Tn elevations in the setting of normal c-Tn levels.

HYPOTHESIS

Patients with hs-Tn elevations with normal c-Tn levels on admission blood samples, drawn to rule out acute coronary syndrome (ACS), have a higher mortality risk than those without hs-Tn or c-Tn elevations.

METHODS

A search was made of the PubMed, CENTRAL, EMBASE, CINAHL, EBSCO, and Web of Science databases. Studies evaluating patients with suspected ACS that reported mortality rates for those with elevated hs-Tn levels but normal c-Tn levels on admission were included. A random-effects model was used to pool event rates, and data were reported in odds ratios (95% confidence interval).

RESULTS

Four studies (N = 2033, mean age 64-75 years, 49%-70% male) revealed that nearly 32% of suspected ACS patients with normal c-Tn levels on admission had elevated hs-Tn levels. Elevated hs-Tn levels conferred a significantly higher risk of all-cause mortality vs normal hs-Tn levels (odds ratio: 4.35, 95% confidence interval: 2.81-6.73, P < 0.01), with negligible heterogeneity (I(2) = 0%).

CONCLUSIONS

Elevation of hs-Tn levels predicted a higher risk of mortality in patients with suspected ACS and may aid in the early identification of higher-risk patients in this setting. Future studies are needed to investigate further optimal management strategies.

Atrial fibrillation-induced cardiac troponin I release

BACKGROUND

Cardiac troponin I (cTnI) is highly specific for myocardial damage and for the diagnosis of acute coronary syndrome. We investigated cTnI utility and predictive value in patients with atrial fibrillation (AF) in the acute setting.

METHOD

We studied 354 consecutive patients with the primary diagnosis of AF and clinical symptoms suggestive of myocardial ischemia presenting to our emergency department. cTnI was obtained on presentation. Patients with ST-segment elevation myocardial infarction were excluded. Coronary angiography was performed in 100 patients.

RESULTS

cTnI was elevated (>0.09 μg/L) in 51 of 354 (15%) patients. The mean cTnI in these patients was 0.37 μg/L (0.09-3.14). In 23 of 100 patients undergoing coronary angiography, cTnI was elevated. Only 6 of these 23 patients (26%) had significant stenosis. In 77 of 100 patients undergoing coronary angiography, cTnI was normal, revealing significant stenosis in 25 patients (33%). The positive predictive value of elevated cTnI for a coronary intervention was 26% and the negative predictive value was 68%. Using multivariate logistic regression, we found that heart rate on presentation, the presence of angina pectoris, left ventricular ejection fraction, serum creatinine, and hemoglobin independently predicted elevated cTnI level.

CONCLUSION

These data are the first to show that AF in the acute setting is frequently associated with cTnI elevations. AF patients with high heart rate and/or angina pectoris often show false elevated cTnI levels. These findings are relevant for clinicians evaluating patients with acute AF and myocardial ischemia symptoms. Appropriate clinical guidelines must be established that also consider AF-related elevations in cTnI.

Association between troponin T and ICU mortality, a changing trend

Background

Initially elevated levels of troponin predict adverse outcomes in patients admitted to the intensive care unit (ICU). No research team has investigated the changes in concentration of cardiac troponin T (cTnT) during ICU stay and their association with patient outcome.

Objective

We investigated whether the change in cTnT levels during ICU stay could predict outcomes (death or survival).

Methods

In this cohort study, all patients admitted to the medical ICU (10 beds) from January to July 2008 were enrolled. Troponin levels were evaluated within the first 24 hours of ICU admission and on the fourth, seventh and 10th days after admission.

Results

The study population (135 patients) had a mean age of 60.9 ± 21.5 years. The outcome was significantly different with regard to normal or elevated cTnT concentrations on the first and seventh days of follow up (p = 0.03 and 0.023, respectively). This difference was non-significant for cTnT levels on the fourth and 10th days after admission (p = 0.69 and 0.78, respectively). The change in cTnT levels was not significantly different between the deceased and discharged patients (p = 0.4).

Conclusion

Changes in cTnT levels during ICU stay did not show a significant trend (power: 0.26). Patients whose cTnT levels were increased on the first and seventh days of ICU stay had a worse survival, which could be associated with cardiac events on admission or at specific times during the stay in ICU.

