Combinatorial Determination of Ischemia Modified Albumin and Protein Carbonyl in the Diagnosis of NonST-Elevation Myocardial Infarction

The clinical significance of ischaemia-modified albumin in acute coronary syndrome and hypertension

BACKGROUND

Early diagnosis of acute coronary syndrome is more and more important because of its mortality and morbidity. Hypertension is one of the pathogenesis of acute coronary syndrome, which often leads to stenosis and ischaemia. Ischaemia-modified albumin is sensitive for the occurrence of ischaemia, which attracted us in the significance of ischaemia-modified albumin in patients with chest pain, especially patients complicated with hypertension.

METHODS

In total, 200 patients with acute chest pain were included in the study. According to the diagnostic criteria, patients were divided into acute coronary syndrome group and non-ischaemic chest pain group. Cardiac biomarkers were measured with 30 minutes in emergency department, including cardiac troponin T, creatine kinase MB, and ischaemia-modified albumin. Receiver operating characteristic curve (ROC) analysis was used for the sensitivity and specificity of ischaemia-modified albumin in the early diagnosis of acute coronary syndrome. Comparisons between ischaemia-modified albumin and cardiac Troponin T were done between groups.

RESULTS

The demographics in two groups were not significantly different in most aspects. Compared with non-ischaemic chest pain group, serum levels of ischaemia-modified albumin and cardiac Troponin T were significantly higher in acute coronary syndrome group. ROC analysis showed that ischaemia-modified albumin had a good sensitivity and specificity in early diagnosis of acute coronary syndrome. The level of ischaemia-modified albumin in acute coronary syndrome patients with hypertension was higher than that in non-ischaemic chest pain patients.

CONCLUSIONS

In patients complained with acute chest pain, the serum measurement of ischaemia-modified albumin is potential valuable for the early diagnosis of acute coronary syndrome, especially combined with ECG. The serum level of ischaemia-modified albumin in acute coronary syndrome patients is significantly associated with hypertension.

Adeno-associated virus 9 vector-mediated cardiac-selective expression of human secretory leukocyte protease inhibitor attenuates myocardial ischemia/reperfusion injury

Protease enzymes contribute to the initiation of cardiac remodeling and heart failure after myocardial ischemic/reperfusion (I/R) injury. Protease inhibitors attenuate protease activity and limit left ventricular dysfunction and remodeling. Previous studies showed the cardioprotective effect of secretory leukocyte protease inhibitor (SLPI) against I/R injury. However, overexpression of SLPI gene in cardiovascular diseases has only been investigated in an in vitro experiment. Here, cardiac-selective expression of the human secretory leukocyte protease inhibitor (hSLPI) gene and its effect on I/R injury were investigated. Adeno-associated virus (AAV) serotype 9 carrying hSLPI under the control of cardiac-selective expression promoter (cardiac troponin, cTn) was intravenously administered to Sprague–Dawley rats for 4 weeks prior to coronary artery ligation. The results showed that myocardial-selective expression of hSLPI significantly reduced infarct size, cardiac troponin I (cTnI), creatine kinase-MB (CK-MB), and myoglobin levels that all served to improve cardiac function. Moreover, overexpression of hSLPI showed a reduction in inflammatory cytokines, oxidatively modified protein carbonyl (PC) content, ischemia-modified albumin (IMA), and necrosis and cardiac tissue degeneration. In conclusion, this is the first study to demonstrate cardiac-selective gene delivery of hSLPI providing cardioprotection against myocardial I/R injury in an in vivo model.

Ischemia-Modified Albumin: Origins and Clinical Implications

Albumin is one of the most abundant proteins in the body of mammals: about 40% of its pool is located in the intravascular space and the remainder is found in the interstitial space. The content of this multifunctional protein in blood is about 60-65% of total plasma proteins. A decrease in its synthesis or changes of functional activity can destabilize oncotic blood pressure, cause a violation of transporting hormones, fatty acids, metals, and drugs. Albumin properties change under ischemic attacks associated with oxidative stress, production of reactive oxygen species, and acidosis. Under these conditions, ischemia-modified albumin (IMA) is generated that has a reduced metal-binding capacity, especially for transition metals, such as copper, nickel, and cobalt. The method of determining the cobalt-binding capability of HSA was initially proposed to evaluate IMA level and then licensed as an ACB test for routine clinical analysis for myocardial ischemia. Subsequent studies have shown the viability of the ACB test in diagnosing other diseases associated with the development of oxidative stress. This review examines recent data on IMA generation mechanisms, describes principles, advantages, and limitations of methods for evaluation of IMA levels, and provides detailed analysis of its use in diagnostic and monitoring therapeutic efficacy in different diseases.

