Search PubMed⌕ Search

Biomedical subjects

D G Beevers

Publications and source records attributed to D G Beevers.

At least 127 records · Page 7Linked to original sources

Evidence of platelet activation in hypertension.

To test the hypothesis that platelet activation is present in hypertension, we measured plasma markers beta thromboglobulin and soluble P-selectin in hypertensive patients and normotensive controls. Both markers were raised in the patients (P < 0.05), and in a subgroup of patients, beta thromboglobulin was reduced with successful treatment of hypertension with the ACE inhibitor quinapril. We suggest that reversible platelet activation is present in hypertension. This may be a contributing factor to the link between this risk factor and the development of thrombotic disease such as stroke.

Cross-Sectional Studies↗

Malignant hypertension in young women is related to previous hypertension in pregnancy, not oral contraception.

Previous studies have suggested that one-third of women of childbearing age who develop malignant phase hypertension (MHT) are likely to be taking oral contraceptives (OC). We surveyed 104 women with a history of MHT. None of the 65 aged > 45 years were taking OC or other sex hormones. Thirty-nine (mean age 34.9 years, SD 8.0) were aged 15-44 years at presentation: 22 Caucasian, 10 Black/Afro-Caribbean and seven Indo-Asian. Of these 39, 22 had a history of hypertension in pregnancy (group 1), and 17 did not (group 2). Three of group 1 also had a history of OC-induced hypertension. None were pregnant, but one was taking an OC at presentation with MHT. Blood pressures at presentation and follow-up, and mean serum urea and creatinine at presentation were similar between groups, as was median survival (96 vs. 47 months, Lee-Desu statistic 0.75, p = 0.38). There was a trend towards poorer renal function at follow-up in group 1 patients, with higher mean serum urea and creatinine levels. The causes of death were renal failure (5), stroke (4) and heart disease (2). The OC was not a common cause of MHT-amongst our sample of women of childbearing age, but a past history of hypertension in pregnancy was important. Such patients also had a longer duration of hypertension and poorer renal function at follow-up.

Adolescent↗

Does renal function improve after diagnosis of malignant phase hypertension?

BACKGROUND: The nature of the relationship between high blood pressure and kidney damage is controversial. There is a view that essential non-malignant hypertension does not cause renal damage in patients with normal renal function and no proteinuria at first presentation. In contrast, patients with malignant hypertension (MHT) not due to underlying renal disease often exhibit progressive renal impairment, although there can be a dissociation between short-term changes in renal function and the long-term renal outcome. It has been established that the association of MHT and renal impairment is associated with a grave prognosis. OBJECTIVE: To investigate further the changes in renal function after diagnosis of MHT. METHODS: We studied the clinical features, renal function and survival of patients on the West Birmingham MHT Register. Patients presenting with no or only mild-to-moderate renal impairment (defined as an initial serum creatinine level < 300 micromol/L) were categorized as group 1 patients. Patients with severely impaired renal function, defined as a serum creatinine level > or = 300 micromol/l at presentation, were categorized as group 2 patients. Patients who subsequently suffered a deterioration in renal function were defined as those whose serum creatinine level had risen at follow-up (group A). Patients with an invariant or improving renal function at follow-up were those whose serum creatinine level neither rose nor fell (group B). Clinical characteristics and survival of patients in group 1 were therefore compared with those of patients in group 2; features of patients in group A were compared with those of patients in group B. RESULTS: We studied a total of 169 patients with MHT [107 men, aged 49.4 +/- 13.3 years (mean +/- SD)]. Of these, 136 (80.5%) patients had an initial serum creatinine level < 300 micromol/l (group 1). After a median follow-up of 53 months (interquartile range 15-103), the serum creatinine level of 56.8% (96 of 169) patients had risen (group A). Patients with MHT with only mild-to-moderate renal impairment at presentation (creatinine level < 300 micromol/l, group 1) had lower serum urea, creatinine and blood pressure levels at follow-up compared with those of patients with initially impaired renal function. Although there was no significant change in follow-up serum urea and creatinine levels compared with initial levels in patients in group 2 (paired Wilcoxon test, NS), there was a significant deterioration in renal function in patients in group 1 (P = 0.001). Group 2 patients had a shorter median survival time than did group 1 patients (15 versus 59 months, Lee-Desu statistic 15.4, P = 0.0001). Patients whose serum creatinine level had risen (group A) had significantly higher initial serum urea and creatinine levels and follow-up blood pressures than did those whose renal function had remained invariant or improved (group B). However, there was no significant difference between the median survival times of patients in groups A and B (51 versus 58 months, Lee-Desu statistic 0.377, P = 0.54). CONCLUSION: We suggest that renal function continues to deteriorate in some patients with MHT, despite a good degree of control of their blood pressures having been achieved at follow-up. However, the renal function of 16 of the 33 patients with severe renal impairment at presentation either remained invariant or was found to have improved at follow-up. There was no evidence that those cases whose renal function remained invariant were confined to those who had presented with less renal impairment. The severity of MHT at presentation and the amount of renal impairment did not predict the outcome. In contrast the quality of control of the blood pressure that had been obtained at follow-up did predict the outcome. Careful monitoring of renal functioning and effective treatment of the blood pressure is mandatory in patients with MHT.

