Novel delivery system for verapamil designed to achieve maximal blood pressure control during the early morning

Because the risk of cardiovascular events appears to be greatest in the early morning, this period is a time during which adequate blood pressure (BP) control appears to be most desirable. In this study, a controlled-onset extended-release system (COER-24) that delivers verapamil in a manner designed to achieve maximal levels of drug during the early morning surge in BP was compared with placebo. Ninety-five patients with mild to moderate hypertension were studied. Of this group, 49 patients (mean age 57.6 +/- 1.4 years; 35 men and 14 women) were randomized to take verapamil COER-24 240 mg at 10 PM, and 46 subjects (mean age 55.8 +/- 1.5 years; 29 men and 17 women) were randomized to take placebo. Ambulatory BP monitoring was performed after a 4-week initial placebo period and was repeated after 4 weeks of treatment with verapamil or placebo. Verapamil COER-24 resulted in significant (p < 0.001) decreases in mean whole-day systolic and diastolic BP (-8.2/-6.3 mm Hg; baseline 152/93.0 mm Hg) when compared with placebo (+0.3/-0.9 mm Hg; baseline 150.3/93.2 mm Hg). From 6 AM to noon, verapamil COER-24 resulted in a change in systolic and diastolic BP of -11.6/-9.0 mm Hg, which was significantly (p < 0.001) greater than the change that occurred with placebo (-0.5/-1.0 mm Hg) during the same period. In the last 4 hours of the dosing interval (6 PM to 10 PM), verapamil COER-24 caused significantly greater (p < 0.001) decreases in BP (-7.4/-4.8 mm Hg) than did placebo (+2.7/+1.0 mm Hg). These data demonstrate that the COER-24 system, when administered in the late evening, achieves maximal BP reduction during the early morning hours. Moreover, BP reductions were sustained throughout the 24-hour period.

Combination therapy with diuretics: an evolution of understanding

One of the current recommendations for the treatment of hypertension is a stepped-care approach in which a second drug is added to a first-line agent when adequate blood pressure control has not been achieved. It has been well demonstrated in multiple studies that the response rate to any single class of antihypertensive agent, given as monotherapy, is approximately 45-55%. Thus, in approximately half of the hypertensive population, a second drug will be required. This is not surprising, since it is now well recognized that hypertension is a multifaceted disease process. The use of combination therapy with low-dose diuretics (< 25mg hydrochlorothiazide [HCTZ] or its equivalent) has become a very attractive alternative choice to first-line therapy. The data from clinical trials clearly demonstrate that 6.25 mg or 12.5 mg HCTZ has an additive or synergistic effect on blood-pressure reduction when used in combination with most drugs. At low doses, the side-effect profile with diuretics is similar to placebo. Furthermore, metabolic side effects are significantly reduced when diuretics are used in low doses. The use of low-dose diuretics in combination with other first-line agents significantly enhances blood-pressure control and reduces the likelihood of adverse events and alteration in carbohydrate, lipid, and electrolyte metabolism. Thus, combination therapy with low-dose diuretics provides an attractive alternative approach to first-line treatment of essential hypertension.

Angiotensin II receptor inhibition. A new therapeutic principle

Angiotensin II receptor antagonists represent a new class of drugs that provide a site-specific blockade of the effects of angiotensin II. Losartan potassium, the first compound of this drug class, has recently become available in the United States. The clinical experience with angiotensin II receptor antagonists has demonstrated that these drugs are safe and efficacious for the treatment of hypertension and, possibly, congestive heart failure. Unlike with angiotensin-converting enzyme inhibitors, the incidence of cough observed with angiotensin receptor antagonists is similar to that with placebo. Although several angiotensin receptors have been characterized, the effects of losartan and other angiotensin receptor antagonists under development are selective for the angiotensin II type 1 receptor. Unlike angiotensin-converting enzyme inhibitors, angiotensin receptor antagonists do not inhibit bradykinin metabolism or enhance prostaglandin synthesis. The antihypertensive efficacy of the angiotensin receptor antagonists has been documented to be similar to that of angiotensin-converting enzyme inhibitors. If the findings of clinical studies corroborate the initial reports on efficacy and safety, it seems likely that the angiotensin receptor antagonists will be added to the list of drugs that have been deemed suitable for first-line therapy in the treatment of hypertension and congestive heart failure.

