Use of romiplostim in patients with chronic idiopathic thrombocytopenic purpura during perioperative period.

INTRODUCTION: In patients with chronic idiopathic thrombocytopenic purpura (cITP), the platelet count tends to be quite variable and, in the majority of cases, specific therapy is not warranted on a regular basis. However, patients with low platelet count (<30 nL) or with bleeding complications would require therapy, such as prednisolone, intravenous immunoglobulin infusions, splenectomy and/or immunosuppression. Romiplostim, a thrombopoietin agonist, has also proven to be useful in improving platelet counts. cITP can be associated with bleeding complications perioperatively. As such, a higher platelet count is warranted (approximately 80 nL), particularly for invasive surgeries, such as orthopaedic surgery, cardio-thoracic surgery, head and neck surgery and abdominal surgery, where risk of bleeding is quite high already. AIM: The aim of this study is to evaluate the safety and efficacy of short-term use of romiplostim, perioperatively. METHODS: Patients with chronic ITP requiring major surgical interventions were enrolled in the study. Patients with malignancies or myelodysplastic syndromes, major bleeding disorders, under 18 years of age or pregnancy were excluded. CONCLUSION: This study has shown that the use of romiplostim is safe and effective in improving platelet counts preoperatively and that this could achieve excellent haemostasis, with no associated bleeding complications or rebound thrombocytopenia. A larger study involving multiple centres is required to verify these findings.

How can we improve junior doctor prescribing?

The large number of medications available has complicated the learning of drug therapy for medical students at a time when pharmacology training has been substantially reduced. Attempts to remedy this include: improving the pharmaco-therapeutics curriculum; interactive web-based learning and students developing a personal formulary. The approach adopted by the University of Wollongong Medical School is to integrate clinical pharmacology throughout the course, with the Student Preferred-drugs Formulary linking pharmacology and common diseases. Evidence from other countries suggests this should enhance prescribing by medical graduates.

The burden of healthcare-associated Clostridium difficile infection in a non-metropolitan setting.

OBJECTIVE: Healthcare-associated Clostridium difficile infection (HCA-CDI) remains a major cause of morbidity and mortality in industrialized countries. However, few data exist on the burden of HCA-CDI in multi-site non-metropolitan settings. This study examined the introduction of an antimicrobial stewardship programme (ASP) in relation to HCA-CDI rates, and the effect of HCA-CDI on length of stay (LOS) and hospital costs. METHODS: A comparative before-and-after intervention study of patients aged ≥16 years with HCA-CDI from December 2010 to April 2016 across the nine hospitals of a non-metropolitan health district in New South Wales, Australia was undertaken. The intervention comprised a multi-site ASP supported by a clinical decision support system, with subsequent introduction of email feedback of HCA-CDI cases to admitting medical officers. MAIN OUTCOME MEASURES: HCA-CDI rates, comparative LOS and hospital costs, prior use of antimicrobials and proton pump inhibitors, and appropriateness of CDI treatment. RESULTS: HCA-CDI rates rose from 3.07 to 4.60 cases per 10,000 occupied bed-days pre-intervention, and remained stable at 4 cases per 10,000 occupied bed-days post-intervention (P=0.24). Median LOS (17 vs six days; P<0.01) and hospital costs (AU$19,222 vs $7861; P<0.01) were significantly greater for HCA-CDI cases (N=91) than for matched controls (N=172). Half of the patients with severe HCA-CDI (4/8) did not receive initial appropriate treatment (oral vancomycin). CONCLUSIONS: HCA-CDI placed a significant burden on the regional and rural health service through increased LOS and hospital costs. Interventions targeting HCA-CDI could be employed to consolidate the effects of ASPs.

Protein binding of aspirin and salicylate measured by in vivo ultrafiltration.