Adult↗

Ambulatory blood pressure monitoring in acute stroke. The West Birmingham Stroke Project.

BACKGROUND AND PURPOSE: Ambulatory blood pressure monitoring (ABPM) devices are increasingly used in the assessment of hypertension, but their value in patients after a stroke is unknown, despite the fact that hypertension is an important cause of stroke and many patients have relatively high blood pressure (BP) levels at presentation. We therefore investigated the clinical use of a 24-hour oscillometric ABPM device in patients after acute stroke. We also investigated ABPM in different types of stroke (thrombosis, hemorrhage, and transient ischemic attack) and ethnic and sex differences. METHODS: BP was measured manually with a standard mercury sphygmomanometer, and ABPM measurements were made with an oscillometric device. The first reading obtained with the ABPM device was compared with simultaneous manual BP measurements. Mean daytime and nighttime pressures were also analyzed to determine the frequency of nocturnal BP falls ("dipping"). RESULTS: We studied 86 patients (48 men; mean +/- SD age, 64.2 +/- 9.2 years) admitted with acute-onset stroke (ictus within 12 hours) in a district general hospital. Thirty-one patients (36.0%) had a previous history of hypertension. The median percentage of successful BP readings by ABPM was 92% (interquartile range, 72 to 98). There was no significant difference in manual BP levels compared with the first simultaneous systolic or diastolic ABPM measurements. Systolic BPs recorded by ABPM were significantly higher in black patients with acute stroke and in patients with intracerebral hemorrhage, who also showed a trend toward higher nocturnal BPs. There was no difference in BPs between men and women and those who were alive or dead 6 months later (P = NS). There was also no difference between mean day and night systolic BP (mean difference, 1.9 mm Hg; P = .08), although mean daytime diastolic BP was higher than mean nighttime diastolic BP (mean difference, 2.4 mm Hg; P = .01). Patients with stroke therefore demonstrated a loss of diurnal BP rhythm and may be considered "nondippers"; there was also a trend toward "reverse dipping" in patients with intracranial hemorrhage. CONCLUSIONS: This study demonstrates higher systolic BPs as recorded by ABPM (but not manually) in patients with intracerebral hemorrhage than in those with cerebral infarcts; higher levels were also found in blacks. ABPM recordings are useful in the assessment of BP in patients with stroke, who may be considered nondippers.

Black or African American↗

A survey of atrial fibrillation in general practice: the West Birmingham Atrial Fibrillation Project.