Antihypertensive therapy and quality of life. Influence of blood pressure reduction, adverse events, and prior antihypertensive therapy

Quality of life is an important attribute of antihypertensive therapy. Previous studies have not addressed the importance of a patient's prior pharmacotherapy on quality of life, which may serve as the basis of reference for a new therapy. Nor have previous studies compared commonly used quality of life instruments for consistency, or investigated whether improvement or worsening of quality of life correlates with adverse events or blood pressure reduction. Two hundred eighteen hypertensive patients with diastolic blood pressure (95 to 114 mm Hg) after a 4- to 5-week placebo washout period were enrolled in a randomized double-blind, parallel group dose-escalation trial to compare the effects of amlodipine (2.5 to 10 mg), bisoprolol (2.5 to 10 mg)/hydrochlorothiazide (HCTZ) 6.25, and enalapril (5 to 20 mg) on blood pressure, adverse events, and quality of life. Three quality of life instruments (General Well-Being Index, Vital Signs Quality of Life, Zung Self-Rating Depression Scale) were administered during original therapy, after placebo washout, and after 12 weeks of optimally titrated clinical trial pharmacotherapy. Our results demonstrated that removal from prior therapy had no detectable influence on subsequent evaluation of quality of life. The three quality of life instruments were consistent with the changes observed with the three therapies: a trend toward better quality of life with amlodipine and bisoprolol/HCTZ. Adverse events, but not systolic or diastolic blood pressure reduction correlated directly with changes in quality of life.

Measurement of short-term, intermediate, and long-term outcomes of treating hypertension

Hypertension is widely treated by primary care physicians as well as by cardiologists and other specialists. Clinical progress is often monitored by blood pressure measurements and other routine evaluations, but more sophisticated approaches may be required to learn whether treatment is effectively protecting the heart, kidneys, and other susceptible areas. Outcome measures therefore involve quantification of short-term, intermediate and long-term clinical observations; and, in addition, assessment of overall effectiveness must take into account economic factors and the levels of satisfaction perceived by patients, physicians, and health plans.

Once-daily monotherapy with trandolapril in the treatment of hypertension

Once-daily antihypertensive drugs that control blood pressure (BP) for the full 24-h dosing period, enhance patient compliance and may reduce the cardiovascular complications of hypertension which occur with increased frequency in the early morning. Since some once-daily agents are more effective than others in maintaining antihypertensive effects toward the end of the 24-h dosing interval this study was designed to evaluate the duration of antihypertensive action of trandolapril using 48 h ambulatory blood pressure monitoring (ABPM) in 41 patients with mild-to-moderate essential hypertension. Twenty-four hour ABPM was performed on two consecutive days (48 h) after a 4 week single blind placebo run-in period and repeated after an 8 week double-blind period during which 20 patients were randomized to treatment with trandolapril (2-4 mg once-daily) and 21 patients to matching placebo. During the second 48 h monitoring period, placebo rather than active medication was taken by both of the groups at the beginning of the second 24 h segment. Trandolapril reduced ambulatory systolic and diastolic BP by 9.4 and 6.2 mm Hg respectively (P < or = 0.01) during the first 24 h of the post treatment monitoring period while placebo increased the systolic and diastolic BPs in the same period by 3.8 and 2.6 mm Hg (P < 0.05). During the second monitoring period (hours 25-48), trandolapril reduced systolic and diastolic BP by 5.6 and 3.9 mm Hg while placebo increased BP by 2.3 and 1.6 mm Hg (P < 0.03). When compared to placebo by 2 h time blocks, throughout the 2 days of monitoring, trandolapril produced clinically significant decreases in systolic and diastolic BP for 30 and 28 h following dosing. This indicates that trandolapril can be considered a true once-daily antihypertensive agent.

