The relationship between serum concentration of cardiac troponin I in chronic renal failure patients and cardiovascular events.

OBJECTIVE: The purpose of this study was to evaluate the relationship between serum cardiac troponin I in asymptomatic chronic renal failure patients and cardiovascular events. BACKGROUND: Short-term follow-up studies on this subject produced conflicting results. MATERIAL AND METHOD: A total of 63 asymptomatic patients with chronic renal failure (CRF) with regular hemodialysis were followed for 18 months for cardiac mortality, myocardial infarction events and interventional procedures such as percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass graft (CABG). Serum cTnI and other blood chemistries were measured at the time of the study. RESULTS: Forty seven chronic dialysis patients (75%) had an elevated level of cTnI concentration more than the 0.08 ng/ml cutoff but only fourteen patients (22%) had and elevated cTnI concentration of more than the AMI cutoff (0.4ng/ml). When using the 0.08 ng/ml cutoff, the NT-proBNP concentrations of the elevated groups were significantly higher than the normal groups. The authors also found that the elevated groups above the AMI cutoff had significantly higher cardiovascular events. CONCLUSION: Elevated cTnI concentrations are commonly found in chronic renal failure patients. The AMI cutoff level of cTnI (0.4 ng/ml) seem to have a benefit for predicting the cardiovascular events in asymptomatic chronic renal failure patients while the 0.08 ng/ml cutoff doesn't have usefulness for this purpose. Further studies are needed to clarify this hypothesis.

An open, randomized trial of three-day treatment with artesunate combined with a standard dose of mefloquine divided over either two or three days, for acute, uncomplicated falciparum malaria.

The combination of artesunate and mefloquine is currently one of the most effective treatments for multidrug-resistant Plasmodium falciparum malaria. Simultaneous, rather than sequential treatment with the two drugs, would allow better patient compliance. We therefore evaluated three-day treatment with artesunate combined with either 2 or 3 days of mefloquine co-administered once a day with artesunate. The study was an open, randomized trial for acute, uncomplicated falciparum malaria and was conducted at the Bangkok Hospital for Tropical Diseases. One hundred and twenty adult patients were randomized to two treatment groups. Group 1 patients received 4 mg/kg/day of artesunate for 3 days and 3 daily doses of 8.0 mg/kg/day mefloquine given with artesunate. Group 2 patients received the same dose of artesunate and the same total dose of mefloquine (25 mg/kg). However, the mefloquine was given as 15 mg/kg on the first day and 10 mg/kg/ on the second day, again with artesunate. The baseline demographic and clinical characteristics of the patients in the two groups were similar. The cure rates for the 3-day and 2-day mefloquine regimens were 100% and 99%, respectively. There were no significant differences in either median fever clearance times (group 1=32 hours; group 2=33 hours) or mean parasite clearance times (group 1=42.3 hours; group 2=43.3 hours). Both regimens were well tolerated and there were no significant differences in the incidence of adverse effects. Nausea or vomiting occurred in 3.8% of patients in both groups and transient dizziness occurred in 4% of group 1 and 9% of group 2 patients. These results suggest that a 3-day regimen of mefloquine administered with artesunate is effective and well tolerated. This practical regimen could improve patient compliance.

Serum magnesium in Thai coronary artery disease patients.

Hypomagnesemia or magnesium (Mg) deficiency has been hypothesized to play a role in coronary artery disease (CAD). The authors aimed to evaluate serum Mg concentration in 100 CAD patients compared with 100 healthy controls. Mean values of serum Mg level in CAD and the control group were 2.14 +/- 0.39, 2.24 +/- 0.3 mg/dL respectively (P=0.052). The prevalence of Mg deficiency was 12 per cent in the CAD patients, and 5 per cent in the control group (odds ratio=2.59, 95% confident interval = 0.88-7.65, P=0.063). There was no significant difference in the serum Mg level between the 2 groups, although it tended to be lower in CAD patients. The prevalence of Mg deficiency did not differ significantly between the study group, however, it tended to be higher in CAD patients. These findings demonstrated that CAD patients may be associated with Mg deficiency, and contribute to the pathogenesis of CAD or acute thrombosis. Following this evidence, Mg treatment may be necessary in CAD patients with Mg deficiency or acute myocardial infarction (AMI).

Serum concentrations of lipids and apolipoprotein E in angiographically defined coronary artery disease patients.