OBJECTIVE: Methods for measuring protein binding of drugs generally require direct measurement of the concentration of unbound drug and thus may require a highly sensitive assay. In vivo ultrafiltration has been used to determine protein binding of endogenous substances. We have examined its value for measuring protein binding of drugs because it requires measurement of only the concentration of total drug, not unbound drug, in plasma. METHODS: The protein binding of aspirin and its metabolite salicylate was measured in 29 healthy subjects 20 minutes after a single oral dose of 600 mg soluble aspirin, by the new method, in vivo ultrafiltration, as well as by a standard method, in vitro ultracentrifugation. RESULTS: The data for salicylate were examined systematically to determine the optimal method of determining estimates of protein binding by in vivo ultrafiltration. Estimates of protein binding of salicylate were 81.7% +/- 10.1% (mean +/- SD) by the in vivo method and 81.6% +/- 11.3% by in vitro ultracentrifugation. Bland-Altman analysis of agreement showed that within-individual differences in percentage of protein binding determined by the two methods did not differ significantly from zero (mean difference, 0.07%; 95% confidence interval, -2.33 to +2.46). There was a highly significant correlation between estimates of protein binding by the two methods (r = 0.82; p = 0.001). Protein binding of aspirin was estimated of protein binding by the two methods (r = 0.82; p = 0.001). Protein binding of aspirin was estimated at 58.3% +/- 9.6% by in vivo ultrafiltration and could not be estimated by in vitro ultracentrifugation because the concentration of unbound aspirin in plasma was below the limit of detection for the assay. CONCLUSION: In vivo ultrafiltration can be used to measure protein binding of drugs and has potential advantages over conventional methods. A sensitive assay may not be required because the unbound drug need not be measured, measurement in vivo may maintain more physiologic conditions, and it may be useful in measuring protein binding of drugs that are degraded rapidly in vitro.

Association of panic disorder and panic attacks with hypertension.

PURPOSE: Previous studies of the association between hypertension and panic disorder were uncontrolled or involved small numbers of patients. PATIENTS AND METHODS: We compared the prevalence of panic disorder and panic attacks in 351 patients with documented hypertension who were randomly selected from all hypertensive patients registered in one primary care practice with age- and gender-matched normotensive patients from the same practice and with hypertensive patients attending a hospital clinic. All three groups completed questionnaires for panic disorder based on standard criteria, as well as the Hospital Anxiety and Depression scale. RESULTS: The prevalence of current (previous 6 months) panic attacks was significantly greater in primary care patients with hypertension (17%, P <0.05) and hospital-based hypertensive patients (19%, P <0.01) than in normotensive patients (11%). Similar results were seen for lifetime panic attacks (35% versus 39% versus 22%; both P for comparisons with normotensive patients <0.001). The prevalence of panic disorder was significantly greater in primary care patients with hypertension (13%) than normotensive patients (8%, P <0.05). Anxiety scores were significantly higher in both hypertensive groups than in normotensive patients. Depression scores were significantly higher in hospital-based hypertensive patients than in the other two groups. The reported diagnosis of hypertension antedated the onset of panic attacks in a large majority of patients (P <0.01). CONCLUSIONS: Physicians caring for patients with hypertension should be aware of the significantly greater prevalence of panic attacks in these patients.

Implication of recent trials with b-hydroxy-b-methylglutaryl coenzyme A reductase inhibitors for hypertension management.

BACKGROUND: There is broad agreement that statin treatment should be targeted at absolute coronary heart disease (CHD) risk but no consensus on the level of risk to target. We have examined the implications of adopting three different treatment policies for the management of hypertensive patients in the UK using data from treated hypertensives aged 35-69 years included in the Health Survey for England (1993). METHODS: We calculated the proportion of hypertensive patients with existing atherosclerotic cardiovascular disease requiring statin treatment for secondary prevention of CHD. For those without atherosclerotic cardiovascular disease (primary prevention), we estimated CHD risk from the Framingham equation and examined the proportion with CHD risk exceeding thresholds of 4.5, 3 and 1.5% per year. RESULTS: Twenty-one percent of treated hypertensives would require statin treatment for secondary prevention of CHD. When the CHD event threshold for statin treatment was set at > or =4.5% per year [equivalent to a number needed to treat (NNT) in 5 years of 13] a further 0.6% of hypertensive patients were identified for treatment; at a threshold of 3.0% per year (NNT = 20) 5.5% of patients were identified for primary prevention; and at a threshold of 1.5% per year (NNT = 40) 28.5% of patients were identified for primary prevention. CONCLUSIONS: Those needing secondary prevention are first priority for statins and 21% of hypertensive patients will require treatment Formulation of guidelines for primary prevention should take into account the NNT; the proportion of patients targeted for treatment; the cost-effectiveness and the total cost of treatment. Current British guidance will entail treating an additional 5.5% of hypertensive patients for primary prevention and therefore 27% of hypertensive patients.