Role of hypertension in coronary artery disease

Historically, stroke, heart failure and renal insufficiency were seen as the major complications of untreated hypertension. More recently, it has become evident that coronary heart disease is probably the most common outcome of this condition. Unlike the other complications of hypertension, coronary events have not been reduced in a meaningful fashion by traditional antihypertensive drug therapy. A partial explanation may lie in the fact that hypertension typically consists of a syndrome of inherited metabolic and cardiovascular abnormalities, and treatment that focuses primarily on blood pressure without taking into account the other factors that contribute to atherosclerotic disease can have only limited protective effects. The coronary hypothesis in hypertension extends this reasoning into 3 separate components. First is an intrinsic tendency to excessive proliferative and hypertrophic activity in vascular tissue, presumably reflecting growth-promoting activity stimulated by increased endocrine and local paracrine effects; second is the impact of the commonly encountered concomitant risk factors, including high blood pressure, that exaggerate and accelerate development of the underlying atherosclerotic lesions; third are hemodynamic factors, including increased variability and sustained elevations of blood pressure, that can destabilize vascular lesions and precipitate acute events. Treatment of these hemodynamic factors in elderly patients, whose underlying vascular changes are already well advanced, is likely to effectively reduce the incidence of vascular endpoints. In younger patients, ongoing vascular proliferative changes and the impact of concomitant risk factors are equally as important as hemodynamic forces in producing coronary disease, and effective treatment must take all these issues into account.

Controlling blood pressure throughout the day: issues in testing a new anti-hypertensive agent

Lessons learned from ambulatory blood pressure (BP) monitoring strongly influence the development of new anti-hypertensive drugs. Efficacy should be demonstrated not only in the conventional clinical setting, but also throughout the full 24 h day, including the important early morning hours near the end of dosing intervals. Preservation of the circadian pattern, including appropriate day/night BP differences, may be a further important goal of therapy. The reproducibility of ambulatory monitoring measurements, together with the absence of placebo effects with this technique, adds greatly to its power and efficiency. Moreover, the use of ambulatory monitoring to accurately diagnose hypertension and exclude non-confirmed or white coat hypertensives from clinical trials adds further sensitivity to quantifying drug action. This technique was recently applied to the evaluation of the new angiotensin II receptor antagonist losartan. Hypertensive patients diagnosed by ambulatory monitoring were divided into four groups: placebo, losartan 50 mg once daily, 100 mg once daily or 50 mg twice daily. Compared with placebo, which had no effect, all three losartan regimens decreased SBP and DBP significantly. There was no difference in efficacy between the two once daily regimens, although 50 mg twice daily was slightly more effective than 50 mg once daily but not statistically significantly different from 100 mg once daily. However, all losartan groups exhibited sustained BP reductions throughout the 24 h dosing interval and preserved the circadian BP patterns. Ambulatory monitoring was thus able to accurately quantity the efficacy and the key chronobiological aspects of anti-hypertensive therapy with losartan in an efficient and cost-effective manner.

The evolving paradigm of hypertension

Although it is convenient to think of hypertension in its renal, epidemiologic, and vascular eras, a new perspective is rapidly coming to the forefront. As we become more critical in evaluating the performance of our health care systems, it is obvious that the major problems in hypertension do not lie entirely with unsolved problems of physiology or therapeutics. Rather, we have come to realize that a large number of our hypertensive patients remain inadequately treated or, even more commonly, are receiving no treatment at all. Outcomes research into strategies for enhancing patient compliance with treatment and research dealing with other issues associated with clinical effectiveness are emerging as leading priorities.

Hypertension in the elderly: 24 h ambulatory blood pressure results from a placebo-controlled trial

Calcium channel blockers are increasingly used to treat hypertension in elderly patients. To assess the effects of low-dose, long-acting verapamil on blood pressure (BP) and quality of life (QOL) in elderly patients, verapamil 120-240 mg of placebo was given once daily for 8 weeks to 76 patients aged > or = 60 years. After a 4-week placebo wash-out period, patients with a sitting DBP of 95-110 mm Hg and a mean daytime (6 am to 6 pm) ambulatory DBP > or = 90 mm Hg were entered into the study. Twenty four-hour BP monitoring as well as QOL self-assessment and digit span testing of cognitive function were performed at the end of the placebo wash-out and double-blind treatment periods. Patients treated with verapamil showed a significant decrease in mean whole-day BP, while those treated with placebo showed a small increase in BP. Treatment differences between the two groups in SBP and DBP were each statistically significant (P < 0.01). Significant differences were also seen when the 24 h period was divided into daytime and night-time readings. Both QOL and digit span testing scores were unchanged from baseline for verapamil-treated patients and were not different from the placebo-treated group. The results of this study demonstrate consistent and significant decreases in BP throughout the 24 h period with no adverse effects on QOL or cognitive function this this formulation of verapamil in elderly hypertensive patients.