Apolipoprotein (apo) E is an important component of plasma lipoproteins and influences lipoprotein metabolism through its action as a receptor ligand. The association of serum apo E concentrations and coronary artery diseases (CAD) was investigated in 100 CAD patients (71 men, 29 women, mean age 62.0 years) and 155 healthy volunteers (87 men, 68 women, mean age 50.6 years). Patients with CAD had lower serum apo E concentrations (5.1+1.3 mg/dL) than the healthy volunteers (5.9+1.8 mg/dL, p <0.001). There were no significant differences between the number of disease vessels and the concentration of serum apo E. Serum apo E concentrations may have an anti-atherosclerotic effect and the serum apo E levels could be a useful parameter for defining cardiovascular risk factor.

Screening for mutations in exons encoding the ligand-binding domain of the LDL receptor gene using PCR-CFLP and PCR-SSCP.

Primary hypercholesterolemia includes both monogenic disorders and polygenic conditions. Two well defined monogenic disorders are familial hypercholesterolemia (FH) and familial defective apolipoprotein (apo) B-100 (FDB). Both disorders convey high risk of premature coronary artery disease. FH and FDB are caused by mutations in LDL receptor and apo B-100 genes, respectively. In the present study, mutations in both genes in Thai subjects with primary hypercholesterolemia were screened. For apo B-100 gene, a common mutation R3500Q was screened. This mutation was not observed in the patients (n = 45). For LDL receptor gene, mutations in the exons encoding the ligand-binding domain were screened. By PCR-CFLP analysis, 18 abnormal CFLP patterns in exon 4, the hot spot for mutations, were found in patients (n=45). One of the DNA samples with abnormal CFLP patterns was previously identified and reported as a possible disease-causing mutation, namely D151Y. For the other exons, the screening technique was PCR-SSCP. Abnormal SSCP patterns in DNA samples from patients (n=20) were found as follows, two in exon 3, one in exon 5 and another one in exon 6. Further characterization by DNA sequencing and family studies for these abnormal patterns are underway.

Roxithromycin in prevention of acute coronary syndrome associated with Chlamydia pneumoniae infection: a randomized placebo controlled trial.

The role of Chlamydia pneumoniae infection in precipitating acute coronary syndrome (ACS) is unclear. Some studies have indicated that intervention with macrolide antibiotics might reduce coronary events in patients with ACS. A double blind, randomized, placebo-control trial was conducted on 84 ACS patients. Patients were randomized to 30 days of treatment with roxithromycin (150 mg, twice daily) or matching placebo. The follow-up period was 90 days, and the primary clinical end point included cardiovascular death, unplanned revascularization and recurrent angina/MI. Anti-C. pneumoniae IgG positive in 24 of 43 (55.8%) patients in the roxithromycin group and 23 of 41 (56.1%) patients in the placebo group. Anti-C. pneumoniae IgA positive in 20 of 43 (46.5%) patients in the roxithromycin group and 13 of 41 (31.7%) patients in the placebo group. Thirty-three cardiac events occurred (2 cardiovascular deaths, 9 CABG, 12 PTCA and 10 recurrent angina/MI) with 17 events in the roxithromycin group and 16 events in the placebo group. There was no significant difference of cardiac events between the roxithromycin and placebo groups. The present study suggests that antibiotic therapy with roxithromycin is not associated with reduction of cardiac events as reported by other investigators. However, therapeutic interventions may need to be specifically targeted to a group of patients who are confirmed with chronic C. pneumoniae infection.

Prevalence of hyperhomocysteinemia in normal healthy Thai subjects.

The concentration of circulating total homocysteine is a sensitive marker of inadequate folate and vitamin B12 status. The elevations of plasma homocysteine concentration are associated with an increased risk of vascular disease. The primary goals of this study were to identify plasma homocysteine concentrations in Thai residents and to test for differences in homocysteine levels among sex and age categories. The authors measured plasma total homocysteine concentrations in 3,345 Shinawatra employees (1,133 males, 2,212 females aged between 20-65 years) by using fluorescence polarization immunoassay (FPIA) method. The mean plasma homocysteine concentrations of males and females were 11.495 and 8.547 micromol/L respectively. Plasma homocysteine concentrations were significantly lower in females than in males (p < 0.0001). The age-specific plasma homocysteine levels were lower in females than in males for each group, but the levels of each group was not significantly different both in males and females. When more than 12 micromol/L was used as the cut-off value, it was found that 33.6 per cent of males and 6.69 per cent of females were classified as hyperhomocysteinemia subjects. The authors concluded that the prevalence of hyperhomocysteinemia in Thai males is more common than in females. Further investigation should be done to clarify the association between serum folate, vitamin B12, vitamin B6 concentrations and plasma homocysteine concentration.

