Elevated troponin level is not synonymous with myocardial infarction

Pseudo-infarction electrocardiographic changes in delayed onset hypoparathyroidism: A case report

Key Clinical Message

The high-risk "Shark Fin" electrocardiogram (ECG) pattern has been associated with transmural ischemia but can also result from electrolyte anomalies. Therefore, the decision for invasive coronary catheterization requires a detailed history and dedicated biochemical tests.

Abstract

Pseudo-infarction ECG pattern resembling "Shark Fin" was demonstrated in a 76-year-old lady with a previous total thyroidectomy who presented with unspecific symptoms. An incidental finding of hypokalemia and hypocalcemia was thought to be related to delayed onset hypoparathyroidism. Potential etiologies like coronary vasospasm and catecholamine-associated myocardial injury were suggested.

Prevalence, Determinants and Clinical Significance of Cardiac Troponin-I Elevation among Individuals with Hypertensive Emergency: A Prospective Observational Study

Introduction

Cardiac troponin-I (cTnI) elevation release during hypertensive emergencies (HEs) is a frequent epiphenomenon that may tangle management of individuals being treated for HEs. The primary objective of this study was to determine the prevalence, determinants, and clinical significance of cTnI elevation and secondary objective was to find out the prognostic significance of cTnI elevation in patients admitted for HE in the emergency department (ED) of a tertiary care hospital.

Methodology

The investigator has employed the quantitative research approach with a prospective observational descriptive design. The population of this study comprised of 205 adults, which included both males and females, who were more than or 18 years of age. The subjects were selected by non-probability purposive sampling technique. The study was conducted from August 2015 to December 2016 (16 months). Ethical permission was obtained from the Institutional Ethics Committee (IEC), Max Super Speciality Hospital, Saket, New Delhi and well-informed written consents were taken from the subjects. The analysis of data was done with the help of SPSS, version 17.0.

Results

Out of 205 patients in the study, cTnI elevation was found in 102 patients (49.8%). Moreover, there was increased duration of stay in the hospital in patient with elevated cTnI level with mean duration stay 1.55 ± 0.82 (p <0.001). In addition, cTnI elevation was associated with increased mortality, 11 out of 102 in an elevated cTnI group (10.8%) with p <0.002.

Conclusion

It was found that cTnI elevation in individuals affected by various clinical factors. The authors highlighted a high frequency of mortality among the individuals presented with HE with elevated cTnI level, whereas the presence of cTnI was associated with greater odds of death.

How to cite this article

Gupta K, Kiran M, Chhabra S, Mehta M, Kumar N. Prevalence, Determinants and Clinical Significance of Cardiac Troponin-I Elevation among Individuals with Hypertensive Emergency: A Prospective Observational Study. Indian J Crit Care Med 2022;26(7):786-790.

Impact of Cardiac Injury on the Clinical Outcome of Children with Convulsive Status Epilepticus

Objectives: the aim of this study was to determine the impact of cardiac injury on clinical profile, cardiac evaluation and outcome in patients hospitalized with convulsive status epilepticus (CSE). Materials and methods: this prospective observational study included 74 children with CSE. Cardiac injury was evaluated and defined using combination of cardiac troponin, electrocardiography (ECG) and echocardiography. Clinical outcome and mortality rates were compared in patients with and without cardiac injury. Results: A total of 74 patients with CSE were included in the study. Thirty-six (48.6%) patients demonstrated markers of cardiac injury. ECG changes occurred in 45.9% and echocardiographic signs of left ventricular systolic and diastolic dysfunction reported in 5.4% and 8.1%, respectively. The mean length of hospital stays and need for ICU admission were significantly higher in patients with cardiac injury compared to others. One third of patients with cardiac injury needed mechanical ventilation and this was significantly higher than patients without (p = 0.042). hypotension and/or shock developed in 25% of cardiac injury patients and most of them required inotropic support; this was significantly higher than others without markers of cardiac injury. The overall mortality in cardiac injury group was higher (13.9% vs. 2.6%); however, this difference was not statistically significant. Conclusion: Markers of cardiac injury were common and associated with poor clinical outcome and higher risk of mortality in patients with CSE, so extensive routine cardiovascular evaluation is essential in these patients.

Prognostic value of cardiac troponin levels in patients presenting with supraventricular tachycardias

BACKGROUND

An association between paroxysmal supraventricular tachycardias (PSVT) and elevated cardiac troponin I (cTnI) has been reported in small studies, even in the absence of significant coronary artery or structural heart disease. We sought to explore the prognostic significance of elevated cTnI among patients presenting with PSVT.

METHODS

This is a retrospective single-center observational study conducted between January 2014 and Decemebr 2016. 165 patients (60% men, mean age 55 ± 17 year-old) with an acute episode of regular supraventricular tachyarrhythmia were admitted to the emergency department at Rambam Medical Center. 131 patients had at least one serum cTnI value measured. Of those, 57 had a positive result, defined as serum cTnI of more than 0.028 ng/dL.

RESULTS

Multivariate analysis showed that heart rate > 150 beats per minute (bpm) on admission (OR = 3.9; 95% CI 1.1.6-9.5; p < 0.003) and history of coronary artery disease (CAD) (OR = 3.4; 95% CI 1.2-10.1; p = 0.026) were the only independent predictors of cTnI elevation. After mean follow-up period of 23 ± 7 months, the combined primary outcome of death, coronary intervention (PCI) or myocardial infarction (MI) occurred in 7 patients (12.3%) out of 57 patients with positive cTnI and in zero patients with negative cTn (p = 0.002). Cox proportional hazard model showed that elevated cTnI on admission was an independent predictor of adverse outcomes only in patients with known coronary artery disease (CAD) (HR = 3.3, p = 0.05).

CONCLUSION

Elevated cTnI among patients presenting with PSVT appears to have prognostic significance only in patients with history of CAD. In this patient group elevated cTnI is associated with increased risk of adverse cardiac outcomes. We therefore believe serum cTnI should be measured selectively, such as in patients with symptoms of ischemic chest pain and a high pretest likelihood of having CAD.

