Role of risk factors for major coronary heart disease events with increasing length of follow up.
(33/30946)
BACKGROUND: It has been suggested that the predictive value of certain risk factors for coronary heart disease (CHD) measured at one point in time diminishes with increasing length of follow up. DESIGNS AND METHODS: The relation was examined between a wide range of risk factors and the risk of major CHD events over 15 years' total (cumulative) follow up and for three separate five year periods (0-5.0, 5.1-10.0, and 10.1-15.0 years) in men with and without diagnosed CHD in a large prospective study of 7735 men aged 40-59 years. SETTING: General practices in 24 towns in the UK. RESULTS: The cumulative CHD event rate for all men was 9.4/1000 person-years for the 15 years of follow up. In men with no recall of a diagnosis of CHD, the established risk factors-serum total cholesterol, high density lipoprotein cholesterol, systolic and diastolic blood pressure, physical activity, body mass index (BMI), alcohol intake, diabetes mellitus, parental history, and evidence of CHD on chest pain questionnaire or on ECG-were predictive of CHD events occurring in the three specific periods after baseline measurement. Blood pressure (systolic and diastolic) was still predictive of events occurring 10.1-15.0 years later with some attenuation in the relative risk associated with systolic blood pressure. The risks associated with blood glucose and serum insulin concentration, factors measured with greater imprecision, attenuated with longer follow up and were not predictive of events occurring 10. 1-15.0 years later. In men with recall of diagnosed CHD, the absolute risk was very high (38.8/1000 person-years); only cigarette smoking, BMI, total cholesterol, and serum insulin were predictive of CHD events occurring 10.1-15.0 years later. CONCLUSION: In men without recall of diagnosed CHD most major risk factors measured in middle age predict risk of CHD events occurring in up to 15 years of follow up, both cumulatively and in the three separate five year periods. Risk factors measured at one point in time in middle age may be regarded as reliable indicators for long term prognosis of major CHD events on a group basis, despite the changes that may take place in these risk factors in some individuals during prolonged follow up. (+info)
Arterial thromboembolism in patients with sick sinus syndrome: prediction from pacing mode, atrial fibrillation, and echocardiographic findings.
(34/30946)
OBJECTIVE: To evaluate whether thromboembolism in sick sinus syndrome can be predicted by pacing mode, atrial fibrillation, or echocardiographic findings. METHODS: Patients were randomised to single chamber atrial (n = 110) or ventricular (n = 115) pacing. They were divided into subgroups with and without brady-tachy syndrome at time of randomisation. The occurrence of atrial fibrillation and thromboembolism during follow up were investigated and compared with echocardiographic findings. RESULTS: The annual risk of thromboembolism was 5.8% in patients with brady-tachy syndrome randomised to ventricular pacing, 3.2% in patients without brady-tachy syndrome randomised to ventricular pacing, 3% in patients with brady-tachy syndrome randomised to atrial pacing, and 1.5% in patients without brady-tachy syndrome randomised to atrial pacing. In atrial paced patients without brady-tachy syndrome at randomisation and without atrial fibrillation during follow up, the annual risk of thromboembolism was 1.4%. Left atrial size measured by M mode echocardiography was of no value in predicting thromboembolism. CONCLUSIONS: Arterial thromboembolism in patients with sick sinus syndrome is very common and is associated primarily with brady-tachy syndrome at randomisation and with ventricular pacing. The risk of thromboembolism is small in atrial paced patients in whom atrial fibrillation has never been documented. (+info)
Does withdrawal of different antiepileptic drugs have different effects on seizure recurrence? Further results from the MRC Antiepileptic Drug Withdrawal Study.
(35/30946)
One thousand and thirteen patients, in remission of epilepsy for at least 2 years, were randomized to continued therapy or slow withdrawal over 6 months and were followed up for a median period of 5 years. At the time of randomization 83% of patients were receiving monotherapy with carbamazepine (237 patients), phenobarbitone/primidone (72 patients), phenytoin (184 patients) or valproate (228 patients) in low doses, and plasma levels were below the usual optimal range. The most important factor determining seizure recurrence was continued therapy, which was the case for barbiturates, phenytoin and valproate. There was no significant difference for patients taking carbamazepine at randomization, because of a low rate of recurrence in those withdrawing treatment. The difference between carbamazepine and other drugs was not explained by differences in covariate prognostic factors. There was no evidence that withdrawal of phenobarbitone was associated with withdrawal seizures. These data provide unique evidence for the effectiveness of standard antiepileptic drugs as monotherapy. The results for carbamazepine may be open to a number of interpretations. (+info)
A risk assessment for exposure to grunerite asbestos (amosite) in an iron ore mine.
(36/30946)
The potential for health risks to humans exposed to the asbestos minerals continues to be a public health concern. Although the production and use of the commercial amphibole asbestos minerals-grunerite (amosite) and riebeckite (crocidolite)-have been almost completely eliminated from world commerce, special opportunities for potentially significant exposures remain. Commercially viable deposits of grunerite asbestos are very rare, but it can occur as a gangue mineral in a limited part of a mine otherwise thought asbestos-free. This report describes such a situation, in which a very localized seam of grunerite asbestos was identified in an iron ore mine. The geological occurrence of the seam in the ore body is described, as well as the mineralogical character of the grunerite asbestos. The most relevant epidemiological studies of workers exposed to grunerite asbestos are used to gauge the hazards associated with the inhalation of this fibrous mineral. Both analytical transmission electron microscopy and phase-contrast optical microscopy were used to quantify the fibers present in the air during mining in the area with outcroppings of grunerite asbestos. Analytical transmission electron microscopy and continuous-scan x-ray diffraction were used to determine the type of asbestos fiber present. Knowing the level of the miner's exposures, we carried out a risk assessment by using a model developed for the Environmental Protection Agency. (+info)
Gestational trophoblastic disease: does central nervous system chemoprophylaxis have a role?