Post-Ischemic Treatment of Recombinant Human Secretory Leukocyte Protease Inhibitor (rhSLPI) Reduced Myocardial Ischemia/Reperfusion Injury

Myocardial ischemia/reperfusion (I/R) injury is a major cause of mortality and morbidity worldwide. Among factors contributing to I/R injury, proteolytic enzymes could also cause cellular injury, expand the injured area and induce inflammation, which then lead to cardiac dysfunction. Therefore, protease inhibition seems to provide therapeutic benefits. Previous studies showed the cardioprotective effect of secretory leukocyte protease inhibitor (SLPI) against myocardial I/R injury. However, the effect of a post-ischemic treatment with SLPI in an in vivo I/R model has never been investigated. In the present study, recombinant human (rh) SLPI (rhSLPI) was systemically injected during coronary artery occlusion or at the onset of reperfusion. The results show that post-ischemic treatment with rhSLPI could significantly reduce infarct size, Lactate Dehydrogenase (LDH) and Creatine kinase-MB (CK-MB) activity, inflammatory cytokines and protein carbonyl levels, as well as improving cardiac function. The cardioprotective effect of rhSLPI is associated with the attenuation of p38 MAPK phosphorylation, Bax, caspase-3 and -8 protein levels and enhancement of pro-survival kinase Akt and ERK1/2 phosphorylation. In summary, this is the first report showing the cardioprotective effects against myocardial I/R injury of post-ischemic treatments with rhSLPI in vivo. Thus, these results suggest that SLPI could be used as a novel therapeutic strategy to reduce myocardial I/R injury.

Pineapple consumption reduced cardiac oxidative stress and inflammation in high cholesterol diet-fed rats

BACKGROUND

Hypercholesterolemia is a major risk factor for cardiovascular disease. It has been reported that pineapple contains healthy nutrients and phytochemicals associated with antioxidant and anti-inflammatory capacities. No investigation exists concerning the effect of pineapple consumption modulating hypercholesterolemia-induced cardiac damage in high-cholesterol diet (HCD)-fed rats. This study evaluated the effect of pineapple consumption on lipid-lowering, cardiac oxidative stress and inflammation in HCD-fed rats.

METHODS

Male Sprague-Dawley rats were fed with HCD, in the presence and absence of Pineapple (Ananas comosus L.) cv. Pattavia powder for 8 weeks. Then, serum lipid profiles, liver and renal function tests, cardiac oxidative stress and pro-inflammatory cytokines were determined.

RESULTS

Daily pineapple consumption reduced weight gain, serum lipid profiles, atherogenic coefficient (AC), cardiac risk ratio (CRR), and liver enzyme activity, without causing renal dysfunction. Pineapple consumption also restores cardiac protein carbonyl (cPC) content, reduces cardiac malondialdehyde (MDA), cardiac pro-inflammation cytokine IL-6 and IL-1β levels.

CONCLUSION

Pineapple possesses antioxidant and lipid-lowering properties and daily consumption alleviates hypercholesterolemia-induced cardiac lipid peroxidation and pro-inflammation elevation in an in vivo model. This study demonstrates that pineapple is a potential candidate for cardioprotection against hypercholesterolemia.

Correlation IMA with TIMI frame count in slow coronary flow: can it be a guide for treatment?

AIM

Coronary slow flow (CSF) is defined as late opacification in epicardial coronary arteries with no significant stenosis. The aim of this study is to evaluate the relationship between ischemia-modified albumin (IMA) by using Spectrophotometer in CSF.

METHODS

Level of IMA was measured by spectrophotometer. CSF patients were chosen for the determination of IMA level. All obtained data were compared with control groups.

RESULTS

Serum IMA levels increased in the CSF group. It was observed that there was a significant increase in IMA levels in patients with CSF when compared to controls (p < 0.05).

CONCLUSION

IMA may play a role in the pathogenesis of CSF. IMA levels in the serum can be considered as a marker to predict coronary slow flow. IMA level can be used as a guide for coronary slow flow. Also, as increases number square frame, value IMA Increases similarly. It was found that the severity of impotence was correlated with CSF. Therefore, the IMA level may be predictive of the course of treatment. This study is the first one to show the relationships of IMA in CSF. In addition, further studies should be performed on IMA in CSF patients.

p38 MAPK Inhibitor (SB203580) and Metformin Reduces Aortic Protein Carbonyl and Inflammation in Non-obese Type 2 Diabetic Rats

