MRC trial of treatment of mild hypertension: principal results. Medical Research Council Working Party

Benefit-risk assessment of investigational drugs: current methodology, limitations, and alternative approaches

Development of investigational drugs is a process integrated traditionally into four overlapping phases. The goal is to introduce new therapies to clinical medicine by assessing benefits and risks associated with administering the new drug. Benefit assessment is performed with respect to the disease for which the drug may comprise an effective treatment. In contrast, safety assessment is relatively standardized across many pharmacologic classes of agents. For purposes of benefit-risk assessment, investigational drugs are developed to provide benefit in three major disease categories: acute, episodic, and chronic. Benefit assessment is the major focus of conventional methodologies. Inherent limitations of risk assessment produced by conventional approaches are illustrated by the historical inability to detect toxicities of various drugs until large patient populations have been treated, typically after the drug is marketed. Alternative approaches to overcome these limitations include assessment of safety in studies specifically designed to optimize such evaluation and more extensive safety testing of investigational drugs in patient subgroups at higher risk. Such approaches serve the interest of patients, physicians, and developers by facilitating the development of new therapies by providing a more complete benefit-risk assessment prior to initial marketing of the drug.

The effects of antihypertensive drugs on serum lipids and lipoproteins. II. Non-diuretic drugs

This review examines the effects of various antihypertensive drugs on blood lipids, lipoproteins, and apolipoproteins. A large number of studies have documented the elevation of total cholesterol, triglycerides, low density lipoprotein (LDL) cholesterol, and very-low density lipoprotein (VLDL) cholesterol with many thiazide-type diuretic drugs, albeit mainly in short term studies. When added to thiazide diuretics, both beta 1-selective and non-selective beta-blocking drugs elevate total triglycerides and VLDL triglycerides, lower high density lipoprotein (HDL) cholesterol and raise the ratio of total cholesterol to HDL cholesterol ratio. Most non-selective beta-blockers have similar effects when used as monotherapy, but the beta 1-selective agents appear not to affect HDL cholesterol in monotherapy. Prazosin appears free of adverse lipid effects and has improved lipid-lipoprotein concentrations in many studies. Preliminary data on several other drugs also suggest a favourable lipid profile and additional study is warranted - among these are guanabenz, clonidine, pindolol, labetalol, indapamide, and guanfacine. Elevations in serum triglycerides are often ignored on various counts, but triglycerides have been found to be a strong risk factor in European studies and in women over the age of 50 years in the Framingham study. Despite the unfavourable short term effects of diuretics, the theoretical risk of the lipid-lipoprotein changes remains unclear because HDL cholesterol and the total cholesterol to HDL cholesterol ratio are often unchanged. For this and other reasons, a long term trial comparing thiazide-type diuretics with drugs with the most favourable lipid-lipoprotein profile is needed. Until this is accomplished, in most settings diuretic-based regimens are still preferred initially since they are of proven, if limited, efficacy against the cardiovascular complications of hypertension.

Implications of recent clinical trials in systemic hypertension. Results of a multicenter trial of nitrendipine, for mild to moderately severe systemic hypertension

Results of the European Working Party group study and the Medical Research Council clinical trial in mild hypertension have important implications for the practicing physician. They appear to confirm 2 previous impressions. The first is that therapy for elderly patients with both systolic and diastolic hypertension is beneficial; cardiovascular mortality can be reduced by lowering blood pressure. These data are consistent with the findings in the 60- to 69-year-old cohort in the Hypertension Detection and Follow-up Program study in the US. The second is that specific treatment with antihypertensive agents in patients with mild hypertension will decrease overall cardiovascular mortality compared with placebo treatment. The approach to treatment in both of these studies was relatively simple, using a diuretic as step 1 therapy in the European study, and either a diuretic or a beta-adrenergic inhibiting agent in the Medical Research Council study. These data provide further evidence for the benefits of treatment of hypertension.

