Cardiovascular risks of hypertension: lessons from observational studies

Hypertension is an acknowledged major risk factor for cardiovascular disease and death in both men and women. Despite a historical focus by clinicians on the importance of diastolic blood pressure (DBP) risks, epidemiologic data from numerous large-scale studies have clearly demonstrated that both systolic blood pressure (SBP) and DBP are important determinants of cardiovascular risk. Recent analyses have described notable risks associated with isolated and borderline elevations of SBP, which predominate in the elderly, emphasizing the independent contribution of elevated SBP in determining overall risk. Overviews of large-scale treatment trials show that antihypertensive drug treatment confers a favorable net clinical benefit in patients with diastolic and isolated systolic hypertension, and the magnitude of risk reduction is comparable to that expected from the observational data. However, at any level of SBP or DBP, the absolute magnitude of risk varies widely depending on the burden of coexisting risk factors present. Therefore, it is essential that decisions regarding the urgency, risks and benefits of antihypertensive drug treatments be informed by accurate determinations of overall cardiovascular risk.     

Arterial hypertension: current large therapeutic trials

In this review, the design and objectives of ongoing clinical trials in essential hypertension are discussed along with the main results obtained from previously published therapeutic trials. In a meta-analysis of 14 of the major primary prevention trials in hypertension, the difference in diastolic blood pressure between the intervention groups and the control groups was only 5-6 mmHg. This difference was associated with significant reductions in all stroke events (42 per cent), all coronary heart disease events (14 per cent) and in cardiovascular mortality (21 per cent). In elderly hypertensive patients, available studies have shown that antihypertensive treatment reduces the incidence of non-fatal cardiovascular events without significantly modifying cardiovascular mortality. Most of these results were obtained with beta-blockers or diuretics. Despite official recommendation as first line monotherapy, none of the three new antihypertensive classes has been shown to have beneficial effects on hard primary endpoints such as cardiovascular morbidity and mortality. Several ongoing large scale randomized controlled trials vs. beta-blockers or diuretics are addressing this important issue. Moreover, other effects of antihypertensive treatment such as the 'J-curve phenomenon', the rate of change in the carotid wall thickness or the exact beneficial effects in elderly patients are being investigated in some of these studies.     

Arterial hypertension in children

It is considered hypertension in children, the persistent increase of the blood pressure values above percentile 95 for age and sex, in no less than three determinations, with adequate register techniques. Blood pressure is maintained mainly by the regulation of metabolism of sodium and water in the intravascular space, through the adequate balance of intake, filtration, reabsorption and renal throughout. It is also regulated by hormonal factors. Weight gain control in teen-agers could be useful to prevent high blood pressure in adults. In children, it is generally secondary to renal, reno-vascular, endocrinological or tumoral diseases. Clinical manifestations and the recommended diagnostic procedures are analysed to detect the most frequent causes of hypertension at different ages. Most cases response with antihypertensive drugs in combination with hyposodic diet. For the hypertensive crisis, asa diuretics and powerful antihypertensive drugs may be employed. Patients with chronic renal insufficiency could also need dialytic treatments. Renovascular diseases require almost always invasive treatments. Better prognosis in children with severe high blood pressure is related with recent diagnostic procedures, surgical techniques and antihypertensive drugs improvements.     

Commentary: patient education presentations

Medical students often learn how to teach through observation of residents and attendings. The project described enables them to actively teach groups of patients, and allows them to begin developing their own style of teaching. It also demonstrates to the students that teaching is a skill to be learned, and methods may vary tremendously.     

Structured patient education for out-patients with hypertension in general practice: a model project in Germany