Retrospective Study of Risk Factors for Myocardial Damage in Patients With Critical Coronavirus Disease 2019 in Wuhan

BACKGROUND The novel severe acute respiratory syndrome coronavirus 2 threatens human health, and the mortality rate is higher in patients who develop myocardial damage. However, the possible risk factors for myocardial damage in patients with coronavirus disease 2019 (COVID-19) are not fully known. METHODS AND RESULTS Critical type patients were selected randomly from 204 confirmed COVID-19 cases occurring in Renmin Hospital of Wuhan University from February 1, 2020 to February 24, 2020. Univariate analyses were used to compare the 2 groups: the myocardial damage group and the non-myocardial damage group. A total of 82 critical patients with COVID-19 were recruited: 34 with myocardial damage and 48 without myocardial damage. A total of 30 patients died in the myocardial damage group, and 20 died in the non-myocardial damage group. In univariate analysis, the proportion of elderly patients (>70 years old, 70.59% versus 37.50%; P=0.003) and patients with cardiovascular disease (41.18% versus 12.50%; P=0.003) was higher among myocardial damage patients than among non-myocardial damage patients. Multivariate analysis showed that age >70 years old (hazard ratio [HR], 2.44; 95% CI, 1.01-5.40), CRP (C-reactive protein) >100 mg/L (HR, 1.92; 95% CI, 0.94-3.92), lactate dehydrogenase >300 U/L (HR, 2.67; 95% CI, 1.03-6.90), and lactic acid >3 mmol/L (HR, 3.25; 95% CI, 1.57-6.75) were independent risk factors for myocardial damage in patients with COVID-19. CONCLUSIONS Old age (>70 years old), CRP >100 mg/L, lactate dehydrogenase >300 U/L, and lactic acid >3 mmol/L are high-risk factors related to myocardial damage in critical patients with COVID-19.

Chest pain with less than 20% change in high sensitivity troponin T - a low risk cohort?

Background: Patients with chest pain are risk-stratified using serial high-sensitivity troponin (T) assays (hsTnT). Those with change in (Δ)hsTnT <20% are often categorised as low-risk and are less likely to be managed as acute coronary syndromes (ACS). We sought to characterise such a population of 'low-risk' chest pain presenters.Methods: We performed a retrospective cohort analysis of sequential patients admitted to our centre over a 1-year period with chest pain, absence of ST-elevation, with elevated hsTnT concentrations, and compared demographic, clinical and outcome data according to ΔhsTnT.Results: Three hundred and eleven patients were subdivided by ΔhsTnT [<20% (n = 80), 20-100% (n = 78), >100% (n = 153)]. Baseline demographic data were well-matched across the three subgroups; atrial fibrillation was more common in the two lower magnitude ΔhsTnT groups. Obstructive coronary artery disease (CAD) - while less common in those with ΔhsTnT <20% (66.2%) compared to the 20-100% (73.1%) and >100% (75.9%) groups (p = 0.03) - remained high in this lower risk group, and indeed revascularisation occurred in >60% of patients, equally frequently in all three groups. Using absolute ΔhsTnT ≥9ng/L within the ΔhsTnT <20% group provided incremental value in ruling in ACS, with a positive predictive value of 74.1%. ΔhsTnT was a univariate but not a multivariate predictor of obstructive CAD.Conclusions: Obstructive CAD and need for revascularisation are frequent in chest pain presenters with ΔhsTnT <20%. The increasing focus on hsTnT algorithms to exclude ACS and promote early discharge without adequate clinical risk stratification modelling risks misdiagnosis of patients presenting with acute myocardial ischaemia with a low-level hsTnT rise.

Impact of Left Ventricular Hypertrophy on Peak Serum Troponin T Levels in Patients With Acute Myocardial Infarction

Previous studies have reported that peak serum troponin I levels were disproportionately elevated in patients with acute anterior ST-segment elevation myocardial infarction (STEMI) and left ventricular (LV) hypertrophy (LVH) compared with those with normal LV mass. The purpose of this retrospective study was to assess the relation of peak serum troponin T levels in patients with normal LV mass and in subjects with mild, moderate, and severe LVH in patients with acute STEMI or non-ST segment elevation myocardial infarction (NSTEMI) when stratified on variables that might be expected to affect serum troponin T levels. The study population consisted of 262 patients; 91 with STEMI and 161 with NSTEMI. Serum troponin levels and 2-dimensional echocardiograms were obtained within the first 24 hours of hospitalization for STEMI or NSTEMI. There was no significant difference in serum troponin T levels in LV mass and/or LVH groups (p = 0.3210). There was no significant difference in serum troponin T levels in LV mass and/or LVH groups when these data were stratified on third variables including serum creatinine >1.2 mg/dl (p = 0.3681), LV ejection fraction <60% (p = 0.0978), STEMI (p = 0.2576), NSTEMI (p = 0.4994), and location of severe coronary stenosis (p = 0.1981). The results of this study suggest that there is no association between peak serum troponin T levels and LV mass and/or LVH groups when such groups are stratified on a third variable that may influence peak serum troponin T levels.

Increased level of high-sensitivity cardiac Troponin T in a geriatric population is determined by comorbidities compared to age

High level of cardiac Troponin T (hs-cTnT) in geriatric population has been considered as an age-related phenomenon, which may question the interpretation of the increase of hs-cTnT in this population. The challenge is what is the primary cause of the increased hs-cTnT levels in elderly patients without AMI.

Objective

The aim of the current study was to determine the impact of aging on hs-cTnT levels in elderly patients without acute cardiac events but in the presence of comorbidities.

Methods

Sociodemographic and clinical data were collected from 6977 medical records of patients aged ≥65 years without acute coronary events but for whom hs-cTnT measurements were available. The patients were stratified based on age, troponin levels and the number of comorbidities.

Results

The results suggested that the likelihood of increased hs-cTnT was related to the presence of comorbidities independently of their number (p < 0.05). The adjusted odds ratio (AOR) for both advanced age and having comorbidity was statistically significant, however for the old group (74 ≥ age ≥ 84 years) the chance of having elevated troponin regarding age compared to the presence of comorbidity was 1.070 vs. 1.216, whereas for the old-old group (≥85 years) it was found to be 1.071 vs. 1.311. Besides statistical significance for age, from a clinical standpoint, the AOR of 1.070 may not be considered clinically relevant.

Conclusion

Increased hs-cTnT levels were associated with the presence of pre-existing comorbidities independently of age. Increased hs-cTnT levels in the elderly should always be considered as pathological, and a specific etiology should be searched.

CCTA in patients with positive troponin and low clinical suspicion for ACS: a useful diagnostic option to exclude obstructive CAD

PURPOSE

It is uncertain whether patients with elevated troponin and non-classical presentation of acute coronary syndrome (ACS) should receive coronary CT angiography (CCTA). A proportion of these patients will have no coronary artery disease (CAD) and would benefit from non-invasive investigations and expedited discharge. Objectives were to determine most common diagnoses and rate of ACS among patients with positive troponin and low clinical suspicion of ACS who received CCTA.

METHODS

IRB approved retrospective analysis of 491 consecutive patients in a level I trauma center ED referred for CCTA between April 4, 2015 to April 2, 2017. Patients were included if there was an elevated troponin (TnI > 0.045 μg/L) and atypical chest pain within 24 h prior to imaging. One hundred one patients met inclusion criteria; 17 excluded due to technical factors or history. Scans performed on dual-source CT.