Comparison and additivity of nitrendipine and hydrochlorothiazide in systemic hypertension

Calcium channel blockers are highly effective antihypertensive agents and provide a good alternative to other medications used as initial or monotherapy. Although the calcium channel blockers act as peripheral vasodilators, they are unique among this group of drugs in lowering blood pressure in a sustained manner; several compensatory mechanisms are inhibited by virtue of either direct or indirect effects of these agents. In recent years, hypertension has generally been treated with a step-care approach, the limitations of which are now becoming apparent. Today, 4 classes of agents are effective and well tolerated as single therapy and might therefore be considered as first-line drug therapy: diuretics, beta blockers, converting enzyme inhibitors and calcium channel blockers. Preliminary results from an ongoing double-blind randomized trial comparing nitrendipine (a calcium channel blocker) and hydrochlorothiazide (a diuretic) in mild to moderate hypertension will be presented. Results from 63 patients showed the 2 agents to be equivalent in antihypertensive effects and in frequency of adverse reactions. Other data indicate that when nitrendipine and hydrochlorothiazide were combined, a further decrease in blood pressure was observed. Patient characteristics affecting drug choice and clinical situations in which calcium channel blockers can be used most effectively can now often be delineated.

Hypertension and the risk of ischaemic heart disease

The magnitude of the effect of hypertension as a risk factor for acute myocardial infarction (AMI) was estimated in 250 patients who presented with a first AMI who were aged 35-64 years (199 survivals and 51 deaths within 24 h), whose names were obtained from a community-based register of myocardial infarctions in the Hunter Region of New South Wales. The cases were matched by sex, age and residential area, and control subjects were obtained from a random population sample from the same region. A history of hypertension (odds ratio, 5.5; 95% confidence limits, 3.4 and 8.9) and treatment for hypertension (odds ratio, 4.2; 95% confidence limits, 2.5 and 7.2) were each significantly (P less than 0.0001) associated with an increased risk of AMI--persons with treated or untreated hypertension were four to five times more likely to develop AMI than were persons without hypertension. Adjustment for smoking did not affect the association between hypertension and the incidence of AMI. Cigarette smoking appears to have had less influence on the incidence of AMI (odds ratio, 1.7; 95% confidence limits, 1.1 and 2.4; P less than 0.01) than did a history of hypertension. Twenty-four per cent of the first AMIs that occurred in the study population were attributable to hypertension (after adjustment for smoking) and twenty-seven per cent were attributable to smoking (after adjustment for hypertension).

Efficacy of antihypertensive drug treatment according to age, sex, blood pressure, and previous cardiovascular disease in patients over the age of 60

Results of the European Working Party on High Blood Pressure in the Elderly (EWPHE) trial have been analysed in relation to age, sex, blood pressure, and previous cardiovascular disease. Cardiovascular mortality and the cardiovascular study-terminating events were significantly and independently related to treatment, age, cardiovascular complications at randomisation, and systolic but not diastolic blood pressure. The benefits of treatment observed in the trial seemed to be independent of entry blood pressure and the presence or absence of cardiovascular complications at entry. There was some evidence that treatment effect decreases with advancing age. Little or no benefit from treatment could be demonstrated in patients over the age of 80 years, the great majority of whom were women.

Adverse reactions and interactions with beta-adrenoceptor blocking drugs

beta-Blocking drugs are widely used throughout the world and serious adverse reactions are relatively uncommon. Most of those which do occur are pharmacologically predictable and may be avoided by ensuring that patients who are to be given beta-blockers do not have a predisposition to the development of bronchospasm, cardiac failure or peripheral ischaemia. In some situations, the use of a beta 1-selective blocking drug may reduce the risk of a severe adverse reaction, but there is little evidence that other ancillary properties such as partial agonist activity are of relevance in this context. Long term experience with many of the beta-blockers in current use suggests that unpredictable major adverse reactions such as the practolol oculomucocutaneous syndrome are unlikely to be repeated, although some of these drugs may be associated with immunological disturbances and some have been implicated in the development of retroperitoneal fibrosis. beta-Blocking drugs appear to be associated with a number of subjective side effects including muscle fatigue, peripheral coldness and some neurological symptoms. These side effects are highly subjective and are therefore difficult to quantify and it is not known whether they are of major importance in terms of their effect upon patients' overall well-being. It cannot be assumed that simply because such side effects can be elicited that they do, in fact, matter. However, because beta-blockers are often prescribed for patients who have no symptoms and for whom the benefits of therapy are generally small, such side effects would be of considerable importance if they had an overall effect upon quality of life. There are theoretical reasons to suppose that the incidence and severity of such side effects may be related to the ancillary properties of the individual drugs, but there is little evidence that parameters such as beta 1-selectivity, or partial agonist activity are clinically important determinants of the severity of these side effects. Lipophilicity, however, may be associated with an increased incidence of neurological symptoms. beta-Blocking drugs may cause a variety of metabolic disturbances including an increase in serum VLDL-cholesterol concentrations. However, long term studies have not shown that such disturbances are associated with an increased risk of cardiovascular disease, indicating that such metabolic changes may not be of major importance in practice. beta-Blocking drugs may be involved in a number of interactions with other drugs, but few of these have been shown to be of clinical significance.(ABSTRACT TRUNCATED AT 400 WORDS)