Low-dose drug combination therapy: an alternative first-line approach to hypertension treatment

To investigate the concept that the initial treatment of hypertension with low doses of two antihypertensives that have different modes of action and additive effects may achieve control of blood pressure and minimize the dose-dependent adverse effects seen with conventional monotherapy, a randomized, double-blind parallel group dose-escalation study was conducted. After a 4 to 5 week placebo washout period, 218 men and women with diastolic blood pressure between 95 and 114 mm Hg were randomly allocated to take: amlodipine (2.5 to 10 mg), enalapril (5 to 20 mg), and the low-dose combination of bisoprolol (2.5 to 10 mg) with 6.25 mg of hydrochlorothiazide (HCTZ). All drugs were administered once daily, titrated to optimal response, and taken for a total of 12 weeks. Blood pressure was measured 24 hours after dose. The response rates (either a diastolic blood pressure < or = 90 mm Hg or a decrease of diastolic pressure > or = 10 mm Hg) were 71% for bisoprolol-6.25 mg HCTZ, 69% for amlodipine, and 45% for enalapril. The mean decreases in systolic/diastolic blood pressure from baseline were 13.4/10.7, 12.8/10.2, and 7.3/6.6 mm Hg for bisoprolol-6.25 mg HCTZ, amlodipine, and enalapril, respectively. The mean change with enalapril was less than the other drugs (p < 0.01), although the once-daily dosing of enalapril and the maximum dose of 20 mg might not have been optimal for this agent.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood pressure effects of the angiotensin II receptor blocker, losartan

BACKGROUND

Losartan potassium, the first nonpeptide selective blocker of angiotensin II at the AT1 receptor, has been shown to exhibit clinical antihypertensive effects. The aim of the present study was to characterize the efficacy and duration of action of losartan by ambulatory blood pressure monitoring.

METHODS

The study was performed in nonblack hypertensive patients whose baseline untreated clinical diastolic blood pressures were 95 mm Hg or higher and whose average 24-hour ambulatory diastolic blood pressures were 85 mm Hg or higher. Patients were randomized, double-blind, into four treatment groups: placebo (n = 32) or losartan, 50 mg once daily (n = 29), 100 mg once daily (n = 30), or 50 mg twice daily (n = 31). Clinical and 24-hour ambulatory blood pressures were measured at baseline (off treatment for at least 4 weeks) and after 4 weeks of treatment.

RESULTS

By clinical sphygmomanometer measurements at the end of the 24-hour or 12-hour dosing intervals (trough), all three losartan dosages were significantly more effective than placebo at decreasing systolic and diastolic blood pressures. By average 24-hour ambulatory systolic/diastolic blood pressure measurements, the decreases produced were 0.0/0.2 mm Hg for placebo and 9.2/6.9, 9.9/6.4, and 13.2/8.5 mm Hg, respectively, for losartan, 50 mg once daily, 100 mg once daily, and 50 mg twice daily. All drug effects were different from placebo (P < .01). The effects of losartan, 50 mg twice daily, were not significantly different from those of losartan, 100 mg once daily, but, as expected, the effects were greater than those of losartan, 50 mg once daily (P < .05). Addition of hydrochlorothiazide, 12.5 mg/d, during an additional 2-week treatment period in patients whose clinical diastolic blood pressure remained at 85 mm Hg or higher while receiving monotherapy produced additional and clinically meaningful blood pressure decrements that were similar in all four treatment groups. There was no clinically important difference in the incidence of adverse events among the losartan-treated and placebo groups [corrected].

CONCLUSION

Ambulatory blood pressure monitoring, which virtually eliminated antihypertensive placebo responses, demonstrated clear 24-hour efficacy for losartan, 50 mg once daily, as well as for higher doses of 100 mg once daily and 50 mg twice daily. This AT1 receptor blocker had antihypertensive effects that appeared additive when combined with low-dose diuretic therapy. Losartan was generally well tolerated.