Panic disorder, anxiety and depression in resistant hypertension--a case-control study.

BACKGROUND: It has been suggested that panic disorder can cause or contribute to hypertension or resistance to antihypertensive drugs. OBJECTIVE: To compare the prevalences of panic disorder, panic attacks, anxiety and depression between patients with resistant hypertension and age- and sex-matched patients with non-resistant hypertension. DESIGN: A case-control study of patients attending the Sheffield Hypertension Clinic, using self-completed postal questionnaires to assess panic disorder, anxiety and depression. PATIENTS CASES: With resistant hypertension were defined as patients who presently or previously had systolic blood pressure above 160 mmHg or diastolic blood pressure above 90 mmHg despite the use of three or more antihypertensive agents at full dose. For each of 136 cases, one control with non-resistant hypertension, defined as controlled to < or = 160/90 mmHg by one or two antihypertensive agents, was identified by a bias-free method. Cases and controls were matched for age and sex. MAIN OUTCOME MEASURES: Lifetime and current prevalence of panic attacks, the prevalences of panic disorder, anxiety and depression by Hospital Anxiety and Depression Scale scores, and the severity and frequency of panic attacks. RESULTS: Of the resistant hypertensive patients, 33% had experienced a panic attack compared with 39% of the control non-resistant hypertensives (resistant-non-resistant -6%, 95% confidence interval -19 to +7%). Twelve per cent of the resistant patients and 14% of controls fulfilled the criteria for a current or previous diagnosis of panic disorder (resistant-non-resistant -2%, 95% confidence interval -11% to +7%). There were also no significant differences between the groups in the prevalences of current panic attacks, panic attacks rated as moderate or worse, spontaneous panic attacks and in the frequency of panic attacks. There remained no significant difference between the groups for panic attacks and panic disorder when the analysis was limited to those patients who had idiopathic hypertension. The two groups did not differ significantly in scores for anxiety and depression measured by the Hospital Anxiety and Depression Scale. CONCLUSION: We observed no differences in the prevalences of panic, anxiety and depression between patients with resistant hypertension and non-resistant controls. These factors are probably not implicated in resistance to drug treatment. However, the prevalences of panic disorder and panic attacks were remarkably high in both groups of patients attending a hospital hypertension clinic. The relationship between panic disorder and hypertension deserves further study in a general hypertensive population.

The rationale for differing national recommendations for the treatment of hypertension.

This article examines the rationale for the differences in the guidelines for hypertension management of four national or international bodies: the Joint National Committee (JNC-V), The World Health Organization/International Society of Hypertension (WHO-ISH), the British Hypertension Society (BHS), and the New Zealand guidelines. These guidelines agree on many aspects of management, but differ on two very important points-the drugs of first choice for hypertension, and the indications for drug treatment of uncomplicated mild hypertension. JNC-V recommends treatment routinely of all people with a sustained blood pressure of 140/90 mm Hg, whereas the BHS guidelines advise treatment routinely at 160/100 mm Hg. Such differences in the threshold for treatment have a major impact on the proportion of the adult population to be treated, and on the benefit from treatment. JNC-V was heavily influenced by the Hypertension Detection and Follow-up Program (HDFP), which appeared to show a large benefit from the treatment of uncomplicated mild hypertension, whereas the BHS guidelines were influenced by the Medical Research Council (MRC) Trial, which showed a very small benefit. However, the apparent differences in absolute benefit between these, and other, randomized controlled trials is related entirely to differences in the absolute cardiovascular risk of the populations studied. In populations and in individual patients the benefit from antihypertensive treatment is determined by the absolute cardiovascular risk. Blood pressure by itself is a very weak predictor of risk or benefit from treatment. In uncomplicated mild hypertension the need for drug therapy should be based on the absolute risk of cardiovascular complications, estimated by considering age, sex, serum cholesterol level, diabetes mellitus status, and smoking habits, in addition to blood pressure. Doctors cannot estimate absolute risk accurately informally or intuitively, and the next generation of guidelines should incorporate a simple but accurate method for estimating cardiovascular risk, similar to that in the New Zealand guidelines. The decision to treat, or not treat, uncomplicated mild hypertension should be based on a formal estimate of absolute cardiovascular risk and not on an arbitrary blood pressure threshold. As regards drugs of first choice, the available evidence supports strongly the stance of JNC-V and JNC VI that diuretics and beta-blockers should be preferred unless they are contraindicated, or unless there are positive indications for other drug classes.

