Attitudes and practices of New Zealand anaesthetists with regard to epidural and subarachnoid anaesthesia.

A survey was conducted among 259 New Zealand specialist anaesthetists to assess attitudes and practices with regard to epidural or subarachnoid anaesthesia (ESA). Ninety-four per cent replied and virtually all of the respondents indicated that they performed ESA at some time. ESA was used by most anaesthetists for most patients undergoing major hip or knee surgery, abdomino-perineal resection, cystectomy, caesarean section or transurethral resection of the prostate, ESA was used is about half of patients undergoing abdominal aortic aneurysm repair, femoro-popliteal bypass or thoracotomy and there was marked variation between anaesthetists in the frequency of using ESA for these procedures.

Blood pressure lowering for the primary and secondary prevention of coronary and cerebrovascular disease.

An overview of the 17 completed randomised trials of antihypertensive treatment demonstrates that a 5-6 mm Hg reduction in DBP reduced stroke risk by 38% (SD 4) and CHD risk by 16% (SD 4). These results indicate that a few years' treatment with diuretic- or beta-blocker-based therapy produces most or all of the long-term stroke avoidance and much of the long-term CHD avoidance that would be predicted from observational epidemiological studies, given the blood pressure reductions that were achieved in the trials. The relative risk reductions were similar in trials of older and younger patients, although the absolute reduction in events was more than twice as great in the trials in older patients.

Fletcher Challenge-University of Auckland Heart & Health Study: design and baseline findings.

Aims: The aims of this prospective observational study are to determine the relationship of sociodemographic factors, psychological factors and several factors measured in blood, with the risk of coronary heart disease (CHD) in a New Zealand population.

Methods: Participants were recruited from two sources: employees of the Fletcher Challenge Group and individuals listed on the general electoral roll for the Auckland region. Baseline and follow up risk factor data were obtained from a questionnaire, blood samples and a simple physical examination.

PROGRESS (perindopril protection against recurrent stroke study): rationale and design. PROGRESS Management Committee [corrected].

Rationale: Patients with a history of cerebrovascular disease have a very high risk of stroke, and usual levels of both systolic and diastolic blood pressure are directly and continuously associated with this risk. Trials of blood pressure lowering in patients with transient ischaemic attacks or stroke have been too small to reliably detect the effects on stroke risk of the modest blood pressure reductions achieved.

Objectives: The primary objective of PROGRESS is to determine precisely the effects of blood pressure reduction with an angiotensin converting enzyme (ACE) inhibitor-based regimen on the stroke risk in patients with a history of transient ischaemic attacks or minor stroke.

Hospital admissions and deaths due to congestive heart failure in New Zealand, 1988-91.

Aims: Congestive heart failure is believed to be a major public health problem in most Western countries; however, little is known about the extent of morbidity and mortality from congestive heart failure in New Zealand. This paper reports data on hospital admissions and mortality due to congestive heart failure in New Zealand during the years 1988-91.

Methods: All data were obtained from the New Zealand Health Information Service.

Absence of effect of simvastatin on the progression of lens opacities in a randomised placebo controlled study. Oxford Cholesterol Study Group.

Aims: A detailed assessment of ophthalmic effects of an HMG CoA reductase inhibitor, simvastatin, was performed.

Methods: Six hundred and twenty one individuals considered to be at increased risk of coronary heart disease were randomised, following an 8 week placebo 'run in' period, to receive 40 mg daily simvastatin, 20 mg daily simvastatin, or matching placebo. Patients with a baseline corrected visual acuity better than 6/24 and without a history of cataract were eligible for detailed ophthalmic assessment at 6 months (539 patients assessed) and at 18 months (474 patients assessed).

Blood pressure and mortality among men with prior myocardial infarction. Multiple Risk Factor Intervention Trial Research Group.

Background: The purpose of the present study was to describe the relation between blood pressure (systolic [SBP] and diastolic [DBP]) and death from coronary heart disease (CHD) and all causes for men with a history of myocardial infarction (MI).

Methods And Results: The study cohort consisted of men aged 35 to 57 years screened for the Multiple Risk Factor Intervention Trial (MRFIT) in 1973 through 1975 and followed for survival for an average of 16 years through 1990. There were 5362 men who reported prior hospitalization for a heart attack of at least 2 weeks' duration at the initial screening of MRFIT.

Association of angiotensinogen gene T235 variant with increased risk of coronary heart disease.

Several genes, including some encoding components of the renin angiotensin system, are associated with the risk of cardiovascular diseases. There have been reports linking a homozygous deletion allele of the angiotensin converting enzyme (ACE) gene (DD) with an increased risk of myocardial infarction, and some variants of the angiotensinogen gene with an increased risk of hypertension. In a case-control study of a caucasian population from New Zealand, we examined the associations with coronary heart disease (CHD) of ACE DD and of a mis-sense mutation with methionine to threonine aminoacid substitution at codon 235 in the angiotensinogen gene (T235).

Systematic underestimation of treatment effects as a result of diagnostic test inaccuracy: implications for the interpretation and design of thromboprophylaxis trials.

Many clinical trials that have assessed strategies for the prevention of deep vein thrombosis have employed diagnostic tests that are less accurate than venography. The correct interpretation of these trials has been the subject of considerable debate. This paper attempts to quantify the likely effects of the use of inaccurate diagnostic tests (in particular fibrinogen scanning) on the validity and precision of estimates of treatment effects.

Blood pressure, antihypertensive treatment and stroke risk.

