Cardiac troponin I elevation in acute pulmonary embolism is associated with right ventricular dysfunction

Prognostic value of ECG among patients with acute pulmonary embolism and normal blood pressure

OBJECTIVE

To investigate the prognostic value of electrocardiography (ECG) alone or in combination with echocardiography in patients with acute pulmonary embolism and normal blood pressure.

METHODS

Consecutive adult patients presenting to the emergency department at Azienda Ospedaliero-Universitaria Careggi with the first episode of pulmonary embolism were included. Patients with systolic blood pressure less than 100 mm Hg were excluded. ECG and echocardiography were performed within 1 hour from diagnosis and evaluated in a blinded fashion. Right ventricular strain was diagnosed in the presence of one or more of the following ECG findings: complete or incomplete right ventricular branch block, S1Q3T3, and negative T wave in V1-V4. The main outcome measurement was clinical deterioration or death during in-hospital stay. The association of variables with the main outcome was evaluated by multivariate Cox survival analysis.

RESULTS

A total of 386 patients with proved pulmonary embolism were included in the study; 201 patients (52%) had right ventricular dysfunction according to echocardiography, and 130 patients (34%) showed right ventricular strain. Twenty-three patients (6%) had clinical deterioration or died. At multivariate survival analysis, right ventricular strain was associated with adverse outcome (hazard ratio 2.58; 95% confidence interval, 1.05-6.36) independently of echocardiographic findings. Patients with both right ventricular strain and right ventricular dysfunction (26%) showed an 8-fold elevated risk of adverse outcome (hazard ratio 8.47; 95% confidence interval, 2.43-29.47).

CONCLUSION

Right ventricular strain pattern on ECG is associated with adverse short-term outcome and adds incremental prognostic value to echocardiographic evidence of right ventricular dysfunction in patients with acute pulmonary embolism and normal blood pressure.

Role of inflammation in right ventricular damage and repair following experimental pulmonary embolism in rats

Right ventricular (RV) dysfunction is associated with poor clinical outcome following pulmonary embolism (PE). Previous studies in our laboratory show that influx of neutrophils contributes to acute RV damage seen in an 18 h rat model of PE. The present study describes the further progression of inflammation over 6 weeks and compares the neutrophil and monocyte responses. The RV outflow tract became white in colour by day 1 with influx of neutrophils (tissue myeloperoxidase activity increased 17-fold) and mononuclear cells with characteristics of M1 phenotype (high in Ccl20, Cxcl10, CcR2, MHCII, DNA microarray analysis). Matrix metalloproteinase activities were increased and tissue was thinned to produce a translucent appearance in weeks 1 through 6 in 40% of hearts. RV contractile function was significantly reduced at 6 weeks of PE. In this later phase, there was accumulation of myofibroblasts, the presence of mononuclear cells with M2 characteristics (high in scavenger mannose receptors, macrophage galactose lectin 1, PDGFR1, PDGFRbeta), enrichment of the subendocardial region of the RV outflow tract with neovesels (alpha-smooth muscle immunohistochemistry) and deposition of collagen fibres (picrosirius red staining) beginning scar formation. Thus, while neutrophil response is associated with the early, acute inflammatory events, macrophage cells continue to be present during the proliferative phase and initial deposition of collagen in this model, changing from the M1 to the M2 phenotype. This suggests that the macrophage cell response is biphasic.

COPD and PE: a clinical dilemma

Dyspnea in patients with known chronic obstructive pulmonary disease (COPD) can be a clinical challenge due to the nonspecific nature of atypical presentations. Typical features of fever, productive cough, and wheezing on presentation support COPD exacerbation, while absence of such findings may warrant further evaluation for underlying etiologies, including pulmonary embolism (PE). It is suspected that one in four patients with atypical COPD exacerbation may have PE as an underlying or concomitant cause of acute dyspnea. This review discusses the clinical presentation of COPD and PE, and presents an overview of the rationale for pursuing work-up for thromboembolic disease in the setting of known obstructive lung diseases.

Guidelines on the diagnosis and management of acute pulmonary embolism: the Task Force for the Diagnosis and Management of Acute Pulmonary Embolism of the European Society of Cardiology (ESC)

Non-thrombotic PE does not represent a distinct clinical syndrome. It may be due to a variety of embolic materials and result in a wide spectrum of clinical presentations, making the diagnosis difficult. With the exception of severe air and fat embolism, the haemodynamic consequences of non-thrombotic emboli are usually mild. Treatment is mostly supportive but may differ according to the type of embolic material and clinical severity.

Thromboembolism in pregnancy

Venous thromboembolism in pregnancy is a clinical emergency that has been associated with significant risk for maternal and fetal morbidity and mortality. The adaptation of the maternal hemostatic system to pregnancy predisposes women to an increased risk of thromboembolism. A timely diagnosis of deep venous thrombosis is crucial because up to 24% of patients with untreated deep venous thrombosis develop a pulmonary embolism. Recent clinical guidelines identify compression venous ultrasound as the best way to diagnose deep venous thrombosis in pregnancy and CT pulmonary angiography as the best way to diagnose pulmonary embolism in pregnancy. Therapy involves supportive care and anticoagulation with unfractionated or low molecular weight heparin, depending on the clinical scenario.