Gastric outflow obstruction caused by gall stones and leading to death by complex metabolic derangement.

A 67 year old woman was admitted with a three week history of vomiting, having become increasingly confused for three days. Investigations revealed deranged serum biochemistry consistent with a combination of a diabetic non-ketotic hyperosmolar state and a metabolic alkalosis consistent with gastric outflow obstruction. She was treated with intravenous saline, intravenous insulin, and subcutaneous heparin, but did not improve clinically and had an asystolic cardiac arrest the following day; she was transferred to the intensive care unit and despite treatment with inotropes she died 40 hours after admission. Necropsy revealed that the stomach was massively dilated with gas and stomach contents, and contained many small black faceted gall stones. In addition a large nonfaceted brown-yellow gall stone was wedged in the pyloric antrum causing total obstruction. The patient had died from a complex metabolic derangement including non-ketotic hyperosmotic diabetic coma and metabolic alkalosis precipitated by the acute gastric outflow obstruction complicated by previously undiagnosed type II diabetes mellitus.

Is the Framingham risk function valid for northern European populations? A comparison of methods for estimating absolute coronary risk in high risk men.

OBJECTIVE: To examine the validity of estimates of coronary heart disease (CHD) risk by the Framingham risk function, for European populations. DESIGN: Comparison of CHD risk estimates for individuals derived from the Framingham, prospective cardiovascular Münster (PROCAM), Dundee, and British regional heart (BRHS) risk functions. SETTING: Sheffield Hypertension Clinic. Patients-206 consecutive hypertensive men aged 35-75 years without preexisting vascular disease. RESULTS: There was close agreement among the Framingham, PROCAM, and Dundee risk functions for average CHD risk. For individuals the best correlation was between Framingham and PROCAM, both of which use high density lipoprotein (HDL) cholesterol. When Framingham was used to target a CHD event rate > 3% per year, it identified men with mean CHD risk by PROCAM of 4.6% per year and all had CHD event risks > 1.5% per year. Men at lower risk by Framingham had a mean CHD risk by PROCAM of 1.5% per year, with 16% having a CHD event risk > 3.0% per year. BRHS risk function estimates of CHD risk were fourfold lower than those for the other three risk functions, but with moderate correlations, suggesting an important systematic error. CONCLUSION: There is close agreement between the Framingham, PROCAM, and Dundee risk functions as regards average CHD risk, and moderate agreement for estimates within individuals. Taking PROCAM as the external standard, the Framingham function separates high and low CHD risk groups and is acceptably accurate for northern European populations, at least in men.

Persistent dry cough with enalapril: incidence depends on method used.

In a cohort of 136 hypertensive patients started consecutively on enalapril the incidence of persistent dry cough by life-table analysis was 14.6% (95% CI 10.2-19.0%). The incidence in women (19.2%; 95% CI 11.3-27.1%) was twice that in men (9.7%; 95% CI 6.6-12.8%). Dry cough was unrelated to age, smoking habit, renal function, or the dose and duration of enalapril treatment. In one half of patients who developed cough enalapril had to be stopped. The incidence of withdrawal due to cough was 6.0% (95% CI 4.5-7.5%), and cough was by far the most common reason for discontinuing enalapril treatment. Reviewing previous studies of enalapril-induced cough, it is evident that postmarketing surveillance studies have grossly underestimated the incidence and importance of this side-effect. Surveys in hospital clinics have slightly underestimated the true incidence through failure to use life-table methods of analysis.

The role of ACE inhibitors in the management of hypertension.

ACE inhibitors have antihypertensive efficacy similar to that of thiazides, beta-blockers and calcium antagonists. They are simple to prescribe and to take, and are relatively free from subjective side-effects apart from persistent dry cough. There are few specific concerns about safety, but experience of long-term use is still relatively limited. They are valuable additional or alternative antihypertensive drugs when standard therapy is contraindicated or fails to control blood pressure.