(37/30946)
In the UK there are standardized surveillance procedures for gestational trophoblastic disease. However, there are differences in practice between the two treatment centres in terms of definition of persistent gestational trophoblastic disease, prognostic risk assessment and chemotherapeutic regimens. The role of prophylactic chemotherapy for cerebral micrometastatic disease in persistent gestational trophoblastic disease is unclear. We have analysed the outcome of 69 patients with lung metastases who elsewhere might have received prophylactic intrathecal chemotherapy. Of the 69 patients, 67 received intravenous chemotherapy only. The other two patients had cerebral metastases at presentation. One patient who received only intravenous chemotherapy subsequently developed a cerebral metastasis, but this patient's initial treatment was compromised by non-compliance. This experience supports our current policy of not treating patients with pulmonary metastases, without clinical evidence of central nervous system (CNS) involvement, with prophylactic intrathecal therapy. (+info)
Alcohol consumption and breast cancer oestrogen and progesterone receptor status.
(38/30946)
We examined the role of alcohol on the risk of breast cancer by the joint oestrogen receptor (ER) and progesterone receptor (PR) status of the tumour using data from two case-control studies conducted in Los Angeles County, USA. Eligible premenopausal patients were 733 women aged < or =40 years and first diagnosed from 1 July 1983 to 1 January 1989. Eligible postmenopausal patients were 1169 women aged 55-64 years and first diagnosed from 1 March 1987 to 31 December 89. Patients were identified by the University of Southern California Cancer Surveillance Program. Neighbourhood controls were individually matched to patients by parity (premenopausal patients) and birth date (+/-3 years). ER and PR status were obtained from medical records for 424 premenopausal and 760 postmenopausal patients. The analyses included 714 premenopausal and 1091 postmenopausal control subjects. Alcohol use was generally not associated with premenopausal risk of breast cancer, regardless of hormone-receptor status. Among the postmenopausal women, those who consumed, on average, > or =27 g of alcohol/d experienced an odds ratio (OR) of 1.76 [95% confidence interval (CI) 1.14-2.71] for ER-positive/PR-positive breast cancer relative to women who reported no alcohol consumption. Alcohol use was less clearly associated with risk of other receptor types among postmenopausal women. These data suggest that alcohol may preferentially increase risk of ER-positive/PR-positive breast cancer in postmenopausal women. (+info)
Prolonged QT interval predicts cardiac and all-cause mortality in the elderly. The Rotterdam Study.
(39/30946)
AIMS: To examine the association between heart-rate corrected QT prolongation and cardiac and all-cause mortality in the population-based Rotterdam Study among men and women aged 55 years or older and to compare the prognostic value of the QT interval, using different formulas to correct for heart rate. METHODS AND RESULTS: After exclusion of participants with arrhythmias or bundle branch block on the ECG, the study population consisted of 2083 men and 3158 women. The QT interval was computed by the Modular ECG Analysis System (MEANS). Data were analysed using Cox' proportional hazards model. Participants in the highest quartile of the heart-rate corrected QT interval had about a 70% age- and sex-adjusted increased risk for both all-cause mortality (hazard ratio (HR) 1.8; 95% CI:1.3-2.4) and cardiac mortality (HR 1.7; 95% CI:1.0-2.7) compared to those in the lowest quartile. In women, the increased risk associated with prolonged QT for cardiac death was more pronounced than in men. These risk estimates did not change after adjustment for potential confounders, including history of myocardial infarction, hypertension and diabetes mellitus. CONCLUSION: A prolonged heart-rate corrected QT interval is an independent predictor for cardiac and all-cause mortality in older men and women. The risk associated with prolonged QT is hardly affected by the heart-rate correction formula used. (+info)
Incidence and clinical relevance of coronary calcification detected by electron beam computed tomography in heart transplant recipients.
(40/30946)
BACKGROUND: Patients treated by cardiac transplantation who survive beyond one year are at significant risk from fatal coronary artery disease. The development of coronary artery calcification in these patients is discussed and methods available to detect it are reviewed. OBJECTIVES: To assess the clinical importance of coronary artery calcium in heart transplant recipients. METHODS: In a cohort of 102 cardiac transplant recipients, electron beam computed tomography was used to measure calcium in the coronary arterial wall 63 days to 9.1 years (median 4.6 years) after transplantation. The results were compared with angiographic findings and with conventional coronary disease risk factors. The patients were followed for a mean of 2.12 years (1.2-4.02 years) to assess the relationship between these findings and future cardiac events. RESULTS: Forty-one (40.2%) had a stenosis of > 24% in one or more major coronary artery at angiography. Forty-six (45%) had a coronary calcium score > 0. The absence of calcium had a negative predictive value with respect to angiographic disease in any vessels of 87.5%. Logistic regression revealed that dyslipidaemia, systemic hypertension and organ ischaemic time were significant predictors of calcification. At follow-up, both an abnormal coronary angiogram and coronary calcium were found to be the only significant predictors of late events. Multivariate analysis suggested that the detection of coronary calcium did not offer any additional predictive information over that provided by the angiogram itself. CONCLUSION: Electron beam computed tomography is well suited to the assessment of calcium in the coronary arteries of heart transplant recipients, although the mechanisms of this calcification remain poorly understood. Calcium is detected more frequently than would be suggested by studies using intravascular ultrasound. It is associated with the presence of angiographic disease, and with some conventional risk factors for coronary disease. At follow-up the presence of coronary calcium was associated with an adverse clinical outcome, as it is in conventional ischaemic heart disease. (+info)