Therapeutic traditions in Northern Ireland, Norway and Sweden: II. Hypertension. WHO Drug Utilization Research Group (DURG)

A questionnaire survey based on hypertension case histories was performed among a representative sample of 400 GP's and hospital doctors in Northern Ireland, Norway and Sweden, countries having markedly different utilization of antihypertensive drugs. We found a greater propensity to start antihypertensive drug treatment in Northern Ireland than in Norway and Sweden. This was true both in mild diastolic and isolated systolic hypertension. Yet the utilization of antihypertensive drugs in Sweden is about 60% higher than in Northern Ireland and 30% higher than in Norway. Swedish physicians preferred beta-blockers as their first choice to a greater extent than physicians in Northern Ireland and Norway who selected thiazides more often. In general, the choice of drugs agreed with the sales and prescribing patterns in the three countries. Besides providing more insight in therapeutic traditions the study indicates that the lower prescribing of antihypertensive drugs in Northern Ireland, and to some extent in Norway, compared to Sweden, might be due to differences in true or apparent morbidity.

The effects of antihypertensive drugs on serum lipids and lipoproteins, I. Diuretics

Potassium-losing diuretic drugs, when used in the treatment of hypertension, cause unfavourable short term alterations in blood lipid and lipoprotein concentrations. The disturbance is characterised by increases in total cholesterol of 4 to 13%, in low density lipoprotein (LDL) cholesterol of 7 to 29%, in very-low density lipoprotein (VLDL) cholesterol of 7 to 56%, and in total triglyceride of 14 to 37%. The disturbance is variable among patients and over time in individual patients; it is absent in some. In long term treatment the data are fragmentary, but total cholesterol and triglycerides usually return to baseline values or below. The variability of the lipid response to diuretics has several consequences: firstly, it necessitates a sizeable study population (minimum of 30 patients) in order to document convincingly its presence or absence; secondly, lipoprotein fractions must be examined to define the pattern of the disturbance; and thirdly, the subsidence of the diuretic-induced lipid effects in long term treatment may be more apparent than real because even larger decreases have been noted in untreated groups in the few studies that wisely included these important controls for comparison. While the cause of the lipid-lipoprotein aberration is unclear, existing data suggest that certain attributes of the study population influence the response, i.e. age, habitual diet, hormonal milieu (gender), baseline cholesterol concentrations, and induced glucose intolerance. The apparent absence of lipid alterations with indapamide needs to be substantiated and compared with low doses of a standard thiazide-type drug. The lipid-lipoprotein effects of diuretics seem inconsequentially small, but they may contribute to the disappointing failure of diuretic-based regimens to lower the incidence of coronary heart disease in hypertensive patients. Nevertheless, diuretic-based treatment remains the only therapeutic regimen of proven benefit to congestive heart failure in patients with hypertension, and it is superior to beta-blockade in preventing stroke. Hence, alternative antihypertensive drug regimens must be compared prospectively with diuretics in order to verify any theoretic superiority.

Interaction of nonsteroidal anti-inflammatory drugs with antihypertensive and diuretic agents. Control of vascular reactivity by endogenous prostanoids

Indomethacin and some other nonsteroidal anti-inflammatory drugs partially antagonize the blood pressure lowering effect of drugs used to treat hypertension. They can also produce a mild elevation of blood pressure in normotensive individuals. The elevated arterial pressure caused by these agents is associated with increases in the vascular resistance of mainly the renal and splanchnic beds. This may be due to direct inhibition of the synthesis of vasodilator prostanoids, or it may be due to indirect potentiation of the action of the sympathetic nervous system or of angiotensin II. Nonsteroidal anti-inflammatory drugs also cause renal retention of sodium and this probably contributes to their hypertensive effects. In humans, the sodium retention may involve increased reabsorption in the proximal tubule. Although a direct tubular action is possible, these drugs may change proximal sodium reabsorption by their vascular effects. However, the exact mechanism is not understood. These interactions are clinically significant and may complicate the treatment of common diseases.