BACKGROUND: The management of atrial fibrillation (AF) has changed substantially in recent years, especially with a greater appreciation of the prophylactic role of antithrombotic therapy against stroke. There is therefore a need for further information on the prevalence of AF in Britain, the prevalence of (and contraindications to) anticoagulant treatment, and the factors that influence doctors' decisions in treating AF, including the investigation of patients with this arrhythmia. AIM: To investigate the prevalence, clinical features and management of patients with AF in a general practice setting. METHOD: Cross-sectional survey of patients using treatment prescriptions and clinical records in two general practices from the west of Birmingham (serving a patient population of 16,519) where 4522 subjects (27.4%) were aged > or = 50 years. RESULTS: One hundred and eleven (2.4%) patients who were aged > or = 50 years were found to be in AF (42 males; mean age 76.6, SD 9.1); 77.5% were Caucasian, 2.7% Afro-Caribbean, 0.9% Asian, and 0.9% mixed race; in 20 cases there was no information on ethnicity. Of the AF patients, 5.4% were aged 50-60 years, 16.2% aged 61-70 years, 20.7% aged 71-75 years, 20.7% aged 76-80 years, 24.3% aged 81-85 years, and 12.6% aged > 85 years old, with female patients being significantly older than males. Eighty-one patients (73%) had chronic AF, while 30 patients (27%) had paroxysmal AF. The most common associated factors were hypertension (36.9%) and ischaemic heart disease (28.8%), with no obvious cause for AF in six patients. Cardiac failure was associated with AF in 34 patients (30.6%), and stroke had occurred in 29 patients (18%). Only 20 patients (18%) had had an echocardiogram, 26 (23.4%) a chest X-ray, and 58 (52.3%) thyroid function test. Only 30.6% had ever presented to hospital practice. Warfarin was prescribed to 40 patients (36%), with anticoagulation intensity monitoring by the general practitioner (GP) in three cases (7.5%), by a hospital clinic in 30 (75%), and by both GP and hospital in seven cases (17.5%). Of those not anticoagulated (n = 71), only 12 patients (16.9%) had contraindications to warfarin therapy. Patients treated with warfarin were younger than those who were not prescribed warfarin (71.3 versus 79.6 years, P < 0.001). Aspirin was being prescribed for 21 patients (18.9%), primarily for previous myocardial infarction. Only five patients (4.5%) had ever had attempted cardioversion. CONCLUSION: Atrial fibrillation is a common arrhythmia in general practice, and is commonly associated with hypertension, ischaemic heart disease and heart failure. There is a suboptimal application of standard investigations and use of antithrombotic therapy or attempted cardioversion; and few patients have presented to hospital practice. Guidelines on the management of this common arrhythmia in general practice are required.

Aged↗

Soluble P-selectin in atherosclerosis: a comparison with endothelial cell and platelet markers.

von Willebrand factor and soluble thrombomodulin are established plasma markers of endothelial cell dysfunction, whilst beta thromboglobulin is an established plasma marker of platelet activity. Soluble P-selectin may be the product of either or both types of cell and levels of all four molecules have been previously found to be increased in atherosclerosis. To determine the relationship of soluble P-selectin to the endothelial cell and platelet products, we measured the four indices in a case control study of 55 patients with peripheral vascular disease and 55 age and sex matched controls. von Willebrand factor (p < 0.0001), beta thromboglobulin (p = 0.0006), soluble P-selectin (p = 0.0021) and soluble thrombomodulin (p = 0.021) were all raised in the patients. Soluble P-selectin correlated with beta thromboglobulin (r = 0.34, p = 0.019) but failed to correlate with either endothelial cell marker. Co-culture of endothelial cells in vitro with bovine thrombin resulted in increased levels of von Willebrand factor in the supernatants but levels of soluble thrombomodulin and soluble P-selectin were not enhanced. Exposure of endothelial cell monolayers to elastase resulted in different patterns of release of von Willebrand factor, soluble thrombomodulin and soluble P-selectin. We suggest that soluble P-selectin is unlikely to arise from the endothelium and may be a new marker of platelet activation in atherosclerosis.

Aged↗

Doctors, nurses, pharmacists and patients--the Rational Evaluation and Choice in Hypertension (REACH) survey of hypertension care delivery.

