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.

Reversibility of tachycardiomyopathy after successful radiofrequency catheter ablation: intermediate results.

Left ventricular function in patients with tachycardia induced cardiomypopathy can improve after cessation of the arrhythmia. We reported the intermediate results of 10 patients, 6 men and 4 women, with tachycardiomyopathy who successfully underwent radiofrequency catheter ablation (RFCA) for incessant tachycardia. Three had right atrial tachycardia, 5 ventricular tachycardia (2 and 3 from the right and left ventricles, respectively), 1 atrial flutter and 1 right accessory pathway. During the mean follow-up period of 19 months (range 11-38 months), one patient, right atrial tachycardia, had recurrence and reablation was successfully done without recurrence. Left ventricular ejection fraction, endsystolic and diastolic diameters from echocardiography gradually improved from 35 per cent, 51 and 61 mm to 58 per cent, 36 and 52 mm, respectively (p<0.001). The mean duration of reversibility was 7 months (range 1-15 months). There was no recurrence of tachycardiomyopathy after the return of left ventricular function. Conclusion, RFCA can terminate tachyarrhythmia and lead to significant improvement of left ventricular diameters and systolic function in patients with tachycardia induced cardiomyopathy.

A 5-year prospective study of conventional risk factors of coronary artery disease in Shinawatra employees: a preliminary prevalence survey of 3,615 employees.

We conducted a prevalence survey of conventional risk factors of coronary artery disease in 3,615 Shinawatra employees and we planned to prospectively follow up this population to determine the impact of the risk factors in the development of coronary disease. The prevalence of hypertension, diabetes mellitus, hyperlipidemia, obesity, physical inactivity and smoking were 7.4 per cent, 1.4 per cent, 21.1 per cent, 13.9 per cent, 76.3 per cent and 16.3 per cent respectively. The awareness of hypertension, diabetes mellitus and hyperlipidemia were 42.2 per cent, 78 per cent and 32.9 per cent respectively. The prevalence of the risk factors was more common in males and increased with increasing age. Dependent variables which were associated with hypertension included: excessive weight; male sex; increasing age; hypercholesterolemia and diabetes mellitus. Variables which were associated with diabetes mellitus were hypertriglyceridemia, hypertension, male sex, increasing age and excessive weight.. Variables which were associated with hypercholesterolemia were hypertriglyceridemia, high HDL-cholesterol, increasing age, excessive weight and hematocrit level while overweight, hypercholesterolemia, low HDL-cholesterol, smoking, hematocrit level, low income and increasing age were associated with hypertriglyceridemia. Excessive weight was associated with hypertriglyceridemia, low HDL-Cholesterol, presence of hypertension, hypercholesterolemia, diabetes mellitus, increasing age and low education.

Correlation of serum lipoprotein(a) with the clinical presentation of Thai coronary artery disease patients.

Elevated serum levels of lipoprotein(a) [Lp(a)] confer an increased risk of coronary artery disease (CAD) and have been confirmed as a strong and independent risk factor for this disease. This case-control study was to determine the significance of elevated Lp(a) levels for the existence of CAD by systematically recording cardiovascular risk factors in diagnostic coronary angiography in a group of patients. Two hundred thirty seven consecutive patients (175 men, 62 women, aged 61+/-10 years) which comprised 24 acute myocardial infarction (AMI), 76 unstable angina (UA) and 137 stable angina (SA) who underwent coronary angiography, were used as cases. One hundred seventy normal healthy volunteers (95 men, 75 women, and aged 58+/-15 years) were used as controls. Lp(a) concentration were measured by an immunoturbidimetric method (Roche Diagnostics, Switzerland). There was a significant difference between Lp(a) levels in UA compared with the control subjects (44.2+/-49.0 vs. 27.6+/-25.3 mg/dL, p = 0.0006). When we compared SA and the control group (35.6+/-31.3 vs. 27.6+/-25.3 mg/dL, p = 0.0139) there was a significant difference between these two groups. UA patients also had a significantly higher prevalence of abnormal Lp(a) (>30 mg/dL) compared with the normal healthy control group (43.2% UA vs. 28.8% control, OR = 1.90, 95%CI = 1.08-3.32, p = 0.0248). SA patients also had the same finding as UA patients in a higher prevalence of abnormal Lp(a) when compared with the control group (45.2% SA vs. 28.8% control, OR = 2.04, 95%CI = 1.27-3.27, p = 0.0028). These data further support the role of Lp(a) in atherosclerotic coronary disease and the pathogenesis of acute coronary syndromes.