Does angiotensin-II protect against strokes?

In the Medical Research Council trial for the treatment of mild hypertension, bendrofluazide showed an unexpected and sizeable benefit compared with propranolol in the reduction of stroke. It is suggested that this difference reflects the opposing actions of these drugs on the renin-angiotensin system. The hypothesis that angiotensin-II protects the distal smaller cerebral vessels, which are the usual site of vessel rupture in intracerebral haemorrhage, indicates that long-term benefit of angiotensin-converting-enzyme inhibitors in the treatment of hypertension cannot be assumed.

Diuretic-induced hypokalemia and cardiac arrhythmias

Premature ventricular contractions have long been recognized as a complication of severe diuretic-induced hypokalemia. Likewise, diuretic-induced mild hypokalemia is known to have an arrhythmogenic potential in patients who are concurrently being treated with digitalis compounds. Recent studies using exercise and ambulatory monitoring of the electrocardiogram suggest that diuretic-induced premature ventricular contractions may be a more common phenomenon than was previously recognized. The risk of this form of ventricular ectopic activity is controversial. However, the available data are substantial enough to warrant some precautions on the part of the clinician.

Coronary heart disease death, nonfatal acute myocardial infarction and other clinical outcomes in the Multiple Risk Factor Intervention Trial. Multiple Risk Factor Intervention Trial Research Group

The Multiple Risk Factor Intervention Trial was a randomized clinical study to test whether a special-intervention (SI) program aimed at reducing serum cholesterol levels, blood pressure and cigarette smoking would prevent coronary heart disease (CHD) in middle-aged men. The main endpoint reported here is the percentage of participants experiencing first major CHD events (either nonfatal acute myocardial infarction [AMI] or CHD death) during 7 years of follow-up. This outcome was slightly less frequent in the 6,428 SI men than in the 6,438 men assigned to their usual source of care (UC). However, the relative difference--either 1% (95% confidence interval -17% to 16%) or 8% (95% confidence interval -5% to 20%), depending on how AMI was classified--was not statistically significant. Regression analyses within the SI and UC groups suggested that the cholesterol and cigarette smoking interventions reduced the number of first major CHD events: the associations between lowering the levels of these 2 factors and reductions in CHD rates were significant (p less than 0.001) and of the anticipated magnitude. A similar analysis of antihypertensive treatment in the SI group revealed no favorable association between lowering blood pressure and CHD rate, and other subgroup comparisons suggested that a mixture of beneficial and adverse effects may underlie this finding. Thus, the nonsignificant overall UC/SI contrast in CHD rates may reflect a combination of the expected beneficial effects of the cholesterol and smoking interventions with unexpected heterogeneous effects of the antihypertensive intervention. Seven of 8 other prespecified cardiovascular endpoints occurred less frequently among SI than among UC men, the difference being nominally significant (p less than 0.05) for angina pectoris, congestive heart failure and peripheral arterial disease.

Long-term trends in biochemical data obtained from two population surveys

A study has been made of the variations in monthly mean values of 10 serum constituents in subjects participating in two partly-concurrent long-term epidemiological surveys. Closely similar patterns of variation were found in men in both surveys and in men and women in one survey. During the 6 years of the study, four types of variation of the monthly mean concentrations were identified in varying combinations: abrupt changes of less than 2% not detected by quality control procedures; a gradual drift in mean value; haphazard variations in mean values; and seasonal variations in bilirubin and urea, identical in men and women. The implications of these findings for the design of long-term epidemiological surveys, and the criteria for designating variations as seasonal, are discussed.

