Marker For Acute Myocardial Infarction Research Articles

Combination of Platelet expression of PKCepsilon and cardiac troponin-I for early diagnosis of chest pain patients in the emergency department

A rapid differential diagnosis of the clinical conditions underlying chest pain is a relevant clinical issue. Specifically, a fast rule-in or -out of acute myocardial infarction (AMI) is mandatory to improve diagnostic outcome and cost-effectiveness of patient management. We demonstrated that Protein Kinase C (PKC) epsilon is selectively expressed by platelets from AMI patients, accounting for increased platelet activation. Thus, we hypothesized that PKCepsilon-expressing platelets may represent a pathophysiological marker of AMI that could be utilized in combination with troponin-I, the conventional marker of cardiac injury, to add diagnostic information in chest pain workup. In 94 chest pain patients consecutively admitted to Parma University Hospital, we tested the diagnostic performance of flow-cytometric detection of PKCepsilon expressing platelets in discriminating AMI vs. non-AMI conditions. We demonstrated that PKCepsilon-expressing platelets were significantly higher in patients with AMI. Flow cytometry detection of PKCepsilon-expressing platelets showed high sensitivity and specificity (87.5% and 84.4%, respectively) and good diagnostic accuracy (AUC: 0.875). The combination of PKCepsilon expressing platelets and cardiac troponin clearly discriminates patients with 100% and 0% of probability to be affected by AMI. Overall, we highlighted a dual marker strategy potentially useful for a rapid rule-in or -out of myocardial infarction in chest pain patients.

Long-Range Surface Plasmon-Polariton Waveguide Biosensors for Human Cardiac Troponin I Detection.

Straight long-range surface plasmon-polariton (LRSPP) waveguides as biosensors for label-free detection are discussed. The sensors consist of 5-μm-wide 35-nm-thick gold stripes embedded in a low-index optical-grade fluoropolymer (CYTOPTM) with fluidic channels etched to the Au surface of the stripes. This work demonstrates the application of the LRSPP biosensors for the detection of human cardiac troponin I (cTnI) protein. cTnI is a biological marker for acute myocardial infarction (AMI), often referred to as a heart attack, which can be diagnosed by elevated levels of cTnI in patient blood. Direct and sandwich assays were developed and demonstrated over the concentration range from 1 to 1000 ng/mL, yielding detection limits of 430 pg/mL for the direct assay and 28 pg/mL for the sandwich assay (1 standard deviation), the latter being physiologically relevant to the early detection or onset of AMI. In addition, a novel approach for data analysis is proposed, where the analyte response is normalized to the response of the antibody layer.

A novel electrochemiluminescence resonance energy transfer system for simultaneous determination of two acute myocardial infarction markers using versatile gold nanorods as energy acceptors.

A novel electrochemiluminescence resonance energy transfer (ECL-RET) system using versatile gold nanorods as energy acceptors was introduced into the ECL biochemical analysis. A spatial- and potential-resolved platform coupled with the ECL-RET strategy was developed for simultaneous determination of two acute myocardial infarction markers.

Development of cardiac troponin-I biosensor based on boron nitride quantum dots including molecularly imprinted polymer

The cardiac Troponin-I (cTnI) is one of the subunits of cardiac troponin complexes and a pivotal biochemical marker of acute myocardial infarction (AMI). Due to its myocardial specificity, cTnI is widely used for the diagnosis of AMI diseases. In this study, a novel imprinted biosensor approach based on boron nitride quantum dots (BNQDs) was presented for cTnI detection in plasma samples. Various characterization methods such as scanning electron microscope (SEM), transmission electron microscope (TEM), x-ray diffraction (XRD), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used for all characterizations of nanomaterials. After the characterization analysis, cTnI imprinted electrode was developed in the presence of 100.0 mM pyrrole containing 25.0 mM cTnI. After that, the analytical studies of cTnI in plasma samples were performed by using cTnI imprinted biosensor. The results of the study have revealed that 0.01–5.00 ng mL−1 and 0.0005 ng mL−1 were found as the linearity range and the detection limit (LOD). Moreover, the selectivity of cTnI imprinted glassy carbon electrode (GCE) was investigated for plasma sample analysis in the presence of other nonspecific and specific proteins including cardiac myoglobin (MYG), bovine serum albumin (BSA) and cardiac troponin T (cTnT), respectively. Furthermore, the prepared biosensor was examined in terms of stability, repeatability, reproducibility and reusability. Finally, the imprinted biosensor was applied to the plasma samples having high recovery.