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.

Myocardial injury after radiofrequency catheter ablation.

Radiofrequency catheter ablation has been a good treatment option for various types of cardiac arrhythmia. However there is concern about myocardial injury associated with radiofrequency catheter ablation. We studied myocardial injury with biochemical markers and echocardiogram in 41 consecutive patients who underwent electrophysiology study (EP study) and radiofrequency catheter ablation (RFCA) at our institute from April to July 2000. The concentration of biochemical markers (CK-MB mass, troponin T and myoglobin) and result of the echocardiograms were analyzed with other characteristics. In 41 patients subjected to EP study with possible RFCA, abnormal levels of troponin T, CK-MB mass and myoglobin were found in 46 per cent, 15 per cent and 44 per cent immediately after procedure, which went up to 64 per cent, 22 per cent and 2 per cent at twenty four hours. Compare to the group with normal troponin T level, the patients with abnormal level at 24 hours after RFCA had a longer procedure time (119+/-44 min. vs 90+/-22 min.), more frequent use of impedance ablation catheters (65% vs 27%), more RF applications (9+/-8 vs 18+/-16) and more ventricular ablation sites (69% vs 9%). The echocardiogram results showed no remarkable abnormality in any patients. Troponin T was the most sensitive marker to detect thermal myocardial injury associated with radiofrequency catheter ablation. Prolonged procedure time, RF applications, the use of impedance ablation catheter and ventricular ablation site were associated with elevated troponin T concentration after RFCA.

Reliability of Thai version of SF-36 questionnaire for the evaluation of quality of life in cardiac patients.

Quality of life is an important measurement of medical outcomes. Reliability of a Thai version of the SF-36 questionnaire has never been reported. The objective of this study was to determine the reliability of a Thai version of the SF-36 questionnaire in cardiac patients. We developed a Thai version of the SF-36 questionnaire and tested it in 212 cardiac patients. Reliability of the Thai version of the SF-36 questionnaire was assessed by internal consistency using Cronbach's Alpha statistic and inter-item correlation. We demonstrated that Cronbach's Alpha coefficient of every aspect of QOL exceeded 0.7, and all inter-item correlation exceeded 0.4. In conclusion, the Thai version of the SF-36 questionnaire is a valuable tool in assessing medical outcomes and medical research in Thai patients with cardiac disease. Whether it can be used in other diseases remains unknown.

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.

Impaired fasting glucose, diabetes mellitus and coronary risk factors.

The authors conducted a prevalence survey of impaired fasting glucose and diabetes mellitus in 3,615 Shinawatra employees, and we also determined various risk factors of coronary artery disease such as blood pressure level, body mass index and serum lipids. The prevalence of impaired fasting glucose and diabetes mellitus were 1.7 per cent and 0.8 per cent respectively. The prevalences were more common in males and increased with increasing age. Coronary risk factors were higher in impaired fasting glucose (IFG) and diabetes mellitus (DM) when compared with normal glucose levels. There were also significant differences between impaired fasting glucose and diabetes mellitus, except for pulse pressure, serum cholesterol level, LDL-cholesterol level and HDL-cholesterol level.

Comparison of supraventricular tachycardia from concealed bypass tract and Wolff-Parkinson-White syndrome.

