Biomarkers in acute myocardial injury

Valproic acid treatment attenuates caspase-3 activation and improves survival after lethal burn injury in a rodent model

Burn injury may result in multiple organ dysfunction partially because of apoptotic cell death. The authors have previously shown that valproic acid (VPA) improves survival in a dog burn model. The aim of this study is to examine whether a VPA improves survival in a rodent burn model and whether this was because of inhibition of cell apoptosis. Rats were subjected to third-degree 55% TBSA burns and randomized to treatment with a VPA (300 mg/kg) or normal saline. One group of animals was monitored for 12 hours for survival analysis; another group was killed at 6 hours after injury, and brains, hearts, and blood samples were harvested for examination. Plasma creatine kinase (CK)-MB activities and neuron-specific enolase (NSE) levels were measured to evaluate the cardiac and brain damages. The effects of a VPA on acetylation of histone H3 and caspase-3 activation were also evaluated. Major burn injury resulted in a significant decrease in the acetylation of histone H3, and there was an increase in plasma CK-MB activities, NSE concentrations, and tissue levels of activated caspase-3. A VPA treatment significantly increased the acetylation of histone H3 and survival of the animals after major burn injury. In addition, a VPA treatment significantly attenuated the plasma CK-MB activities, an NSE concentrations, and inhibited caspase-3 activation after major burn injury. These results indicate that a VPA can attenuate cardiac and brain injury, and can improve survival in a rodent model of lethal burn injury. These protective effects may be mediated in part through the inhibition of caspase-3 activation.

Value of heart-type fatty acid-binding protein (H-FABP) for emergency department patients with suspected acute coronary syndrome

OBJECTIVE

The aim of this study is testing the value of H-FABP in the early diagnosis of ACS alone or with routinely used biomarkers such as myoglobin, CK-MB, and cTn I in patients who admitted to emergency department (ED) with complaint of chest pain and suspected acute coronary syndrome.

MATERIAL AND METHODS

This prospective and cross-sectional study was performed at the Emergency Department of University hospital between June 2009 and September 2010. Patients who were admitted with chest pain within first 48 hours and suspected ACS were enrolled to the study. Blood samples were taken for CK-MB, myoglobin, cTnI and H-FABP The patients were divided into two groups (ACS and non ACS). Statistical analyse were used for relation of biomarkers with diagnosis of ACS.

RESULTS

A 66 patients were included to the study. H-FAPB values were positive in 15.2% patients. When H-FABP was added to routinely used biomarkers in the diagnosis of ACS, increasing was observed in all sensitivity, specificity, PPV and NPV values. However, this increase was not statistically significant.

CONCLUSION

H-FABP did not provide any significant change in early diagnosis and exclusion of ACS diagnosis when used either alone or combination with routinely used biomarkers.

Toxicological in vitro and subchronic evaluation of LASSBio-596

LASSBio-596, 2-[4-(1,4-tiazinan-4-ylsulfonyl) phenylcarbamoyl] benzoic acid, is an achiral compound containing a subunit carboxylic amide, was capable of preventing induced mechanical and morphological changes in the lungs that commonly caused the onset of asthma. Previous studies to determine the acute toxicity of oral LASSBio-596 at dose of 2000mg/kg caused no deaths in any of the tested animals. To further evaluate the safety of LASSBio-596, in vitro and in vivo tests were carried out. Regarding to in vitro test were used renal, hepatic, pulmonary, cardiac, neurologic and intestinal cell lines. They were evaluated using neutral red (NR) and [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assays. Micronuclei also was performed. Concerning to in vivo was performed subchronic on Wistar rats at doses of 10, 50, and 250mg/kg and zebrafish test. The in vitro tests results showed the safety of LASSBio-596. However, subchronic toxicity study results revealed changes in the blood parameters of amylase, alanine aminotransferase (ALT), aspartate aminotransferase (AST), glucose and creatine kinase (CK) which is used for cardiotoxicity evaluation, although, did not identify any histopathological alterations. However, zebrafish test demonstrated cardiac damage. It was impossible to estimate the no-observed-adverse-effect-levels and lowest observed-adverse-effect level due to the presence of cardiotoxicity in all tested doses.