Release of cardiac troponin I from viable cardiomyocytes is mediated by integrin stimulation

Elevated cardiac troponin-I (cTnI) levels have been demonstrated in serum of patients without acute coronary syndromes, potentially via a stretch-related process. We hypothesize that this cTnI release from viable cardiomyocytes is mediated by stimulation of stretch-responsive integrins. Cultured cardiomyocytes were treated with (1) Gly-Arg-Gly-Asp-Ser (GRGDS, n = 22) to stimulate integrins, (2) Ser-Asp-Gly-Arg-Gly (SDGRG, n = 8) that does not stimulate integrins, or (3) phosphate-buffered saline (control, n = 38). Cells and media were analyzed for intact cTnI, cTnI degradation products, and matrix metalloproteinase (MMP)-2. Cell viability was examined by assay of lactate dehydrogenase (LDH) activity and by nuclear staining with propidium iodide. GRGDS-induced integrin stimulation caused increased release of intact cTnI (9.6 +/- 3.0%) as compared to SDGRG-treated cardiomyocytes (4.5 +/- 0.8%, p < 0.001) and control (3.0 +/- 3.4%, p < 0.001). LDH release from GRGDS-treated cardiomyocytes (15.9 +/- 3.8%) equalled that from controls (15.2 +/- 2.3%, p = n.s.), indicating that the GRGDS-induced release of cTnI is not due to cell necrosis. This result was confirmed by nuclear staining with propidium iodide. Integrin stimulation increased the intracellular and extracellular MMP2 activity as compared to controls (both p < 0.05). However, despite the ability of active MMP2 to degrade cTnI in vitro, integrin stimulation in cardiomyocytes was not associated with cTnI degradation. The present study demonstrates that intact cTnI can be released from viable cardiomyocytes by stimulation of stretch-responsive integrins.

Outpatient management of stable acute pulmonary embolism: proposed accelerated pathway for risk stratification

Pulmonary embolism (PE) is a major health problem and a cause of worldwide morbidity and mortality. The current standard therapy for acute PE encourages admitting patients to the hospital for administration of parenteral anticoagulation therapy as a bridge to oral vitamin K antagonists. Prognostic models that identify patients with stable (nonmassive) acute PE (SPE) who are at low risk for adverse outcome have recently been reported. Based on these risk stratification models, hospital-based therapy is warranted for patients with PE who meet the criteria associated with a high risk for adverse outcome. However, a growing body of evidence suggests the feasibility of partial outpatient management and accelerated hospital discharge (AHD) in a subset of patients with SPE. Prospective validation of these risk stratification models for predicting patient suitability for AHD is needed.

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.

Comparison of troponin I and N-terminal-pro B-type natriuretic peptide for risk stratification in patients with pulmonary embolism

OBJECTIVE

We compared the usefulness of plasma N-terminal-pro B-type natriuretic peptide and troponin I levels for risk stratification of patients with pulmonary embolism.

METHODS

This was a prospective study performed in an emergency department. N-terminal-B-type natriuretic peptide assay and troponin I were performed blindly at admission in patients with pulmonary embolism confirmed by imaging tests. A complicated pulmonary embolism was defined as any of the following: death, cardiopulmonary resuscitation, requirement for mechanical ventilation, use of pressors, thrombolysis, surgical embolectomy or admission in an intensive care unit.

RESULTS

Sixty patients (mean age+/-standard deviation of 72+/-15 years) were included. Seventeen (28%) patients had adverse events: all were admitted in intensive care unit, one was treated with surgical embolectomy and one with thrombolysis, and three died. The median N-terminal-pro B-type natriuretic peptide level (95% confidence interval) was higher in the group of patients with complicated pulmonary embolism, 4086 pg/ml (505-8998) versus 352 pg/ml (179-662), respectively (P<0.05). The mean value of troponin I was similar in the complicated pulmonary embolism group, 0.09+/-0.17 microg/l versus 0.08+/-0.41 microg/l, respectively (P=0.93). The best threshold value of N-terminal-pro B-type natriuretic peptide was 1000 pg/ml, and the receiver operating characteristic curve demonstrated that N-terminal-pro B-type natriuretic peptide significantly predicted the complicated pulmonary embolism with an area under the receiver operative curve of 0.72 (0.58-0.83) (P<0.05), whereas troponin I did not [area under the receiver operative curve of 0.58 (0.42-0.71)].

CONCLUSION

Unlike troponin I, N-terminal-pro B-type natriuretic peptide may be an accurate marker of in-hospital complication after pulmonary embolism.

Prognostic value of troponins in acute pulmonary embolism: a meta-analysis

BACKGROUND

Whether elevated serum troponin levels identify patients with acute pulmonary embolism at high risk of short-term mortality or adverse outcome is undefined.