ACE inhibitors, angiotensin II antagonists and cough. The Losartan Cough Study Group.

One hundred and thirty five non-smoking hypertensive patients with ACE inhibitor cough confirmed by lisinopril rechallenge and placebo dechallenge were recruited into a double-blind random parallel-group comparison of losartan 50 mg, lisinopril 20 mg and hydrochlorothiazide 25 mg each given once daily for a maximum of 8 weeks. The aim of the study was to compare the incidence of cough with the angiotensin II antagonist losartan, the ACE inhibitor lisinopril and the hydrochlorothiazide in hypertensive patients with previous ACE inhibitor cough. Cough detected by self-administered questionnaire was the primary end-point, and cough frequency by visual analogue scale a secondary end-point. The incidence of cough with losartan (29%) was lower than that for lisinopril (72%, P < 0.01) and similar to that for hydrochlorothiazide (34%). Cough frequency by visual analogue scale was lower for losartan than lisinopril (P < 0.01) and similar to that for hydrochlorothiazide. The specific selective AT1 angiotensin II receptor antagonist losartan is significantly less likely than lisinopril to cause cough in patients who previously have had ACE inhibitor cough. ACE inhibitor cough is likely to be related to non-specific kininase II inhibition.

Effect of coffee and cigarette smoking on the blood pressure of patients with accelerated (malignant) hypertension.

There is a strong association between cigarette smoking and accelerated hypertension. In mild hypertension smoking cigarettes has a distinct pressor effect and caffeine a small but more prolonged pressor action. Coffee and cigarette smoking together have an additive effect on blood pressure (BP). We have examined the interaction of cigarette smoking and drinking coffee on the BP of six patients who presented with accelerated hypertension (mean BP 240/140 mm Hg) and were heavy smokers and caffeine users. After initial control of the BP, the effects of smoking alone, coffee plus smoking, and placebo were examined in a balanced cross-over study. Baseline BP averaged 154/91 mm Hg and remained stable for 90 min after abstention from smoking and caffeine (placebo). Cigarette smoking without caffeine caused a modest rise in BP (mean 9/8 mm Hg), but the combination of coffee plus cigarette smoking caused a progressive increase in BP to an average 21/17 mm Hg (P < 0.05/P < 0.002) higher than placebo values. The effect of coffee was significantly additive to that of smoking alone. Smoking plus coffee ingestion shifted the BP from acceptable (155/94 mm Hg) to poor control (175/107 mm Hg). This pressor effect was observed despite treatment, and with amounts of caffeine and cigarettes which were in no way unusual for these patients. We propose that the association of cigarette smoking with accelerated hypertension may reflect an extreme pressor effect of combined smoking and caffeine use in some patients.

Should cholesterol be measured in all hypertensives?

Guidelines for the management of hypertension, and those for hyperlipidaemia, advocate measurement of cholesterol in all hypertensive subjects. It is suggested that knowledge of serum cholesterol should influence the choice of anti-hypertensive agent because thiazides and beta-blockers may influence lipids adversely. However, the changes in lipids associated with low-dose thiazides and beta-blockers are small, not sustained and do not appear to affect prognosis adversely. Some believe that knowledge of serum cholesterol may help target the treatment of mild hypertension more accurately by predicting an increased risk of vascular complications of hypertension. However, serum cholesterol does not predict the risk of cardiovascular complications in hypertensive women. It does predict coronary heart disease (but not stroke) in men, but coronary risk can be estimated satisfactorily without knowledge of serum cholesterol. Suggestions that cholesterol should be lowered in hypercholesterolaemic hypertensive patients to reduce the incidence of coronary heart disease are understandable. However, the diet recommended for this has no useful effect on serum cholesterol, and the benefit of lipid-lowering drugs for cholesterol reduction only exceeds the risk in patients at very high risk of coronary mortality, for example those who have had a myocardial infarction. Hypertension alone will not place individuals at high enough risk to warrant drug therapy for cholesterol reduction. We conclude that the current guidelines are incorrect, and that routine measurement of cholesterol in all hypertensive patients is not justified.