Microvascular and macrovascular diseases are the main causes of morbidity in type 2 diabetes patients through chronic hyperglycaemic condition via oxidative stress and inflammation. Reactive oxygen species (ROS) activate p38 MAPK phosphorylation and inflammation which enhances protein modification by carbonylation. The use of metformin and a p38 MAPK inhibitor is hypothesised to reduce ROS production and inflammation but effects of metformin and p38 MAPK inhibitor (SB203580) on ROS production and inflammation in vascular type 2 diabetes mellitus non-obese (T2DM) have not been investigated. The Goto-Kakizaki rat T2DM model was divided into three groups as T2DM, T2DM treated with 15 mg/kg bw metformin and T2DM treated with 2 mg/kg bw SB203580 for 4 weeks. Rat aortas were isolated and protein carbonyl (PC) contents were measured by spectrophotometric DNPH assay. Aortic IL-1ß level was determined by ELISA. Results showed that aortic PC contents in the T2DM group were significantly higher than in non-diabetic rats. Treatment with metformin or SB203580 significantly reduced PC contents while only metformin significantly reduced IL-1ß levels. Findings indicated that metformin reduced ROS production and inflammation in diabetic vessels and possibly reduce vascular complications in non-obese T2DM.

Characterization of advanced glycation end products and their receptor (RAGE) in an animal model of myocardial infarction

Circulating advanced glycation end products (AGE) and their receptor, RAGE, are increased after a myocardial infarction (MI) episode and seem to be associated with worse prognosis in patients. Despite the increasing importance of these molecules in the course of cardiac diseases, they have never been characterized in an animal model of MI. Thus, the aim of this study was to characterize AGE formation and RAGE expression in plasma and cardiac tissue during cardiac remodeling after MI in rats. Adult male Wistar rats were randomized to receive sham surgery (n = 15) or MI induction (n = 14) by left anterior descending coronary artery ligation. The MI group was stratified into two subgroups based on postoperative left ventricular ejection fraction: low (MIlowEF) and intermediate (MIintermEF). Echocardiography findings and plasma levels of AGEs, protein carbonyl, and free amines were assessed at baseline and 2, 30, and 120 days postoperatively. At the end of follow-up, the heart was harvested for AGE and RAGE evaluation. No differences were observed in AGE formation in plasma, except for a decrease in absorbance in MIlowEF at the end of follow-up. A decrease in yellowish-brown AGEs in heart homogenate was found, which was confirmed by immunodetection of N-ε-carboxymethyl-lysine. No differences could be seen in plasma RAGE levels among the groups, despite an increase in MI groups over the time. However, MI animals presented an increase of 50% in heart RAGE at the end of the follow-up. Despite the inflammatory and oxidative profile of experimental MI in rats, there was no increase in plasma AGE or RAGE levels. However, AGE levels in cardiac tissue declined. Thus, we suggest that the rat MI model should be employed with caution when studying the AGE-RAGE signaling axis or anti-AGE drugs for not reflecting previous clinical findings.

Role of "Ischemia Modified Albumin" (IMA) in acute coronary syndromes

BACKGROUND

Diagnosis of acute coronary syndrome (ACS) is important, due to the associated very high mortality. Failure to diagnose ACS is a problem both for the patients and the clinicians. Ischemia modified albumin (IMA) has already been licensed by the US Food and Drug Administration for the diagnosis of suspected myocardial ischemia.

METHODS

Patients attending the emergency department (ED) within 6 h after having features of ACS were selected. IMA was done on admission. Blinded to the IMA results patients were fully evaluated and a diagnosis of non-ischemic chest pain (NICP), unstable angina (UA) or myocardial infarction (MI) was made. Later IMA results were correlated in each group.

RESULTS

Mean IMA value was 56.38 ± 23.89 u/ml in NICP group whereas in UA group it was 89.00 ± 7.76 u/ml and MI group was 87.50 ± 9.62 u/ml. This showed a sensitivity of 92% and specificity of 87%. The positive predictive value of the test was 88% and negative predictive value was 94%. In 16 patients an early diagnosis could be made when compared with Trop-T. Of the 89 patients 11 patients died in hospital. The IMA value was compared between this group and the patients who survived. Patients who died had a mean IMA value of 88.5 with a standard deviation of 5.33 whereas in patients who survived the mean value was 78.26 which was not statistically significant.

CONCLUSION

In conclusion the benefit of the test would be to rule out ACS in patients who present early to ED with inconclusive diagnosis.

Predictive value of the novel risk score BETTER (BiomarkErs and compuTed Tomography scorE on Risk stratification) for patients with unstable angina

BACKGROUND

The Braunwald classification and TIMI (Thrombolysis In Myocardial Infarction) risk score are used to stratify cardiovascular risk in patients with unstable angina (UA). However, these scores have a limited capacity in the practice of cardiology.

OBJECTIVES

This study sought to develop a new score, based on blood biomarkers and coronary computed tomographic angiography (CCTA) characteristics, for patients with UA.