Despite ongoing efforts by the medical profession, many hypertensive patients either refuse treatment or have blood pressures that are not adequately controlled. A key reason is likely to be the side effects of many antihypertensive drugs. We have investigated further reasons for stopping or altering antihypertensive treatment, and the patterns of prescribing in Britain by mounting a series of surveys amongst family doctors, practice nurses and their patients with hypertension. A total of 178 GPs and 158 practice nurses provided completed replies suitable for analysis. In addition, 948 patients were surveyed via their GP and 1167 were surveyed via their local pharmacist (600 unprompted, 567 prompted). Thirty-two percent of GPs stated that hypertensive patients generally consulted because they were experiencing drug side effects and 42% of all switches of drug therapy occurred because patients experienced side effects. The GPs perceived that 18% of their hypertensive patients did not comply with the antihypertensive therapy, and, of non-compliant patients, 22% were not complying due to drug side effects. The 158 practice nurses reported that 29% of patients they saw discussed drug side effects. Hypertensive patients were more likely to discuss the side effects of their antihypertensive treatments with the practice nurse than their doctor. Forty-six percent of 948 patients who were surveyed via their GP did not know what antihypertensive drug class they were taking. The most frequently mentioned reason for patients changing medication was drug side effects (42%) or lack of efficacy (39%). Fifty-nine percent of patients had never asked about possible side effects, but 34% reported that they had experienced unacceptable side effects. With some prompting by pharmacists, many hypertensive patients would discuss their antihypertensive drugs and any side effects. This survey highlights the lack of communication about potential side effects between the doctor and hypertensive patient, and the important role of the practice nurse. Our survey also shows that hypertension is not being managed as effectively as it could be and GPs appear to be spending the majority of their consulting time discussing and dealing with the side effects of treatment. This, therefore, suggests that drugs with a cleaner side effect profile could save valuable GP time and resources. Better communication with patients about side effects is, therefore, likely to improve compliance with hypertensive treatment.

Antihypertensive Agents↗

Acute admissions with heart failure to a district general hospital serving a multiracial population.

To assess te incidence, clinical characteristics and current strategies in the management of patients with acute heart failure, we conducted a prospective survey of all acute medical admissions with heart failure to a district hospital serving a city centre population of 300,000 people in a multiracial community. Of 7451 such admissions, 348 (4.7%) were diagnosed as having acute heart failure: 265 Caucasian (76.1%), 27 black/Afro Caribbean (7.7%), 56 Indo-Asian (16.1%). Complete clinical data were available from 260 patients. The main presenting symptom was dyspnoea in 233 patients (89.6%) and chest pain in 60 patients (23.1%); 139 patients (53.5%) had a history of ischaemic heart disease, 87 (33.5%) hypertension and 49 (18.8%) had diabetes; 103 patients (39.6%) had a previous history of heart failure; 75 patients (28.8%) were in atrial fibrillation. An echocardiogram was performed in 89 patients (34.2%). On admission, ACE inhibition was prescribed to only 78 patients (30.0). The diagnosis of heart failure was stated on the hospital inpatient data sheet (KMR-1) in only 170 patients (65.4%). Following admission, 50 patients (19.2%) died while in the wards. Heart failure is a common problem among acute medical admissions and has a poor prognosis. The KMR-1 diagnosis may underestimate the prevalence of heart failure.

Aged↗

Ethnic differences in pre-admission levels of physical activity in patients admitted with myocardial infarction.