Relationship of left ventricular structure to maximal heart rate during exercise

Previous investigators using clinical, hemodynamic, or exercise parameters to predict maximal exercise heart rate (HRmax) have demonstrated age to be the major determinant. Regression coefficients have ranged from -0.3 to -0.6, leaving approximately two thirds of the variance in HRmax unexplained. Because cardiac size and function are directly related to stroke volume and should influence HRmax, we studied 114 male subjects (aged 19 to 73 years) with two-dimensional and M-mode echocardiography who underwent maximal treadmill testing with respiratory gas analysis. Seventy-three were normotensive (diastolic BP < 95 mm Hg) and 41 were hypertensive. As in previous studies, HRmax was inversely related to age (HRmax = 199-0.63[age], r = -0.47, p < 0.001). M-mode left ventricular (LV) diastolic dimension (LVD) added significantly to the explanation of the variance in HRmax (r = -0.57, p < 0.001) (HRmax = 236 - 0.72 [age]-6.8 [LVD]). Thus, the larger the heart, the lower the HRmax. No other echocardiographic measurement or derived parameter added significantly to the explanation of the variance in HRmax. To evaluate the effects of hypertension on HRmax, we studied hypertensives and normotensives separately. Only age was significantly related to HRmax in the normotensives (r = -0.50, p < 0.001). In the hypertensive subjects, however, both age and relative wall thickness (RWT) (which describes LV wall thickness in relation to LV chamber size) were significantly related to HRmax. Age explained 45% of the observed variance in HRmax (r = 0.67, p < 0.001) and RWT added modestly (9%) but significantly to the relationship (HRmax = 173-0.96[age]+94 [RWT], p < 0.001), together explaining 54% of the variance observed in HRmax. Thus, HRmax is inversely related to LVD and patients with larger ventricles achieve lower HRmax. In hypertensives, the amount of LV muscle mass in relation to chamber size is an additional predictor of HRmax. However, despite controlling for age, sex, and cardiovascular disease, and the inclusion of echocardiographic indices of cardiac size and function, a large portion of the variance in HRmax could not be explained. The unexplained variance in HRmax is most likely due to intersubject variability in resting cardiac size, volume, function, and other as yet undefined factors.

Diagnosis of mild hypertension by ambulatory blood pressure monitoring

BACKGROUND

Between 20% and 30% of patients with clinically diagnosed hypertension have normal blood pressure (BP) values during automated ambulatory 24-hour BP monitoring. It has not been clear, however, whether these patients can be regarded as normotensive or whether they should be treated in the same way as confirmed hypertensive patients.

METHODS AND RESULTS

Ambulatory BP monitoring was performed in 88 normal control subjects and 171 hypertensive patients (office diastolic BP > or = 90 mm Hg on three visits; never treated or off treatment for more than 6 months). Hypertensive patients were classified as nonconfirmed or white coat (n = 58) if their 24-hour diastolic averages were < 85 mm Hg and at least 15 mm Hg lower than their office values. For comparisons, white coat patients were pair-matched with normal subjects by 24-hour diastolic averages and sex, and by similar age and weight; there were 40 such pairs. White coat patients were likewise pair-matched with confirmed hypertensive patients by identical office BPs (51 pairs). Participants were studied by individualized treadmill testing, Doppler echocardiography, and assays of resting plasma catecholamines, upright plasma renin and aldosterone, and lipid, glucose, and insulin concentrations. Because of the matching, compared with normal subjects, patients with white coat hypertension and normal subjects had identical 24-hour BP averages. The white coat patients exhibited slightly greater variability among individual readings (obtained each 15 minutes) throughout the day [P < .05]), but there were no differences in hemodynamic responses to exercise. Plasma norepinephrine (P < .05), renin and aldosterone (P < .01 for each), and insulin and low-density lipoprotein cholesterol levels (P < .01 for each) were higher in the white coat group, as were left ventricular septal wall (P < .05) and muscle mass (P = .07) echocardiographic measurements. When compared with the confirmed hypertensive patients, the white coat patients had higher renin (P < .01) but were otherwise similar. Within the white coat group, plasma norepinephrine correlated with total cholesterol and triglycerides (P < .05 for each), and aldosterone correlated with left ventricular mass (P < .01); there were no significant correlations within the normal control subject or confirmed hypertension groups.

