The association of apolipoprotein B and low density lipoprotein with cardiovascular risk factors in the Thai population.

BACKGROUND: Although direct and calculated low density lipoprotein cholesterol (LDL-cholesterol) has been widely used as an important predictor for cardiovascular risk, many studies have shown that apolipoprotein B (apo B) may be a more important lipoprotein marker. MATERIAL AND METHOD: We performed a cross-sectional study on 191 volunteers who were Shinawatra employees during their annual physical check up. The following cardiovascular risk factors were recorded or measured: direct and calculated LDL, apo B, gender age, total cholesterol, triglyceride, HDL-cholesterol (HDL), calculated LDL, fasting plasma glucose (FPG), systolic and diastolic blood pressure, smoking status, body mass index (BMI), waist circumference, and waist-hip ratio (WHR). Apo B, direct LDL and calculated LDL levels were tested for their associations with other potential cardiovascular risk factors. RESULTS: There were a total of 76 men and 115 women with an average age of 28.8 +/- 5.4 years. Male gender, cigarette smoking, high cholesterol, high triglyceride, high fasting plasma glucose, hypertension, high WHR and high BMI were associated with increased apo B level. Only male gender and high cholesterol were associated with increased calculated and direct LDL level. The association of direct and calculated LDL-cholesterol level with cardiovascular risk factors appears to be similar. CONCLUSION: We demonstrated that apo B level correlates more with other cardiovascular risk factors compared to direct and calculated LDL-cholesterol. The clinical relevance of this finding needs to be explored in large-scale studies.

Radiofrequency catheter ablation for various tachyarrhythmias: experience in the Bangkok Heart Institute.

Radiofrequency catheter ablation (RFCA) is the first-line therapy for various tachyarrhythmias. The authors reports experience of RFCA for various types of tachyarrhythmia in 80 consecutive patients, 85 tracts of ablation, from May 2001 to October 2002. The mean age was 40 years, range 6-81 years. Seventy four and 13 tracts of ablation were supraventricular and ventricular arrhythmia, respectively. The results are shown below. [table: see text] Conclusion: RFCA is an effective method to cure various types tachyarrhythmia. Long-term follow-up should be evaluated in patients with paroxysmal atrial fibrillation.

Clinical experience of sirolimus-eluting stents in patients with coronary artery disease at Bangkok Heart Institute.

Drug eluting stents represent one of the fastest growing fields in interventional cardiology today. From a recent study, the sirolimus eluting stent (SES) (CYPHER, Cordis, Johnson & Johnson) appear to demonstrate a remarkable efficacy and safety in preventing restenosis. From the present study, the authors reported clinical experience of SES in 40 consecutive patients with coronary artery disease (CAD) between 25th June and 11th October, 2002. The mean age was 59 +/- 12.16 years (mean +/- SD) and 80 per cent of the patients were male. The majority of the patients had chronic stable angina and most percutaneous coronary interventions were performed by elective procedure (85%). Thirty-five per cent of the patients had single vessel disease and 42.5 per cent of the patients had double vessel disease. The authors successfully implanted 52 (69.3%) SES in 75 target lesions revascularization. Twenty-four (60%) of the patients had more than 1 vessel intervention. Twenty-seven (67.5%) of the patients had complete revascularization by percutaneous coronary intervention (PCI) and only 16 of 27 patients (59.3%) who had complete revascularization with SES. The SES were usually implanted at middle part of the left anterior descending artery (MLAD) (11 lesions), proximal part of the left anterior descending artery (PLAD) (8 lesions), middle part of the right coronary artery (MRCA) (8 lesions) and middle part of the left circumflex artery (MLCX) (6 lesions). The authors had to cover plaque entirely with SES, so SES implantation usually took longer than the bare stent (BS). The authors followed the initial clinical outcome of the patients within 1 month after discharge. Few adverse clinical events were found during 1 month follow-up because SES have a very low rate of restenosis in the short-term so, we have to follow-up the patients over a longer period and will report the clinical outcome in the next study.

