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Biomedical subjects

C G Isles

Publications and source records attributed to C G Isles.

At least 19 recordsLinked to original sources
PubMed2002

High incidence of renal failure requiring short-term dialysis: a prospective observational study.

BACKGROUND: Previous estimates of incidence of acute renal failure (ARF) requiring renal replacement therapy have varied from 18 to 75 patients per million per year, but have been beset by problems of definition. AIM: To investigate whether the '90-day rule' provides a more reliable, reproducible and robust estimate of the need for short-term dialysis. SETTING: District general hospital serving a population of 147 000. DESIGN: Prospective observational study. METHODS: Patients who received renal replacement therapy in Dumfries and Galloway between 01/01/94 and 31/12/2000 were divided into two groups: long-term dialysis (> or =90 days) and short-term dialysis (<90 days). RESULTS: Of 302 patients, 193 received short-term dialysis, giving an incidence for short-term dialysis of 187 patient episodes per million per year (95%CI 170-203). Use of a more conventional definition for ARF (including all ARF and acute-on-chronic renal failure, but excluding patients with chronic renal failure who present acutely) produced a similar estimate at 176 patients per million per year (95%CI 160-193). DISCUSSION: The 90-day rule estimated the incidence of short-term dialysis/ARF at nearly twice the incidence of chronic renal failure requiring dialysis, and more than twice the most recent estimate of the incidence of ARF in the UK. The main attraction of the 90-day rule is its simplicity. If the high level of short-term dialysis/ARF found in our study is confirmed by other centres, there are significant resource implications for the provision of renal care.

Acute Kidney Injury↗
PubMed2001

Population implications of lipid lowering for prevention of coronary heart disease: data from the 1995 Scottish health survey.

OBJECTIVE: To determine the proportion of the population, firstly, with cholesterol >/= 5.0 mmol/l and, secondly, with any cholesterol concentration, who might benefit from statin treatment for the following: secondary prevention of coronary heart disease (CHD); primary prevention at CHD risk 30%, 20%, 15%, and 6% over 10 years; and primary prevention at projected CHD risk 20% over 10 years (CHD risk at age 60 years if actual age < 60 years). SUBJECTS: Random stratified sample of 3963 subjects aged 35-64 years from the Scottish health survey 1995. RESULTS: For secondary prevention 7.8% (95% confidence interval (CI) 6.9% to 8.6%) of the population with cholesterol >/= 5.0 mmol/l would benefit from statins. For primary prevention, the prevalence of people at CHD risk 30%, 20%, 15%, and 6% over 10 years is 1.5% (95% CI 1.2% to 1.9%), 5.4% (95% CI 4.7% to 6.1%), 9.7% (95% CI 8.8% to 10.6%), and 32.9% (95% CI 31.5% to 34.4%), respectively. At projected CHD risk 20% over 10 years, 12.4% (95% CI 11.4% to 13.5%) would be treated with statins. Removing the 5.0 mmol/l cholesterol threshold makes little difference to population prevalence at high CHD risk. CONCLUSIONS: Statin treatment would be required for 7.8% of the population for secondary prevention. For primary prevention, among other factors, guidelines should take into account the number of patients needing treatment at different levels of CHD risk when choosing the CHD risk to target. The analysis supports a policy of targeting treatment at CHD risk 30% over 10 years as a minimum, as recommended in current British guidelines, with a move to treating at CHD risk 15% over 10 years as resources permit.

Adult↗
PubMed2000

Identifying patients at risk for coronary heart disease: implications from trials of lipid-lowering drug therapy.

Abnormal lipid levels contribute significantly to the risk of coronary heart disease (CHD), which is increased further in the presence of other risk factors. The association between elevated low-density lipoprotein (LDL) cholesterol and CHD risk is well established, and large primary and secondary prevention studies of HMG-CoA reductase inhibitors (statins) have shown conclusively that lowering LDL cholesterol levels reduces CHD events and total mortality. Regardless of the intervention used (diet, surgery, drugs), reduction of plasma cholesterol has consistently produced a reduction in cardiovascular risk. Absolute benefit is greatest in those who are at highest risk initially, and trial results suggest that the lower the LDL cholesterol level achieved, at least down to LDL of 3.0 mmol/l, then the lower is the CHD event risk. Epidemiological data also point to the negative impact of other lipids on CHD risk. Low levels of high-density lipoprotein (HDL) and high levels of triglycerides (particularly in conjunction with an LDL/HDL ratio >5) are particularly strong risk factors for CHD. Thus, although prevention trials to date have primarily assessed the impact of LDL lowering on CHD events, the initial assessment of CHD risk should consider a more detailed atherogenic profile including HDL and triglyceride levels. A general approach to preventing cardiovascular disease should include strategies to reduce the overall CHD risk by lifestyle modification and management of modifiable risk factors such as smoking, hypertension and diabetes. Based on data from recent prevention studies, and because they are the most potent lipid-lowering agents available for lowering LDL cholesterol, statins have appropriately become the drug of choice for most patients with hyperlipidaemia who require drug therapy.