Unlabelled: ASSOCIATION BETWEEN BLOOD PRESSURE AND STROKE: Data from prospective observational studies indicate that usual levels of blood pressure are directly and continuously related to the risk of stroke. The strength of this association has been substantially underestimated by many previous analyses that have not taken account of the regression dilution bias; correction for this increases the strength of the association between blood pressure levels and stroke risk by about 60%. From corrected analyses it is apparent that a prolonged difference in usual systolic/diastolic blood pressure levels of just 9/5 mmHg would eventually confer about a one-third difference in stroke risk, with similar proportional effects in hypertensives and normotensives.

Blood pressure, antihypertensive drug treatment and the risks of stroke and of coronary heart disease.

Most evidence about the effects of blood pressure on the risks of cardiovascular disease derives from two principal sources: prospective non-randomised observational studies of the associations between blood pressure and the incidence of stroke and of coronary heart disease, and randomised trials of antihypertensive drug therapy. The focus of the first part of this chapter concerns the evidence from observational studies, which--despite the possibility of confounding by other risk factors--may be more relevant to the eventual effects of prolonged blood pressure differences on stroke and coronary heart disease risk. The focus of the second part concerns the evidence from randomised trials of antihypertensive drug treatment, which are more relevant to assessing how rapidly, and to what extent, the epidemiologically expected reductions in stroke or in coronary heart disease are produced by suddenly lowering blood pressure in middle and old age.

Pharmacological thromboprophylaxis in hip and knee surgery: a survey of New Zealand orthopaedic surgeons.

A survey was conducted of the attitudes and practices of New Zealand orthopaedic surgeons on the use of pharmacological thromboprophylaxis (PT) for patients undergoing major hip or knee surgery. A questionnaire was sent to all 106 consultant surgeons known to perform hip or knee surgery and a response rate of 89% was obtained. The results suggested that while almost all surgeons used PT at some time, only about one-third of elective surgery patients and just a few per cent of patients with neck of femur fracture (NOFF) receive PT.

Beta-blockers in heart failure: promising or proved?

Despite recent improvements in the management of congestive heart failure, the prognosis of many patients with this condition remains poor. The level of neurohormonal activation appears to be predictive of survival, and clinical studies indicate that inhibition of overactivated neurohormonal systems may be beneficial. Activation of the renin-angiotensin-aldosterone system is well documented in heart failure, and angiotensin-converting enzyme inhibition now has an established role in treatment based on evidence of hemodynamic, symptomatic and mortality benefit.

Three-year follow-up of the Oxford Cholesterol Study: assessment of the efficacy and safety of simvastatin in preparation for a large mortality study.

We report the results of a randomized single-centre study designed to assess the effects of simvastatin on blood lipids, blood biochemistry, haematology and other measures of safety and tolerability in preparation for a large-scale multicentre mortality study. Six hundred and twenty-one individuals considered to be at increased risk of coronary heart disease were randomized, following a 2-month placebo 'run-in' period, to receive 40 mg daily simvastatin, 20 mg daily simvastatin or matching placebo. Their mean age was 63 years, 85% were male, 62% had a history of prior myocardial infarction (MI), and the mean baseline total cholesterol was 7.

Cholesterol reduction and death from non-coronary causes: evidence from randomised controlled trials.

An overview of randomised trials of cholesterol reduction (26 trials, 50,000 patients, net cholesterol reduction approximately 10%) provides clear evidence of a reduction in the incidence of coronary heart disease (CHD) after just a few years of treatment. Overall, the observed reduction in CHD death (9% +/- 3) was only half as large as the reduction in non-fatal myocardial infarction (19% +/- 4), although both were statistically significant (2p < 0.005).

Estimation of arterial stiffness, compliance, and distensibility from M-mode ultrasound measurements of the common carotid artery.

Background And Purpose: Arterial stiffness may indicate early vascular changes that predispose to the development of major vascular disease. The repeatability of a variety of indices of arterial stiffness calculated from a standard carotid arterial M-mode ultrasound image was investigated.

Methods: Twenty-six asymptomatic normal subjects were imaged and had blood pressure recordings on each of two separate occasions at least 1 day apart.

The effects of blood pressure reduction in older patients: an overview of five randomized controlled trials in elderly hypertensives.

Direct evidence about the effects of antihypertensive treatment on vascular disease in older patients is available from five randomized trials conducted exclusively in patients over the age of 60 years. These trials involved a total of 12,483 individuals with systolic or diastolic hypertension (mean age = 72 years, mean entry blood pressure = 181/88 mmHg). Over an average follow-up period of 4.

B-mode ultrasound images of the carotid artery wall: correlation of ultrasound with histological measurements.

B-mode ultrasound is being used to assess carotid atherosclerosis in epidemiological studies and clinical trials. Recently the interpretation of measurements made from ultrasound images has been questioned. This study examines the anatomical correlates of B-mode ultrasound of carotid arteries in vitro and in situ in cadavers.

Management of raised blood pressure in New Zealand: a discussion document.

A report to the National Advisory Committee on Core Health and Disability Support Services, New Zealand, on the management of raised blood pressure recommends that decisions to treat raised blood pressure should be based primarily on the estimated absolute risk of cardiovascular disease rather than on blood pressure alone. In general, patients with a blood pressure of 150-170 mm Hg systolic or 90-100 mm Hg diastolic, or both, should be given treatment to lower blood pressure if the risk of a major cardiovascular disease event in 10 years is more than about 20%. The results of clinical trials indicate that, at this level of absolute risk, 150 people would require treatment to reduce the annual number of cardiovascular events by about one.