| Background/ Objective: Heart failure is one of the severe cardiovascular diseases of which the morbidity increases rapidly during the recent years. Due to increased the morbidity of heart failure in elders, the morbidity of heart failure will go up as people's living conditions and medical conditions improves greatly, which has caused the heavy societal and economic burden. Therefore, the research on the pathogenesis and the effective therapy will be benefit to improve the quality of life in patients with heart failure.There are chronic ischemia and hypoxia of myocardium during the heart failure, and these abnormal changes could lead to the different degree of myocardial injuries. It might be assumed that the degree of myocardium injury would be parallel to the severity of heart failure. However, there is no the accurate technique or method reported so far with the higher sensitivity and specificity for the detection of myocardial injury.The injury of myocardial membrane could make the leakage of little molecular proteins from cytoplasm, such as MB isoenzyme of creatine kinase(CK-MB) , cardiac troponin I(cTnI) , cardiac troponin T(cTnT) , myohemoglobin(MHb) and the recently reported heart-type fatty acid binding protein(H-FABP). All of them might be the important markers of myocardium injury. At present, they have been often used for the diagnosis of acutemyocardial infarction(AMI) and unstable angina pectoris, but there is little study on whether or not the serum concentration CK-MB, cTnl and H-FABP could reflect the changes of the myocardial injury in patients with heart failure.Exercise training is one of methods that have been often recently used in the treatment of cardiac dysfunction. Exercise training could improve the quality of life of patients with heart failure through the several kinds of mechanism. Thus, exercise training has been becoming an important part of the rehabilitative therapy for patients with heart failure. However, it has not been reported so far that whether or not the improvement of symptoms would be coincident with the changes of myocardial injury, that is, whether or not the exercise training could improve the myocardial injury in patients with heart failure.The objective of the present study is to assess the importance of the markers of myocardial injury in the evaluation of the severity of heart failure, and the clinical value of different markers of myocardial injury in the pre- and post-exercise training in patients with chronic heart failure.Materials and Methods:1. Patients involved: 18 healthy persons and 76 patients with chronic heart failure who were in our hospital from 1 October 2003 to 3 April 2004 had involved in this study. All patients with heart failure were coronary heart disease(CAD) patients. The patients with acute coronary syndrome, activated myocarditis, uncorrected heart valvular disease such as severe aortic stenosis and kidney dysfunction were excluded. According to the classes of New York Heart Association (NYHA) standard, the patients with heart failure were divided into three groups. In each of three groups, the patients were divided into two subgroups according to whether or not exercise training. The ratio of gender > age among groups and between subgroups are similar with each other^ >0.05).2. Methods:2.1 Regular regime: After being in hospital, all patients have regular regime, angiotensin converting enzyme inhibitor digitoxin were used regularly, P-receptor blocker was used if the patient has no contraindication to it. Diuretics and nitrate were used according to patients' conditions, severe patients suck low flow oxygen. Patients in exercise training group have exercise training according to specific program additionally.2.2 Harvesting and conservancy of collections: 5ml empty stomach vein bloods were collected inward 24 hours after being in hospital and after 8 weeks. CK—MB and troponin I were detected immediately, the rest of collections were preserved in -70°C refrigerator, for detecting H-FABP at the same time.2.3 Statistical analysis. All continuous data were expressed as means± 1 standard deviation, SPSS 10.0 for windows was used to analyze all data. Comparisons of continues variables among multiple groups were performed by single- factor ANOVA. Comparisons between groups were performed with unpaired Student's /-test. Pearson's correlation coefficient (r) was used to determine the relationship among groups. A value of P<0.05 was considered to be statistically significant.Results:1. Comparisons among groups of the different class of heart failure patients and control group before (exercise training) therapy: serum levels of H-FABP > cTnI> CK-MB in each group of patients with heart failure are all higher than those of control group(P<0.05); and these values increased as NYHA-class increased; but there are the significant differences of cTnl and H-FABP between the groups of exercise training and non-exercise training (7><0.05); the significant difference of CK-MB was observed only between NYHAII group and NYHAIV group( P<0.05); the value of H-FABP in control group ^ NYHA II group ^ NYHAIII group > NYHAIV group were respectively(1.74±0.86) ug/L, (3.17±1.57) ug/L, (6.66±1.65) ug/L and (9.52±1.97) ug/L; the