Circulating miR-323-3p and miR-652: candidate markers for the presence and progression of acute coronary syndromes

BACKGROUND

The prognostic utility of circulating plasma microRNA in patients with acute coronary syndromes (ACS) has been proposed but not yet demonstrated. We set out to investigate circulating microRNA levels in patients incurring recent ACS and examined associations with neurohormones, cardiac structure and function, and survival over 5 years of follow-up.

METHODS

An initial screen of 375 microRNAs was performed in 35 ACS patients and 16 healthy controls. Candidates identified from the initial screen (miR-323-3p, miR-652, miR-27b, miR-103 and miR-208a) were validated in a further cohort of 200 patients at baseline (~ 30 days post-ACS) and at 4 and 12 months post-ACS, and compared with 100 controls.

RESULTS

In the validation cohort, significantly higher levels in patients were replicated for miR-323-3p, miR-652 and miR-27b (10-fold, 2.3-fold and 2.3-fold, respectively, adjusted p<0.05). Lower levels of miR-103 were not replicated and miR-208a was undetectable. From baseline to 4 months post-admission, miR-323-3p and miR-652 remained elevated in patients compared to controls (adjusted p<0.01), with no further change in levels between 4 and 12 months; whereas miR-27b fell to control levels by 4 months. Baseline levels of miR-652 in the lowest tertile were significantly associated with readmission for heart failure (log-rank p<0.001). In combination with NT-proBNP and LVEF, miR-652 significantly improved risk stratification (p<0.001).

CONCLUSIONS

Our study identifies miR-652 as a novel candidate biomarker for post-ACS prognosis beyond existing biomarkers of LVEF and NT-proBNP. Moreover circulating miR-323-3p was markedly elevated in patients for at least a year post-ACS and may be a stable biomarker for ACS.

Serum ischemia modified albumin and vascular endothelial growth factor levels following intravitreal bevacizumab injections

PURPOSE

Previous reports have demonstrated that the serum levels of vascular endothelial growth factor (VEGF) are reduced after intravitreal injections of bevacizumab. This study aimed to determine the serum levels of ischemia-modified albumin (IMA), a marker of ischemia, and VEGF following intravitreal injections of bevacizumab.

METHODS

This was a prospective study. Blood samples were drawn prior to injection and at 1, 7, and 30 days after injection.

RESULTS

A total of 11 patients participated in this study. Mean serum IMA levels were lower than baseline during follow-up, with statistically significant differences compared to baseline levels at day 1 and day 30 (preinjection: 49.82 ± 15.28 ng/mL; 44.57 ± 12.01 ng/mL, p = 0.007, and 43.71 ± 13.82 ng/mL, p = 0.001, respectively). Mean serum VEGF levels were lower than baseline throughout the follow-up period (from 307.45 ± 273.45 pg/mL at baseline to 159.55 ± 120.68 pg/mL at day 30). Mean serum VEGF levels were significantly lower compared to baseline levels at day 1 and day 7 (147.09 ± 106.08 pg/mL, p = 0.014; 72.91 ± 50 pg/mL, p = 0.011, respectively).

CONCLUSIONS

In this study, mean serum IMA and VEGF levels were lower following intravitreal bevacizumab injections.

Clinical usefulness of novel serum and imaging biomarkers in risk stratification of patients with stable angina

Inflammatory mediators appear to be the most intriguing yet confusing subject, regarding the management of patients with acute coronary syndromes (ACS). The current inflammatory concept of atherosclerotic coronary artery disease (CAD) led many investigators to concentrate on systemic markers of inflammation, as well as imaging techniques, which may be helpful in risk stratification and prognosis assessment for cardiovascular events. In this review, we try to depict many of the recently studied markers regarding stable angina (SA), their clinical usefulness, and possible future applications in the field.