Historical perspective on the management of hypertension

Remarkable progress has been made during the past 30 years in the management of hypertension, a disease that affects approximately one out of every four adults in the United States. In the 1960s, at least half of the individuals with hypertension were unaware of their disease, and the blood pressures of fewer than 20 percent were controlled at normotensive levels. In contrast, in the 1980s, only a small percentage, perhaps as few as 10 or 15 percent of hypertensive patients, are unaware of their disease and, in many parts of the country, more than 60 percent are being treated to goal blood pressure levels. More effective treatment of hypertension is probably a major reason for the 45 percent decrease in stroke mortality rates in the last 12 years alone and for the dramatic decrease in the number of hypertensive patients in whom renal failure or congestive heart failure develops. In addition, at least a portion of the 25 to 30 percent decrease in coronary mortality rates can probably be attributed to better management of patients with hypertension. The availability of antihypertensive drugs in the 1950s (rauwolfia preparations, veratrum derivatives, thiocyanates, hydralazine, and the ganglion blockers) and the discovery of more effective agents in the period from the 1960s to the present have dramatically improved the prognosis of hypertensive patients. Thiazide diuretics, centrally acting sympatholytic agents, beta-adrenergic inhibitors, and, more recently, selective alpha-adrenergic inhibitors, converting-enzyme inhibitors, and calcium entry blockers are examples of these medications. All of these agents have some side effects, with varying patient acceptability. The search continues for newer drugs that are well tolerated, that lower blood pressure by reducing peripheral resistance, and that produce few metabolic changes. A detailed review of the physiologic effects of antihypertensive medications, as well as a critique of the clinical trials and some of the problems noted in the pharmacologic management of hypertension, is presented.

Role of selective alpha 1 blockers in the therapy of hypertension

As millions more patients with mild hypertension are being brought into active drug therapy, the need for effective medications that are safe for long-term use has increased. This is, in part, as a result of the adverse effect on coronary heart disease mortality observed in two of the major therapeutic trials, the Oslo Study and the Multiple Risk Factor Intervention Trial. In both of these, the diuretic-first, stepped-care approach was used. Administration of diuretics is frequently associated with such biochemical abnormalities as hypokalemia, hypercholesterolemia, and hyperglycemia. Thus, the wisdom of the routine use of a diuretic as the first choice of therapy is being questioned. Alternative drugs for initial therapy include beta blockers and selective alpha 1 blockers. With beta blockers, there is a tendency for serum triglycerides to increase and high-density lipoprotein cholesterol to decline, as well as a tendency for an undesirable reduction in cardiac output and an increase in peripheral resistance. Selective alpha 1 blockers, because they lower blood pressure in a hemodynamically more favorable manner and have a tendency to improve the lipid profile, are becoming increasingly attractive as initial therapy for mild hypertension and also as part of the combination needed for more severe disease. The favorable results noted with the new selective alpha 1 blocker terazosin strongly support its addition to the list of preferred drugs for initial therapy.

Fifteen year survival of patients presenting with hypertension to a hospital clinic

The survival has been determined for the 404 patients who presented to the Hammersmith Hospital Hypertension Clinic during the years 1962 to 1966 and in whom the untreated blood pressure was known. The fifteen year survival ranged from 72% for young men aged 30-49 at presentation to 27% for men aged 60-69. Sixty-eight percent of the deaths were cardiovascular or renal, 33% of all deaths were from ischaemic heart disease (IHD), 17% from stroke and 3% from renal causes. Death from any cause was predicted with statistical significance by age, the presence of accelerated or malignant hypertension, impaired renal function, smoking at presentation and systolic blood pressure. Death was not predicted by hypokalaemia, hyperuricaemia (after adjusting for renal function) and obesity.

Enalapril, atenolol, and hydrochlorothiazide in mild to moderate hypertension. A comparative multicentre study in general practice in Norway

Enalapril, atenolol, and hydrochlorothiazide were compared in a double-blind randomised parallel study in general practice. 436 patients with mild to moderate hypertension were included at 76 centres. A two-week placebo run-in period was followed by 16 weeks of monotherapy. The initial doses were: enalapril 20 mg; atenolol 50 mg; and hydrochlorothiazide 25 mg. These were doubled if treatment was not effective after 4 weeks. Adverse reactions were the main reason for withdrawal from the study (9 on enalapril, 19 on atenolol, and 8 on hydrochlorothiazide). Systolic and diastolic blood pressures were significantly reduced in all three groups. The reduction in systolic blood pressure was greater on enalapril than on atenolol. Serum potassium was reduced and uric acid increased on hydrochlorothiazide. Fasting blood sugar rose on atenolol but fell on enalapril. The frequency of adverse reactions was acceptable in all three groups. After 16 weeks on treatment significantly more adverse reactions were recorded in the atenolol group than in the enalapril group. Enalapril is effective and well tolerated in patients with mild to moderate hypertension.