Adult↗
PubMed1999

A randomised double-blind study comparing nifedipine GITS 20 mg and bendrofluazide 2.5 mg administered once daily in mild-to-moderate hypertension.

A multicentre, randomised, double-blind, parallel group comparison of nifedipine GITS 20 mg (Adalat LA) once daily and bendrofluazide 2.5 mg once daily in patients with mild-to-moderate hypertension was conducted. Two hundred patients with a diastolic blood pressure (BP) in the range 95 to 109 mm Hg were randomised to active treatment for 6 weeks. For the per-protocol efficacy population, both treatments resulted in clinically significant mean reductions of trough diastolic BP (nifedipine GITS -8.9 mm Hg, bendrofluazide -7.9 mm Hg) and systolic BP (nifedipine GITS -10.4 mm Hg, bendrofluazide -10.5 mm Hg). The study demonstrated that nifedipine GITS was 'at least equivalent' to bendrofluazide in the reduction of trough diastolic BP (one-sided upper 95% confidence limit, 0.5 mm Hg), where inequivalence had been pre-defined as a difference in mean diastolic BP of > or =5 mm Hg. Both drugs were well tolerated, the overall incidence of adverse events in the nifedipine GITS treatment group being 34.0% (34/100) and in the bendrofluazide treatment group being 29.0% (29/100). The commonest events (incidence > or =5%) were headache, constipation, 'flu syndrome and vasodilatation with nifedipine GITS and headache and nausea with bendrofluazide. An increased incidence of elevations of plasma urea and glucose was observed in patients treated with bendrofluazide (9.6% and 30.4% respectively) compared to those treated with nifedipine GITS (3.1% and 18.8% respectively). Nifedipine GITS 20 mg once daily is 'at least equivalent' to bendrofluazide 2.5 mg once daily in reduction of blood pressure in patients with mild-to-moderate hypertension.

Aged↗
PubMed1999

Management of renovascular disease: a review of renal artery stenting in ten studies.

To evaluate the efficacy and safety of renal artery stents in renovascular disease, we identified 10 descriptive studies containing sufficient information for systematic evaluation. No randomized comparisons of stenting with angioplasty or with surgery were found. Overall, stents were placed in 416 renal arteries in 379 patients, mean age 64 years (range 27-84), 56% male. Of the stenoses, 97% were atheromatous (inter-study range 71-100%), 80% ostial (22-100%) and 31% bilateral (12-87%). The clinical indication for stenting was usually hypertension with or without mild renal impairment. Radiological indications for stenting were: narrowing of > or = 50% (in 9/10 studies) as a result of elastic recoil (58%) or dissection (2%) at the time of angioplasty; restenosis some time after angioplasty (15%); or as a primary procedure (25%). Technical success was reported in 96-100% of procedures. Restenosis (> or = 50% narrowing), evaluated in 312/416 (75%) arteries, generally between 6 and 12 months, was 16% overall. Hypertension was cured by stenting (DBP < or = 90 mmHg on no treatment) in 34/379 (9%) overall and in 34/207 (16%) of those whose renal function was normal initially. Six of 379 (1.6%) patients died within 30 days of stenting, but in only two (0.5%) was death judged to be procedure-related. Complications, other than those which led to dialysis, occurred in 42/379 (13%) patients, one third requiring intervention, ranging from blood transfusion to a surgical bypass procedure. Renal function as judged by serum creatinine concentration (SCC) improved in 26%, stabilized in 48% and deteriorated in 26% of patients whose renal function was impaired initially (SCC > 133 mumol/l). In one study, with average baseline SCC > 200 mumol/l, successful stenting slowed the rate of progression of renal failure when renal function was deteriorating beforehand. Nine of 379 (2.4%) patients, including 7/14 (50%) whose SCC was > or = 400 mumol/l initially, required dialysis after stenting. Stenting should be offered by specialist centres as a secondary procedure for unsuccessful angioplasty, or restenosis following angioplasty, to patients with renovascular disease and uncontrolled hypertension, advancing renal failure or pulmonary oedema.