METHODS AND RESULTS

We performed a meta-analysis of studies in patients with acute pulmonary embolism to assess the prognostic value of elevated troponin levels for short-term death and adverse outcome events (composite of death and any of the following: shock, need for thrombolysis, endotracheal intubation, catecholamine infusion, cardiopulmonary resuscitation, or recurrent pulmonary embolism). Unrestricted searches of MEDLINE and EMBASE bibliographic databases from January 1998 to November 2006 were performed using the terms "troponin" and "pulmonary embolism." Additionally, review articles and bibliographies were manually searched. Cohort studies were included if they had used cardiac-specific troponin assays and had reported on short-term death or adverse outcome events. A random-effects model was used to pool study results; funnel-plot inspection was done to evaluate publication bias; and I2 testing was used to test for heterogeneity. Data from 20 studies (1985 patients) were included in the analysis. Overall, 122 of 618 patients with elevated troponin levels died (19.7%; 95% confidence interval [CI], 16.6 to 22.8) compared with 51 of 1367 with normal troponin levels (3.7%; 95% CI, 2.7 to 4.7). Elevated troponin levels were significantly associated with short-term mortality (odds ratio [OR], 5.24; 95% CI, 3.28 to 8.38), with death resulting from pulmonary embolism (OR, 9.44; 95% CI, 4.14 to 21.49), and with adverse outcome events (OR, 7.03; 95% CI, 2.42 to 20.43). Elevated troponin levels were associated with a high mortality in the subgroup of hemodynamically stable patients (OR, 5.90; 95% CI, 2.68 to 12.95). Results were consistent for troponin I or T and prospective or retrospective studies.

CONCLUSIONS

Elevated troponin levels identify patients with acute pulmonary embolism at high risk of short-term death and adverse outcome events.

Acute pulmonary embolism: risk stratification in the emergency department

Pulmonary embolism is a common disease associated with a high mortality rate. Death due to pulmonary embolism occurs more commonly in undiagnosed patients before hospital admission or during the initial in-hospital stay. Thus, mortality could be reduced by prompt diagnosis, early prognostic stratification and more intensive treatment in patients with adverse prognosis. Mortality is particularly high in patients with pulmonary embolism presenting with arterial hypotension or cardiogenic shock. In patients with pulmonary embolism and normal blood pressure, a number of clinical features and objective findings have been associated with a high risk of adverse in-hospital outcome. Advanced age and concomitant cardiopulmonary disease are clinical risk factors for in-hospital mortality. The Bburden of thromboembolism, as assessed by lung scan or spiral CT, and right ventricle overload, as assessed by echocardiography and probably spiral CT, have been claimed to be risk factors for in-hospital mortality. Elevated serum levels of troponins have been shown to be associated with right ventricular overload and adverse in-hospital outcomes in patients with pulmonary embolism. Despite the currently available evidence, no definite prognostic value can be assigned to any of the individual risk factors or cluster of them. Large prospective trials should be carried out to validate individual risk factors or clusters of risk factors able to identify patients with acute pulmonary embolism at high risk for in-hospital mortality. These patients could afford the trade-off of an increased risk of side effects related to a more aggressive treatment, such as thrombolysis or surgical or interventional procedures.

Cardiac troponins in the intensive care unit: common causes of increased levels and interpretation

BACKGROUND AND OBJECTIVES

Clinical chemistry is an important component of the diagnosis of many conditions, and advances in laboratory science have brought many new diagnostic tools to the intensive care unit clinician, including new biomarkers of cardiac injury like troponin T and I. Interpretation of these clinical laboratory results requires knowledge of the performance of these tests.

SETTING AND PATIENTS

This article reviews the interpretation and performance of diagnostic markers of myocardial injury in patients with diverse clinical conditions of interest to critical care practitioners.

CONCLUSIONS

Cardiac troponin I and T, regulatory components of the contractile apparatus, are sensitive indicators of myocardial injury and have become central to the diagnosis of myocardial infarction. The troponins are also released in a number of clinical situations in which thrombotic complications of coronary artery disease and resultant acute myocardial infarction have not occurred. These situations include conditions like pulmonary embolism, sepsis, myocarditis, and acute stroke. Elevated troponins in these conditions are thought to emanate from injured myocardial cells and, in most circumstances, have been associated with adverse outcomes. Practitioners should be mindful of the wide spectrum of diseases that may result in elevated troponin when interpreting these measurements.

Can elevated troponin I levels predict complicated clinical course and inhospital mortality in patients with acute pulmonary embolism?

OBJECTIVE

The purpose of this study was to evaluate the value of elevated cardiac troponin I (cTnI) for prediction of complicated clinical course and in-hospital mortality in patients with confirmed acute pulmonary embolism (PE).

METHODS AND RESULTS

This study was a retrospective chart review of patients diagnosed as having PE, in whom cTnI testing was obtained at emergency department (ED) presentation between January 2002 and April 2006. Clinical characteristics; echocardiographic right ventricular dysfunction; inhospital mortality; and adverse clinical events including need for inotropic support, mechanical ventilation, and thrombolysis were compared in patients with elevated cTnI levels vs patients with normal cTnI levels. One hundred sixteen patients with PE were identified, and 77 of them (66%) were included in the study. Thirty-three patients (42%) had elevated cTnI levels. Elevated cTnI levels were associated with inhospital mortality (P = .02), complicated clinical course (P < .001), and right ventricular dysfunction (P < .001). In patients with elevated cTnI levels, inhospital mortality (odds ratio [OR], 3.31; 95% confidence interval [CI], 1.82-9.29), hypotension (OR, 7.37; 95% CI, 2.31-23.28), thrombolysis (OR, 5.71; 95% CI, 1.63-19.92), need for mechanical ventilation (OR, 5.00; 95% CI, 1.42-17.57), and need for inotropic support (OR, 3.02; 95% CI, 1.03-8.85) were more prevalent. The patients with elevated cTnI levels had more serious vital parameters (systolic blood pressure, pulse, and oxygen saturation) at ED presentation.