Supraventricular tachycardia (SVT) is a common problem. There are 2 types of accessory atrioventricular pathway (AP) causing SVT: one can conduct antegradely (WPW syndrome) and another can conduct only in a retrograde direction (concealed bypass tract or CBT). There are little data of the significance and difference of the two types in Thailand. The objectives of this study were to compare characteristics of patients, accessory pathways and outcome of radiofrequency catheter ablation (RFCA) between the 2 types of accessory pathways. We reviewed the electrophysiology report of patients with supraventricular tachycardia from the accessory pathway who were referred for RFCA. There were 74 males and 74 females at a mean age of 37 years. CBT accounts for 44 per cent of SVT from AP. Compared to CBT, WPW syndrome was more in the right-sided location, more associated with heart disease, a higher number of accessory pathways, more inducible atrial fibrillation and more difficult to do ablation. However, the overall success rate of RFCA was similar. Although the recurrence rate was 8.4 per cent, all patients with recurrence were successfully reablated. We concluded from this study that RFCA is a highly effective method for the treatment for both forms of accessory pathway although there are some differences between WPW syndrome and CBT.

Are routine checkups necessary?: The Shinawatra's employee study.

The authors performed a survey in 3,615 Shinawatra employees aged 18-60 years to determine the abnormalities found with routine checkup. The annual checkup included: history taking. anthropometric measurement, physical examination, complete blood count, urine analysis, chest roentgenography, blood chemistry (fasting blood glucose, BUN, creatinine, uric acid, AST/ALT, cholesterol, triglyceride and HDL-cholesterol). The prevalence of abnormalities with management change detected by complete blood count, urine analysis was low and we did not recommend the routine use of complete blood count and urine analysis. The prevalence of hypertension was more common in males and the prevalence increased sharply after the age of 25 years in males and 40 years in females. The prevalence of abnormalities of BUN, creatinine (both males and females) and uric acid (in females) was very low. There was high prevalence of high AST/ALT which suggested hepatitis in our population, and the prevalence was more common in males beginning at a young age. Diabetes mellitus was more common in males especially after the age of 45 years. Chest roentgenography abnormalities were found in 9.4 per cent and the prevalence of abnormalities increased with age and was common after the age of 44 years. Most of the abnormalities found by chest roentgenography were pulmonary infiltration and cardiomegaly. The authors' findings did not recommend the routine use of complete blood count, urine analysis, fasting BUN and creatinine. We recommend routine blood pressure measurement in males aged 25 years or more and in females aged 40 years or more. We suggest routine blood cholesterol measurement in both sexes, blood triglyceride measurement in males aged 25 years or more and fasting blood sugar tests in males aged more than 44 years, chest roentgenography in males and females after the age of 45 years.

Biosense mapping for ablation of ventricular tachycardia in cardiomyopathy.

Using conventional technology, radiofrequency ablation of ventricular tachycardia in cardiomyopathy is frequently unsuccessful because of hemodynamic instability, multiple foci and recurrences. The Biosense CARTO nonfluoroscopic mapping and navigation system, when used to locate the area of the scar or reentry circuit, has the potential to improve the successful ablation, and reduce the rate of recurrence. We report 2 cases here of ventricular tachycardia in cardiomyopathy in which Biosense mapping was useful to identify the area of scar in 1 case, and the area of microreentry circuits in another. Radiofrequency ablation was possible and successful, while the use of conventional mapping was impossible or had recurrence.

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.

Radiofrequency catheter ablation: 5 years experience at Siriraj Hospital.

Between February 1995 to May 2000, 626 consecutive patients underwent radiofrequency catheter ablation for various types of cardiac arrhythmia. The mean age was 41 years, range 1-85 years. Mapping and ablation were guided by intracardiac electrogram and anatomical approaches. The initial success, compliction, recurrent and final success rates are shown below:- [table; see text] Conclusion, RFCA is an effective treatment and should be considered as first line treatment for certain tachyarrhythmia.

Hyperhomocysteinemia in patients with coronary artery disease.

Hyperhomocysteinemia has been recognized as a risk factor of atherosclerosis. This study was aimed to measure the risk of coronary artery disease in patients with hyperhomocysteinemia. Age, HDL level, tHcy level and history of DM were independent risk factors for coronary artery disease. The level of tHcy of 11.0 mmol/L provides the best sensitivity and specificity of predicting coronary artery disease.

Obesity and risk factors of coronary heart disease in healthy Thais: a cross-sectional study.