Serum N-terminal pro-brain natriuretic peptide in normal Thai subjects.

Aminoterminal portion of pro-brain natriuretic peptide (NT-proBNP) appears to be useful in the screening, diagnosis and prognosis of left ventricular dysfunction and congestive heart failure. The purpose of this study was to determine the values of serum NT-proBNP in normal Thai subjects compared with subjects from other countries. The design is a cross sectional study. The authors enrolled 243 consecutive healthy subjects (134 males and 109 females) from the checkup department of Bangkok Hospital for NT-proBNP measurement. The serum fraction was measured for NT-proBNP concentration by using Elecsys 2010 (Roche Diagnostics, Switzerland). The concentrations of NT-proBNP in normal Thai subjects were 33.30 +/- 35.43 pg/ml. The NT-proBNP levels increased with age (age < or = 50 years = 27.56 + 28.77 pg/ml and age > 50 years = 47.20 +/- 45.18 pg/ml, p < 0.001). Females usually have higher NT-proBNP than males (females = 40.42 +/- 31.59 pg/ml, males = 27.51 +/- 37.40 pg/ml, p = 0.0045). This study established the NT-proBNP concentrations in normal Thai subjects, which were not different from other studies. The authors suggested the normal cut-off values for subjects aged < or = 50 years should be 100 pg/ml and the normal cut-off values for subjects aged > 50 years should be 200 pg/ml. The NT-proBNP assay could be used as a rule out marker for heart failure in patients and may trigger further cardiac investigation.

Accuracy of international normalized ratio determined by portable venous-blood coagulation monitor versus a central laboratory.

BACKGROUND: The CoaguChek is a portable monitor unit for measuring the international normalized ratio (INR). The purpose of the study was to evaluate the accuracy of a portable prothrombin time (PT) monitor (CoaguChek, Roche Diagnostics, Mannheim, Germany) compared with the laboratory method. MATERIAL AND METHOD: Paired venous blood INRs were performed in 220 consecutive outpatient tests mainly in anticoagulated (n = 210) and non-anticoagulated (n = 10) individuals. Accuracy was evaluated in 220 tests by parallel assessment of INRs (CoaquChek and laboratory). Accuracy was determined using statistic regression analysis and clinical agreement (expanded and narrow criteria). Agreement in dual INR measurement also was evaluated as a function of increasing INR. RESULTS: The CoaguChek significantly correlated with the laboratory measurement (r = 0.89). The proportion of dual INR measurements that satisfied the clinical relevant expanded, and narrow agreement criteria was 90 per cent and 86 per cent respectively. Eighty-two per cent of all dual measurements were within 0.5 INR units. The accuracy of the portable monitor was greatest for INR values less than 3.0; above this INR level the portable monitor overestimated laboratory INR values. CONCLUSIONS: The CoaguChek is an accurate alternative to laboratory assessment of INR at values < 3.0. The authors suggest the use of the monitor in non anticoagulated patients or anticoagulated patients at values less than 3, as most physicians in Thailand prefer lower INR than in Western countries.

Role of the plasma brain natriuretic peptide in differentiating patients with congestive heart failure from other diseases.