The protective effect of quercetin on IMA levels and apoptosis in experimental ovarian ischemia-reperfusion injury

OBJECTIVE

To investigate the protective effect of quercetin (QE), an anti-inflammatory and anti-oxidant agent, on torsion-detorsion induced histopathological changes and blood IMA levels in experimental ovarian ischemia-reperfusion (IR) injury.

STUDY DESIGN

Twenty-four female Wistar rats were randomly divided into four groups in this study (n=6). Group I, (sham operation); Group II, torsion-detorsion plus saline (IR); Group III, torsion-detorsion plus solvent (dimethylsulfoxide: DMSO, IR+DMSO); Group IV, torsion-detorsion plus 15 mg/kg/bw quercetin (IR+QE) injected intraperitoneally 30 min prior to detorsion. After 3h of reperfusion, the right ovaries were removed surgically. The ovary tissue samples were fixed in 10% formalin solution for histopathological and immunohistochemical examination. Blood samples were obtained at the end of the procedures for each group of animals.

RESULTS

Ovarian sections in Groups II and III showed higher follicular cell degeneration, hemorrhage, vascular congestion and edema when compared with Group I. Administration of quercetin in rats significantly prevented degenerative changes in the ovary. Significantly less histopathological changes were found in Group IV compared with Groups II and III. Caspase-3 and TUNEL positive cells were detected in the ovarian surface, follicle epithelium, and stromal cells in all experimental groups, and there was a significant increase in Groups II and III compared with Group I (P<0.05). Treatment with quercetin decreased the number of caspase-3 and TUNEL positive cells. IR increased the ischemia modified albumin (IMA) levels in comparison to the sham group (1.06 ± 0.10 ABSU and 0.92 ± 0.08 ABSU, P<0.05). Quercetin administration before IR reduced the levels of IMA (0.93 ± 0.08 ABSU, P<0.05).

CONCLUSION

Administration of quercetin is effective in preventing tissue damage induced by IR injury in ovaries.

Correlation between the severity of coronary artery lesions and levels of estrogen, hs-CRP and MMP-9

The aim of this study was to investigate the correlation between the severity of coronary artery lesions in patients with acute coronary syndromes (ACS) and levels of estrogen, high-sensitivity C-reactive protein (hs-CRP) and matrix metalloproteinase-9 (MMP-9). A total of 65 patients with ACS, 33 patients with stable angina pectoris (SAP) and 36 healthy controls were randomly enrolled. Patients with ACS were subdivided into two groups: Acute myocardial infarction (AMI; n=30) and unstable angina pectoris (UAP; n=35). Serum levels of estrogen, hs-CRP and MMP-9 were detected in the four groups of subjects. Serum estrogen levels in patients with AMI, UAP and SAP were significantly lower than those in the control group (P<0.05). Estrogen levels were also significantly different among the AMI, UAP and SAP groups (P<0.05), with a progressive increase across the three respective groups. Compared with healthy subjects, patients with AMI had the highest levels of hs-CRP and MMP-9, followed in descending order by those with UAP and SAP (P<0.05). Levels of hs-CRP and MMP-9 were also significantly different among the AMI, UAP and SAP groups (P<0.05). Serum estrogen levels were negatively correlated with hs-CRP and MMP-9 levels (r=−0.6634 and −0.6878, respectively; both P<0.05). hs-CRP and MMP-9 levels correlated positively (r=0.7208, P<0.05). The number of stenosed coronary vessels was negatively correlated with estrogen levels (r=−0.6467, P<0.05), and positively correlated with hs-CRP and MMP-9 levels (r=0.6519 and 0.6835, respectively; both P<0.05). In conclusion, serum estrogen, hs-CRP and MMP-9 levels were significantly correlated with the severity of coronary artery lesions. There was also a significant correlation between serum estrogen, hs-CRP and MMP-9 levels. These data indicate that serum estrogen, hs-CRP and MMP-9 have the potential to be used as biomarkers for evaluating the severity of coronary artery lesions and the stability of coronary artery plaques.