Assessing the clinical utility of biomarkers in medicine

Biomarkers in medicine have gained immense scientific and clinical interest in recent years. Biomarkers are potentially useful in the contexts of primary, secondary and tertiary prevention. Some of the characteristics of an ideal biomarker include that they are safe and easy to measure, are associated with acceptable costs (including those of the follow-up tests), and there is scientific evidence to suggest that biomarker use/modification influences disease outcomes. Additionally, variation in biomarker levels with gender and ethnicity should be elucidated, and the biomarker should have 'good performance characteristics' (i.e., sensitivity, specificity, positive- and negative-predictive values and positive- and negative-likelihood ratios). Risk prediction scores can combine information from several different biomarkers in order to estimate an individual's risk of developing an outcome, such as disease or death. Three commonly employed methods to test if a biomarker will add to traditional risk prediction models are model discrimination, model calibration and risk reclassification. 'Multimarker' strategies serve to integrate information from multiple biomarkers into risk prediction but may be limited by the presence of highly correlated biomarkers, economic costs and selection bias of biomarker candidates in a particular study sample. In the future, integration of biomarkers identified using emerging technologies from the 'omics fields (including genomics, proteomics, metabolomics, lipomics, ribomics and pharmacogenomics) may be useful for the 'personalization' of treatment/disease prevention.

Developing and assessing cardiovascular biomarkers

Atherosclerosis is a slow process that over time can lead to fatal events. Early identification and prediction of future risk can allow for preventive strategies to be instituted. There is an increasing interest in utilizing novel biomarkers in cardiovascular disease screening and management. These novel biomarkers may help in cardiovascular disease risk assessment and treatment monitoring, and some may be treatment targets. To be useful for risk prediction, novel biomarkers need to show a significant association with cardiovascular disease events and bring additional value in risk stratification when added to known risk prediction models. Biomarkers used for treatment monitoring need to show that they can serve as good surrogates of cardiovascular disease status. In this article, we present 3 biomarkers that are currently approved by the U.S. Food and Drug Administration for use in cardiovascular disease management and risk assessment: C-reactive protein, lipoprotein-associated phospholipase A2, and myeloperoxidase. Other new biomarkers have also been shown recently to help in cardiovascular disease risk prediction and management. In this article, we will review 2 of these new biomarkers: cardiac troponin T measured by a highly sensitive assay and brain natriuretic peptide.

Implications of lowering threshold of plasma troponin concentration in diagnosis of myocardial infarction: cohort study

OBJECTIVE

To assess the relation between troponin concentration, assay precision, and clinical outcomes in patients with suspected acute coronary syndrome.

DESIGN

Cohort study.

SETTING

Tertiary centre in Scotland.

PARTICIPANTS

2092 consecutive patients admitted with suspected acute coronary syndrome were stratified with a sensitive troponin I assay into three groups (<0.012, 0.012-0.049, and ≥0.050 µg/L) based on the 99th centile for troponin concentration (0.012 µg/L; coefficient of variation 20.8%) and the diagnostic threshold (0.050 µg/L; 7.2%).

MAIN OUTCOME MEASURE

One year survival without events (recurrent myocardial infarction, death) in patients grouped by troponin concentration.

RESULTS

Troponin I concentrations were <0.012 µg/L in 988 patients (47%), 0.012-0.049 µg/L in 352 patients (17%), and ≥0.050 µg/L in 752 patients (36%). Adoption of the 99th centile would increase the number of people receiving a diagnosis of myocardial infarction from 752 to 1104: a relative increase of 47%. At one year, patients with troponin concentrations of 0.012-0.049 µg/L were more likely to be dead or readmitted with recurrent myocardial infarction than those with troponin concentrations <0.012 µg/L (13% v 3%, P<0.001; odds ratio 4.7, 95% confidence interval 2.9 to 7.9). Compared with troponin ≥0.050 µg/L, patients with troponin 0.012-0.049 µg/L had a higher risk profile but were less likely to have a diagnosis of, or be investigated and treated for, acute coronary syndrome.

CONCLUSION

Lowering the diagnostic threshold to the 99th centile and accepting greater assay imprecision would identify more patients with acute coronary syndrome at risk of recurrent myocardial infarction and death but would increase the diagnosis of myocardial infarction by 47%. It remains to be established whether reclassification of these patients and treatment for myocardial infarction would improve outcome.