RESULTS

Eighty-four patients (47 men, 37 women) with median TnI of 0.11 ± 0.21 μg/L underwent CCTA 8.20 ± 6.41 h after first elevated Tn. Mean age was 53.2 ± 14.6 years. CCTA demonstrated absence of CAD in 39 patients (46.4%; 20 M, 19 F). CAD < 25% stenosis was observed in 24 (28.6%; 9 M, 15 F). CAD with 25-50% stenosis was observed in seven (8.3%; six M, one F). CAD > 50% stenosis was observed in 11 (13.1%; 9 M, 2 F), and non-diagnostic in three (3.6%, 3 M, 0 F). Forty-six (56.8%) were discharged directly from ED with median stay 15.82 ± 6.41 h.

CONCLUSIONS

Use of CCTA in ED patients with elevated troponin and low clinical suspicion for ACS allowed obstructive CAD to be excluded in 83%.

Arrhythmogenic cardiomyopathy: what blood can reveal?

Blood, serum and plasma represent accessible sources of data about physiological and pathologic status. In arrhythmogenic cardiomyopathy (ACM), circulating nucleated cells are routinely used for detection of germinal genetic mutations. In addition, different biomarkers have been proposed for diagnostic purposes and for monitoring disease progression, including inflammatory cytokines, markers of myocardial dysfunction and damage, and microRNAs. This review summarizes the current information that can be retrieved from the blood of ACM patients and considers the future prospects. Improvements in current knowledge of circulating factors may provide noninvasive means to simplify and improve the diagnosis, prognosis prediction, and management of ACM patients.

Novel Biomarkers to Detect Target Organ Damage in Acute Hypertension

PURPOSE OF REVIEW

Early lowering of blood pressure is advised for patients with severe hypertension associated with signs of impending or progressive organ damage, whereas aggressive treatment is not recommended in patients with asymptomatic severe hypertension. As treatment goals for asymptomatic hypertension and true hypertensive emergency drastically differ, it is essential to identify patients with evidence of impending or progressive organ damage. Biomarkers may assist providers in identifying high-risk patients who would benefit from early blood pressure reduction.

RECENT FINDINGS

In this review, we discuss both currently available and investigational biomarkers that may help identify patients who might benefit from more aggressive therapy. We focus on serum and urinary biomarkers associated with acute cardiovascular, renal, and cerebrovascular damage. There is a dearth of literature regarding the use of biomarkers to assess acute hypertension-related target organ damage. We are primarily forced to draw conclusions on the use of biomarkers from studies of related conditions such as acute heart failure. Further research is needed on the clinical significance of abnormal levels of novel biomarkers of renal, cardiac, and cerebral dysfunction in the setting of severe hypertension, particularly in those patients without overt clinical signs of organ failure.

Retrospective cause analysis of troponin I elevation in non-CAD patients: Special emphasis on sepsis

BACKGROUND

Troponin I is one of the most commonly tested biochemical markers in the emergency room (ER) and in the hospital setting. Besides coronary artery disease (CAD), demand ischemia with underlying tachycardia, anemia, hypertensive emergency, congestive heart failure, kidney disease, sepsis, and pulmonary embolism have also been reported to cause troponin I elevations. Few reports have excluded patients with CAD, and no study has summarized the proportion of these factors relative to an increased troponin I level.

METHODS

The aim of this retrospective study was to investigate the level of contribution of causative factors in troponin I elevation. Charts of patients tested for troponin I during an ER visit or during hospitalization were collected. Patients with known CAD, abnormal stress tests, cardiac catheterizations, or discharge without an adequate cardiac evaluation were excluded. Logistic regression was used to identify predictors of elevated troponin I levels.

RESULTS

A total of 586 patients were investigated in this study. Age, hemoglobin (Hb), heart rate (HR), glomerularfiltration rate, atrial fibrillation, congestive heart failure (CHF), and sepsis were significant predictors of elevated troponin I by analysis in univariate logistic regression (all P < .001). In multivariate logistic regression, sepsis, CHF, age, Hb, and HR were independent predictors of troponin I (all P < .01). A simple clinical scoring system was generated with 1 score on patients with age ≥ 60, Hb < 10 g/dL, and HR ≥ 100 beats per minute (bpm). The prevalence of elevated troponin I was 4%, 16%, 38%, and 50% for patients with scores of 0, 1, 2, and 3, respectively. In patients without sepsis and CHF, the chances of elevated troponin I were 2%, 11%, 28%, and 43%.

CONCLUSIONS

Sepsis was found to be the strongest independent cause of elevated troponin I levels in non-CAD patients. The scoring system composed of age, hemoglobin (Hb), and heart rate (HR) can assist clinical evaluation of elevated troponin I test in non-CAD patients.

Coronary angiography-related myocardial injury as detected by high-sensitivity cardiac troponin T assay

AIMS

We sought to evaluate rates and mechanisms of myocardial injury and type 4a myocardial infarction (MI) after an elective diagnostic coronary angiography (CAG) as detected by high-sensitivity cardiac troponin T (hsTnT) assay.

METHODS AND RESULTS

Cardiac troponin concentrations were measured in consecutive patients before and after undergoing an elective CAG -with or without coronary intervention (PCI)- using an hsTnT assay. The study population consisted of 545 patients: 320 (58.7%) patients received only an elective CAG and another 225 patients (41.3%) received an additional PCI. Significant hsTnT increases occurred in 97 (30.3%) cases within the CAG group and in 152 (67.6%) cases within the PCI group. Rates of normal baseline hsTnT values (<99th percentile upper reference limit) were 75.9% in the CAG group and 71.6% in the PCI group. In cases with normal baseline hsTnT values, peak levels meeting criteria of MI type 4a according to the second or third version of the universal MI definition were observed in five (1.6%) and one (0.3%) cases within the CAG group, as well as in 32 (14.2%) and 22 (9.8%) cases within the PCI group, respectively.

CONCLUSIONS

Use of the hsTnT assay may allow identification of myocardial injury during an uneventful diagnostic coronary angiography in the absence of any coronary or non-coronary interventions.

Hazards with ordering troponin in patients with low pretest probability of acute coronary syndrome

BACKGROUND

In clinical practice, we progressively rely on biomarkers, without estimating the pretest probability. There is not enough support for the use of cardiac troponin (cTn) I in the management of noncardiac patients. We studied the rate at which this test was ordered, the prevalence of detection of a positive result in noncardiac patients, and the impact of this incidental finding on clinical management.

METHODOLOGY

Patients admitted from December 2011 to 2013 to our community hospital with diagnosis of noncardiac disease who had positive cTn were included. Data collected included final diagnosis, patient disposition, cardiac monitoring, cardiology consult, and cardiac biomarker testing.