Proteomic mapping of proteins released during necrosis and apoptosis from cultured neonatal cardiac myocytes

Cardiac injury induces myocyte apoptosis and necrosis, resulting in the secretion and/or release of intracellular proteins. Currently, myocardial injury can be detected by analysis of a limited number of biomarkers in blood or coronary artery perfusate. However, the complete proteomic signature of protein release from necrotic cardiac myocytes is unknown. Therefore, we undertook a proteomic-based study of proteins released from cultured neonatal rat cardiac myocytes in response to H2O2 (necrosis) or staurosporine (apoptosis) to identify novel specific markers of cardiac myocyte cell death. Necrosis and apoptosis resulted in the identification of 147 and 79 proteins, respectively. Necrosis resulted in a relative increase in the amount of many proteins including the classical necrotic markers lactate dehydrogenase (LDH), high-mobility group B1 (HMGB1), myoglobin, enolase, and 14-3-3 proteins. Additionally, we identified several novel markers of necrosis including HSP90, α-actinin, and Trim72, many of which were elevated over control levels earlier than classical markers of necrotic injury. In contrast, the majority of identified proteins remained at low levels during apoptotic cell death, resulting in no candidate markers for apoptosis being identified. Blotting for a selection of these proteins confirmed their release during necrosis but not apoptosis. We were able to confirm the presence of classical necrotic markers in the extracellular milieu of necrotic myocytes. We also were able to identify novel markers of necrotic cell death with relatively early release profiles compared with classical protein markers of necrosis. These results have implications for the discovery of novel biomarkers of necrotic myocyte injury, especially in the context of ischemia-reperfusion injury.

Clinical significance of ischemia-modified albumin in the diagnosis of doxorubicin-induced myocardial injury in breast cancer patients

Background

Ischemia-modified albumin is an altered serum albumin that forms under conditions of oxidative stress, a state also associated with doxorubicin-induced myocardial injury.

Objective

The aim of this study was to better assess diagnostic and prognostic significance of ischemia-modified albumin in patients with breast cancer undergoing doxorubicin chemotherapy.

Methods

Blood samples were collected from 152 breast cancer patients before and after each cycle of doxorubicin chemotherapy to measure the serum levels of ischemia-modified albumin, cardiac troponin T and creatine kinase-MB. We also monitored cardiac function during a 12 month follow-up.

Results

There was a significant difference in ischemia-modified albumin levels before and after each cycle of chemotherapy and the ischemia-modified albumin concentration positively correlated with the cumulative dose of doxorubicin (r = 0.212, P < 0.05). The combination of ischemia-modified albumin with cardiac troponin T and creatine kinase-MB increased the sensitivity to 0.920 and the specificity to 0.830 in the diagnosis of doxorubicin-induced myocardial injury. The optimal cutoff for ischemia-modified albumin concentration was 112.09 U/ml. The rate of change for ischemia-modified albumin levels correlated negatively with the rate of change for left ventricular ejection fraction at one year (r = –0.221, P < 0.05).

Conclusion

Ischemia-modified albumin may be a clinically potential new marker for diagnosing doxorubicin-induced myocardial injury, and is helpful to predict long-term impairment of cardiac function.

A gold nanoparticles enhanced surface plasmon resonance immunosensor for highly sensitive detection of ischemia-modified albumin

In this study a novel sensitive nanogold particle sensor enhancement based on mixed self-assembled monolayers was explored and used to construct a Surface Plasmon Resonance (SPR) immunosensor to detect Ischemia Modified Albumin (IMA). Compared with a direct binding SPR assay at a limit of detection (LOD) of 100 ng/L, gold nanoparticles (AuNPs) of 10 nm dramatically improved the LOD of IMA to 10 ng/L. Meanwhile, no interfering substance that may lead to false positive results was identified. These results suggested that the SPR biosensor presented superior properties, and provided a simple label-free strategy to increase assay sensitivity for further acute coronary syndrome (ACS) diagnosis.