Cardiac biomarkers in acute myocardial infarction

Each year, a large number of patients are seen in the Emergency Department with presentations necessitating investigation for possible acute myocardial infarction. Patients can be stratified by symptoms, risk factors and electrocardiogram results but cardiac biomarkers also have a prime role both diagnostically and prognostically. This review summarizes both the history of cardiac biomarkers as well as currently available (established and novel) assays. Cardiac troponin, our current "gold standard" biomarker criterion for the diagnosis of myocardial infarction has high sensitivity and specificity for this diagnosis and therapies instituted in patients with elevated troponin have been shown to influence outcomes. Other markers of myocardial necrosis, inflammation and neurohormonal activity have also been shown to have either diagnostic or prognostic utility, but none have been shown to be superior to troponin. The measurement of multiple biomarkers and the use of point of care markers may accelerate current diagnostic protocols for the assessment of such patients.

An assessment of the concentration-related prognostic value of cardiac troponin I following acute coronary syndrome

In 2004 the British Cardiac Society redefined myocardial infarction by cardiac troponin I (cTnI) concentration: ≤ 0.06 μg/L (unstable angina), >0.06 to < 0.5 μg/L (myocardial necrosis), and ≥ 0.5 μg/L (myocardial infarction). We investigated the effects of this classification on all-cause mortality in 1,285 patients from the Evaluation of the Methods and Management of Acute Coronary Events (EMMACE)-2 registry. There were 528 deaths (6.6-year all-cause mortality 41.1%). Survival was greatest in the cTnI ≤ 0.06-μg/L subgroup at 30 days (p = 0.005), 6 months (p = 0.015), 1 year (p = 0.002), and 6.6 years (p = 0.045). After adjustment there was no significant difference in survival between the cTnI >0.06- to < 0.5-μg/L and ≥ 0.5-μg/L subgroups. Increased mortality (hazard ratio, 95% confidence interval) was associated with ages 70 to 80 years (2.58, 1.17 to 3.91) and >80 years (3.30, 3.50 to 5.06), peripheral vascular disease (1.50, 1.16 to 1.94), heart failure (1.36, 1.05 to 1.83), diabetes mellitus (1.68, 1.36 to 2.07), severe left ventricular systolic dysfunction (1.50, 1.00 to 2.21), and creatinine per 10 μmol/L (1.65, 1.02 to 1.08), whereas ages 50 to 60 years (0.55, 0.32 to 0.96), β blockers (0.53, 0.44 to 0.64), aspirin (0.80 0.65 to 0.99), angiotensin-converting enzyme inhibitors (0.67, 0.56 to 0.80), statins (0.73, 0.59 to 0.90), and revascularization (0.33, 0.12 to 0.92) were associated with a lower risk of death. In conclusion, although quantitative evaluation of cTnI concentration in patients with acute coronary syndrome with cTnI > 0.06 μg/L was associated with no added prognostic information, the dichotomization of patients by cTnI status ("positive" and "negative") facilitates acute coronary syndrome risk stratification.

Impact of gender on clinical outcomes after mTOR-inhibitor drug-eluting stent implantation in patients with first manifestation of ischaemic heart disease

BACKGROUND

Women have a worse outcome than men after percutaneous coronary intervention (PCI). However, in the drug-eluting stent (DES) era, limited data are available about the impact of gender-related differences on clinical outcome. Furthermore, many series have also included patients previously treated by coronary-artery bypass grafts or PCI, which may bias the evaluation of DES-related clinical events at follow up. We aimed to assess the impact of gender on clinical outcomes in a consecutive series of patients at first manifestation of coronary artery disease (CAD) undergoing PCI with mTOR-inhibitor DES.

METHODS AND RESULTS

A total of 138 consecutive patients (age 64 ± 13 years, female gender 29%) undergoing successful mTOR-inhibitor DES implantation [sirolimus-eluting stent (SES); zotarolimus-eluting stent (ZES); and everolimus-eluting stent (EES)] for the treatment of stable chronic angina or an acute coronary syndrome, as their first clinical manifestation of CAD, were prospectively enrolled between February 2008 and May 2009. Major adverse cardiac events (MACE), defined as a combination of cardiac death, myocardial infarction (MI), and clinically driven target lesion revascularization (TVR) at 12-month follow up, constituted the endpoint of the study. Fifty-one (37%) patients received SES; 46 (33%) patients received ZES; and 41 (30%) patients received EES. At follow up, 21 (15%) patients experienced a MACE. Three (2%) patients had cardiac death, five (4%) had MI, while 13 (9%) patients underwent clinically driven TVR. MACE occurred more frequently in females than males [10 (25%) vs. 11 (11%), p = 0.05]. At Cox regression analysis, the only independent predictors of MACE were female gender and implantation of more than one stent [hazard ratio (HR) 3.70, 95% confidence interval (CI) 1.46-9.36, p = 0.006; HR 1.26, 95% CI 0.99-2.74, p = 0.01, respectively].