RESULTS

Cardiac troponin I was ordered for 1700 patients in our emergency department. Seven hundred fifty patients had a positive cTn. Of the 750 patients, 412 had a positive cTn without any clinical suspicion of an acute coronary syndrome. An incidental finding of a positive cTn leads to ordering of cTn on average 4 times during admission, cardiac monitoring of 379 (91.99%) patients for at least 1 day, and a cardiac consultation for 268 (63.65%) of these patients. None of these patients was candidates for an invasive cardiac intervention. Seventy-eight (19.17%) patients were admitted to the cardiac care unit and subsequently transferred to the medical intensive care unit.

CONCLUSIONS

A positive cTn in patients diagnosed with a nonacute coronary syndrome was associated with increased cardiac biomarker testing, telemetry monitoring, and cardiology consults. This study supports adherence to national guidelines for the use of cTn, to reduce hospital cost and resource utilization.

Diagnostic implications of an elevated troponin in the emergency department

Objective. To determine the proportion of initial troponin (cTn) elevations associated with Type I MI versus other cardiovascular and noncardiovascular diagnoses in an emergency department (ED) and whether or not a relationship exists between the cTn level and the likelihood of Type I MI. Background. In the ED, cTn is used as a screening test for myocardial injury. However, the differential diagnosis for an initial positive cTn result is not clear. Methods. Hospital medical records were retrospectively reviewed for visits associated with an initial positive troponin I-ultra (cTnI), ≥0.05 μg/L. Elevated cTnI levels were stratified into low (0.05–0.09), medium (0.1–0.99), or high (≥1.0). Discharge diagnoses were classified into 3 diagnostic groups (Type I MI, other cardiovascular, or noncardiovascular). Results. Of 23,731 ED visits, 4,928 (21%) had cTnI testing. Of those tested, 16.3% had initial cTnI ≥0.05. Among those with elevated cTn, 11% were classified as Type I MI, 34% had other cardiovascular diagnoses, and 55% had a noncardiovascular diagnosis. Type I MI was more common with high cTnI levels (41% incidence) than among subjects with medium (9%) or low (6%). Conclusion. A positive cTn is most likely a noncardiovascular diagnosis, but Type I MI is far more common with cTnI levels ≥1.0.

Predictive value of biomarkers for the prognosis of acute pulmonary embolism in Japanese patients: Results of the Tokyo CCU Network registry

BACKGROUND

Several studies from Western countries have reported associations between cardiac troponin and B-type natriuretic peptide (BNP) levels and acute pulmonary embolism prognosis; however, the number of such reports from Asian countries, including Japan, is limited. Thus, we evaluated the relationship between blood biochemical findings and acute-phase pulmonary embolism prognosis in Japanese patients.

METHODS

The subjects included 441 patients with acute pulmonary embolism (191 men, 250 women; average age, 65.8±16.0 years) treated at Tokyo CCU Network Institutions from 2009 to 2011 and registered via survey forms. The association between blood biochemical findings at admission and 30-day mortality was investigated.

RESULTS

The median BNP value was 186.5pg/mL (25th to 75th interquartile range: 49.8-500pg/mL) of 210 cases. No deaths were recorded among those with BNP levels <90pg/mL (n=70), whereas significantly higher mortality (10 deaths/140 cases, 7.1%; p=0.033) was observed among those with BNP levels ≥90pg/mL. A qualitative cardiac troponin test was positive in 58 of the 204 cases (28.4%), with a significantly higher mortality incidence (p=0.017) among the troponin-positive cases [6 (10.3%) versus 3 (2.1%) deaths among the 146 troponin-negative cases]. The overall mean blood glucose level at admission of 331 cases was 152.0±74.0mg/dL, and 30-day mortality significantly increased with blood glucose values (p=0.048).

CONCLUSIONS

Troponin, BNP, and blood glucose levels are useful prognostic biomarkers for acute pulmonary embolism in Japanese patients.

Acute One-Stop Cardiovascular Magnetic Resonance Imaging for Differential Diagnosis in Patients with Acute Coronary Syndrome and Unobstructed Coronary Arteries

OBJECTIVE

We aimed to evaluate the contributions of acute one-stop cardiovascular magnetic resonance (CMR) imaging to the differential diagnosis of acute coronary syndrome (ACS) and unobstructed coronary arteries.

SUBJECTS AND METHODS

In this study, 32 consecutive patients who presented with ACS and unobstructed coronary arteries on angiography were enrolled between January 2010 and December 2012. Acute one-stop CMR, including cine, angiography, black-blood, first-pass perfusion and late gadolinium enhancement (LGE) imaging, was performed with a pre-specified algorithm which was decided on by the doctors for all patients. The intimal flap in the aorta and the filling defect in the pulmonary artery were detected on MR angiography imaging. Left ventricular wall motion and ventricular thickness were analyzed in cine-mode sequences. The LGE images were reviewed for the presence, anatomical distribution and extent of contrast enhancement.

RESULTS

The acute one-stop CMR study was completed in all the 32 patients without adverse events. The overall time duration was between 15 and 60 min. Of the 32 patients, a CMR diagnosis was made in 30 (93.8%). Aortic dissection was detected in 3 patients, pulmonary embolism in 2, hypertrophic cardiomyopathy in 2, acute myocardial infarction in 5, acute myocarditis in 16 and stress cardiomyopathy in 2. No confirmed diagnosis was established in the remaining 2 patients with normal CMR.

CONCLUSION

Acute one-stop CMR allowed for the identification of an aetiology in most of the patients in this study. It may prove to be of immense help in establishing a differential diagnosis in patients presenting with acute chest pain, elevated troponin I and normal coronary arteries.

Identificação e distribuição de lesões cardíacas em bovinos intoxicados por Amorimia exotropica

Amorimia exotropica é um arbusto escandente que pertence à família Malpighiacea, cujo princípio tóxico é o monofluoracetato de sódio e possui ação cardiotóxica em bovinos. Ela é a única representante, na região Sul do país, do grupo de plantas que causam morte súbita associada ao exercício. Este trabalho identificou e mapeou as lesões cardíacas observadas em bovinos intoxicados naturalmente por A. exotropica. Selecionaram-se nove corações bovinos, provenientes de um surto de intoxicação natural pela planta em uma propriedade de gado de corte do Rio Grande do Sul e procedeu-se o mapeamento de oito regiões topográficas distintas (ápice, ventrículos direito e esquerdo, septo interventricular, músculos papilares direito e esquerdo e átrios direito e esquerdo). À avaliação macroscópica quatro bovinos apresentaram lesão focal e bem delimitada no músculo papilar esquerdo. Estas áreas na histologia correspondiam à necrose de coagulação em diferentes estágios de evolução, similares a infartos. Todos os bovinos apresentavam necrose de cardiomiócitos, caracterizadas por retração e hipereosinofilia citoplasmática e fragmentação celular em todas as áreas amostradas. A severidade da injúria celular foi avaliada pela imuno-histoquímica anti-troponina C, a qual demonstrou acentuada perda e/ou diminuição de marcação citoplasmática em células necróticas. O músculo papilar esquerdo foi a região mais acometida nos casos de intoxicação por Amorimia exotropica.