Initial therapy for mild hypertension

The treatment of mild hypertension has been a subject of controversy because its benefits versus risks are not as well established as they are for moderate to severe hypertension. Results of several studies, however, now show that treatment reduces the frequency of stroke in those with milder blood pressure elevations. New guidelines published by the Joint National Committee recommend that treatment of mild hypertension begin with either a diuretic or a beta blocker. The effect on the most common complication of mild hypertension, that is, coronary heart disease (myocardial infarction and sudden cardiac death), has, however, not been encouraging in studies in which diuretics have been used as first-line treatment. Two large-scale primary preventive studies compared the efficacy of diuretics and beta blockers in reducing coronary heart disease in hypertensive patients; results were in favor of beta blocker regimens in men. So far there is some evidence, but no hard scientific proof, that certain beta blockers offer advantages over diuretics in preventing myocardial infarction and sudden cardiac death in hypertensive patients. A major concern with the use of diuretics is the risk of hypokalemia; this can be reduced when they are combined with beta blockers.

Prevalence and prognostic significance of hypercholesterolemia in men with hypertension. Prospective data on the primary screenees of the Multiple Risk Factor Intervention Trial

To assess the impact of serum cholesterol level on the risk of fatal coronary heart disease for men with high blood pressure, the six-year follow-up data from 361,662 men (aged 35 to 57 years) screened in 18 cities in the recruitment effort for the Multiple Risk Factor Intervention Trial were evaluated. Of these men, 356,222 reported no history of hospitalization for myocardial infarction; 100,032 of these 356,222 had a baseline mean diastolic blood pressure equal to or greater than 90 mm Hg. For those men with high blood pressure, the overall age-adjusted six-year rate of coronary heart disease death was 79 percent higher than for those with diastolic blood pressure less than 90 mm Hg. Compared with men with diastolic blood pressure less than 90 mm Hg and serum cholesterol below 182 mg/dl, men with diastolic blood pressure equal to or greater than 90 mm Hg had the following relative risks, based on the serum cholesterol level: for those with a serum cholesterol level less than 182 mg/dl, risk was 1.64; for those with a level of 182 to 202 mg/dl, risk was 2.14; for those with a level of 203 to 220 mg/dl, risk was 3.14; for those with a level of 221 to 244 mg/dl, risk was 3.29; and for those with a level equal to or greater than 245 mg/dl, risk was 5.14. Thus, for men with high blood pressure, serum cholesterol related to coronary heart disease risk in a strong, graded way, over the entire distribution of serum cholesterol, from levels of 182 mg/dl and higher. This was the case for hypertensive male smokers and nonsmokers, with cigarette use associated with a further marked increase in risk--at least a doubling of the mortality rate--at any level of serum cholesterol. These data underscore the necessity for a strategy of comprehensive care for persons with high blood pressure, including approaches to both nutritional and hygienic counseling and drug treatment, aimed at controlling all of the established major risk factors influencing prognosis.

Coronary heart disease and treatment of hypertension. Some Oslo Study data

The Oslo Hypertension Study began in 1972; patients were followed for an average of 66 months (range: 60 to 78). A total of 785 healthy men, aged 40 to 49, with mild hypertension was randomly assigned to either a drug-treated group or to an untreated control group. Hydrochlorothiazide was used alone in 36 percent of patients, in combination with propranolol in 26 percent, and with methyldopa in 20 percent. Other drugs, including combinations with hydrochlorothiazide, were used in 18 percent. A total of 95 percent of patients in the drug-treated group received hydrochlorothiazide. Complications of hypertension such as stroke and aneurysm occurred only in the control group. Coronary events were more numerous in the drug-treated group; thus, the total incidence of cardiovascular complications did not significantly differ between the treated and untreated groups. After five and 10 years, total mortality was the same in both groups. However, the coronary heart disease mortality rate at 10 years was significantly greater in the drug-treated group than in the untreated control group (14 versus three, p less than 0.01). This article presents possible reasons for the failure of antihypertensive drug therapy to prevent coronary heart disease. The adverse effect of diuretics and beta-adrenergic blockers, both on lipid and carbohydrate metabolism, is contrasted with the effect of the alpha-adrenergic blocker prazosin, which has been shown to have no adverse effect on the blood lipid profile. In a short-term trial that was part of the Oslo Study, prazosin was found to reduce total serum cholesterol by 9 percent, low-density lipoprotein and very-low-density lipoprotein cholesterol by 10 percent, and total triglycerides by 16 percent. All these changes are statistically significant.