Serum ischaemia-modified albumin level is an irrelevant predictive factor for ischaemic duration in mesenteric ischaemia

BACKGROUND

Acute mesenteric ischaemia is an emergency condition that requires urgent and expeditious diagnosis and immediate surgical or medical intervention. The initial hours are critical for the recovery of the affected bowel segment. Thus, its clinic diagnostic biomarkers are important when it comes to reducing mortality and morbidity rates.

METHODS

Twenty-four male Sprague-Dawley rats were included in the study. The rats were divided into three equal groups. Those in Group I were sacrificed to determine the basal serum values of ischaemia-modified albumin (IMA) after a simple laparotomy. The superior mesenteric artery (SMA) was clamped in a simple laparotomy in Groups II and III; blood samples were taken at 120 minutes in Group II and 360 minutes in Group III. The serum IMA levels were identified from the blood samples and the results obtained were compared statistically.

RESULTS

The serum IMA levels were determined to be 22±6 (22) μ/L, 34±7 (34) μ/L and 36±4 (37) μ/L in Groups I, II and III, respectively. The differences between the groups were not statistically significant.

CONCLUSION

Our results showed that the serum IMA level is not an appropriate biomarker for acute mesenteric ischaemia. Additionally, the IMA level is not an appropriate biomarker for the detection of ischaemia duration. However, future studies should be conducted to clarify the efficacy of serum IMA levels under different ischaemic conditions.

Metabolomics in the diagnosis of acute myocardial ischemia

Despite recent advances in the diagnosis of myocardial ischemia, its biochemical identification in patients with acute chest pain is still a challenge, and alternative approaches for further improvement are needed. Metabolic alterations are the first consequences of acute myocardial ischemia. Metabolomics coupled with potent multivariate analyses allows for a simultaneous and relative quantification of thousands of different metabolites within a given sample. Thus, this discipline might exert a great impact on medical practice in cardiovascular medicine by providing a wealth of relevant biochemical data. Metabolomics is a promising tool to improve current, single biomarker-based approaches by identifying metabolic biosignatures that embody global biochemical changes in disease. This is especially relevant for conditions requiring early treatment like myocardial ischemia. This review discusses the potential application of metabolomics in the diagnosis of myocardial ischemia.

Effects of acute exercise and xanthine oxidase inhibition on novel cardiovascular biomarkers

Several sports have been associated with a postexercise increase of cardiac, liver, and skeletal muscle biomarkers of injury. Exhaustive or acute physical exercise causes an increased generation of reactive oxygen species, resulting in cellular injury. Thus, exercise and training may trigger pathophysiological changes in serum concentrations of a variety of biomarkers. In this study, we aimed to evaluate the variation of novel biomarkers of stress and cardiovascular disease such as copeptin, midregional part of proadrenomedullin (MR-proADM), growth differentiation factor 15 (GDF15), soluble vascular endothelial growth factor receptor, and placental growth factor along with uric acid before and after acute high-intensity exercise and allopurinol administration. We also assessed whether allopurinol administration may affect the circulating levels of these biomarkers by inhibition of XO activity. This is a double-blind, placebo-controlled study in which 12 professional football players were divided into 2 experimental groups. An oral dose of 300 mg of allopurinol was administered to one group of six participants 4 hours before a match of the Spanish Football League, whereas the other 6 participants received placebo (cellulose). Venous blood samples were obtained before the match (baseline) and twelve hours afterwards (post-match). Serum MR-proADM levels increased significantly in the placebo group, whereas serum GDF15 levels increased significantly in both the placebo and allopurinol group after the match. No differences in the other parameters tested were found after the match in any experimental group. The trend toward postexercise increase of serum MR-proADM and GDF15 levels shows that the metabolism of these proteins is clearly imbalanced after exercise, which thereby represents a potential source of biological variability in their clinical assessment.