Pressor effect of hyperventilation in healthy subjects.

Hyperventilation is an important feature of panic disorder, and an association has been reported between panic disorder and hypertension. We have examined the effect of hyperventilation on the blood pressure (BP) of healthy subjects. Twenty six subjects were randomised in a balanced two-period cross-over study to compare the effects of hyperventilation with that of normal breathing on sitting BP, heart rate and the electrocardiogram. Each study phase lasted 40 min, with 15 min of baseline observation, 5 min of hyperventilation or normal breathing, and 20 min of continued observation. Hyperventilation significantly increased SBP by 8.9 mm Hg (95% CI 3.8-13.8, P < 0.01), diastolic blood pressure by 8.2 mm Hg (95% CI 1.7-14.7, P < 0.05), mean arterial pressure by 10.0 mm Hg (95% CI 3.3-16.7, P < 0.01) and heart rate by 36 beats/min (95% CI 31-44, P < 0.01). The changes in diastolic and mean arterial pressure correlated significantly with the total volume of air expired during hyperventilation (r = 0.57, p < 0.01 and r = 0.50 P < 0.01, respectively), but not with the change in expired carbon dioxide. In the electrocardiogram, T wave changes occurred in the inferior leads in 10 of 26 subjects, but there were no significant changes in other measurements. Hyperventilation significantly increased the BP of healthy subjects, and the role of hyperventilation in the link between panic disorder and hypertension deserves further study.

Might non-pharmacological treatment disadvantage patients with hypertension?

Weight reduction, moderate salt restriction and alcohol reduction are effective in lowering blood pressure (BP), and are feasible interventions for long-term management of hypertension. When used in combination these non-pharmacological measures are significantly inferior to drug therapy in anti-hypertensive effect. When they are implemented as a first step in the treatment of mild hypertension, resorting to drug therapy only if non-pharmacological measures fail, anti-hypertensive drugs can be avoided in about 40% of patients. However, BP control is again significantly inferior with this strategy compared with drug therapy without non-pharmacological advice. Those given advice on non-pharmacological measures may therefore have suboptimal protection against cardiovascular complications. This is particularly so when the threshold for drug treatment is set at a DBP of > or = 100 mmHg, as many patients will be left untreated with DBPs between 90 and 99 mm Hg as a result of non-pharmacological measures. Non-pharmacological treatment may thus stand between patients and anti-hypertensive drug therapy, which nowadays is simple, well-tolerated, safe and proven effective in preventing cardiovascular disease. The role of non-pharmacological therapy needs to be reconsidered.

Dietary reduction of serum cholesterol concentration: time to think again.

OBJECTIVE: To evaluate the long term efficacy of diets in lowering serum cholesterol concentration. DESIGN: Descriptive overview of 16 published controlled trials of six months' duration or longer. SETTING: Trials had been conducted in hospital clinics (6), industry (3), mental hospitals or institutions (3), and in general populations (4). PATIENTS: Trials had been conducted in high risk subjects (5), in unselected healthy subjects (6), or for secondary prevention in patients with coronary heart disease (5). Women were included in only four trials. INTERVENTIONS: Diets equivalent to the step 1 diet were employed in eight trials, with individual intervention by dietitians (3) or occupational physicians (2) or with population advice (3). Intensive diets which were more rigorous than the step 2 diet were employed in eight trials. MAIN OUTCOME MEASURES: Net change in serum total cholesterol concentration in subjects receiving treatment with diet compared with values in control subjects after six months to 10 years. RESULTS: In five trials with the step 1 diet as individual intervention the net reduction in serum cholesterol concentration ranged from 0% to 4.0% over six months to six years. In trials with population education reductions in cholesterol concentrations were 0.6-2.0% over five to 10 years. When population and individual dietary advice were combined changes in cholesterol concentration ranged from a fall of 2.1% to a rise of 1.0% over four to 10 years. Diets more intensive than the step 2 diet reduced serum cholesterol concentration by 13% over five years in selected high risk men in the population; by 6.5-15.1% over two to five years in hospital outpatients; and by 12.8-15.5% over one to four and a half years in patients in institutions. CONCLUSIONS: The response to a step 1 diet is too small to have any value in the clinical management of adults with serum cholesterol concentrations above 6.5 mmol/l. Current guidelines recommend screening of serum cholesterol concentration in healthy subjects, followed by treatment with a step 1 diet. The guidelines should be reviewed to provide a more realistic estimate of the effect of a step 1 diet and of the likely need for lipid lowering drugs.

beta blockade and intermittent claudication: placebo controlled trial of atenolol and nifedipine and their combination.