Lipids and hypertension. Implications of new guidelines for cholesterol management in the treatment of hypertension

The approach to management of cardiovascular risk factors has been greatly enhanced by the recent publication of results from several large intervention studies. This increased knowledge has led to rapid changes in perspective and to some controversies regarding cardiovascular risk management. The major cardiovascular disease risk factors are high blood pressure, elevated serum cholesterol, and cigarette smoking. In the past, physicians have paid little attention to the latter two factors, focusing primarily on severe hypertension. Initially, the pharmacologic treatment of hypertension consisted mostly of thiazide diuretics, since they were the only agents generally available that were well-tolerated by most patients. Over the past decade, however, new data from large-scale intervention studies and the development of many new classes of antihypertensive agents have considerably improved the approach to managing all three primary risk factors. Recently published results of major clinical trials are likely to further alter physicians' perspectives and influence their practice habits. This article proposes an approach to comprehensive risk management that simultaneously involves all the major risk factors, with emphasis on blood pressure and lipids. The rationale for this integrated approach is based on the following facts: Hypertension trials have not convincingly demonstrated that lowering blood pressure alone reduces the risk for coronary heart disease; Cholesterol lowering has been shown conclusively to reduce the risk of coronary heart disease; Several classes of antihypertensive agents have now been found to significantly affect blood lipids, either adversely or beneficially; and Past observational epidemiologic studies have shown a positive association between blood lipids (cholesterol and triglycerides) and blood pressure, implying that these two conditions commonly occur together. The background supporting these facts, as well as a practical approach to the treatment of hypertension that takes into consideration the management of blood lipids, is provided in this article.

Epidemiology of atherosclerosis: an updated overview

Ongoing epidemiologic research continues to provide new insight into the multifactorial etiology of atherosclerosis and coronary artery disease (CAD). Cigarette smoking remains a primary risk factor; low tar and nicotine cigarettes have apparently not contributed to a reduced incidence of CAD and cardiovascular death. The stepwise risk of increasing levels of diastolic blood pressure to cardiovascular death is well known; however, elevated systolic blood pressure may be a more potent risk factor. The benefits of treating diastolic blood pressure greater than or equal to 115 mm Hg are indisputable; the benefits of treating milder hypertension, i.e., diastolic blood pressure between 90 and 114 mm Hg, probably outweigh the risks, but controversy persists. Low-density lipoprotein cholesterol, which comprises approximately 70% of total cholesterol, is strongly associated with CAD. Studies continue to relate hypercholesterolemia and CAD, showing approximately a 2% reduction in disease for each 1% reduction in total cholesterol. The influences of diabetes mellitus, thrombosis and psychosocial factors in the genesis of CAD are reviewed, as well as the evidence supporting the synergistic hazard presented by risk-factor clusters. High-density lipoprotein cholesterol bears an inverse, protective relation to CAD. Factors affecting high-density lipoprotein levels, e.g., obesity/exercise, cigarette smoking, alcohol consumption and postmenopausal use of estrogen in women, are also reviewed in light of recent findings. Additional investigation is necessary to clarify the benefits and risks associated with the treatment or modification of known risk factors and to identify others.