CONCLUSION

Our results indicate that elevated cTnI levels are associated with higher risk for inhospital mortality and complicated clinical course. Troponin I may play an important role for the risk assessment of patients with PE. The idea that an elevation in cTnI levels is a valuable parameter for the risk stratification of patients with PE needs to be examined in larger prospective studies.

Prognostic role of right ventricular dilatation and troponin I elevation in acute pulmonary embolism

Acute pulmonary embolism continues to cause significant morbidity and mortality despite advances in diagnosis and treatment. This retrospective analysis aimed to determine whether the combination of elevated troponin I and right ventricular dilatation (RVD) could provide a more powerful predictor for risk evaluation. The study data comprised records of 110 patients with either high-probability ventilation/perfusion lung scan or positive spiral computed tomography. All cause 100-day mortality was 18.2%. The hypotension and RVD variables significantly influenced 100-day mortality. For the combination of RVD and raised troponin I, the 100-day mortality rate was 31%. Notably, the group with elevated troponin I and no RVD had a 100-day mortality rate of only 3.7%. The combination of RVD and elevated troponin had a positive predictive value of 31% and a negative predictive value of 88% for 100-day mortality. Compared with existing reports, conflicting conclusions for the individual prognostic role of elevated troponin I, cancer, and heart failure were obtained. These conflicting conclusions most likely resulted from inappropriate cut-off troponin I values and the modest sample size. In conclusion, the combination of elevated troponin and RVD was able to identify a subset of patients most likely to benefit from aggressive therapy.

Cardiac inflammation contributes to right ventricular dysfunction following experimental pulmonary embolism in rats

Acute right ventricular (RV) failure following pulmonary embolism (PE) is a strong predictor of poor clinical outcome. Present studies test for an association between RV failure from experimental PE, inflammation, and upregulated chemokine expression. Additional experiments test if neutrophil influx contributes to RV dysfunction. PE was induced in male rats by infusing 24 microm microspheres (right jugular vein) producing mild hypertension (1.3 million beads/100 g, PE1.3), or moderately severe hypertension (2.0 million beads/100 g, PE2.0). Additional rats served as vehicle sham (0.01% Tween 20, Veh). In vivo RV peak systolic pressures (RVPSP) increased significantly, and then declined following PE2.0 (51 +/- 1 mm Hg 2 h; 49 +/- 1, 6 h; 44 +/- 1, 18 h). RV generated pressure of isolated, perfused hearts was significantly reduced in PE2.0 compared with PE1.3 or Veh. MCP-1 protein (ELISA) was elevated 21-fold and myeloperoxidase activity 95-fold in RV of PE2.0 compared with Veh or PE1.3. CINC-1, CINC-2, MIP-2, MCP-1, and MIP-1alpha mRNA also increased in RV of PE2.0. Histological analysis revealed massive accumulation of neutrophils (selective esterase stain) and monocyte/macrophages (CD68, ED-1) in RV of PE2.0 hearts in regions of myocyte damage. Electron microscopy showed myocyte necrosis and phagocytosis by inflammatory cells. LV function was normal and did not show increased inflammation after PE2.0. Treatment with anti-PMN antibody reduced RV MPO activity and prevented RV dysfunction. Conclusions-PE with moderately severe pulmonary hypertension (PE2.0) resulted in selective RV dysfunction, which was associated with increased chemokine expression, and infiltration of both neutrophils and monocyte/macrophages, indicating that a robust immune response occurred with RV damage following experimental PE. Experimental agranulocytosis reduced RV, suggesting that neutrophil influx contributed to RV damage.

La troponine et les autres marqueurs de souffrance myocardique, quelle signification en médecine interne ?

PURPOSE

Troponin is now the gold standard for the diagnosis of myocardial infarction. Aiming at improving the management of a patient suspect of an acute coronary syndrome, this article will point the interpretation of troponin dosages according to the clinical presentation and concomitant diseases.

ACTUALITIES

First, the interest of troponin dosage as compared with other markers of myocardial ischemia will be underlined. Then, the literature available about troponin in cardiovascular diseases but also in extracardiac diseases will be analysed. Finally, the difficulties of assay will be discussed.

PERSPECTIVES

The availability of a sensitive and specific marker such as troponin is definitively a progress in the management of patients with an acute coronary syndromes. But it remains a biological contribution to the global management of the patient. It is important to know the causes susceptible to increase the levels of troponin to avoid a wrong interpretation of the dosage, leading to diagnostic but also therapeutic mistakes.

Prognostic Significance of Inverted T Waves in Patients With Acute Pulmonary Embolism

BACKGROUND

The significance of inverted T waves remains unclear in patients with acute pulmonary embolism (PE).