Dissection of mechanisms of a chinese medicinal formula: danhong injection therapy for myocardial ischemia/reperfusion injury in vivo and in vitro

Traditional Chinese medicine uses a systemic treatment approach, targeting multiple etiological factors simultaneously. Danhong injection (DHI), a very popular Chinese medicine injection, is reported to be effective for many cardiovascular conditions. The primary active ingredients of DHI, and their systemic and interrelated mechanism have not been evaluated in an established myocardial ischemia/reperfusion (MI/R) model. We identified the main active constituents in DHI, including hydroxysafflor yellow A (A), salvianolic acid B (B), and danshensu (C), by HPLC fingerprint analysis and assessed their effect on MI/R rats and cardiomyocytes. These 3 compounds and DHI all decreased the levels of IL-1, TNF-α, and MDA, increased those of IL-10 and SOD activity in vivo and in vitro, and had antiapoptotic effects, as shown by flow cytometric analysis and TUNEL assay. Moreover, these compounds increased phosphorylation of Akt and ERK1/2 in cardiomyocytes. Interestingly, we found compound A exerted a more prominent anti-inflammatory effect than B and C, by decreasing NF-κB levels; compound B had more powerful antioxidative capacity than A and C, by increasing Nrf2 expression; compound C had stronger antiapoptotic ability than A and B, by lowering caspase-3 activity. Our results elucidate the mechanisms by which DHI protects against MI/R induced injury.

Chest pain with elevated troponin assay in adolescents

OBJECTIVE

We sought to describe the evaluation, treatment, and follow-up of adolescents who presented to a single institution with chest pain and an elevated troponin I value in the absence of typical symptoms of pericarditis or myocarditis. Materials and methods We performed a retrospective review of patients in the age group of 10-18 years of age with no history of significant heart disease admitted to our institution from 2000 to 2010 after presenting with chest pain and an elevated troponin I value.

RESULTS

A total of 16 patients were identified with a median age of 16.5 years (range 11.2-17.8 years). Of these 13 (81%) were male and 10 (63%) showed evidence of localised ST elevations on electrocardiogram. The median peak troponin I level was 17.8 nanograms per millilitre (range 0.89-227, normal less than 0.4). There were eight patients (50%) with a diagnosis of coronary vasospasm, three patients (20%) with atypical myopericarditis, one patient with coronary anomaly, one patient with hypercoagulable disorder, and one patient with prolonged supraventricular tachycardia. In two patients, no definitive diagnosis was made. There was one patient who needed catheter-based intervention, which involved stenting of a coronary artery after a procedure-related complication.

CONCLUSIONS

In our cohort of adolescents without history of significant cardiac disease, chest pain and elevated troponin I levels were attributed to a variety of causes. Although coronary vasospasm and atypical myopericarditis were seen most commonly, coronary anomaly was identified in one case. Magnetic resonance imaging proved a useful diagnostic tool to assess coronary artery anatomy and myocardial changes suggestive of myocarditis. On the basis of these results and a review of the literature, a general evaluation algorithm is presented.

Refining diagnostic microRNA signatures by whole-miRNome kinetic analysis in acute myocardial infarction

BACKGROUND

Alterations in microRNA (miRNA) expression patterns in whole blood may be useful biomarkers of diverse cardiovascular disorders. We previously reported that miRNAs are significantly dysregulated in acute myocardial infarction (AMI) and applied machine-learning techniques to define miRNA subsets with high diagnostic power for AMI diagnosis. However, the kinetics of the time-dependent sensitivity of these novel miRNA biomarkers remained unknown.

METHODS

To characterize temporal changes in the expressed human miRNAs (miRNome), we performed here the first whole-genome miRNA kinetic study in AMI patients. We measured miRNA expression levels at multiple time points (0, 2, 4, 12, 24 h after initial presentation) in patients with acute ST-elevation myocardial infarction by using microfluidic primer extension arrays and quantitative real-time PCR. As a prerequisite, all patients enrolled had to have cardiac troponin T concentrations <50 ng/L on admission as measured with a high-sensitivity assay.