OBJECTIVE: To determine the effects of the beta 1 selective adrenoceptor blocker atenolol, the dihydropyridine calcium antagonist nifedipine, and the combination of atenolol plus nifedipine on objective and subjective measures of walking performance and foot temperature in patients with intermittent claudication. DESIGN: Randomised controlled double blind four way crossover trial. SETTING: Royal Hallamshire Hospital, Sheffield. SUBJECTS: 49 patients (40 men) aged 39-70 with chronic stable intermittent claudication. INTERVENTIONS: Atenolol 50 mg twice daily; slow release nifedipine 20 mg twice daily; atenolol 50 mg plus slow release nifedipine 20 mg twice daily; placebo. Each treatment was given for four weeks with no washout interval between treatments. MAIN OUTCOME MEASURES: Claudication and walking distances on treadmill; skin temperature of feet as measured by thermistor and probe; blood pressure before and after exercise; subjective assessments of walking difficulty and foot coldness with visual analogue scales. RESULTS: Atenolol did not significantly alter claudication distance (mean change -6%; 95% confidence interval 1% to -13%), walking distance (-2%; 4% to -8%), or foot temperature. Nifedipine did not alter claudication distance (-4%; 3% to -11%), walking distance (-4%; 3% to -10%), or foot temperature. Atenolol plus nifedipine did not alter claudication distance but significantly reduced walking distance (-9%; -3% to -15% (p less than 0.003)) and skin temperature of the more affected foot (-1.1 degrees C; 0 to -2.2 degrees C (p = 0.05)). These effects on walking distance and foot temperature seemed unrelated to blood pressure changes. CONCLUSIONS: There was no evidence of adverse or beneficial effects of atenolol or nifedipine, when given singly, on peripheral vascular disease. The combined treatment, however, affected walking ability and foot temperature adversely. This may have been due to beta blockade plus reduced vascular resistance, which might also explain the reported adverse effects of pindolol and labetalol on claudication.

Coronary and cardiovascular risk estimation for primary prevention: validation of a new Sheffield table in the 1995 Scottish health survey population.

OBJECTIVE: To examine the accuracy of a new version of the Sheffield table designed to aid decisions on lipids screening and detect thresholds for risk of coronary heart disease needed to implement current guidelines for primary prevention of cardiovascular disease. DESIGN: Comparison of decisions made on the basis of the table with absolute risk of coronary heart disease or cardiovascular disease calculated by the Framingham risk function. The decisions related to statin treatment when coronary risk is >/=30% over 10 years; aspirin treatment when the risk is >/=15% over 10 years; and the treatment of mild hypertension when the cardiovascular risk is >/=20% over 10 years. SETTING: The table is designed for use in general practice. SUBJECTS: Random sample of 1000 people aged 35-64 years from the 1995 Scottish health survey. MAIN OUTCOME MEASURES: Sensitivity, specificity, and positive and negative predictive values of the table. RESULTS: 13% of people had a coronary risk of >/=15%, and 2. 2% a risk of >/=30%, over 10 years. 22% had mild hypertension (systolic blood pressure 140-159 mm Hg). The table indicated lipids screening for everyone with a coronary risk of >/=15% over 10 years, for 95% of people with a ratio of total cholesterol to high density lipoprotein cholesterol of >/=8.0, but for <50% with a coronary risk of <5% over 10 years. Sensitivity and specificity were 97% and 95% respectively for a coronary risk of >/=15% over 10 years; 82% and 99% for a coronary risk of >/=30% over 10 years; and 88% and 90% for a cardiovascular risk of >/=20% over 10 years in mild hypertension. CONCLUSION: The table identifies all high risk people for lipids screening, reduces screening of low risk people by more than half, and ensures that treatments are prescribed appropriately to those at high risk, while avoiding inappropriate treatment of people at low risk.