METHODS AND RESULTS

The relationship of the number of leads with inverted T waves to the severity of PE in 40 patients with acute PE was studied. Patients were classified into 3 groups according to the number of leads with inverted T waves on the admission electrocardiogram (ECG): 15 patients, <or=3 leads (group L); 12 patients, 4-6 leads (group M); and 13 patients, >or=7 leads (group H). In groups L, M and H, the rates of right ventricular dysfunction on echocardiography were 47%, 92% and 100% (p<0.01), respectively, and the rates of in-hospital complicated events (including death or the need for catecholamine support, cardiopulmonary resuscitation or mechanical cardiovascular support because of hemodynamic instability) were 0%, 8% and 46% (p=0.004), respectively. On multivariate analysis, arterial hypotension at presentation (odds ratio (OR) 8.96, p=0.049) and inverted T waves in >or=7 leads on the admission ECG (OR 16.8, p=0.037) were the only independent predictors of in-hospital complicated events.

CONCLUSIONS

The number of leads with inverted T waves may be a useful and simple marker of increased risk for early complications in patients with acute PE.

The acutely decompensated right ventricle: pathways for diagnosis and management

Decompensated right ventricular (RV) failure is becoming increasingly common as the prevalence of predisposing conditions grows. Advances in diagnosis and management have granted insights into the following pathophysiologic mechanisms of RV dysfunction: impaired RV contractility, RV pressure overload, and RV volume overload. Emerging imaging modalities, such as cardiac MRI, and new therapeutic agents, such as pulmonary selective vasodilators, have expanded our options for evaluation and management, respectively. An improved understanding of pathophysiology and technologic progress provides us with new pathways in the diagnosis and hemodynamic support of these often critically ill patients.

Update on the diagnosis and management of pulmonary embolism

Pulmonary embolism (PE) is a common and often fatal disease. In the US, an estimated 40-53 people per 100,000 are diagnosed with PE annually and approximately 60,000 die from the disease. Diagnosis is difficult because symptoms are non-specific; however, a quick and accurate diagnosis is critical because, with appropriate therapy, the risk of recurrent (and potentially fatal) PE can be greatly reduced. Recent publication of prediction rules and improved non-invasive diagnostic tools have simplified diagnostic algorithms for PE. The efficacy of the standard treatment for PE, initial administration of continuous i.v. unfractionated heparin overlapped with long-term oral anticoagulation, is well established. However, newer treatment options such as low-molecular-weight heparins and the pentasaccharides may offer similar efficacy with improved convenience.

Der akute Thoraxschmerz

Acute chest pain is the leading cause of hospital admissions worldwide and absorbs extensive financial and hospital resources for diagnosis and management. A missed diagnosis of acute myocardial infarction is still associated with a poor outcome and represents one of the most common reasons for lawsuits in the USA. The present article gives a summary on the features of cardiac and non-cardiac chest pain, provides an overview of diagnostic algorithms, and points out the important differential diagnoses.

Prognostic significance of troponin elevation and right ventricular enlargement in acute pulmonary embolism

The troponin I values and echocardiographic data of 141 patients with acute pulmonary embolism (PE) were correlated with 30-day mortality. Patients with elevated troponin and right ventricular enlargement are at significantly greater risk for death after PE than patients with only 1 or with neither adverse prognostic marker.

Acute pulmonary embolism: an update on diagnosis and management

Pulmonary embolism (PE) is a common problem. Given the significant overlap of symptoms and signs between the presentation of PE and acute coronary syndromes, it becomes clear that cardiologists must be familiar with the diagnosis and treatment of PE. The critical issue is always to consider PE in the diagnosis of chest pain. It is then important to determine the likelihood of the diagnosis. For patients at moderate-to-high risk, helical CT provides a rapid and noninvasive diagnostic tool. Several other imaging studies are also available including ventilation/perfusion (V/Q) scan, magnetic resonance imaging, and pulmonary arteriography. Echocardiography can also provide valuable prognostic information. Several biomarkers including the d-dimers, troponins, and natriuretic peptides may provide additional information. The cornerstone of treatment includes anticoagulation. For patients with massive or submassive PE, thrombolysis and embolectomy should be considered. Finally, both primary and secondary prevention are critical to the long-term health of the patient.

Biomarker-based risk assessment model in acute pulmonary embolism

AIMS

Despite growing interest in biomarkers application for risk evaluation in acute pulmonary embolism (APE), no decision-making levels have been defined.

METHODS AND RESULTS

We developed a biomarker-based risk stratification in 100 consecutive, normotensive on admission, APE patients (35 males, 65 females, 62+/-18 years). On admission serum NT-proBNP and cardiac troponin T (cTnT) levels were assessed and echocardiography was performed. All-cause 40-day mortality was 15% and APE mortality was 8%. In univariable analysis, cTnT>0.07 microg/L predicted all-cause mortality, hazard ratio (HR) 9.2 (95% CI: 3.3-26.1, P<0.0001), and APE mortality, HR 18.1 (95% CI: 3.6-90.2, P=0.0004); similarly, NT-proBNP>7600 ng/L predicted all-cause and APE mortalities [HR 6.7 (95% CI: 2.4-19.0, P=0.0003) and 7.3 (95% CI: 1.7-30.6, P=0.007)]. NT-proBNP<600 ng/L indicated uncomplicated outcome. Multivariable analysis revealed that cTnT>0.07 microg/L was the most significant independent predictor, whereas NT-proBNP and systemic systolic blood pressure measured on admission and echocardiographic parameters were non-significant. APE mortality in patients with NT-proBNP> or =600 ng/L and cTnT> or =0.07 microg/L reached 33%. NT-proBNP<600 ng/L indicated group without deaths. APE mortality for patients with NT-proBNP> or =600 ng/L and cTnT<0.07 microg/L was 3.7%. Incorporation of echocardiographic data did not improve group selection.