Improved rate control reduces cardiac troponin T levels in permanent atrial fibrillation

BACKGROUND

Detectable levels of troponins are often found in serum of patients with atrial fibrillation (AF), and recent reports suggest that Tn concentrations are independently related to patient prognosis.

HYPOTHESIS

We hypothesized that treatment with common rate-reducing drugs might lower the levels of cardiac troponin T (TnT) in patients with permanent AF. We also wanted to investigate whether the different drugs would impact the Tn levels differently.

METHODS

Sixty patients were included (mean age 71 ± 9 years, 18 women) in this randomized crossover study. All patients had stable, permanent AF without ischemic heart disease or congestive heart failure. Diltiazem 360 mg, verapamil 240 mg, metoprolol 100 mg, and carvedilol 25 mg were administered once daily for 3 weeks, in a randomized sequence. At baseline and on the last day of each treatment period, TnT concentrations were measured at rest and after a maximal exercise test.

RESULTS

TnT was detectable in all patients. In 22% of the patients, TnT concentrations were above the threshold normally used for diagnosing myocardial infarction. All drugs reduced the levels of TnT significantly compared with baseline (P < 0.001 for all), but there were no significant differences between the treatments. Levels of TnT increased significantly in response to exercise testing (P < 0.001 for all).

CONCLUSIONS

Elevated TnT was demonstrated in a large proportion of stable patients with permanent AF without ischemic heart disease. A moderate reduction of heart rate by the study drugs was associated with a significant reduction in levels of TnT.

Cardiac troponin I elevation with supraventricular tachycardia: two case reports and review of the literature

Background

Although cardiac troponin I gives excellent accuracy in the identification of myocardial necrosis, it can also be elevated in a series of diseases other than acute coronary syndromes.

Case presentation

We present two cases of Chinese patients with a high serum troponin I level after an acute episode of paroxysmal supraventricular tachycardia with normal coronary arteries via angiography.

Conclusion

Abnormal troponin elevations can be seen in patients presenting with paroxysmal supraventricular tachycardia and angiographically-normal coronary arteries. Caution is advised with the use of invasive assessments such as coronary angiography in the differential diagnosis of patients with paroxysmal supraventricular tachycardia and elevated troponin levels.

High sensitivity troponin T in acute medicine; more questions than answers?

BACKGROUND

Troponin testing in acute medicine is routine. The introduction of a high sensitivity assay (hs Tn T) has created uncertainty regarding the clinical significance of 'abnormal' troponin T levels. The previous assay could not detect troponin levels <30 ng/l.

AIMS AND METHODS

To characterize those with a hs Tn T ≥14 ng/l. Prospective cohort study of consecutive admissions to an acute medical unit.

RESULTS

Troponin was measured in 564 consecutive patients (∼50% of all admissions) over 1 month; was ≥14 ng/l in 224 (40%) of which 220 patients had demographic data for this analysis. Median (inter-quartile range) peak troponin was 47.5 ng/l (24-130) and 36% had a Tn T between 14 and 30 ng/l. Mean [standard deviation (SD)] age was 72 (12) years and 57% were male. Only 44 patients (20%) had an acute myocardial infarction, reflecting the increased sensitivity but reduced specificity of the assay. Prognosis was poor with 31% mortality at 1 year. Over a mean (SD) follow-up of 648 (61) days, there were 87 deaths (40%). Those with a primary non-cardiac diagnosis (n = 126) had poorer survival than those with a primary cardiac diagnosis (n = 94). Troponin elevation related to sepsis conferred a very poor prognosis with 24 deaths (70%) over the follow-up period.

CONCLUSION

Elevated hs Tn T is very common in acute medicine, but myocardial infarction as an explanation is uncommon. Overall, the prognosis is poor with a tendency to worse outcomes in those with a primary 'non-cardiac' diagnosis.

Elevated troponin predicts long-term adverse cardiovascular outcomes in hypertensive crisis: a retrospective study

BACKGROUND

Hypertensive crisis is associated with poor clinical outcomes. Elevated troponin, frequently observed in hypertensive crisis, may be attributed to myocardial supply-demand mismatch or obstructive coronary artery disease (CAD). However, in patients presenting with hypertensive crisis and an elevated troponin, the prevalence of CAD and the long-term adverse cardiovascular outcomes are unknown.

OBJECTIVE

We sought to assess the impact of elevated troponin on cardiovascular outcomes and evaluate the role of troponin as a predictor of obstructive CAD in patients with hypertensive crisis.

METHODS

Patients who presented with hypertensive crisis (n = 236) were screened retrospectively. Baseline and follow-up data including the event rates were obtained using electronic patient records. Those without an assay for cardiac Troponin I (cTnI) (n = 65) were excluded. Of the remaining 171 patients, those with elevated cTnI (cTnI ≥ 0.12 ng/ml) (n = 56) were compared with those with normal cTnI (cTnI < 0.12 ng/ml) (n = 115) at 2 years for the occurrence of major adverse cardiac or cerebrovascular events (MACCE) (composite of myocardial infarction, unstable angina, hypertensive crisis, pulmonary edema, stroke or transient ischemic attack).

RESULTS

At 2 years, MACCE occurred in 40 (71.4%) patients with elevated cTnI compared with 44 (38.3%) patients with normal cTnI [hazard ratio: 2.77; 95% confidence interval (CI): 1.79-4.27; P < 0.001]. Also, patients with elevated cTnI were significantly more likely to have underlying obstructive CAD (odds ratio: 8.97; 95% CI: 1.4-55.9; P < 0.01).

CONCLUSION

In patients with hypertensive crisis, elevated cTnI confers a significantly greater risk of long-term MACCE, and is a strong predictor of obstructive CAD.

Blood specimen biomarkers of inflammation, matrix degradation, angiogenesis, and cardiac involvement: a future useful tool in assessing clinical outcomes of COPD patients in clinical practice?

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation that is not fully reversible; this airflow limitation is both progressive and associated with an abnormal inflammatory response of the lung to noxious particles or gasses. COPD is undoubtedly an umbrella term, and it seems unlikely that all patients with COPD have the same underlying disease processes; thus, there is a need for differential treatment of different subgroups. A potential solution is to find modifiable biomarkers that can assist in drug development and distinguish subgroups of COPD. With the exception of lung function tests, there are currently no well-validated biomarkers or surrogate endpoints that can be used to establish the efficacy of a drug for COPD. This article discusses biomarkers of inflammation (fibrinogen, C-reactive protein, pulmonary and activation-regulated chemokine/CC-chemokine ligand-18, serum surfactant protein D, interleukin (IL)-6, IL-8 and tumor necrosis factor α, complement factor C5a), angiogenesis factors as a part of the pathogenetic aspect in this disease (vascular endothelial growth factor, angiogenin, and IL-8), and matrix degradation biomarkers. Troponin and natriuretic peptides are presented as biomarkers of cardiac involvement in the light of COPD comorbidities. Trials based on research on known clinical variables such as FEV1, BODE, and 6MWT in combination with biomarkers from lung and blood specimens will probably clarify part of the prognosis and natural history of the disease. This will also represent an additional step in COPD phenotyping and new treatment possibilities.