value of cTnl in control group ^ NYHA II group ^ NYHAIII group >NYHAIV group were respectively (0.11±0.09) ug/L, ( 0.23±0.07 ) ug/L, (0.45±0.11) ug/L and (0.76±0.19) ug/L; the value of CK-MB in control group,NYHA II group > NYHAIII group ^ NYHAIV group were respectively (6.72±2.05) ug/L, (13.58±3.15) ug/L, ( 14.48±4.36) ug/Land (16.30±3.89)ug/L).see details in table 1 -. figure 1, figure 2^ figure 3.2. Comparisons between pretreatment and post-treatment in groups according to the different classes of heart failure: in the same NYHA class group, the serum level of H-FABP.. cTnI> CK-MB decreased in post-treatment (the value of H-FABP in NYHA II , NYHAIIK NYHAIV were respectively(2.35±1.48) ug/L, (3.13±1.26) ug/Land (5.57±1.34) ug/L; the value of cTnl in NYHA IK NYHAIIK NYHAIV were respectively (0.16±0.08) ug/L,(0.36±0.07) ug/Land (0.57±0.10) ug/L; the value of CK-MB in NYHA IK NYHAIIL NYHAIV were respectively (12. 33±1.73) U/L, (12.86±3.03) U/L and (14.43±3.52) U/L).There were significant differences of H-FABP between pretreatment and post-treatment in each of groups (P<0.05); there were also significant differences of cTnl between pretreatment and post-treatment, (/><0.05); however, there was no significant difference of CK-MB between pretreatment and post-treatment(P>0.05). See details in table 1.3. Comparisons between regular regime group and regular regime+ exercise training group: After being treated, the value of H-FABP^ cTnI> CK-MB are all reduced, but the degrees of reduction in regular regime + exercise training group were greater than those in regular regime group.( After being treated, in NYHA II group ,the reduced values of H-FABP in regular regime group and regular regime + exercise training group were respectively(0.44 + 0.13) ug/Land (0.98 + 0.16) ug/L ( PO.05); the reduced values of cTnl in regular regime group and regular regime + exercise training group were respectively (0.05 + 0.02) ug/Land (0.10 + 0.02) ug/L ( P<0.05); the reduced values of CK-MB in regular regime group and regular regime + exercise training group were respectively (1.50 + 2.24) U/L and (1. 42 ± 1. 56)U/L( />>0.05); In NYHAIII group, the reduced values of H-FABP in regular regime group and regular regime + exercise training group were respectively (2.37 + 0.61) ug/Land (4.35+1.06) ug/L (/><0.05); the reduced values of cTnl in regular regime group and regular regime + exercise training group were respectively (0. 04 ±0. 01) ug/L and(0. 12 ±0. 04) ug/L( PO.05); the reduced values of CK-MB in regular regime group and regular regime + exercise training group were respectively (1. 08 + 1. 62) U/L and (2.00+1.94) U/L( P >0.05); In NYHAIV group, the reduced values of H-FABP in regular regime group and regular regime + exercise training group were respectively (3.15 + 0.69) ug/Land (4.69 + 0.50) ug/L( ?<0.05);the reduced values of cTnl in regular regime group and regular regime + exercise training group were respectively (0. 10 + 0. 03) ug/L and ( 0. 27 + 0.05) ug/L( P<0.05); the reduced values of CK-MB in regular regime group and regular regime + exercise training group were respectively (1.22 ±1.54) U/L and (2.50 + 2.20) U/L( P<0.05). see details in table 2 ■, figure4> figure 5 and figure 6.4. The correlation analysis: Before being treated, there was a high correlative relationship (Y=0.07+0.06X, r=0. 751, P<0. 01) between H-FABP and cTnl; the high correlative relationship (Y=0.09+0.02X, r=0. 440, P<0. 05) was observed between cTnl and CK-MB; there was a high correlative relationship (Y=1.35+0.32X, r=0. 463, P<0. 01) between H-FABP and CK-MB. see details in figure7^ figure8^ figure9.Conclusions:1. There is significant myocardial injury in patients with heart failure, and the degree of myocardial injury has changed as the severity of chronic heart failure changed: the degree of myocardial injury increased with the aggravated heart failure and decreased with improved heart failure.2. The markers of myocardial injury such as cTnK H-FABP > CK-MB might be used as the reliable markers for the evaluation the severity of chronic heart failure: The level of these three values increased as conditions of the patientsgets aggravated and decreased as conditions of the patients gets relieved, and there were correlative relationships between them, especially between cTnl and H-FAB?. it was indicated that these three markers could reflect the severity and dynamic changes of myocardial injury in patients with chronic heart failure.3. Compared with CK-MB, cTnl and H-FABP have higher significances in the evaluation of changes of myocardial injury in patients with heart failure, especially H-FABP, because H-FABP has small molecular weight and can release to blood rapidly while the myocardial injury happened, therefore, H-FABP is suitable for the accession of the changes of myocardial injury especially.4. Exercise training may ameliorate myocardial injury through several kinds of mechanisms such as the increased capacity of oxidation and increased metabolism of skeletal muscles, improved histological and biological characters of skeletal muscle and ameliorated functions of vascular endothelium and status of neurohormone in patients with chronic heart failure.
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