Oxidative stress markers in acute myocardial infarction treated by primary percutaneous coronary intervention

Oxidative stress markers in acute myocardial infarction treated by primary percutaneous coronary intervention

DIFFERENTIAL CELL COUNT AS DIAGNOSTIC AND PROGNOSTIC MARKER OF ACUTE MYOCARDIAL INFARCTION

Myocardial infarction is a necrosis of myocardial cells due to lack of blood and oxygen supply caused by obstruction of coronary arteries, mostly due to atherosclerosis processes. Increased inflammatory marker level is associated with poor cardiovascular prognosis. This study was aimed to know whether leukocytes count, differential cell count and the Ratio of Neutrophils-Lymphocytes (RNL) could distinguish between types of Acute Myocardial Infarction (AMI) and to evaluate its correlation with mortality. This was a cross-sectional retrospective study using medical records patients which were diagnosed as AMI by clinicians in Cardiac Centre of the Dr. Wahidin Sudirohusodo Hospital during the period of April 1st, 2015 - May 31st, 2016. Statistical analysis used the Mann-Whitney and Chi-Square test, p<0.05 was considered as significant. The total subjects were 435 patients divided into 289 ST- Elevation Myocardial Infarction (STEMI) and 146 Non-ST-Elevation Myocardial Infarction (NSTEMI). There were significant differences in that mean of leukocytes, neutrophils, lymphocytes, monocytes, eosinophils counts and RNL between STEMI and NSTEMI (p <0.05). Significant differences were also found in leukocyte, neutrophils, lymphocytes, eosinophils, basophils and RNL mean between those who died and survived (p <0.05) and a significant correlation between increased leukocytes, neutrophils, basophils counts with mortality (p <0.05). In conclusion, the number of leukocytes and leukocyte count can be used as diagnostic markers of AMI between STEMI and NSTEMI, as well as prognostic markers among patients who died and survived. Routine blood sampling cohort studies in patients with AMI can avoid the bias of the results obtained.

The role of cardiac markers in acute myocardial infarction and unstable angina pectoris discrimination in patients with coronary intensive care unit

Amac : Kardiyak belirtecler; kardiyak ve nonkardiyak hastalarin dogru triajinda fizik muayene bulgulari, Elektrokardiyografi (EKG) ve Ekokardiyografi (ECHO)’ya ek olarak ​​onemini korumaktadir. Bu calismada, koroner yogun bakim unitesindeki Akut Miyokard Infarktusu (AMI) ve Anstabil Angina Pektoris (ASAP) olan hastalarin kardiyak troponin ve Kreatin Kinaz MB (CKMB) test sonuclarini ve klinik verilerini degerlendirerek kabul edilebilir bir strateji gelistirmeyi amacladik. Gerec ve Yontem: Koroner yogun bakim unitesinde yatan 208 hastanin (yas:61±12) klinik ve laboratuvar verileri retrospektif olarak incelendi. Hastalar tanilarina gore uc gruba ayrildi. Grup 1, AMI olan 132 hastadan olustu; Grup 2, AMI olmayan ASAP'li 28 hastadan olustu; Grup 3, nonkardiyak hastaligi olan 48 hastadan (kronik kalp yetmezligi, bobrek yetmezligi, sepsis, vb.) olustu. CKMB seviyeleri Dimension Xpand Plus (Dade Behring Inc, Newark, ABD) marka biyokimya otoanalizorunde immunoinhibisyon yontemiyle olculdu. CTnT (Kardiyak Troponin T) olcumu icin Cardiac T Quantitative Rapid Assay (Roche Diagnostics GmbH, Mannheim, Almanya) hasta basi cihazi kullanildi. Bulgular: Gruplari degerlendirmede biyolojik belirtecler CKMB ve cTnT icin ROC analizi yapildi. AMI grubu icin; CKMB'nin Egri Altindaki Alan (EAA):0.724 (SE=0.041, p<0.001), cTnT'nin EAA:0.741 (SE=0.038, p<0.001); ASAP grubu icin; CKMB'nin EAA:0.536 (SE=0.067, p=0.601), cTnT'nin EAA:0.637 (SE=0.067, p=0.047) olarak tespit edildi. Sonuc: ROC analizi sonuclari ve EAA degerlendirmeleri AMI ve ASAP hastalarinin ayriminda kardiyak belirtecler CKMB ve cTnT’nin tanisal gucunu ortaya koydu. Bu kardiyak belirteclerin birlikte kullanilmasi tanisal gucu artirmaktadir. Nonkardiyak hasta gruplari icin buyuk orneklemli calismalarda ROC analizi faydali olabilir.