Age Distribution↗
PubMed1998

Randomised comparison of percutaneous angioplasty vs continued medical therapy for hypertensive patients with atheromatous renal artery stenosis. Scottish and Newcastle Renal Artery Stenosis Collaborative Group.

BACKGROUND: Data from randomised studies are lacking on the value of interventional procedures in the management of atheromatous renal artery stenosis. This randomised prospective trial compared the effects on blood pressure (BP) and renal function of percutaneous transluminal angioplasty vs medical therapy in hypertensive patients with both unilateral and bilateral disease. METHODS: A total of 135 eligible patients were identified, of whom 55 (44%) were randomised. Eligible patients had sustained hypertension, with a minimum diastolic BP of 95 mm Hg on at least two anti-hypertensive drugs. Renal artery stenosis was defined by renal angiography as at least 50% stenosis in the affected vessel. All patients were observed during an initial 4-week run-in period on a fixed drug regimen and subsequent changes measured from this 4-week baseline. RESULTS: Blood pressure fell during the run-in period in all groups. In patients with bilateral renal artery stenosis randomised to angioplasty, a statistically significant (P<0.05) fall in BP was observed at latest follow-up (range 3-54 months). The mean fall in BP at latest follow-up in the angioplasty group, corrected for the medical group response, was 26/10 mm Hg. In patients with unilateral renal artery stenosis, no statistically significant or clinically important differences in outcome were observed between the two groups. No significant differences or trends in serum creatinine were observed between or within any group during follow-up. Major outcome events (death, myocardial infarction, heart failure, stroke, dialysis) were similar in the angioplasty and medical groups during follow-up. In the 40/135 patients undergoing angioplasty, serious or potentially serious complications attributable to the procedure were observed in 11 patients, bleeding at the arterial site (8 patients) being the most frequent. CONCLUSIONS: In hypertensive patients with atheromatous renal artery stenosis, percutaneous renal angioplasty results in a modest improvement in systolic BP compared with medical therapy alone. This benefit was confined to patients with bilateral disease. No patient was 'cured', renal function did not improve, and intervention was accompanied by a significant complication rate.

Adult↗
PubMed1995

Prevention of coronary heart disease with pravastatin in men with hypercholesterolemia. West of Scotland Coronary Prevention Study Group.

BACKGROUND: Lowering the blood cholesterol level may reduce the risk of coronary heart disease. This double-blind study was designed to determine whether the administration of pravastatin to men with hypercholesterolemia and no history of myocardial infarction reduced the combined incidence of nonfatal myocardial infarction and death from coronary heart disease. METHODS: We randomly assigned 6595 men, 45 to 64 years of age, with a mean (+/- SD) plasma cholesterol level of 272 +/- 23 mg per deciliter (7.0 +/- 0.6 mmol per liter) to receive pravastatin (40 mg each evening) or placebo. The average follow-up period was 4.9 years. Medical records, electrocardiographic recordings, and the national death registry were used to determine the clinical end points. RESULTS: Pravastatin lowered plasma cholesterol levels by 20 percent and low-density-lipoprotein cholesterol levels by 26 percent, whereas there was no change with placebo. There were 248 definite coronary events (specified as nonfatal myocardial infarction or death from coronary heart disease) in the placebo group, and 174 in the pravastatin group (relative reduction in risk with pravastatin, 31 percent; 95 percent confidence interval, 17 to 43 percent; P < 0.001). There were similar reductions in the risk of definite nonfatal myocardial infarctions (31 percent reduction, P < 0.001), death from coronary heart disease (definite cases alone: 28 percent reduction, P = 0.13; definite plus suspected cases: 33 percent reduction, P = 0.042), and death from all cardiovascular causes (32 percent reduction, P = 0.033). There was no excess of deaths from noncardiovascular causes in the pravastatin group. We observed a 22 percent reduction in the risk of death from any cause in the pravastatin group (95 percent confidence interval, 0 to 40 percent; P = 0.051). CONCLUSIONS: Treatment with pravastatin significantly reduced the incidence of myocardial infarction and death from cardiovascular causes without adversely affecting the risk of death from noncardiovascular causes in men with moderate hypercholesterolemia and no history of myocardial infarction.