In a model project, office-based physicians in two regions of Germany provided a structured treatment and teaching programme for out-patients with hypertension. The project was carried out in co-operation with the German Hypertension League and designed to evaluate the practicability and efficacy of the implementation in routine primary health care. A total of 111 primary health care practices in two German districts who had participated in a training course were interviewed. In 43 of these offices documented data of all patients who had received the standardised treatment and teaching were evaluated. The programme was well received by the physicians of which 81% rated the training course and 93% the teaching material as 'very good' or 'good'. A total of 466 patients were trained. Data collected on 272 patients (22 weeks after the intervention) demonstrated the efficacy of the programme at treatment level: reduction of body weight (2 kg, P < 0.001) and blood pressure (from systolic 158+/-18 to 148+/-17 mm Hg, P < 0.001; diastolic 91 +/-9 to 86+/-9, P < 0.001). Sixty-five per cent of patients learned for the first time how to perform blood pressure self-monitoring during the programme. The number of blood pressure readings by the patients' increased significantly from 1+/-3 measurements per week before, to 8+/-7 measurements per week after the programme (P < 0.001). The results of the study demonstrate the practicability and efficacy of the implementation of the programme for patients with hypertension into routine primary health care.     

Arterial hypertension: its impact on perioperative morbidity and mortality

Chronic hypertension is associated with structural as well as functional changes of the vasculature, in particular of the coronary, cerebral and renal circulation. It is important to realise that [1] functional changes are often the result of structural changes, [2] the longer lasting the hypertension, the slower and less complete the regression of structural changes, and [3] acute "normalisation" of arterial pressure in long-standing hypertension may initially induce functionally subnormal smooth muscle and/or cardiac activity because the structure of the cardiovascular system is adapted to function at elevated pressures. Despite a multitude of studies, the impact of hypertension on peri-operative morbidity and mortality remains controversial. There are as many studies seeming to suggest that preoperative hypertension correlates with adverse outcome as there are studies that fail to establish such a relationship. When looking at the combined evidence, one is inclined to conclude that hypertension is a predictor of "soft" outcomes (e.g. peri-operative myocardial ischaemia and transient post-operative neurologic deficit) rather than an independent predictor of "hard" outcomes (e.g. unstable angina, myocardial infarction and cardiac death). In view of lack of convincing outcome data, it is impossible to recommend a generally acceptable management strategy for the hypertensive patient. Although, in general, a gradual reduction of blood pressure over a period of weeks to months is the optimal therapeutic approach, we will be hard-pressed delaying surgery for the sole purpose of "better blood pressure control". With full appreciation and detailed knowledge of the pathophysiology of hypertension, combined with sophisticated haemodynamic monitoring and interventions in the peri-operative period, acutely anaesthetising an inadequately treated hypertensive patient will probably not adversely affect his outcome. Delaying surgery for additional work-up may possibly improve outcome in patients with target organ disease, evidence of secondary hypertension, in the most severe forms of hypertension or sudden-onset hypertension.     

Arterial hypertension in patients on chronic hemodialysis

Arterial hypertension is frequent among chronically dialyzed patients. The kidney obviously plays a major role in arterial blood pressure control. There is a large number of experimental data emphasizing different factors (in addition to renin important in renal hypertension prognosis) such as: sodium balance, angiotensin, etc [1-8]. Sympathetic activity disorders or lack of vasodilatory prostaglandins and quinine may also play a certain role. In uremic patients peripheral arteriolar resistance is increased, unlike normotensive uremic patients or those who prove to be normotensive upon clinical examinations [8, 11-15]. Hypertension occurs in approximately 80% of patients with chronic renal failure, producing a number of complications primarily affecting the CNS and systemic circulation [5-8, 10, 11, 13]. The study concerned patients on chronic dialysis, with a male to female ratio of 69.9%:32.1%. In most of them the underlying disease, which caused chronic renal failure, was glomerulonephritis (60.0%), then pyelonephritis (17.0%) and nephrosclerosis, nephrolithiasis, polycystic kidney and, finally, renal tumours. The effect of permanent haemodialysis during the first year of treatment, was efficacious on hypertension in 1704 (65.1%) patients; in 672 (25.7%) patients therapeutical effects were achieved by dialysis and antihypertensive drugs, while in 240 (9.2%) subjects there was no improvement. General observations suggest that two types of arterial hypertension persisted in patients with chronic renal failure: volume-dependent arterial hypertension which is more frequent (90-95%) among haemodialyzed patients and renin-dependent hypertension. Such findings are of utmost importance indicating that hypervolaemia is one of the major factors in the development of arterial hypertension in patients with chronic renal failure, with renin playing the secondary role. Salt-free diet should be used in the treatment of arterial hypertension for years, a well conducted haemodialysis is highly effective in the control of arterial hypertension among these patients. In our series of patients dialysed three times a week; normalization of blood pressure was faster with lower incidence of hypertensive crises during haemodialysis and with few complications. Water and sodium excess was reduced by frequent haemodialyses and sudden changes in electrolyte, hydrostatic and other metabolic effects were minimized. Increased values of plasma renin activity were observed in a small number of patients. Ultrafiltration is insufficient for normalization of blood pressure. Hypertensive crises were frequent in these patients. Their response to medicaments such as methyldopa, beta-adrenergic blockers or other antihypertensive drugs, was good. Severe changes in blood vessels, especially in fundus oculi blood vessels were frequent in these patients. The life of hypertensive glomerulonephritis patients was especially endangered (graphs 1-6). In addition to the mentioned factors arterial hypertension during haemodialysis may also be of cardiac origin, including increase in cardiac output due to arteriovenous anastomosis, disequilibrium syndrome, changes in osmotic gradient of both extra- and intracellular spaces with resultant arteriolar wall oedema, erythrocyte amount, hypoxia, composition of dialysis fluid (sodium concentration), plasma osmotic pressure, metabolic acidosis and other factors. More recently, natriuretic hormone has also been indentified as a cause of vascular refraction. Peripherial arteriolar resistance as a cause of arterial hypertension among uremic patients must not be forgotten, because the genesis of arterial hypertension in patients with chronic renal failure is multifactorial. The highest percentage refers to volume-dependent arterial hypertension, whereas the percentage of other aetiologic factors is lower. Haemodialysis enables the normalization of blood pressure in most of hypertensive patients.     