Cardiac biomarker changes in camels (Camelus dromedarius) secondary to road transportation

OBJECTIVES

Little is known about cardiac biomarkers in camels despite their extensive use as draft animals. This study was designed to establish reference ranges for the cardiac biomarkers cardiac troponin I (cTnI) and creatine kinase myocardial b fraction (CK-MB) in healthy camels and to investigate their changes in response to road transportation.

ANIMALS

Twenty-five healthy camels transported for a 5 h round-trip journey.

METHODS

None of the camels had evidence of cardiac abnormalities on cardiac auscultation, echocardiography or electrocardiography. Three blood samples were obtained from each camel: 24 h before transportation (T0), within 2 h after unloading (T1) and 24 h after transportation (T2).

RESULTS

The mean cTnI concentration in the camels was 0.032 ± 0.023 ng/mL. All the camels had resting cTnI concentrations of <0.08 ng/mL. At T1, the cTnI concentration was significantly higher (P < 0.001) in all 25 camels compared to values at T0. The CK-MB concentration in the camels was 0.19 ± 0.05 ng/mL. All the camels had resting CK-MB concentrations of <0.33 ng/mL. At T1, the CK-MB concentration was higher in 3/25 camels compared to values at both T0 and T2. Concerning the hematobiochemical variables, significant increases were detected at T1 in total white blood cells, total protein, globulin, magnesium and phosphorus. Cardiac troponin I, CK-MB and all the hematobiochemical parameters had returned to their pre-transport values at T2.

CONCLUSIONS

5 h road transportation might have transient adverse effects on the cardiac muscle of healthy camels.

Clinical significance of troponin elevations in acute decompensated diabetes without clinical acute coronary syndrome

Background

Elevation of cardiac troponin has been documented in multiple settings without acute coronary syndrome. However, its impact on long-term cardiac outcomes in the context of acute decompensated diabetes remains to be explored.

Methods

We performed a retrospective analysis of 872 patients admitted to Temple University Hospital from 2004–2009 with DKA or HHS. Patients were included if they had cardiac troponin I (cTnI) measured within 24 hours of hospital admission, had no evidence of acute coronary syndrome and had a follow up period of at least 18 months. Of the 264 patients who met the criteria, we reviewed the baseline patient characteristics, admission labs, EKGs and major adverse cardiovascular events during the follow up period. Patients were categorized into two groups with normal and elevated levels of cardiac enzymes. The composite end point of the study was the occurrence of a major cardiovascular event (MACE) during the follow up period and was compared between the two groups.

Results

Of 264 patients, 24 patients were found to have elevated cTnI. Compared to patients with normal cardiac enzymes, there was a significant increase in incidence of MACE in patients with elevated cTnI. In a regression analysis, which included prior history of CAD, HTN and ESRD, the only variable that independently predicted MACE was an elevation in cTnI (p = 0.044). Patients with elevated CK-MB had increased lengths of hospitalization compared to the other group (p < 0.001).

Conclusions

Elevated cardiac troponin I in patients admitted with decompensated diabetes and without evidence of acute coronary syndrome, strongly correlate with a later major cardiovascular event. Thus, elevated troponin I during metabolic abnormalities identify a group of patients at an increased risk for poor long-term outcomes. Whether these patients may benefit from early detection, risk stratification and preventive interventions remains to be investigated.

Cardiac Troponin I elevation after epileptic seizure

Background

Cardiac troponin-I (cTNI) is highly specific biomarker to prove myocardial damage, e.g. in acute coronary syndrome (ACS). However, it occurs in other conditions as well. We therefore analysed cTNI increase in patients after generalized convulsive seizure.

Methods

Consecutive patients admitted with acute generalized convulsive seizure were included in case of cTNI measurement on admission. Among 898 selected cases, 53 patients were referred secondary to our department; in 845 cases cTNI measurements on admission were available. In case of multiple admissions (81 cases), only the first admission entered our analysis. In 17 patients elevated cTNI was determined due to ACS; in one patient a myocarditis was found. 5 patients suffered of relevant renal insufficiency. Finally 741 patients were included in the analysis. A cTNI cut-off level of ≥ 0.1 ng/ml was considered. Factors associated with a cTNI increase were analysed subsequently.

Results

The mean age of the study population (n = 741) was 47.8 years (SD ± 18.6), 40.9% were female. In 50 patients (6.7%) a cTNI elevation of unknown origin was found; no obvious cardiac involvement could be detected in these patients who all remained asymptomatic. A vascular risk profile (including at least hypertension, hypercholesterolemia or diabetes) (OR = 3.62; CI: 1.59 to 8.21; p = 0.001) and elevated creatine kinase on admission (OR = 2.36; CI: 1.26 to 4.39; p = 0.002) were independent factors associated with cTNI release.

Conclusion

cTNI release occurs in patients with generalized convulsive seizure with predominance in patients with vascular risk profile.

Troponin I: how high is too high?

Elevated cardiac troponin I can occur in patients with cardiac injury or sepsis. However, extreme elevations of serum cardiac troponin I in pediatric patients without myocardial injury are rare. We present a case of a 14-year-old girl involved in a motor vehicle accident with muscle injury, who was readmitted with sepsis and severely elevated serum cardiac troponin I level in the absence of myocardial injury.

Diagnostic pitfalls at admission in patients with acute superior mesenteric artery occlusion

BACKGROUND

Acute superior mesenteric artery (SMA) occlusion leads to acute intestinal ischemia and is associated with high mortality. Early diagnosis is often missed, and confounding factors leading to diagnostic delays need to be highlighted.

OBJECTIVES

To identify potential diagnostic laboratory pitfalls at admission in patients with acute SMA occlusion.

METHODS

Fifty-five patients with acute SMA occlusion were identified from the in-hospital register during a 4-year period, 2005-2009.