Treatment of hypertension in the elderly

Investigation of preventive measures for hypertension and atherosclerosis is a geriatric medicine priority. While the causes of both isolated systolic hypertension and conventional systolic and diastolic hypertension in the elderly are well defined, the benefits of lowering blood pressure are not. Evidence to support the treatment of symptomatic hypertension is convincing for men 60 years of age; it is not for women in this age group. The need to treat hypertension, particularly isolated systolic hypertension in patients above 75 years old, is still not resolved. Isolated systolic hypertension in older patients is at least as strong a risk factor for cardiovascular disease as is diastolic hypertension. Ongoing trials may answer these questions; in the meantime, drug therapy in this group will vary widely. The elderly hypertensive is more likely than the younger hypertensive to have other diseases; diagnosis of these disorders is crucial. Hypertension arising de novo late in life warrants a search for underlying and possibly remedial causes. Antihypertensive drug therapy to relieve symptoms is difficult to justify, because most elderly hypertensive patients are asymptomatic; however, it has been shown to delay morbid and fatal complications of hypertension. Appropriate therapy for the elderly hypertensive must be individualized and should be associated with few or no side effects. The thiazides are the preferred diuretics for long-term treatment of hypertension in the elderly. Beta blockers are attractive because they are cardioprotective, counter the end organ effect of catecholamines and reduce angina; however, some decrease cardiac output, increase peripheral resistance, decrease renal blood flow and cause fatigue.(ABSTRACT TRUNCATED AT 250 WORDS)

Unexpected effects of treating hypertension in men with electrocardiographic abnormalities: a critical analysis

The relationship between diuretic therapy and possible increased risk of coronary heart disease (CHD), especially sudden death, is controversial. The initial report from the Multiple Risk Factor Intervention Trial (MRFIT) raised the possibility that the increased CHD mortality observed in a subset of special intervention men with hypertension and certain electrocardiographic abnormalities on their baseline examination might be an unexpected adverse effect of diuretic therapy. Subsequent reports from the MRFIT have revealed a stronger association of CHD mortality to hydrochlorothiazide than to chlorthalidone. There was no consistent relationship of CHD mortality to the dose of either drug, to the most recent serum potassium level, or to the presence of ventricular premature beats. Unfavorable trends of the same magnitude were also seen among similar white men in the Hypertension Detection and Follow-up Program and in the Oslo hypertension trial, although the sample sizes in these two studies were too small to yield clearcut conclusions. Clinical studies have shown an increased risk of CHD death among hypertensive men with left ventricular hypertrophy. Such men are also noted to have a higher frequency of ventricular premature beats, even in the absence of diuretic therapy. Other studies have shown that diuretic-induced hypokalemia is accentuated in the presence of epinephrine and that low potassium levels decrease the threshold for ventricular fibrillation. Thus, although the evidence is still incomplete, it is possible that the excess CHD mortality among MRFIT special intervention men with electrocardiographic abnormalities may have been caused by a combination of increased left ventricular mass in the presence of coronary atherosclerosis, and hypokalemia caused by good compliance with diuretic therapy and accentuated by stress-induced increases in circulating catecholamines. Given the very large population of patients receiving diuretic therapy, further evaluation of this possibility is important.

Epidemiological considerations in the treatment of hypertension

Cardiovascular disease continues to be the principal cause of death in Western countries. Epidemiological studies have repeatedly demonstrated a striking relationship between blood pressure and the risk of cardiovascular disease in that those with the highest levels of blood pressure are at the greatest risk for subsequent disease or death. However, most blood pressure-related cardiovascular complications occur at much lower levels of blood pressure. Any attempt to substantially reduce the frequency of blood pressure-related cardiovascular disease mandates treatment of large numbers of asymptomatic subjects who are, on average, only exposed to a slight increase in risk. Based on current demographic trends, this requirement will become even more striking in the future. Non-pharmacological interventions provide the most attractive approach to the prevention and treatment of high blood pressure. However, the efficacy and acceptability of long term non-drug treatment is uncertain. Drug treatment remains the best proven and fundamental approach to the treatment of established hypertension. Based on the lifelong nature of antihypertensive therapy and the changing risk profile of those being treated, a desire to recognise and prevent adverse effects of antihypertensive drug administration is now more important than ever. Special care is essential during the treatment of uncomplicated mild hypertensives with few or no other cardiovascular risk factors.

Acebutolol in the treatment of diabetic patients with hypertension

A double-blind, parallel group comparison study was carried out in 20 diabetic patients with mild to moderate hypertension to assess the effectiveness and tolerance of acebutolol compared with placebo. After a 4-week wash-out period on placebo, patients received either 400 mg acebutolol or placebo once daily for 12 weeks and then placebo for a further 4 weeks. The results showed that acebutolol was more effective than placebo in lowering raised blood pressure in these patients. No deterioration in diabetic control occurred during the study and no significant side-effects of the drug were observed compared with placebo. In particular, the previously described side-effects of beta-blocker therapy in diabetic patients were not observed as a clinical problem in this study.