CONCLUSION

Simultaneous measurement of serum cTnT and NT-proBNP allows for precise APE prognosis. Normotensive patients on admission with cTnT> or =0.07 microg/L and NT-proBNP> or =600 ng/L are at high risk of APE mortality, whereas NTproBNP<600 ng/L indicates excellent prognosis.

Evaluation and management of the acutely dyspneic patient: the role of biomarkers

The etiology of dyspnea can often be difficult to rapidly and accurately determine and can delay timely and appropriate therapies. The current literature reveals important diagnostic, prognostic, and therapeutic implications of several currently used biomarkers: sensitive d -dimer, myoglobin, creatine kinase-MB, cardiac troponins, and b-type natriuretic peptide. These biomarkers were found to have a high sensitivity and negative predictive value for rapidly ruling out potential serious etiologies of dyspnea, namely, pulmonary embolism (PE), acute myocardial infarction (AMI), and congestive heart failure (CHF). In the setting of a low to moderate pretest probability of PE, a negative sensitive d -dimer can rule out a PE with 97% accuracy. After 10 hours from the onset of symptoms, normal levels of myoglobin, creatine kinase-MB, and cardiac troponin I can rule out an AMI with greater than 96% accuracy. A b-type natriuretic peptide level less than 80 pg/mL can confidently rule out decompensated CHF with greater than 99% accuracy. However, no literature was found analyzing the use of these biomarkers in combination. A dyspnea biomarker panel could rapidly and accurately assist a clinician to rule out PE, AMI, and CHF. If a PE, AMI, or CHF is determined to be the cause of dyspnea, a biomarker panel could help risk stratify and help determine initial therapies. Subsequent clinical research is needed to corroborate this postulation.

Pitfalls and problems of relying on serum troponin

Cardiac troponin (cT) is released after myocardial damage. In the appropriate clinical setting, a measured elevation of cT can increase the diagnostic rate of myocardial infarction and acute coronary syndrome. Elevations of cT, however, can occur in a wide variety of other clinical situations. Failure to recognize this can lead to an over-diagnosis of myocardial infarction (MI). We present clinical cases from our institution that illustrate this diagnostic problem, and review similar cases in the literature. We also discuss the implications of an erroneous diagnosis of myocardial infarction, for the patient and for the health services.

Pulmonary embolism and cardiac enzymes

BACKGROUND

Pulmonary embolism (PE) is often associated with chest pain, electrocardiographic changes, and right ventricular (RV) dysfunction on echocardiogram. There have been reports of elevated troponin levels with PE. RV dysfunction and elevated troponin levels have prognostic implications in acute PE. The purpose of this retrospective analysis was to determine whether PE was associated with elevated cardiac enzymes and whether there was any difference among patients who presented with or without chest pain.

METHODS

Records of 93 consecutive patients with high-probability ventilation/perfusion lung scan results for PE were analyzed for the presence or absence of chest pain on presentation, abnormalities in cardiac enzymes, and evidence of RV dysfunction on echocardiogram.

RESULTS

A total of 56 of 93 patients had cardiac enzymes evaluated; 24 of these 56 patients had chest pains, and 32 did not. Only 1 patient of the 56 had abnormal cardiac enzymes. This patient had a known history of coronary artery disease (CAD) and had experienced an acute anterior myocardial infarction. Echocardiograms were performed in 36 of 93 patients. Evidence of RV dysfunction on echocardiograms was found in 22 of these patients. No significant relationship was found between RV dysfunction and chest pains (P > .10).

CONCLUSION

We found no significant relationship between high-probability ventilation/perfusion scan results and abnormalities in cardiac enzymes irrespective of the presence or absence of chest pain. Patients with a history of CAD or RV dysfunction did not have a higher incidence of chest pain when compared with those with no known history of CAD or RV dysfunction.

Cardiac troponin I release in acute pulmonary embolism in relation to the duration of symptoms

PURPOSE

To evaluate the release of cardiac troponin I in normotensive patients with acute pulmonary embolism in relation to the duration of symptoms.

METHODS

Fifty-seven normotensive patients with acute pulmonary embolism were included in the study. Patients were divided into two groups based on the duration of symptoms at presentation: symptoms of < or =72 h, group A; symptoms of >72 h, group B. Serum cardiac troponin I levels were measured at presentation.