CONCLUSIONS

In conclusion, our finding suggests that women may have a worse outcome as compared with men after mTOR-inhibitor DES implantation.

Cardiac troponin T measured by a highly sensitive assay predicts coronary heart disease, heart failure, and mortality in the Atherosclerosis Risk in Communities Study

BACKGROUND

We evaluated whether cardiac troponin T (cTnT) measured with a new highly sensitive assay was associated with incident coronary heart disease (CHD), mortality, and hospitalization for heart failure (HF) in a general population of participants in the Atherosclerosis Risk in Communities (ARIC) Study.

METHODS AND RESULTS

Associations between increasing cTnT levels and CHD, mortality, and HF hospitalization were evaluated with Cox proportional hazards models adjusted for traditional CHD risk factors, kidney function, high-sensitivity C-reactive protein, and N-terminal pro-B-type natriuretic peptide in 9698 participants aged 54 to 74 years who at baseline were free from CHD and stroke (and HF in the HF analysis). Measurable cTnT levels (≥0.003 μg/L) were detected in 66.5% of individuals. In fully adjusted models, compared with participants with undetectable levels, those with cTnT levels in the highest category (≥0.014 μg/L; 7.4% of the ARIC population) had significantly increased risk for CHD (hazard ratio=2.29; 95% confidence interval, 1.81 to 2.89), fatal CHD (hazard ratio=7.59; 95% confidence interval, 3.78 to 15.25), total mortality (hazard ratio=3.96; 95% confidence interval, 3.21 to 4.88), and HF (hazard ratio=5.95; 95% confidence interval, 4.47 to 7.92). Even minimally elevated cTnT (≥0.003 μg/L) was associated with increased risk for mortality and HF (P<0.05). Adding cTnT to traditional risk factors improved risk prediction parameters; the improvements were similar to those with N-terminal pro-B-type natriuretic peptide and better than those with the addition of high-sensitivity C-reactive protein.

CONCLUSIONS

cTnT detectable with a highly sensitive assay was associated with incident CHD, mortality, and HF in individuals from a general population without known CHD/stroke.

Clinical assessment of chest pain and guidelines for imaging

For many emergency facilities, risk assessment of patients with diffuse chest pain still poses a major challenge. In their currently valid recommendations, the international cardiological societies have defined a standardized assessment of the prognostically relevant cardiac risk criteria. Here the classic sequence of basic cardiac diagnostics including case history (cardiac risk factors), physical examination (haemodynamic and respiratory vital parameters), ECG (ST segment analysis) and laboratory risk markers (troponin levels) is paramount. The focus is, on the one hand, on timely indication for percutaneous catheterization, especially in patients at high cardiac risk with or without ST-segment elevation in the ECG, and, on the other hand, on the possibility of safely discharging patients with intermediate or low cardiac risk after non-invasive exclusion of a coronary syndrome. For patients in the intermediate or low risk group, physical or pharmacological stress testing in combination with scintigraphy, echocardiography or magnetic resonance imaging is recommended in addition to basic diagnostics. Moreover, the importance of non-invasive coronary imaging, primarily cardiac CT angiography (CCTA), is increasing. Current data show that in intermediate or low risk patients this method is suitable to reliably rule out coronary heart disease. In addition, attention is paid to the major differential diagnoses of acute coronary syndrome, particularly pulmonary embolism and aortic dissection. Here the diagnostic method of choice is thoracic CT, possibly also in combination with CCTA aiming at a triple rule-out.

Unfractionated heparin during elective PCI: fixed dose or weight adjusted?

INTRODUCTION

To assess two different dosing strategies of unfractionated heparin (UFH) during elective percutaneous coronary intervention (PCI).

AIMS

The optimal dose of heparin during elective PCI in patients with stable angina is unknown. Existing guidelines are based on limited data. We interrogated data from the PCI database. Patients with stable angina undergoing planned transradial PCI for uncomplicated single lesions were included. The main endpoint was troponin I release. We compared a fixed heparin dose (3000 U) UFH to a weight-adjusted dose.