RESULTS

The median age was 76 years; 78% were women. The occlusion was embolic in 53% and thrombotic in 47% of patients. At admission, troponin I was above the clinical decision level (> 0.06 μg/L) for acute ischemic myocardial injury in 9/19 (47%) patients with embolic occlusion. Elevated pancreas amylase and normal plasma lactate were found in 12/45 and 13/27, respectively. A troponin I (TnI) above the clinical decision level was associated with a high frequency of referrals from the general surgeon to a specialist in internal medicine (p = 0.011) or a cardiologist (p = 0.024). The diagnosis was established after computed tomography angiography in 98% of the patients. The overall in-hospital mortality rate was 33%. Attempting intestinal revascularization (n = 43; p < 0.001), with a 95% frequency rate of completion control of the vascular procedure, was associated with a higher survival rate, whereas referral to the cardiologist was associated with a higher mortality rate (p = 0.018).

CONCLUSION

Elevated TnI was common in acute SMA occlusion, and referral to the cardiologist was found to be associated with adverse outcome. Elevated pancreas amylase and normal plasma lactate values are also potential pitfalls at admission in patients with acute SMA occlusion.

Diagnostic contributions of cardiac magnetic resonance imaging in patients presenting with elevated troponin, acute chest pain syndrome and unobstructed coronary arteries

AIMS

Myocardial infarction with unobstructed coronary artery disease represents a serious diagnostic challenge. The role of cardiac magnetic resonance in the management of cardiomyopathies is increasing. We examined the diagnostic contributions of cardiac magnetic resonance in patients presenting with acute chest pain syndrome, elevated serum cardiac troponin concentrations and no significant coronary artery stenoses.

METHODS

Over a 3-year period, 107 consecutive patients (mean age 43.5 years; 62% men) presented to our institution with acute onset of chest pain, elevated serum troponin concentration and unobstructed coronary arteries, and underwent 3-tesla cardiac magnetic resonance at a mean delay of 6.9 days. A diagnosis was made based on: wall motion abnormalities and pericardial effusion on cine mode; myocardial oedema on T2-weighted imaging; abnormalities on first-pass perfusion imaging; and late gadolinium enhancement on T1-weighted imaging.

RESULTS

Cardiac magnetic resonance was normal in 10.3% of patients and contributed a diagnosis in 89.7%, including myocarditis in 59.9%, stress cardiomyopathy (takotsubo syndrome) in 14% and myocardial infarction in 15.8%. Patients with normal cardiac magnetic resonance had a significantly lower mean peak troponin concentration (2.6ng/mL) than patients with diagnostic cardiac magnetic resonance (9.7ng/mL; P=0.01).

CONCLUSION

Cardiac magnetic resonance contributed a diagnosis in nearly 90% of patients presenting with acute chest pain, elevated serum troponin and unobstructed coronary arteries.

Integrin stimulation favors uptake of macromolecules by cardiomyocytes in vitro

Previously, our research group showed that integrin stimulation induces release of cardiac troponin I from viable neonatal rat ventricular cardiomyocytes (NRCMs), but would it also stimulate uptake of exogenous macromolecules? For this purpose, beating NRCMs were incubated without or with an RGD motif-containing peptide (GRGDS) to stimulate integrins in the presence of Texas Red-conjugated ovalbumin (OTR; 45 kDa) or dextran (DTR; 70 kDa). After incubation periods of 8, 16 and 24 hours endocytosis of red label was quantified by fluorescence microscopy. Uptake of OTR and DTR by NRCMs was intensified by GRGDS treatment (p for trend <0.001 and 0.019, respectively) and increased with duration of incubation (p<0.001 for both). The GRGDS-induced uptake of OTR by NRCMs correlated positively with OTR concentration (p<0.001). Experiments with pharmacological inhibitors of endocytosis indicated that in the absence of GRGDS, NRCMs take up OTR by the clathrin-mediated pathway of endocytosis while the GRGDS-dependent OTR uptake occurs by macropinocytosis. Cultures of NRCMs that were stretched cyclically showed ≍4-fold increased uptake of OTR compared to stationary NRCM cultures. Immunofluorescence microscopy revealed that the dysferlin-positive plasma membrane (PM) areas in beating GRGDS-treated NRCMs were ≍3-fold larger than in contracting NRCMs incubated with vehicle (p<0.001). However, in non-beating NRCMs exposure to GRGDS did not induce larger dysferlin-positive PM areas, nor did it stimulate uptake of OTR. After inhibition of dysferlin expression by short hairpin RNA-mediated RNA interference, OTR uptake by contracting NRCMs could no longer be stimulated via GRGDS treatment. We conclude that in NRCMs, stimulation of integrins by RGD motif-containing peptides or stretch cause uptake of labeled macromolecules. The latter process appears to depend on the contractile behavior of the NRCMs and on the PM repair protein dysferlin, probably because of its role in macropinocytosis.

Electrocardiographic ST-segment elevation myocardial infarction in critically ill patients: an observational cohort analysis

OBJECTIVE

To investigate the specificity of the electrocardiographic diagnosis of ST-segment elevation myocardial infarction in the critical care unit setting.

DESIGN

Retrospective observational cohort analysis.

SETTING

An 880-bed tertiary care teaching hospital with 120 intensive care unit beds.

PATIENTS

The population included medical, surgical, trauma, and neurosurgical intensive care unit patients.

INTERVENTIONS

Electrocardiograms were systematically collected to include all consecutive recordings over a 15-month period in which the interpretation software indicated ***ACUTE MI***. Patient demographics, markers of intensive care unit complexity, and hospital mortality were ascertained. The electrocardiograms were then further evaluated by a blinded, board-certified cardiologist for agreement or disagreement with the interpretation software. Serum troponin measurements obtained within 96 hrs of electrocardiogram acquisition were used to determine the likelihood of myocardial infarction.

MEASUREMENTS AND MAIN RESULTS

Over the 15-month study period, the interpretation software diagnosed ST-segment elevation myocardial infarction in 67 of 2243 intensive care unit patients (2.99%) who had an electrocardiogram performed. In the final study population of 46 cases with electrocardiographic ST-segment elevation myocardial infarction, 85% had peak troponin elevation<5 ng/mL, a strong suggestion against clinical ST-segment elevation myocardial infarction. The cardiologist agreed with the computer interpretation in 39% (18 of 46) of cases, but of those 18 patients, only six showed a significant rise in the troponin level. The cardiologist disagreed with the computer interpretation in 60.9% (28 of 46) of cases and of those, one patient had a marked elevation of the cardiac troponin.

CONCLUSIONS

ST-segment elevation myocardial infarction in the intensive care unit is a relatively common electrocardiographic reading both by standard interpretation software and by expert evaluation. In contrast to nonintensive care unit patients who present with chest pain, the electrocardiographic ST-segment elevation myocardial infarction diagnosis seems to be a nonspecific finding in the intensive care unit that is frequently the result of a variety of nonischemic processes. The vast majority of such patients do not have frank ST-segment elevation myocardial infarction.