RESULTS

Mean age was 63+/-18 years and 23 (40%) patients were males. Thirty-three (58%) patients had symptoms of < or =72 h (group A) and 24 (42%) had symptoms of >72 h (group B). Both groups had similar prevalence of right ventricular dysfunction on echocardiography (55% [n=18] in group A vs. 42% [n=10] in group B, p=NS). Sixteen patients had elevated serum cardiac troponin I (mean+/-S.D. 3.3+/-2.3 ng/ml, range 0.6-8.3 ng/ml). Elevated serum cardiac troponin I was strongly associated with right ventricular dysfunction (p=0.015). All patients with elevated serum cardiac troponin I (n=16) were in group A (p<0.0001). Twelve of 18 (67%) patients with (p=0.0005) and 4 of 15 (27%) patients without (p=NS) right ventricular dysfunction had elevated serum cardiac troponin I. Thirteen of 16 (81%) patients with elevated serum cardiac troponin I had duration of symptoms < or =24 h at presentation.

CONCLUSIONS

The dynamics of cardiac troponin I release in acute pulmonary embolism in patients who present with symptoms of < or =72 h duration could be different from those who present with longer duration of symptoms. Therefore, the use of cardiac troponin I in risk stratification of acute pulmonary embolism might be limited to the patients presenting within 72 h of the onset of symptoms.

Elevated Brain Natriuretic Peptide and Troponin I in a Woman with Generalized Weakness and Chest Pain

We report the case of a female patient emergently transferred to our institution with the presumptive diagnosis of myocardial infarction in heart failure given the constellation of symptoms and abnormal laboratory cardiac markers on presentation. However, on closer examination, prior to instituting an invasive cardiac work-up, pulmonary embolism was instead strongly considered to explain a common etiology. Therefore, an echocardiogram was promptly obtained, which revealed the presence of McConnell's sign. This noninvasive imaging modality proved to be critical in the prompt recognition and management of this patient. We reviewed the literature regarding the use of echocardiography and the clinical significance of abnormal cardiac markers in patients presenting pulmonary embolism.

Effects of transvenous pacing on cardiac troponin release

Cardiac troponins are invaluable tools for the detection of minimal myocardial injury. No study to date has analyzed the effect of permanent cardiac pacing on minimal myocardial injury detection by cardiac troponin I (cTnI) measurement. We investigated 76 clinically stable patients (mean age 75 years, range 31-93 years, 59% men) listed for elective endocardial permanent pacemaker insertion. Patients were required to have normal levels of cardiac cTnI, aspartate transaminase (AST) and creatinine kinase (CK) on a venous blood sample taken immediately prior to elective pacemaker implantation. Repeat measurements of AST, CK, and cTnI were performed at a mean of 19.2 post implantation. There was a detectable small rise in cTnI levels above normal in 21% of patients in a second blood sample taken 18-21 hours later (mean cTnI 0.39 +/- 0.37 microg/L, normal < 0.15 microg/L). The only factor that correlated with this rise was prolonged x ray screening time for lead implantation.

Acute pulmonary embolism

Deep vein thrombosis (DVT) and, therefore, pulmonary embolism (PE) are often preventable. Because of the lack of specificity of symptoms and signs, DVT and PE are frequently clinically unsuspected, leading to substantial diagnostic and therapeutic delays and resulting in considerable morbidity and mortality. Furthermore, prophylaxis continues to be dramatically underused. The incidence of venous thromboembolism is high in hospitalized patients, and both surgical as well as medical patients are at risk.

Biomarkers in pulmonary embolism

PURPOSE OF REVIEW

Controversy exists about the precise role of thrombolytic therapy in normotensive patients with pulmonary embolism. To resolve this controversy two major questions must be addressed. First, can a subgroup of normotensive pulmonary embolism patients with a high risk for adverse outcomes, such as in-hospital mortality or early recurrent venous thromboembolism, be identified? Second, is there convincing evidence that the benefits of more aggressive therapy counterbalance its risks?Troponin I and T as well as brain natriuretic peptide (BNP) have recently been introduced as promising tools in the risk assessment of patients with pulmonary embolism.

RECENT FINDINGS

The studies in series of patients with pulmonary embolism showed prevalences of elevated cardiac biomarkers of 16 to 84%. Positive predictive values for in-hospital mortality varied from 6 to 44%, whereas negative predictive values for uneventful outcome were above 93% in all studies.

SUMMARY

Although a correlation between elevated biomarkers and in-hospital mortality in pulmonary embolism patients is present in most of the studies, the positive predictive value appears to be insufficient to extend the indication for thrombolytic therapy to all patients with elevated biomarkers. Future research is necessary to show whether combining different biomarkers with echocardiography is more useful.

Cardiac troponin elevations among critically ill patients

PURPOSE OF THE REVIEW

Elevated levels of cardiac troponins, indicative of the presence of cardiac injury, have been reported in critically ill patients. In this review, the incidence, significance, and clinical relevance of elevated troponin levels among this group of patients will be discussed.

RECENT FINDINGS

It has been shown that elevated cardiac troponin levels can be present among critically ill septic patients without evidence of myocardial ischemia. Recent studies show that elevated troponin levels are also present in a diverse group of critically ill patients without sepsis or septic shock. In addition, several but not all studies show that the mortality rate of troponin-positive patients is significantly higher compared with troponin-negative patients.

SUMMARY

Elevated troponin levels are not only present in patients suffering from acute coronary syndromes but can also be present in critically ill patients. Even minor elevations are specific for myocardial injury. However, every elevated troponin level in the critically ill patient should not be rigorously diagnosed or treated as a myocardial infarction.