RESULTS

Of 698 patients 244 (35.0%) received fixed dose (3000 U) and 454 (65.0%) 70 U/kg weight-adjusted UFH. There was no significant difference in median troponin between the fixed dose and the weight-adjusted groups; 0.17 ng/mL versus 0.14; P= 0.21. The proportion of troponin positive patients was similar in both groups (61.9% in the fixed dose group vs. 58.1%; P= 0.37). There were no deaths or major ischemic events during hospitalization. There was no bleeding requiring transfusion or delaying hospital discharge.

CONCLUSION

In conclusion, this retrospective observational study of elective transradial PCI demonstrated that a reduced, fixed dose of periprocedural heparin was associated with similar postprocedural troponin levels when compared to a standard weight-adjusted regime. Our study further questions the optimal dose of heparin required during elective PCI and suggests a need for further trials.

Evaluating the role of elevated levels of troponin in acute ischemic stroke

Ischemic heart disease and cerebrovascular diseases may coexist in the same patient, and similar risk factors are shared. However, for several years, experimental and observational data have incessantly indicated that neurologically induced myocardial injury exists. This leaves the clinician with a diagnostic dilemma of how to distinguish between neurologically induced myocardial injury and myocardial infarction prior to the stroke. Since various alterations of the ECG have also been reported in this patient category, it has been suggested that elevated troponin levels are somehow neurologically mediated, thus not resulting from direct cardiac release. This review focuses on the available studies that systematically measured troponin in patients with acute ischemic stroke in order to properly interpret troponin elevations in these patients.

Early invasive versus conservative strategies for unstable angina and non-ST elevation myocardial infarction in the stent era

BACKGROUND

In patients with unstable angina and non-ST elevation myocardial infarction (UA/NSTEMI) two strategies are possible, either a routine invasive strategy where all patients undergo coronary angiography shortly after admission and, if indicated, coronary revascularization; or a conservative strategy where medical therapy alone is used initially, with selection of patients for angiography based on clinical symptoms or investigational evidence of persistent myocardial ischemia.

OBJECTIVES

To determine the benefits of an invasive compared to conservative strategy for treating UA/NSTEMI in the stent era.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 1), MEDLINE and EMBASE were searched (1996 to February 2008) with no language restrictions.

SELECTION CRITERIA

Included studies were prospective trials comparing invasive with conservative strategies in UA/NSTEMI.

DATA COLLECTION AND ANALYSIS

We identified five studies (7818 participants). Using intention-to-treat analysis with random-effects models, summary estimates of relative risk (RR) with 95% confidence interval (CI) were determined for primary end-points of all-cause death, fatal and non-fatal myocardial infarction, all-cause death or non-fatal myocardial infarction, and refractory angina. Further analysis of included studies was undertaken based on whether glycoprotein IIb/IIIa receptor antagonists were used routinely. Heterogeneity was assessed using Chi(2) and variance (I(2) statistic) methods.

MAIN RESULTS

In the all-study analysis, mortality during initial hospitalization showed a trend to hazard with an invasive strategy (RR 1.59, 95% CI 0.96 to 2.64). The invasive strategy did not reduce death on longer-term follow up. Myocardial infarction rates assessed at 6 to 12 months (5 trials) and 3 to 5 years (3 trials) were significantly decreased by an invasive strategy (RR 0.73, 95% CI 0.62 to 0.86; and RR 0.78, 95% CI 0.67 to 0.92 respectively). The incidence of early (< 4 month) and intermediate (6 to 12 month) refractory angina were both significantly decreased by an invasive strategy (RR 0.47, 95% CI 0.32 to 0.68; and RR 0.67, 95% CI 0.55 to 0.83 respectively), as were early and intermediate rehospitalization rates (RR 0.60, 95% CI 0.41to 0.88; and RR 0.67, 95% CI 0.61 to 0.74 respectively). The invasive strategy was associated with a two-fold increase in the RR of peri-procedural myocardial infarction (as variably defined) and a 1.7-fold increase in the RR of (minor) bleeding with no hazard of stroke.

AUTHORS' CONCLUSIONS

Compared to a conservative strategy for UA/NSTEMI, an invasive strategy is associated with reduced rates of refractory angina and rehospitalization in the shorter term and myocardial infarction in the longer term. However, the invasive strategy is associated with a doubled risk of procedure-related heart attack and increased risk of bleeding and procedural biomarker leaks. Available data suggest that an invasive strategy may be particularly useful in those at high risk for recurrent events.