Homocysteine and restenosis after percutaneous coronary intervention.

Numerous clinical studies in Western and Asian countries suggest that individuals with elevated blood levels of homocysteine have an increased risk of atherosclerosis, myocardial infarction, cerebral infarction, and deep vein thrombosis. Homocysteine is also known to induce both atherogenic and thrombogenic mediators in cultured vascular cells so that homocysteine may influence the damage of endothelial cells, promote smooth muscle cell growth, induce atherogenic mediators and thrombus formation after coronary angioplasty. The association between homocysteine and restenosis after percutaneous coronary intervention (PCI) has been discussed. In this study, the relationship between plasma homocysteine levels and restenosis after PCI to investigate whether plasma homocysteine levels may be a predictor of restenosis after PCI was examined. One hundred consecutive patients who underwent successful PCI were enrolled and plasma homocysteine level was measured in all patients prior to PCI. Plasma for homocysteine level was obtained in 99 of 100 patients who had angioplasty. The mean plasma homocysteine concentration in the enrolled patients was 13.61 +/- 6.04 micromol/L. The minimum and maximum of plasma homocysteine were 4.40 micromol/L and 50.00 micromol/L, respectively. In healthy subjects, the normal reference range of homocysteine level is 5-15 micromol/L However, recent data suggest that some patients may be at increased cardiovascular and cerebrovascular risk at levels as low as 12 micromol/L. For this reason, both cut off points of homocysteine level > or = 15 micromol/L or > or = 12 micromol/L to identify the high homocysteine level group were used. Of 99 patients, high homocysteine level (> or = 15 micromol/L) was established in 9 patients with restenosis versus 20 patients without restenosis. If the cut off point of homocysteine level > or = 12 micromol/L was used, high homocysteine level was established in 14 patients with restenosis versus 39 patients without restenosis. From both cut off points of homocysteine level, there was no correlation between plasma homocysteine level and the restenosis group. (p>0.05).

Serum nitric oxide levels in patients with coronary artery disease.

Nitric oxide (NO) plays a pivotal role in the pathophysiology of coronary artery disease. The roles of NO are not only physiological but also pathological in the cardiovascular system. An inappropriate release of NO has been linked to the pathogenesis of CAD. The authors investigated whether serum NOx (nitrate and nitrite), a stable end product of NO, level was related to patients with coronary artery disease. The blood chemistry, such as cholesterol, triglyceride, LDL-C, HDL-C and blood sugar, was also measured in comparison with serum NOx. Serum NOx was measured in samples from 20 healthy controls, 20 angina patients without angiographic evidence of coronary lesions (CAG) and 20 angina patients with angiographic evidence of coronary lesions (CAD) by using modified Griess reaction. The mean serum NOx levels in the CAD groups was higher than CAG and control groups (41.3 +/- 5.5, 32.7 +/- 3.9 and 25.7 +/- 3.5 micromol/L, respectively). NOx levels in the CAD group was only significantly higher than the control groups (p < 0.05) but not the CAG groups. There were no significant differences of NOx levels in all age groups. In the CAD group, women showed significantly higher NOx levels than men (64.0 +/- 7.5 and 29.0 +/- 4.7 microl/L, respectively, p < 0.05). Interestingly, the mean serum NOx levels in the CAD groups was significantly higher in a group of abnormal lipid profiles (cholesterol, triglyceride, LDL-C) and blood sugar than in a group of normal profiles. The results suggested that there was an increased NOx levels in patients with coronary artery disease and much higher in patients with multiple underlying conditions such as hyperlipidemia and hyperglycemia. Thus, the measurement of the NOx levels at different times may help to monitor the state and severity of coronary artery disease.

Homozygous DNA variants in exon 9 of the LDL receptor gene in a Thai patient with primary hypercholesterolemia phenotype.