Arterial hypertension in patients with primary glomerulonephritis

Arterial hypertension is a state of blood pressure permanently higher than 160/90 mm Hg (21.3/12.6 kPa). The renal cause of hypertension occurs in about 10% of all cases. The aim of this article was to establish the frequency, the level, and the connection of the hypertension in different types of primary glomerulonephritis. In this study 90 patients with primary glomerulonephritis were observed. Hypertension was present in 45 patients (50%) and different frequency were noticed in different types of glomerulonephritis. The smallest frequency was recorded in the group with minimal changes and IgA nephritis. In the group with mesangioproliferative glomerulonephritis 52% of patients had hypertension and in the group with focal segmental sclerosis 78%. The most frequent hypertension was observed in the group with rapidly progressive glomerulonephritis. Renal failure was more frequent in patients with hypertension. Different frequencies of hypertension was established in different types of glomerulonephritis. It was not severe and was well controlled by remedies. In most cases it suggest a severe glomerular lesions and fast progression of the disease.     

Involving patients: lessons from PACE

In the fourth part of our PACE series, based on the King's Fund Promoting Action on Clinical Effectiveness programme, the first article reviews the experiences of 16 PACE projects that offer tips for involving patients in programmes to implement evidence-based practice, quality initiatives and clinical governance arrangements. The second article provides a more detailed example of one project.     

Immunoconjugates: lessons from animal models

Monoclonal antibody-mediated cancer therapy has evolved through a challenging chain of problems and solutions. The very limited therapeutic success obtained with unarmed monoclonal antibodies has increased the interest in different antibody-based targeting strategies, and numerous preclinical and even clinical studies with immunoconjugates have now been conducted. We comment here on the messages implicit in a recent report on a doxorubicin-anti-carcinoma antibody conjugate and from several other studies.     

Health sector reform: lessons from China

As a result of China's transition to a socialist market economy, its rural health services have undergone many of the changes commonly associated with health sector reform. These have included a decreased reliance on state funding, decentralisation of public health services, increased autonomy of health facilities, increased freedom of movement of health workers, and decreased political control. These changes have been associated with growing inequality in access to health services, increases in the cost of medical care, and the deterioration of preventive programmes in some poor areas. This paper argues that the government's strategy for addressing these problems has overemphasised the identification of new sources of revenue and has paid inadequate attention to factors that influence provider behaviour. The strategy also does not address contextual issues such as public sector employment practices and systems of local government finance. Other countries can learn from China's experience by taking a systematic approach to the formulation and implementation of strategies for health sector reform.