PATIENTS AND METHODS

The study group consisted of 201 patients with confirmed UA. Follow-up time was 1 year; major adverse cardiac events (MACEs) included cardiovascular death, recurrent acute coronary syndrome (ACS), and re-admission to hospital. Blood biomarkers including high-sensitivity cardiac troponin T (Hs-cTnT), high-sensitivity C-reactive protein (Hs-CRP), myeloperoxidase (MPO) N-terminal pro-B-type natriuretic peptide (NT-proBNP), and ischemia-modified albumin (IMA) were measured. CCTA characteristics such as stenosis, plaque, epicardial fat volume (EFV), and calcification were evaluated. After analysis of relationships, the novel risk BETTER (BiomarkErs and compuTed Tomography scorE on Risk stratification) score was assessed in 201 patients.

RESULTS

In all, 25 MACEs (12.44 %) occurred: 2 cardiac deaths (1.00 %), 13 non-fatal myocardial infarctions (6.47 %), 10 recurrent ACS and re-admission in hospital (4.96 %). Serum levels of MPO, NT-proBNP, Hs-TnT, Hs-CRP, and IMA were correlated with MACEs (r = 0.20, r = 0.40, r = 0.18, r = 0.24, p < 0.01, respectively; r = 0.12, p > 0.05). CCTA characteristics of stenosis, plaque, EFV, and calcification were significantly correlated with MACEs (r = 0.53, r = 0.57, r = 0.42, and r = 0.52, all p < 0.01 respectively) and were significantly higher in the MACEs group than in the non-MACEs group. Thus, a new risk score was created combining biomarkers and CCTA statistics into a Cox multivariable for risk prediction of 1-year MACEs: BETTER risk score = MPO•0.1 + Hs-TnT•50 + Hs-CRP•0.4 + stenosis•9 + plaque•13 + EFV•0.2. The areas under the curve (AUC) for the prediction by Hs-cTnT, Hs-CRP, and MPO were 0.536 (95 % CI 0.409-0.662), 0.745 (95 % CI 0.641-0.850), and 0.650 (95 % CI 0.541-0.760), respectively. The AUC for the prediction of CCTA characteristics of stenosis, plaque, and EFV were 0.905 (95 % CI 0.860-0.950), 0.912 (95 % CI 0.867-0.957), and 0.835 (95 % CI 0.752-0.917), respectively. In addition, the AUC was 0.621 (95 % CI 0.492-0.750) for the Braunwald classification and 0.680 (95 % CI 0.559-0.801) for the TIMI score. The AUC for the BETTER risk score was 0.937 (95 % CI 0.902-0.972).

CONCLUSION

The BETTER risk score is new tool specifically developed for patients with UA. The score displays higher prediction accuracy in terms of discrimination and calibration than other currently available scores for risk stratification.

The clinical assessment of ischaemia modified albumin and troponin I in the early diagnosis of the acute coronary syndrome

BACKGROUND

An early identification of the patients with the Acute Coronary Syndrome (ACS) is of prime importance, due to the associated very high mortality. Only about 22% of the patients who present at the emergency cardiology care centres with chest pain, have coronary disease. Ischaemia modified albumin has already been licensed by the US Food and Drug Administration for the diagnosis of suspected myocardial ischaemia.

AIM

The goal of the present study was to assess the diagnostic value of serum ischaemia modified albumin and to compare it with sensitive cardiac troponin I in patients with the acute coronary syndromes like unstable angina and acute myocardial infarction.

METHODS

A diagnostic case control study was conducted on 102 patients who presented to the Emergency Department within 6 hrs of having acute chest pain and on 110 healthy age and sex matched volunteers who formed the control group. The serum Ischaemia Modified Albumin level was estimated by the albumin cobalt binding test by using a digital spectrophotometer, while Troponin I was measured by doing an immunofluroscence assay. A receiver operating characteristic curve was established for ischaemia modified albumin, to determine the cut-off point. The sensitivity and the specificity of ischaemia modified albumin and troponin I for the detection of acute coronary syndromes, were analyzed. The results of ischaemia modified albumin and troponin I alone and in combination, were correlated.

RESULTS

The ischaemia modified albumin (p<0.05) and the troponin I (p<0.001) concentrations were significantly higher in acute myocardial infarction and in unstable angina than in the healthy controls. The sensitivity and the specificity of ischaemia modified albumin for the detection of acute coronary syndromes was 88% and 93% as compared to 87% and 75% respectively for troponin I. The combined use of ischaemia modified albumin and troponin I significantly enhanced the sensitivity to 96%. The area which was under the Receiver Operating Characteristic (ROC) curve of ischaemia modified albumin in acute coronary syndromes was 0.90.

CONCLUSION

Ischaemia modified albumin is a useful biochemical marker for the early diagnosis of acute coronary syndrome. The combined use of ischaemia modified albumin and cardiac troponin I enhances the sensitivity and specificity. Hence, a combination of ischaemia modified albumin and cardiac troponin I can be used as a more precise diagnostic marker for Acute Coronary Syndrome.