Sodium levels during hospitalization with acute myocardial infarction are markers of in-hospital mortality: Soroka acute myocardial infarction II (SAMI-II) project.

Abnormalities in sodium homeostasis are common in hospitalized patients. Hyponatremia upon admission is a poor prognostic marker in acute myocardial infarction (AMI) patients. However, little is known about the association between changes in sodium levels and in-hospital mortality. We delineated changes in sodium levels and studied the association of such changes with in-hospital mortality of AMI patients. Retrospective analysis of AMI patients hospitalized for > 6days. Sodium levels throughout the 6-day post-admission were divided into five equally sized groups (quintiles = Q) and thereafter categorized as follows: Q1 (< 135mEq/L), Q2-Q4 (135-140mEq/L, reference group), and Q5 (≥141mEq/L). in-hospital mortality. A total of 8306 patients (10,416 admissions) were included (mean age 67.8±14.0years, 33.4% women, 45.5% STEMI). In-hospital mortality was 6.6%. Q1 and Q5 upon admission were both related to higher risk for in-hospital mortality, compared with the reference group (OR 1.47 and OR 1.33, respectively, p < 0.001 each). Q1 was more frequent in non-survivors throughout the entire study period, while the prevalence of Q5 levels was similar in survivors and non-survivors upon admission carrying increasing mortality risk thereafter: for Q1 consistent OR 1.50, while for Q5 it, increased from OR 1.32 upon admission to OR 1.90 on the sixth day, p < 0.001. Low and high sodium levels are associated with increased risk for in-hospital mortality in patients with AMI. The risk is unchanged for hyponatremia, while it consistently increases for increased sodium levels.

Role of serum MicroRNA-499 as a diagnostic marker in acute myocardial infarction (AMI)

Acute myocardial infraction is one of the leading causes of morbidity and mortality in developing countries such as India and even worldwide. Its etiology is complicated because of several confounding factors involved in its pathogenesis. Recently, MicroRNA has been recognized to play an important role in predicting the diagnosis and prognosis of myocardial infarction. MiR-499 plays a pivotal role in the recovery of cardiac cell, following injury. Since several studies have profiled several miRs in cardiovascular diseases and of which miR-499 is mainly expressed in the myocardium. Our study is primarily designed to explore the diagnostic role of miR-499 in AMI. The study included 60 AMI patients aged 30–60 years and an equal number of age and gender matched controls. All cases were taken from Mahatma Gandhi Medical College and Research Institute a tertiary healthcare setup and analyzed for miR-499 by RT-PCR, lipid profile, CK (NAC), CK-MB and high sensitivity cardiac Troponin T were analyzed by IFCC approved methods. Unpaired Student's test was performed to compare the mean of the cases with the controls. Pearson correlation was used to study the association of miR with conventional markers. Receiver Operating Characteristic curve was plotted to find out the sensitivity and specificity of miR-499 in AMI. Our study showed significantly high levels of miR499 in AMI patients in comparison to the healthy controls (p=0.012). MiR-499 levels positively correlated with hs-cnTn T (r=0.582, p<0.01) and CK-MB (r=0.443, p<0.01). ROC for miR-499 showed an AUC 0.974 with 93.33% sensitivity and 86.67% specificity which was comparatively higher than the current markers CK-MB (86.67% and 71.67) and hs-cnTn T (90.00% and 81.56%). When these biomarkers analyzed for combined sensitivity increases but the specificity decreases. The results showed that miR-499 has a significant correlation and also had higher sensitivity and specificity when compared to other conventional markers and thus it could serve as a better early diagnostic marker of AMI.