Paradoxical coronary embolism causing non-ST segment elevation myocardial infarction in a case of pulmonary embolism

We describe the case of a 61-year-old woman who simultaneously suffered a pulmonary embolism and a myocardial infarction due to paradoxical coronary artery embolism. Transesophageal echocardiography with injection of agitated hydroxyethyl starch revealed a patent foramen ovale. Thrombophlebistis of the left saphenous vein with extension of thrombus into the femoral vein could be identified as the source of embolism. Paradoxical coronary embolism is an underrecognized cause of MI. Diagnosis is particularly difficult, when MI and PE coincide, because of the similarity in clinical signs and symptoms of both entities. A high level of clinical suspicion and echocardiography, especially if performed soon after presentation, can be the clue to early diagnosis of PDE.

Elevation of cardiac troponins in exacerbation of chronic obstructive pulmonary disease

OBJECTIVES

To investigate the prevalence of serum troponin elevation in patients admitted to hospital with an exacerbation of chronic obstructive pulmonary disease (COPD).

METHODS

We examined the records of all patients admitted to hospital for treatment of COPD for serum troponin measurement, clinical features of myocardial ischaemia, oxygenation (pulse oximetry, arterial blood gas analysis), spirometry, and duration of admission.

RESULTS

Troponin elevation was observed in 58 of 235 (25%) presentations in which troponin was measured. Despite the troponin result, only seven of these 58 patients had been diagnosed with an acute coronary syndrome. New ECG evidence of ischaemia was uncommon. Patients with raised troponins tended to be older (75.7 vs 70.0 years, P = 0.001), had lower pulse oximetry (85.6% vs 89.6%, P = 0.003), were more acidotic (pH 7.34 vs 7.40, P= 0.002) and more hypercapnoeic (pCO2 58.0 vs 49.1, P = 0.04). There were no significant differences in serum creatine kinase. Patients with raised troponins had significantly longer admissions (5 vs 3 days, P = 0.001).

CONCLUSIONS

Serum troponins are commonly raised in acute exacerbations of COPD and appear to reflect the severity of the exacerbation. In the majority of patients there is insufficient evidence to support the diagnosis of an acute coronary syndrome.

Increased cardiac troponin I on admission predicts in-hospital mortality in acute pulmonary embolism

BACKGROUND

To investigate the frequency of cardiac troponin I (cTnI) increases in patients with pulmonary embolism (PE) and to assess the correlation between this finding, the clinical presentation, and outcomes.

METHODS

Consecutive patients admitted to the coronary care unit with acute PE were prospectively enrolled between January 2000 and December 2001. cTnI was sequentially determined. Various cut off concentrations were analysed, but patients were categorised prospectively as having increased or no increased cTnI based on a cut off concentration of 0.6 ng/ml. The main outcome measure was in-hospital mortality.

RESULTS

On admission, 14 of the 48 patients (29%) had cTnI concentrations greater than the receiver operating characteristic curve value used to diagnose acute myocardial infarction (> 0.6 ng/ml). Subsequently, six patients developed increases for an overall prevalence of 42% (20 of 42). The prevalence was higher when lower cut off concentrations were used: 73% (35 of 48) at the 99th centile and 60% (29 of 48) at the 10% coefficient of variability. Increased cTnI > 0.6 ng/ml was associated with a slower oxygen saturation (86 (7)% v 93 (4)%, p < 0.0001) and more frequent involvement of the main pulmonary arteries as assessed by spiral computed tomography (100% v 60%, p = 0.022). In-hospital mortality was 36% (5 of 14) of patients with increases > 0.6 ng/ml v 3% (1 of 42) of patients with lower concentrations (p = 0.008). Increased cTnI > 0.6 ng/ml on admission was the most powerful predictor of mortality (p = 0.046).

CONCLUSIONS

In high risk patients with acute PE, cTnI was frequently detected on admission. It was the strongest independent predictor of mortality.

The impact of right ventricular dysfunction on the prognosis and therapy of normotensive patients with pulmonary embolism

The prognosis and optimal therapy of patients with pulmonary embolism (PE) are strongly influenced by the presence or absence of associated hemodynamic derangements. Patients with normal systemic arterial pressure have a relatively low risk of recurrent PE and death when treated promptly with therapeutic anticoagulation. Those who present with hypotension, shock, or cardiac arrest, however, have a much higher mortality rate and often receive thrombolytic therapy. Recent evidence indicates that the presence of right ventricular (RV) dysfunction identifies a subgroup of normotensive patients with a much more guarded prognosis who may benefit from more intensive therapy with thrombolytic agents. This article reviews our current understanding of the pathophysiology and diagnosis of RV dysfunction and its impact on the prognosis and therapy of normotensive patients with PE.

Prevalence of increased cardiac troponin I levels in patients with and without acute pulmonary embolism and relation of increased cardiac troponin I levels with in-hospital mortality in patients with acute pulmonary embolism

Cardiac troponin I levels were increased in 24 of 147 patients (16%) with documented acute pulmonary embolism and in 20 of 594 patients (3%) without pulmonary embolism (p <0.001). In patients with acute pulmonary embolisms, 8 of 24 (33%) with increased cardiac troponin I levels and 9 of 123 (7%) with normal cardiac troponin I levels died during hospitalization (p <0.001).