Mutation in low density lipoprotein (LDL) receptor gene causes an inherited primary hypercholesterolemia namely familial hypercholesterolemia (FH). In this study, 46 Thai patients with primary hypercholesterolemia were screened for mutations in exon 9 of the LDL receptor gene by polymerase chain reaction-restriction fragment length polymorphism (PCR - RFLP). The analysed fragment was 224 bp in length. According to the published cDNA sequence, exon 9 of the LDL receptor gene contains several hypermutable CpG dinucleotides. Three of these sites are Hpa II recognition sites. PCR product of exon 9 obtained from amplification of wild-type DNA sample would yield four fragments after Hpa II digestion. The expected sizes of these restriction fragments were 15, 30, 40 and 139 bp. All normocholesterolemic subjects (n = 33) showed normal RFLP. However, in one patient (72 year old female), abnormal RFLP from Hpa II digestion of the amplified exon 9 was observed, i.e., a fragment of 70 bp and another one smaller than 139 bp. Such RFLP reflects that exon 9 of both alleles of the LDL receptor gene in this patient lost one and gained one Hpa II site. It is interesting that this patient, eventhough harbouring two mutations on both alleles of the LDL receptor gene (presumably homozygous genotype of FH), apparently revealed lipid levels of heterozygous phenotype of FH without symptoms of coronary artery disease. It has yet to be proved whether these genetic variations are disease-related mutations or presumably common DNA polymorphisms.

Rapid detection of Chlamydia pneumoniae DNA in peripheral blood mononuclear cells of coronary artery disease patients by real-time fluorescence PCR.

Several recent reports including serological, pathological and animal studies have associated Chlamydia pneumoniae with coronary artery disease (CAD). In order to establish whether chronic C. pneumoniae infection is linked to coronary artery disease, clinical intervention trials may be needed. However, to detect eligible patients with persistent infection, a reliable diagnostic marker must be developed for identifying cases and assessing efficacy of antichlamydial therapy. Moreover, the prevalence of circulating C. pneumoniae DNA in CAD patients varied widely from previous reports. A real-time PCR has been established by using HL-1 and HR-1 primer to amplify 437 base pairs product. Confirmation of the product was performed on LightCycler by melting curve analysis of detection probes labeled with LC-Red705. Ninety-five angiographically confirmed CAD patients and 104 normal, healthy volunteers were recruited. The mononuclear cell layer was separated from collected blood and rapid, single step real-time PCR was used to detect C. pneumoniae DNA. C. pneumoniae DNA in peripheral blood mononuclear cells (PBMC) was found in 17 per cent of 95 CAD patients and 1 per cent of 104 normal healthy volunteers (odds ratio 20.86, 95% confidence interval 2.71 - 160.67, p < 0.0001). There was no association between C. pneumoniae DNA in PBMC and serological status. The rapid, real-time PCR showed a clear-cut result between positive and negative cases. PBMC-based real-time PCR may be a useful tool for identifying subjects carrying C. pneumoniae in the circulation or in the vascular wall as well. It will be a specific indicator of current infection and will be used as a marker for assessing the microbiological efficacy of antichlamydial therapy in clinical intervention trials.

Inexpensive, rapid and convenient PCR-minigel SSCP protocol for polymorphisms and mutations analyses of LDL receptor gene.

Hypercholesterolemia has been recognized as a major risk factor of atherosclerosis and coronary artery disease. The elevation in plasma low density lipoprotein (LDL) cholesterol is frequently due to genetic alteration at the genetic locus specifying the LDL receptors, leading to defective catabolism of LDL. In order to facilitate the molecular diagnosis of LDL receptor disorder, single strand conformation polymorphism (SSCP) analysis of polymerase chain reaction (PCR) amplified genomic DNA fragments has become a simple and sensitive screening method for identification of DNA polymorphisms and mutations in LDL receptor gene prior to DNA sequencing. In addition, SSCP patterns can be detected by silver staining to avoid hazardous radioactive material or other costly nonradioactive detection techniques. However, the original SSCP protocol is generally large-formatted, which is both time and reagents consuming as well as cumbersome. Minigel SSCP protocols have thus been devised but they involve, although commercially available, costly precast gels. We describe here a nonradioactive PCR-minigel SSCP protocol which is sensitive, inexpensive, rapid, reproducible and manually convenient. The results in this study demonstrate that minigel-SSCP (gel size: 10 cm x 7.3 cm x 0.075 cm) can detect conformation polymorphisms in PCR-fragments with a comparative sensitivity to large gel SSCP (gel size: 30 cm x 40 cm x 0.04 cm) as exemplified by the SSCP analyses of exon 13 of the LDL receptor gene. For minigel SSCP, the reagents for gel components and silver staining are reduced approximately 9 times and 10 times, respectively. For electrophoresis, electrical power is also reduced 10 times. This improved technique can become routinely used for molecular diagnosis of LDL receptor defect as well as for other genetic disorders.