RESULTS

We found a subset of miRNAs to be significantly dysregulated both at initial presentation and during the course of AMI. Additionally, we identified novel miRNAs that are dysregulated early during myocardial infarction, such as miR-1915 and miR-181c*.

CONCLUSIONS

The present proof-of-concept study provides novel insights into the dynamic changes of the human miRNome during AMI.

Cell-free DNA and outcome in sepsis

Severe sepsis can be a catastrophic condition that is often associated with poor outcomes. The early diagnosis and management of the condition are vital in order to improve the chances of survival. However, owing to the syndromal nature of its definition and the lack of a biomarker able to accurately confirm the condition, the diagnosis of sepsis is challenging. Even more challenging is the prediction of how these patients will respond to the therapy and whether they will survive the intensive care and the hospital admission.

Elevated cardiac troponin in the early post-operative period and mortality following ruptured abdominal aortic aneurysm: a retrospective population-based cohort study

Introduction

Cardiac complications are potentially life-threatening following emergency repair of ruptured abdominal aortic aneurysms (rAAA). Our objectives were to describe the incidence, risk factors, cardiac outcomes and mortality associated with elevated cardiac-specific troponin (cTnI) following repair of rAAA. We hypothesized that early post-operative cTnI elevation (>0.15 mcg/L) in rAAA patients would identify a high-risk subgroup for cardiovascular complications and adverse outcomes.

Methods

This was a retrospective population-based cohort study of all referrals for emergency repair of rAAA in central and northern Alberta, from 1 January 2002 to 31 December 2009. Demographic, clinical, physiologic and laboratory data were extracted, along with cardiac-specific investigations and events in the 72 hours following rAAA repair.

Results

In total, 55% of patients (n = 77/141) had elevated cTnI, of which 12% (n = 9) had ST segment elevation, 23% (n = 18) had ST segment depression, 5% (n = 4) had other ECG changes, and 61% (n = 47) had no diagnostic ECG changes. Those with positive cTnI were more likely to have coronary artery disease (45.5% vs. 23.4%, P = 0.01) and higher Acute Physiology and Chronic Health Evaluation (APACHE) II scores (24.9 vs. 21.4, n = 0.016). cTnI positive patients were more likely to receive vasoactive support (58.4% vs. 14.1%, P < 0.001), had longer intensive care unit (ICU) lengths of stay (8 (3 to 11) vs. 4 (2 to 9) days, P = 0.02) and higher adjusted in-hospital mortality (40.3% vs. 14.1%; OR 4.23; 95% CI, 1.47 to 12.1; P = 0.007).

Conclusions

Elevated cTnI early after rAAA repair is an independent predictor for post-operative complications and death.

Biomarkers: hopes and challenges in the path from discovery to clinical practice

Biomarkers are objectively measured indicators of normal or pathological processes that may be helpful in diagnosis, staging, monitoring treatment, or prognostic evaluation of a disease. Although development of genomic, metabolomic and proteomic technologies has contributed to an explosion in identification of candidate analytes, validation remains expensive and challenging, and successful introduction of new biomarkers to clinical practice occurs at a very slow pace. The goal of this introductory overview is to provide the context for a series of review manuscripts published in the special issue on biomarkers. The promises and challenges of biomarker discovery are highlighted. Discovery and implementation of transformative new biomarkers in clinical practice requires close collaborations between scientists, clinicians and industry. High throughput technologies can identify a myriad of promising candidates but cannot predict their clinical value. In addition to rapid effective and systematic approaches for clinical validation, there is a need to study and establish links between the purported biomarker and the pathophysiologic basis of the disease of interest. Biomarkers are most informative when they provide insights into activation of specific pathways, thus serving as windows into the molecular basis of the disease.