BACKGROUND: Heart failure (HF) is primarily a disease of the elderly. The incidence of congestive heart failure (CHF) in Thailand has been increasing during the last 10 years. Unlike other diseases, physicians have only rough patients' symptoms and physical findings to guide the adequacy of treatment. Recently, there has been evidence of the role of brain natriuretic peptide (BNP) and its use in HF concerning diagnosis, prognosis, and treatment follow-up. The purpose of this study was to determine the sensitivity and specificity of N-terminal part of brain natriuretic peptide plasma level (NT-proBNP) in the diagnosis of HF in Thai patients who presented with dyspnea. METHOD: The design was a cross sectional study. The authors enrolled 50 consecutive patients from the Respiratory Unit with dyspnea from chronic obstructive pulmonary disease (COPD), asthma, or anxiety. The cardiovascular cause of dyspnea such as pulmonary emboli and poor left ventricular ejection fraction (LVEF) were excluded. Forty eight consecutive patients with evidence of HF who presented to the Cardiac Center with a history of dyspnea on exertion were assigned as cases. Five milliliters of venous blood samples were taken and sent together with 200 samples from a normal healthy population from the check up department for NT-proBNP measurement. RESULTS: In case and control groups, there were no statistical significances in sex (males 68.8% vs females 52.0%, p > 0.05) and age (63.3 +/- 14.9 vs 55.6 +/- 16.9; p > 0.05). The mean left ventricular ejection fraction in the case group was 32.4 +/- 9.7 per cent. There was significant difference between value of NT-proBNP in the control group (386 +/- 1,041 pg/ml) and in the case group (8,912 +/- 12,525 pg/ml, p < 0.001). To diagnose HF in patients who presented with dyspnea using the cut-off value of NT-proBNP at > 150 pg/ml in patients with dyspnea the sensitivity was 96 per cent, and the specificity of 72 per cent; at > 200 pg/ml the sensitivity was 96 per cent and the specificity was 80 per cent and at > 300 pg/ml the sensitivity was 94 per cent and specificity of 82 per cent. Plasma level of NT-proBNP increased significantly with increasing New York Heart Association (NYHA) functional class (class II: 1,107 +/- 1,091 pg/ml; class III: 5,097 +/- 4,201 pg/ml, class IV: 19,389 +/- 15,966 pg/ml p < 0.01). There was no significant difference of plasma NT-proBNP levels in patients with ischemic (8,586 +/- 11,601 pg/ml; n = 35) and those with non ischemic cardiomyopathy (9,789 +/- 15,229 pg/ml; n = 13). Plasma NT-proBNP was associated with neck vein distension (p < 0.05) but there was no significant association with S3, paroxysmal nocturnal dyspnea, rales, cardiomegaly, acute pulmonary edema, serum sodium (r = 0.22), ejection fraction (r = -0.18) and subsequent hospital death (p > 0.05). CONCLUSION: Measurement of plasma NT-proBNP proved to be a useful diagnostic test in differentiating HF from other causes in patients who presented with dyspnea.

A randomized clinical trial of the efficacy of radiofrequency catheter ablation and amiodarone in the treatment of symptomatic atrial fibrillation.

The limited efficacy and proarrhythmic risks of antiarrhythmia agents have resulted in alternative therapeutic approaches. Radiofrequency ablation has been reported to be an effective treatment of patients with atrial fibrillation. However, there is no randomized clinical trial comparing drug and radiofrequency ablation. The authors randomized 30 patients with chronic atrial fibrillation refractory to medication into amiodarone and radiofrequency ablation. The primary objective of this study was to compare the efficacy of amiodarone and radiofrequency ablation in the maintenance of sinus rhythm at 1 year after randomization. Pulmonary vein isolation and linear ablation of right atrium was the technique used for radiofrequency ablation. There were no significant differences in baseline patient characteristics between the 2 groups. The results of this study showed that the probability of free from atrial fibrillation was better in the radiofrequency ablation group compared to amiodarone (78.6% in the ablation group and 40% in the amiodarone group, p = 0.018). Radiofrequency ablation results in a significant reduction in symptoms relating to atrial fibrillation and a significant improvement in quality of life, whereas amiodarone had no significant effect on symptoms and quality of life. There was an ischemic stroke as a major complication related to radiofrequency ablation. Amiodarone was associated with adverse effects in 46.7 per cent of patients and needed discontinuation in 1 patient. In conclusion, radiofrequency ablation is an effective alternative treatment in patients with atrial fibrillation refractory to medication.

When should we order preoperative electrocardiography: A systematic review and clinical practice guidelines.