Single Drop Whole Blood Diagnostics: Portable Biomedical Sensor for Cardiac Troponin I Detection

Detection of disease biomarkers from whole blood is very important in disease prevention and management. However, new generation assays like point-of-care or mobile diagnostics face a myriad of challenges in detecting proteins from whole blood. In this research, we have designed, fabricated, and characterized a portable biomedical sensor for the detection of cardiac troponin I (cTnI) directly from whole blood, without sample pretreatments. The sensing methodology is based on an extended gate electrical double layer (EDL) gated field effect transistor (FET) biosensor that can offer very high sensitivity, a wide dynamic range, and high selectivity to target analyte. The sensing methodology is not impeded by electrostatic screening and can be applied to all types of FET sensors. A portable biomedical system is designed to carry out the diagnostic assay in a very simple and rapid manner, that allows the user to screen for target protein from a single drop of blood, in 5 min. This biomedical sensor can be used in hospitals and homes alike, for early detection of cTnI which is a clinical marker for acute myocardial infarction. This sensing methodology could potentially revolutionize the modern health care industry.

Neutrophil-Lymphocyte Ratio as a Prognostic Marker in Acute Myocardial Infarction

Neutrophil-Lymphocyte Ratio as a Prognostic Marker in Acute Myocardial Infarction

Alteration of metabolic genes in peripheral blood isolated from patients with acute myocardial infarction

Accumulating evidence suggests that molecular alterations of peripheral leucocytes are possible diagnostic markers of acute myocardial infarction (AMI). Changed lipid/glucose metabolism is a prominent feature of the pathogenesis of AMI. Silent mating type information regulation 2 homolog 1 (SIRT1) and peroxisome proliferator-activated receptor gamma coactivator factor-α (PGC-1α) regulate mitochondrial function and energy metabolism. Thus, the gene expression of SIRT1 and PGC-1α in peripheral leucocytes isolated from AMI patients and their association with dyslipidemia have been evaluated. Fifty-five male subjects were divided into 40 patients with AMI and 15 healthy control subjects. Peripheral blood samples were obtained on the first day of AMI. Lipid profile parameters were assessed spectrophotometrically. Relative SIRT1 and PGC-1α expression were measured by real-time PCR. Compared with the control group, SIRT1 and PGC-1α expression were significantly decreased in the AMI group. SIRT1 expression was significantly negatively correlated with the age of the participants. SIRT1 expression was significantly positively correlated with PGC-1α expression. Both SIRT1 and PGC-1α expression were negatively correlated with markers of dyslipidemia. In conclusion, SIRT1 and PGC-1α expression are reduced in the acute phase of AMI, which addresses their possible role as potential biomarkers for AMI.

Association of MIR-499a expression and seed region variant (rs3746444) with cardiovascular disease in Egyptian patients

Background: Circulating microRNAs could be powerful markers of acute myocardial infarction (MI) and its functional genetic variants could increase susceptibility to cardiovascular disease (CVD). The current study aimed to quantify the microRNA (miR)-499a levels in serum of MI patients compared to hypertensive and healthy subjects and to investigate the association of its A/G variant rs3746444 with CVD in a sample of an Egyptian population.Methods: Serum miR-499a relative expressions were measured in 110 acute MI patients, 76 hypertensive patients, and 121 healthy controls by Real-time quantitative polymerase chain reaction. MIR-499a genotyping was performed for an additional 107 coronary artery disease patients by Real-time allele discrimination assay.Results: Acute MI patients showed high relative expression of miR-499a (> 105-fold, p < .001), and it was nearly undetectable in healthy controls and hypertensive patients. It showed an area under the curve of 0.953, with a sensitivity of 97.2% and a specificity of 75.0%. ST-elevation MI (STEMI) patients had higher miR-499a serum levels than patients with Non-STEMI. There was a significant association of MIR-499a variant with acute MI but not with hypertension under all genetic models tested. As a new finding, in overall and stratified analysis, the miR-499a variant was not correlated with its expression profile.Conclusions: Circulating miR-499a levels could be a useful biomarker, discriminating acute MI within 12 hours from healthy subjects. Its variant rs3746444 A/G is associated with increased susceptibility to acute MI and CAD in Egyptian population.

Correlation and prognostic role of neutrophil to lymphocyte ratio and SYNTAX score in patients with acute myocardial infarction treated with percutaneous coronary intervention: A six-year experience.