New features of troponin testing in different clinical settings

Cardiac troponin levels are routinely measured for diagnosing acute myocardial infarction. Cardiac troponin measurements also provide information concerning prognosis and the effect of early intervention in patients with acute coronary syndromes. The recent development of highly sensitive cardiac troponin assays permits detection of very low circulating levels. Use of sensitive troponin assays improves overall diagnostic accuracy in patients with suspected acute coronary syndromes, and these assays provide strong prognostic information in stable coronary artery disease and chronic heart failure. However, increased sensitivity comes with a cost of decreased specificity, and serial testing, as well as clinical context and judgment, is likely to become increasingly important in the interpretation of troponin assay results.

Relationship of myocardial ischemia and injury to coronary artery disease in patients with supraventricular tachycardia

Increase of serum troponin I and ST-segment depression are objective markers of myocardial ischemia/injury. Abnormalities of the 2 indicators have been associated with supraventricular tachycardia (SVT) but their relevance for diagnosing acute coronary syndrome and the presence of coronary artery disease (CAD) in this setting have not been clarified. Therefore, we sought to evaluate the frequency of CAD based on increased troponin I and ST-segment depression during SVT. During a 5-year period, 104 patients were admitted with a diagnosis of SVT, 80 of whom had troponin I testing, and 70 of these patients could be assessed for ST-segment changes. Thirty-seven patients (48%) had increased troponin I (mean 1.54 +/- 2.7 ng/dl, normal <or=0.07 ng/dl) and 46 patients (57%) had ST-segment depression >or=1.0 mm. There were no significant differences in baseline characteristics and clinical presentation of patients with and without troponin I increase or ST-segment depression. There was no difference in the diagnosis of CAD by noninvasive or invasive testing in patients with and without increased troponin I. More patients with than without ST-segment depression had evidence of CAD (22% vs none, p = 0.01), but after adjusting for covariates, ST-segment depression was not a significant predictor of CAD. In conclusion, increased troponin I and ST-segment depression are not significant markers of acute coronary syndrome in patients with SVT.

Prognostic significance of cardiac troponin I levels in hospitalized patients presenting with supraventricular tachycardia

Although cardiac troponin I (cTnI) elevation in patients presenting to the hospital with supraventricular tachycardia (SVT) is well recognized, the prevalence, predictors, and prognostic significance of cTnI elevation associated with SVT presentation are not known. We screened records of all patients presenting to 2 hospitals over a 4-year period with the diagnosis of SVT confirmed by 12-lead electrocardiogram, and who had at least 1 measured cTnI level and at least 1 year of follow-up after discharge. The primary endpoint was the occurrence of 1 of the following outcomes: death, myocardial infarction, or cardiovascular rehospitalization. Seventy-eight patients met the study criteria (54% female; mean age, 62.2 +/- 15.8 yr), and 29 patients (37.2%) had an elevated cTnI level of > or =0.06 ng/mL (range, 0.06-7.78 ng/mL). Univariate predictors of elevated cTnI included left ventricular ejection fraction (LVEF) <50%, renal dysfunction, ST-segment depression or left bundle branch block on the electrocardiogram, and moderate or severe regurgitation of any cardiac valve. Predictors of elevated cTnI after multivariate analysis included peak heart rate during SVT (per 15 bpm) (odds ratio [OR], 1.58; 95% confidence interval [CI], 1.01-2.46; p = 0.04) and LVEF <50% (OR, 6.12; 95% CI, 1.40-26.7; p = 0.02). After multivariable adjustment, the presence of elevated cTnI with SVT was associated with increased risk of the primary endpoint of death, myocardial infarction, or cardiovascular rehospitalization (hazard ratio [HR], 3.67; 95% CI, 1.22-11.1; p = 0.02). Mild elevation of cTnI is common in patients presenting to the hospital with SVT, and is associated with increased risk of future cardiovascular events. Further study is needed to determine the mechanisms of SVT-related cTnI elevation and its association with elevated cardiovascular risk.

Pseudo myocardial infarction - a condition in need to be redefined?

Since the introduction of cardiac plasma troponin measurements, a significant number of patients were seen with chest pain, elevated troponin levels but no significant coronary artery disease. Pulmonary embolism, aortic valve disease, myocarditis, sepsis, trauma, arrythmias, stress cardiomyopathy and dilated cardiomyopathy stand among possible causes for this syndrome. In some cases, myocardial strain could be the mechanism underlying this phenomenon, since it is known that the stimulation of stretch-responsive integrins may lead to the release of cardiac troponin I. In the present text, a case is made in favour of classifying this syndrome, of chest pain with increased values for plasma cardiac troponin, with or without ECG changes, in the absence of definite myocardial infarction or coronary artery disease, as pseudo myocardial infarction (PMI). This constitutes a new definition for a concept with decades, formerly centered on clinical and electrocardiographic changes mimicking infarct. The case is based on the search of scientific truth, on avoidance of unnecessary cardiac examinations, on avoidance of unnecessary drug therapy and on avoidance of unnecessary legal liability. PMI should be seen as a working diagnosis, since a more definitive diagnosis can be reached at all time. It should also be seen as a heterogeneous group of patients - several different diseases and conditions can lead to this phenomenon. But it must certainly not be seen as a benign condition, since published studies point in a totally different direction.

Usefulness of elevations in serum choline and free F2)-isoprostane to predict 30-day cardiovascular outcomes in patients with acute coronary syndrome

Our objectives were to evaluate the prognostic value of several biomarkers in patients with acute coronary syndrome (ACS) through an evaluation of the 30-day clinical outcomes. Multiple biomarkers have emerged as potentially useful in risk stratification of ACS. Specifically, markers of vascular inflammation and oxidative stress might be helpful in the determination of clinical outcomes. We evaluated patients presenting with chest pain. ACS was defined by symptoms of cardiac ischemia plus electrocardiographic changes or positive troponin I. Levels of serum troponin I, high sensitivity C-reactive protein, serum choline, and free F(2)-isoprostane were obtained. Patients were followed up for 30 days (n = 108) with determination of nonfatal myocardial infarction, congestive heart failure, need for revascularization, and death. Of the 108 patients, 26 had a cardiac event. Free F(2)-isoprostane and choline levels (but not high-sensitivity C-reactive protein levels) predicted 30-day cardiac events. To determine the value of choline and F(2)-isoprostane levels in predicting 30-day cardiac events, receiver operating curves were generated. The optimal cutoff point of these markers was a serum F(2)-isoprostane level of 124.5 pg/ml (r = 0.82) and a serum choline level of 30.5 mumol/L (r = 0.76). F(2)-isoprostane and choline had a positive predictive value of 57% and 44% and a negative predictive value of 90% and 89%, respectively. In conclusion, serum choline and free F(2)-isoprostane are predictors of cardiac events in ACS. A model that includes an array of biomarkers, including troponin, choline, and free F(2)-isoprostane, might be useful in predicting patients at greater risk of future events in ACS.