Routine preoperative investigation consumes many resources at the time when Thailand is suffering a severe financial crisis. The objectives of the study were to apply a systematic review to answer the question if routine preoperative investigation affects health outcomes; and to construct clinical practice guidelines for preoperative electrocardiography (ECG). The guidelines were prepared for elective, non-cardiothoracic surgery in adult patients. Methods of the study were a Medline search (1980-1998) and a search of studies published in Thailand. Criteria for high validity and reliability were applied to paper selection. The results of the systematic review were discussed among anesthesiologists and other specialists and the guidelines were drawn by consensus. Results from systematic review found that there were no randomized controlled trials to answer the question and no studies reported health outcomes. Routine preoperative investigation yielded few positive results and were not very useful for patient care. From this review and consensus, we proposed the following guidelines: a history questionnaire, physical examination, and indication for investigation. For the preoperative ECG, the indications are: age > 45 years, history of hypertension, heart disease, palpitation or frequent syncope, diabetes, chronic cough for > 3 weeks or pulmonary disease, heavy smoking (> 10 pack /days for> 10 years), radiotherapy or chemotherapy. Preoperative ECG carried out according to these guidelines would be more cost-effective and routine preoperative investigation should be abandoned.

When should we order preoperative complete blood count and urinalysis: A systematic review and clinical practice guidelines.

Routine preoperative investigation is expensive especially at this time when Thailand is suffering a severe financial crisis. Objectives of the study were to apply a systematic review to answer the question whether routine preoperative investigation affected health outcomes; and to construct clinical practice guidelines for preoperative complete blood count (CBC) and urinalysis (UA). The guidelines were prepared for elective, non-cardiothoracic surgery in adult patients. Methods of the study were Medline search (1980-1998) and a search of studies published in Thailand. Criteria for high validity and reliability were applied to paper selection. The results of the systematic review were discussed among anesthesiologists and other specialists and the guidelines were drawn by consensus. Results from the systematic review found that there were no randomized controlled trials to answer the question and no studies reported health outcomes. Routine preoperative CBC and urinalysis yielded few clinically significant positive results and was not very useful for patient care. From this review and the consensus, we proposed a guidelines, which consisted of a history questionnaire, physical examination and indication for investigation. For the pre-operative CBC the indication were: age > 60 years, would have an operation that needed blood transfusion, had acute or chronic blood loss, malnutrition, pregnancy, heart disease, cancer, chronic renal failure, liver disease, severe infection, SLE, connective tissue disease, radiotherapy or chemotherapy. The guidelines for preoperative UA were: pregnancy, diabetes, abnormal urination, chronic renal failure, SLE or connective tissue disease. Preoperative CBC and UA requests according to these guidelines should be more cost-effective and routine preoperative investigation should be abandoned.

Assessment of radiofrequency current-induced myocardial damage based on analysis of cardiac troponin T serum concentration.

The present study investigated the effect of radiofrequency (RF) current energy energy on the release pattern of myocardial marker proteins in 44 patients undergoing RF catheter ablation of supraventricular and ventricular tachycardia serial measurements of the activity of enzyme creatine kinase (enzymatic method), CK-MB isoneration TnT Enzymum ELISA, Boehringer Mannheim). The results showed that nearly all (91 percent) of the patients studied demonstrated a significant elevation in cTnT concentration following transcatheter applications of RF energy, whereas only 12 (27 percent) and 13 (29 percent) patients exhibited a postprocedural increase in CK and CK-MB activity, respectively. In contrast to the variable time for peak activity of CK and CK-MB, 40 of the 44 patients displayed an early peak cTnT concentration at eight hours after the procedure with a subsequent decline thereafter. Levels of cTnT and, to a lesser extent, CK but not CK-MB activity corressory pathways or atrioventricular nodal reentrant tachycardia. In conclusion, cardiac troponin T is a more sensitive indicator of RF energy-induced myocardial injury and has a more uniform pattern of myocardial release than the conventional CK and CK-MB. Determinations of cTnT serum concentration may thus provide a reliable method for assessing the extent of myocardial damage and for monitoring complications developed after radiofrequency or other froms of treascatheter ablation procedures.