The neutrophil/lymphocyte ratio (NLR) has been proposed as a prognostic marker in acute myocardial infarction (AMI). The aim of our study is to demonstrates the correlation between SYNTAX score (SXs) and NLR and its association with 1-year cardiovascular (CV) mortality in patients with ST-segment elevation myocardial infarction (STEMI) or non-ST-segment elevation myocardial infarction (NSTEMI) treated with percutaneous coronary intervention (PCI). Over 6 consecutive years, (1st January 2010 and 1st January 2016) 6560 patients (4841 males and 1719 females, mean age 64.36±11.77years) were admitted for AMI and treated with PCI within 24-h. The study population was divided into tertiles based on the SXs. Both in STEMI and NSTEMI groups, neutrophils and the SXs were significantly higher (p<0.0001) in upper versus lower among NLR tertiles and a significant correlation was found between the NLR and SXs (r=0.617, p<0.0001 and r=0.252, p<0.0001 for STEMI and NSTEMI groups, respectively). One-year CV mortality significantly raised up among the NLR tertiles in both STEMI and NSTEMI patients (p<0.0001). Multivariate analysis revealed that, after adjusting SXs and PAD, an NLR (≥3.9 and ≥2.7 for STEMI and NTEMI patients, respectively) was an independent significant predictor of 1-year CV mortality (OR 2.85, 95% CI 1.54-5.26, p=0.001 and OR 2.57, 95% CI 1.62-4.07, p<0.0001 for STEMI and NSTEMI respectively.) CONCLUSIONS: NLR significantly correlates with SXs and is associated with 1-year CV mortality in patients with STEMI or NSTEMI treated with PCI within 24-h.

Serum Uric Acid Levels As an Independent Short Term Prognostic Marker in Acute Myocardial Infarction

Serum Uric Acid Levels As an Independent Short Term Prognostic Marker in Acute Myocardial Infarction

Polymer matrices with molecular memory as affine adsorbents for the determination of myoglobin as a cardiac marker of acute myocardial infarction by voltammetry

A possibility of myoglobin determination using screen-printed graphite electrodes modified with a poly(o-phenylenediamine)-based molecularly imprinted polymer (MIP) obtained by the electropolymerization of o-phenylenediamine monomer molecules on the surface of a screen-printed graphite electrode in the presence of myoglobin template molecules is considered. It is shown that the conjugation of MIP with multiwall carbon nanotubes (MWCNT) results in an increase in the sensitivity of the MIP-biosensor in the electrochemical determination of myoglobin by the direct registration of the reduction peak of hemoprotein Fe3+ by square wave voltammetry on screen-printed graphite electrodes modified with MWCNT/MIP and MIP. Equilibrium dissociation constants K d for the interaction of myoglobin with MWCNT/MIP- and MIP-electrodes, which equaled (9.8 ± 2.6) × 10–11 and (2.4 ± 0.5) × 10–8 M, respectively, are calculated. It is shown that the sensitivity of the electrochemical MWCNT/MIP-biosensor for myoglobin determination (1.5 × 10–2 A/nmol of myoglobin) is higher than that of the MIP-biosensor (2.0 × 10–4 A/nmol of myoglobin).

Endothelin-1 and nitric oxide in 3-year prognosis after acute myocardial infarction

Background/Aim. Acute myocardial infarction (AMI) is an important cause of mortality/morbidity worldwide. Biomarkers improve diagnostic and prognostic accuracy in AMI. The aim of this study was to investigate an increase of markers of endothelial dysfunction in AMI, measured on the 3rd day after the initial event and to investigate their association with short- and long-term (3-year) prognosis (outcome). Methods. The prospective study included 108 patients with AMI in the experimental group and 50 apparently healthy subjects in the control group. Endothelin-1 (ET-1) and nitric oxide degradation products (NOx) were determined. Results. The average age of the participants in the experimental group was 62 ? 10 years and 59 ? 9 years in the control group; 74.1% of the patients in experimental group were males and 68.8% in the control group. In 74.1% of the patients, ST-elevation myocardial infarction (STEMI) was diagnosed, and 25.9% of the patients presented with non-ST-elevation myocardial infarction (NSTEMI). Thirteen (5.6%) patients died during 3 years and they had significantly higher ET-1 levels compared to survivors [4.02 (2.72?5.93) vs 3.06 (2.23?3.58) pg/mL; p = 0.015]. Endothelin- 1 in 46 (42.6%) patients with composite endpoint (3- year mortality and rehospitalization) was significantly increased compared to other patients [3.14 (2.54?4.41) vs 3.05 (2.18?3.56) pg/mL; p = 0.035]. Intrahospital complications were found in 41 (48%) patients. Participants with echocardiographically detected complications (ventricular dyskinesia, left ventricular thrombus and papillary muscle rupture) had higher ET-1 levels compared to other patients [4.02 (2.78?5.57) vs 3.06 (2.29?3.66) pg/mL; p = 0.012]. Endothelin- 1 concentration above the 75th percentile (&gt; 3.77 pg/mL) was associated with the increased risk for composite endpoint [Log Rank (?2 = 13.44; p &lt; 0.001)]. Patients who were rehospitalized had significantly lower NOx concentration [125.5 (111.4?143.6) vs 139.3 (116.79?165.2) ?mol/L; p = 0.04]. Endothelin-1 positively correlated with high sensitivity troponin I (hsTnI), brain natriuretic peptide (BNP) and a number of leukocytes. Conclusion. Endothelin- 1 and NOx were increased on the 3rd day after AMI, and they were predictors of worse short- and long-term (3- year) prognosis (outcome). Endothelin-1 positively correlated with conventional prognostic markers in AMI.