Anticholesteremic Agents↗
PubMed1995

Management of hypertensive crises.

Hypertensive crises are now uncommon in developed countries, and few doctors will have experience in their management. A review of the drugs used by clinicians in Scotland suggests considerable diversity in approach but broadly follows the best advice that is available in the literature. For emergencies such as hypertensive encephalopathy and hypertension associated with aortic dissection in which irreversible damage would occur within hours if left untreated, patients should probably be admitted to Intensive Care Units and be given nitroprusside. Similarly nitroprusside or nitroglycerin would be appropriate choice for hypertension that is complicated by acute left ventricular failure. By contrast if the risk to the patient is measured in days rather than hours then oral therapy will be quite sufficient. Atenolol or nifedipine retard can safely be given as initial treatment for uncomplicated malignant hypertension, and nifedipine retard can be used for the milder cases of encephalopathy or heart failure. The use of sublingual drugs in the management of hypertensive emergencies and urgencies cannot be recommended as the fall in blood pressure is both unpredictable and uncontrolled with the consequent and unacceptable risk of organ ischaemia.

Aortic Dissection↗
PubMed1995

Blood pressure, 'white-coat' pressor responses and cardiovascular risk in placebo-group patients of the MRC Mild Hypertension trial.

OBJECTIVE AND PATIENTS: To study the relationship between blood pressure and cardiovascular risk in 8654 patients randomly assigned to receive placebo in the Medical Research Council Mild Hypertension trial; 339 patients had a cardiovascular event during 5 years of follow-up. RESULTS: Tracking of blood pressure and regression of blood pressure to and from the mean were demonstrated. Cardiovascular risk was related independently and positively to blood pressure, smoking and cholesterol, and inversely to low-normal plasma sodium. The relationship with blood pressure was stronger when measurements were made at entry to the trial by nurses and weaker when measurements were made by doctors. DISCUSSION: One reason for this finding was that blood pressure increased at entry and, because the rise was greater in females, in whom the risk was lower than in males, a low-risk group predominated in the upper part of the blood pressure distribution. Another reason was that the rise itself conferred little or no cardiovascular risk. This rise might be a 'white-coat' response, because the increase in blood pressure in individuals correlated with the subsequent decrease after entry. CONCLUSION: If the rise is a 'white-coat' effect and if, as the present study suggests, it is common and relatively free from risk, then changes are needed in the design of placebo-controlled trials and in the management of hypertension.

Aged↗
PubMed1993

Incidence of and mortality from cancer in hypertensive patients.

OBJECTIVES: To assess incidence of and mortality from cancer in hypertensive patients taking atenolol, comparing the findings with two control populations and with hypertensive patients taking other drugs. DESIGN: Retrospective analysis of patients first seen in the Glasgow Blood Pressure Clinic between 1972 and 1990. Patients' records were linked with the registrar general's data for information on mortality and with the West of Scotland Cancer Registry for information on incident and fatal cancers. Cancers were compared in patients and controls and in patients taking atenolol, beta blockers other than atenolol, and hypotensive drugs other than beta blockers. SUBJECTS: 6528 male and female patients providing 54,355 years of follow up. SETTING: Hypertension clinic in Glasgow. MAIN OUTCOME MEASURES: Observed numbers of cancers in clinic patients were compared with expected numbers derived from cancer rates in two control populations adjusted for age, sex, and time period of data collection. RESULTS: Cancer mortality was not significantly different in clinic patients as a whole and controls. Incident and fatal cancers were not significantly increased in male or female patients taking atenolol. Cancer incidence did not rise in the clinic after a large increase in prescriptions for atenolol after 1976. CONCLUSION: This analysis does not suggest a link between atenolol and cancer.

Age Factors↗
PubMed1993

Defibrillation by general practitioners: an audit of resuscitation in a Scottish rural practice.

The objective was to review the outcome of resuscitation attempts in a small remote two-partner practice of 2700 patients in Galloway, South West Scotland during the period 1985-1992. During the study period 15 attempts were made to resuscitate the victims of cardiac arrest. Two sub-groups were identified. In the first, nine out of ten patients whose arrest occurred in the presence of a doctor were successfully resuscitated and all proved to be long term survivors. In the second group of five patients whose arrest took place before the arrival of the doctor there were no survivors. We conclude that defibrillation by general practitioners has a valuable contribution to make in reducing the mortality from myocardial infarction in rural practice.

Cardiopulmonary Resuscitation↗