BACKGROUND: Regular exercise is generally considered to reduce the risk of coronary heart disease. Reduced levels of physical activity in Indo-Asians may partly explain why patients from this ethnic group sustain so many heart attacks. AIM: To investigate ethnic differences in pre-admission levels of physical activity amongst patients admitted with myocardial infarction and triggers for the acute cardiac event. DESIGN: Cross-sectional study using standard Baecke questionnaire, which provided a semi-quantitative work score, sport score, leisure score and total activity score of general daily activities, with additional questions on activity at the onset of chest pain. SETTING: Coronary Care Unit, City Centre Teaching Hospital. PATIENTS AND RESULTS: We studied 100 consecutive patients (76 males, mean age 62.3 years, S.D. 12.5; 74 caucasians, 26 Indo-Asians) admitted with myocardial infarction. Most patients were engaged in sedentary activities, including lying in bed (25%), sitting (19%), watching television (14%) and sleeping (6%), whilst only 21% of patients were engaged in physical activity at chest pain onset; there were, however, no ethnic differences in activity at chest pain onset. There was a diurnal variation in chest pain onset, with the mode between 08:00 and 10:00 h. As the mean age of Indo-Asians was significantly lower than caucasians in the whole group (56.3 vs. 64.4 years; t-test, P < 0.002), the Baecke questionnaire analysis was confined to only male patients aged < 70 years (n = 56). Indo-Asian patients with myocardial infarction were found to have a significantly lower overall physical activity score (3.78 vs. 5.33; P = 0.003), leisure time physical activity (2.43 vs. 2.74; P < 0.05) and sporting score (0.14 vs. 0.82; P < 0.01) when compared to caucasians, despite a similar mean age and body mass index. CONCLUSION: The majority of myocardial infarction patients were engaged in sedentary activities at chest pain onset. Although there were no differences between caucasians and Indo-Asians in activity at symptom onset, Indo-Asian patients had a significantly lower overall physical activity score, leisure time physical activity and sporting score compared to caucasians. The lower general physical activity amongst Indo-Asians may in part contribute to the high prevalence of ischaemic heart disease amongst this ethnic group.

Activities of Daily Living↗

Ambulatory blood pressure monitoring in atrial fibrillation.

Ambulatory blood pressure monitoring (ABPM) devices are increasingly used in the assessment of hypertension, but patients with atrial fibrillation are usually excluded because device accuracy in this patient group is unproved. The present study investigates the clinical use of the Spacelabs 90207 oscillometric ABPM device in outpatients with chronic atrial fibrillation and suggests that such devices can be used in clinical practice to assess blood pressure in stable outpatients with chronic atrial fibrillation.

Aged↗

Fibrin D-dimer and beta-thromboglobulin as markers of thrombogenesis and platelet activation in atrial fibrillation. Effects of introducing ultra-low-dose warfarin and aspirin.

BACKGROUND: Previous studies have demonstrated increased markers of thrombogenesis in patients with atrial fibrillation (AF), suggesting the presence of a hypercoagulable or prothrombotic state. The objective of this study was to determine the effects of introducing ultra-low-dose warfarin (1 mg), conventional warfarin, and aspirin. (300 mg) therapy on thrombogenesis and platelet activation in AF. METHODS AND RESULTS: We measured sequential changes in plasma fibrin D-dimer (an index of thrombogenesis) and beta-thromboglobulin (beta-TG, a measure of platelet activation) in 51 patients with chronic AF before and at 2 and 6 weeks after randomization to either 1 mg warfarin or 300 mg aspirin (phase 1). Then all patients were started on conventional warfarin therapy (phase 2) with samples taken 2 and 6 weeks later. Pretreatment results were compared with those from 26 healthy control subjects in sinus rhythm. Baseline (pretreatment) beta-TG and D-dimer levels in patients with AF were elevated compared with those of control subjects (P < .001). In phase 1, there were no significant changes in median levels of fibrin D-dimer or beta-TG, despite warfarin 1 mg or aspirin 300 mg. With standard warfarin therapy (phase 2), there was a reduction in median beta-TG at 6 weeks (P = .025) and a sequential reduction in median D-dimer levels at 2 (P = .001) and 6 (P < .001) weeks compared with baseline levels. CONCLUSIONS: Patients with AF have increased intravascular thrombogenesis and platelet activation compared with patients in sinus rhythm. Introduction of ultra-low-dose warfarin (1 mg) or aspirin 300 mg does not significantly alter these markers, although conventional warfarin therapy reduces beta-TG and fibrin D-dimer levels. This is consistent with the beneficial effect of full-dose warfarin in preventing stroke and thromboembolism in AF and suggests that ultra-low-dose warfarin and aspirin may not exert similar beneficial effects.

Aged↗