Indicators of Quality in the pre-Analytical Phase for Determining Cardiac Markers in Acute Myocardial infarction—CK, CKMB and TnT

Indicators of Quality in the pre-Analytical Phase for Determining Cardiac Markers in Acute Myocardial infarction—CK, CKMB and TnT

A Study of Serum Uric acid levels as a Prognostic Marker in Acute Myocardial Infarction

The aim was to evaluate any significant correlation between elevated serum uric acid levels and prognosis of patients with acute myocardial infarction primarily short term mortality. Methods- In this tertiary centre based prospective study 100 new cases of acute MI were divided into various subcategories using Killip classification .Serum uric acid levels were measured on day 0, 3 and 7.Serum uric acid and Killip class were compared on day 0,3 and 7 to assess the prognosis. Results: Majority of the patients were in the age group of 51-60 years, who accounted for 37 cases i.e. 37% of total cases. In our study out of 100 patients 70 (70%) patients were males whereas 30 (30%) were female patients. Majority of patients (45%) had BMI in the range of 30-34.9 kg/cm 2 .49% patients were diabetics with 33 males and 16 females, and 41% were hypertensive with 27 males and 14 females. History of smoking was present in 59% patients . Previous history of stroke was observed in 6% patients with 4 males and 2 females. Mean uric acid level in patients on day 0 belonging to Killip class I was 4.4 mg/dl compared to 7.01 in Killip class II ,8.29 in Killip class III and 9.87 in Killip class IV. Mean serum uric acid levels on day 7 in patients with Killip class I is 4.67 and those with Killip class II is 6.62 mg/dl.Of the 100 patients, six expired during hospital stay and all 6 belonged to higher Killip class with serum uric acid levels in the highest quartile. Conclusion- Hyperuricemia is an indicator of poor prognosis in acute MI. Serum uric acid can be used as a marker of short term mortality in acute myocardial infarction.

Dityrosine as a marker of acute myocardial infarction? Experiments with the isolated Langendorff heart.

The isolated Langendorff heart was used to evaluate dityrosine as a marker of acute myocardial infarctions. The animal model allowed the generation of local infarctions with defined survival times, as well as infarctions with and without reperfusion. The results showed that dityrosine, at least under the conditions of the animal model, occurs very shortly after early ischemia and infarctions, since positive staining results were already obtained after a survival time of only 5min. Furthermore, it could be proved that the occurrence of dityrosine does not depend on a reperfusion of the ischemic muscle area and that there are no differences in the staining patterns of infarctions with and without reperfusion. Positive staining results for dityrosine in control hearts without infarctions had to be considered when evaluating the tissue samples of the study hearts. In part, the positive staining results of the control hearts seemed to be an artefact of the Langendorff system, easily identifiable by a distinctive staining pattern. Positive staining results in tissue samples of hearts that suffered from arrhythmia on the other hand implied that the occurrence of dityrosine is not specific for myocardial infarctions. Taking into account the results of previous works on human tissue samples, however, these findings did not question the use of dityrosine as a diagnostic tool; they simply showed that myocardial damage due to oxidative stress might occur under various pathologic conditions.