Chronic infections and atherosclerosis.

The established risk factors for atherosclerosis such as hypertension, smoking, diabetes mellitus, hyperlipidemia, and hyperhomocysteinemia do not explain clinical and epidemiological features of coronary heart disease (CHD). The role of infectious disease as a CHD risk factor may partly explain these features. Chronic infection with various microorganisms, particularly, Chlamydia pneumoniae, Cytomegalovirus (CMV) and Helicobacter pylori may play a role in etiological factors, linking inflammation and atherogenesis. Results from epidemiological studies, pathology of atherosclerotic plaques, animal studies, molecular biology and clinical antibiotic trials indicated a positive association between C. pneumoniae infection and CHD. Chronic infection might also influence preexisting plaque by enhancing T cell activation, which participate in destabilization of intimal cap. However, the exact nature of pathophysiological link between the organisms and CHD remains to be elucidated. Future antibiotic interventional studies may help to further clarify the role of chronic infection and inflammation in CHD.

Serum lipoprotein (a) level and restenosis after percutaneous coronary intervention.

Restenosis is regarded as the result of a combination of various pathological events. The mechanisms are complex and not completely understood. In this study, the authors focused on the lipoprotein (a) (Lp (a)). It is one of the novel risk factors in atherosclerotic vascular disease. Numerous clinical studies suggest that individuals with elevated blood levels of Lp (a) have been shown to be associated with atherosclerotic vascular disease. However, whether a high serum concentration of Lp (a) affects restenosis after PCI remains controversial. In this study, the relationship between serum Lp (a) levels and restenosis after PCI was examined to investigate whether serum Lp (a) levels may be a predictor of restenosis after PCI. Of the 100 patients studied, 31 patients (31%) were classified as the restenosis group and 69 patients (69%) the non-restenosis group. Both groups did not significantly differ in serum concentration of total cholesterol, triglyceride, HDL-C, and LDL-C. The mean serum Lp (a) concentration in patients with restenosis was 41.50 +/- 34.99 mg/dL compared with a mean serum Lp (a) concentration of 29.87 +/- 25.47 mg/dL in those without restenosis. There was no statistical significance of Lp (a) level between the restenosis and non-restenosis groups (p=0.06). In healthy subjects, the normal reference range of serum Lp (a) concentration is below 30 mg/dL. From this reference, if a cut off point of serum Lp (a) concentration equal to 30 mg/dL or above to identify high Lp (a) level group was used. High serum Lp (a) level was established in 15 patients with restenosis versus 21 patients without restenosis. From this cut off point of serum Lp (a) level, the authors did not find a correlation between serum Lp (a) level and the restenosis group. (p=0.08).

DHEA(S): the fountain of youth.

Dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) are weak androgens produced primarily by the adrenal gland. Although their plasma concentrations by far exceed those of any other adrenal product, their physiological roles have not yet been determined. In plasma, where the major portion of these hormones is present in the sulfate form, it is possible that DHEAS serves as a reservoir for DHEA. Since various tissues have been shown to contain steroid sulfatases. The peak plasma levels of DHEA and DHEAS occur at approximately age 25 years, decrease progressively thereafter, and diminish by 95 per cent around the age of 85 years. The decline of DHEAS concentrations with aging has led to the suggestion that DHEAS could play a role in itself and be implicated in longevity. Moreover, the epidemiological evidence has shown that adult men with high plasma DHEAS levels are less likely to die of cardiovascular disease. DHEA has also been shown to increase the body's ability to transform food into energy and burn off excess fat. Another recent finding involves the anti-inflammatory properties of DHEA. It has been known that DHEA can lower the levels of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha). It should be pointed out that chronic inflammation is known to play a critical role in the development of the killer diseases of aging: heart disease, Alzheimer's disease and certain types of cancer. In conclusion, DHEA or DHEAS administration combined with conventional treatment may be implicated in particular conditions to improve the quality of life.

Serum dehydroepiandrosterone sulfate, testosterone, and biochemical markers of bone turnover in elderly Thai men.