Association between obesity and conventional risk factors for coronary artery disease is well established. Obesity is currently considered an independent risk for coronary artery disease. The relationship between body mass index (BMI) and fasting plasma lipids and glucose and blood pressures in non-obese subjects is not established. The authors studied relationships between BMI and lipids, and glucose, and blood pressure levels in healthy a population. The authors measured the weights and heights of 3,615 employees of a company during a routine yearly health examination. There were 1,250 males aged 31.3 +/- 6.6 and 2,365 females aged 29.3 +/- 4.9 years old. The average BMI for males and females were 23.5 +/- 3.6 and 20.1 +/- 3.0 respectively. The levels of total cholesterol (Chol), LDL-cholesterol, and triglyceride (TG), fasting plasma glucose (FPG) had a positive relationship with BMI (r = 0.22, 0.26, 0.41, 0.20; p < 0.001). HLD-cholesterol had a negative correlation with BMI (r = -0.36, p < 0.001). Both systolic (SBP) and diastolic (DBP) blood pressures had a positive correlation with BMI. The association persisted after all values were adjusted by age and sex. BMI has a significant positive relationship with the conventional risk factors for coronary artery disease and a negative relationship with HDL-cholesterol.

The prevalence of left ventricular hypertrophy and associated factors in a Thai population.

Electrocardiographic left ventricular hypertrophy (LVH) has been a bad prognostic factor for cardiovascular morbidity and mortality. However the prevalence and prognostic value of LVH are varied among nationalities and populations. Several factors have been shown to associate with LVH. Some factors are treatable such as hypertension. We prospectively studied the prevalence of LVH and associated factors in selected group of Thai population. The study population was 1,606 Shinawatra employees who were 30 year old or more. The prevalence of LVH was 13 per cent (210) among study population. Hypertension, lower body weight and male sex were significantly associated factors. In the subjects with LVH, the prevalence of hypertension was 25.6 per cent, male ratio was 5:1 and mean body weight was 57.7 kg, compare to 9.8 per cent prevalence of hypertension, 2:1 female ratio and mean body weight was 62.3 kg in the group without LVH.

Effect of atenolol on symptomatic ventricular arrhythmia without structural heart disease.

Ventricular arrhythmia (VA) from right ventricular outflow tract (RVOT) is a common problem. Symptomatic patients are usually treated with beta-blockers. There is little data on the systematic evaluation of the drug efficacy. The objectives of this study were 1) To determine proportion of exercise induced ventricular arrhythmia among patients with symptomatic ventricular arrhythmia and 2) to determine the response to beta blockers and the correlation between the response to betablockers and exercise induced VA. We prospectively studied 46 consecutive patients with symptomatic ventricular arrhythmia. Patients recorded their symptom scores underwent exercise testing and 24-hour ambulatory monitoring before treatment and 1 month after atenolol. Exercise induced ventricular arrhythmia was demonstrated in 28 per cent of patients with symptomatic ventricular arrhythmia. Atenolol improves symptoms, decreases PVC count from ambulatory monitoring, increases exercise duration and suppresses malignant form of VA during exercise. These effects are at a similar extent in both groups of patients: those with and without exercise induced VA. However, the effect on ventricular arrhythmia suppression during exercise of atenolol was seen only in patients with increased PVC during exercise. In conclusion, atenolol is a good option in treating patients with symptomatic VA from RVOT regardless of the pattern of PVC response to exercise. Atenolol can suppress PVC during exercise testing better in patients with exercise induced VA compared to those without.

Comparison of parathyroid hormone in angiographically-demonstrated coronary artery disease patients and healthy Thais.

Parathyroid hormone (PTH) influences the calcium metabolism. The idea of cardiovascular effects of PTH is not new. Target cells for PTH are cardiomyocytes and smooth muscle cells. Evidence from previous studies suggest that many patients with heart disease have elevated PTH concentrations. Our objective was to determine PTH status in patients with coronary artery disease (CAD). We compared intact PTH levels in 109 CAD patients with 103 healthy people by electrochemiluminescence immunoassay. Mean values of PTH in healthy Thais and CAD patients were 37.4 +/- 17.9 and 40.2 +/- 21.8 respectively. No statistical difference was shown. In addition, we compared PTH levels among various numbers of coronary occlusion and also found no differences. We propose that intact PTH concentrations in CAD patients are not higher than in the healthy population.