The most abundant human steroid, dehydroepiandrosterone sulfate (DHEAS), may have a multitude of beneficial effects, but declines with age. It is unclear whether DHEAS deficiency is an important factor contributing to increased bone resorption and impaired bone formation or not that leads to their bone loss. Thus, we investigated serum DHEAS, testosterone, osteocalcin (N-MID osteocalcin) and C-terminal telopeptides (beta-CrossLaps) in 121 healthy Thai males without bone diseases. Thirty-nine males (mean age 31.5 +/- 8.2, range 23-42 years) were recruited as the normal adult group and 82 males (mean age 61.2 +/- 7.0, range 52-77 years) were assigned as the elderly group. DHEAS levels were higher in the adult group compared with the elderly subjects (296.8 +/- 93.4 vs 172.6 +/- 99.8 microg/dL, p < 0.0001). Serum osteocalcin concentrations were also higher in the adult group compared with the elderly males (27.9 +/- 11.1 vs 23.2 +/- 7.9 ng/ml, p = 0.0091). However, serum testosterone and C-terminal telopeptides levels were not significantly different between the two groups. We concluded that low DHEAS concentrations are commonly encountered in elderly males and may relate to low osteocalcin levels due to the osteoblast stimulation effects of DHEAS. These findings may be implicated in the treatment of osteoporosis in elderly men by using DHEAS.

Regular exercise and cardiovascular risk factors.

Physical inactivity has been counted as a risk factor for coronary artery disease. Regular exercise has also been reported to reduce risk of cardiovascular disease and its risk factors. We surveyed 3615 subjects for their conventional risk factors of coronary disease and for the frequency of their exercise. We found that subjects who had regular exercise were more likely to have lower triglyceride and resting heart rate. HDL cholesterol was higher in the group of subjects who had regular exercise. There was no difference in fasting plasma glucose, total cholesterol or blood pressure levels between those who had and those who did not have regular exercise.

Prevalence of new coronary risk factors in Thai population.

Many new cardiovascular biomarkers of atherosclerosis have recently been emerging. However, there is a paucity of these data in the Thai population. This study aims to determine the prevalence of these biomarkers of atherosclerosis and the relationship between these new risk factors and other conventional risk factors for atherosclerosis in the healthy Thai population. As a yearly check-up program, we surveyed 3,615 normal healthy populations for their conventional risk factors and some new cardiovascular biomarkers for atherosclerosis. The authors found hyperhomocysteinemia and high level of Lp(a) in 27 per cent and 32 per cent of the cases respectively. Prevalence of recent and past chlamydial infection was found in 30 per cent and 51 per cent respectively.

Biochemical markers of bone turnover in angiographically-demonstrated coronary artery disease patients and healthy Thais.

The patients with coronary artery disease (CAD) were suffering from dyspnea. Physical activity of these patients was limited. Their lifestyle may be contributory factors for osteoporosis. Recent research has shown that biochemical markers may be used to predict future bone loss and identify individuals at risk for osteoporosis. Our objectives were to estimate reference ranges of bone markers in healthy Thais and to compare bone turnover between 105 healthy people and 118 CAD patients by using biochemical markers of bone formation and resorption. Mean values of bone markers in controls and patients were 22.9 +/- 12.9, 21.6 +/- 16.2 respectively for N-Mid osteocalcin and 0.45 +/- 0.30, 0.47 +/- 0.37 respectively for beta-Crosslaps. There was no statistical difference of N-Mid osteocalcin (p=0.50) and beta-Crosslaps (p=0.64) values between groups. Our data from this study suggested that that CAD patients have no higher risk for osteoporosis than healthy people.

Serum cardiac troponin T in unstable angina pectoris patients.

Cardiac troponin T (cTnT) is a regulatory contractile protein not normally found in blood. Its detection in the circulation has been shown to be a sensitive and specific marker for myocardial cell damage. In this study, we used a second-generation enzyme immunoassay for cTnT to determine whether its presence in the serum of patients with unstable angina was a prognostic indicator. Thirty patients with unstable angina pectoris (UAP) and 30 patients with Q-wave acute myocardial infarction (AMI) were screened for serum CK-MB activity and cTnT at 6, 12, 24 and 48 hours after the onset of chest pain, All of the mean concentrations of CK-MB activity determined in UAP patients were less than the upper limit of normal (25 U/L). Meanwhile, the mean concentration of cTnT at 6, 12, 24 and 48 hours after onset of chest pain were higher than the cutoff values (0.1 microg/L), We found that one third of UAP patients had serum cTnT at the time of admission more than 0.1 microg/L and that these groups of patients were associated with a high risk for cardiac events. Our results suggested that patients with elevated serum cTnT could be considered as high-risk patients for developing myocardial infarction, Patients with normal cTnT levels and a low or intermediate clinical risk could be stabilized and further stratified noninvasively.