CONCLUSIONS

Patients with white coat hypertension differ in metabolic, neuroendocrine, and cardiac findings from normal control subjects and have greater BP variability. These changes appear to be mediated by heightened activity of the sympathetic and renin-angiotensin systems. Although these characteristics could reflect an alerting reaction in the clinic due to awareness of their diagnosis, the white coat hypertensive patients also have evidence for additional, more-sustained differences from normal subjects. Thus, this condition appears to be a true variant of hypertension.

Measuring hypertensive cardiovascular risk: the vascular overload concept

Hypertensive cardiovascular risk may be related primarily to vascular overload, the sum of three vascular abnormalities: increased arteriolar resistance, increased large-artery stiffness, and the effect of increased early pulse-wave reflection. A method for quantifying vascular overload as an index can be derived from measurements of mean arterial pressure and pulse pressure. Several lines of evidence support the hypothesis that abnormal artery stiffness and early pulse-wave reflection become larger components of vascular overload as the duration and severity of hypertension increase. Moreover, these studies suggest that vascular overload is a true indicator of hypertensive cardiovascular risk. Increased systolic blood pressure is a surrogate for vascular overload in young and middle-aged hypertensive subjects. Increased pulse pressure and decreased diastolic pressure are superior to increased systolic pressure as surrogates for vascular overload in geriatric isolated systolic hypertension. By itself, diastolic blood pressure is difficult to interpret and may be an epiphenomenon. Therefore new therapeutic goals, are control of systolic pressure in the young and of pulse pressure in the elderly.

Coronary heart disease and hypertension

Coronary disease is a frequent outcome of hypertension. Although clinical trials with conventional antihypertensive agents have shown that the incidence of other complications of hypertension, such as stroke or congestive heart failure, is reduced as predicted, they have failed to show the expected reductions in coronary events. A partial explanation may lie in the fact that hypertension typically consists of a syndrome of inherited metabolic and cardiovascular abnormalities, and treatment that focuses primarily on blood pressure control without taking into account other factors that contribute to atherosclerotic disease can have only limited protective effects. The coronary hypothesis in hypertension extends this reasoning into three separate components. First is an intrinsic tendency to excessive proliferative and hypertrophic activity within vascular tissue, presumably reflecting growth-promoting activity stimulated by increased endocrine and local paracrine effects; next is the impact of the commonly encountered concomitant risk factors, including high blood pressure, that exaggerate and accelerate development of underlying atherosclerotic lesions; and finally hemodynamic factors, including increased variability and sustained elevations of blood pressure, that can destabilize vascular lesions and precipitate acute events. Treatment of these hemodynamic factors in elderly patients whose underlying vascular changes are already well advanced is likely to reduce vascular endpoints effectively, but a broader-based therapeutic approach is required for younger patients, in whom the ongoing proliferative and risk factor aspects of their potential coronary disease must also be targeted.

Modern strategies to prevent coronary sequelae and stroke in hypertensive patients differ from the JNC V Consensus Guidelines

In recent years, government agencies of many countries have established consensus guidelines for the evaluation and treatment of hypertension. Once published, guidelines tend to be perceived as directives by a variety of health care providers. Unfortunately, these guidelines often do not reflect the practices of most hypertension experts. This report summarizes the opinions of seven hypertension experts concerning the impact of "official" guidelines on clinical practice. In addition, the individual therapeutic recommendations of these panel members are summarized. Their different treatment strategies reflect the diversity of first rate treatment plans that aim to reduce the cardiovascular sequelae in individual patients with essential hypertension. Most importantly, not one of these seven treatment strategies followed the "preferred" treatment of the U.S. guidelines, which recommend diuretics and beta-blockers as first-line therapy. The present authors approach the treatment of hypertension as a means to reduce cardiovascular events. Thus, reduction of blood pressure is not the most important therapeutic endpoint. The panel believes that whereas many different drugs can produce effective blood pressure reduction, the modern primary goal of antihypertensive drug therapy is to select a regimen most likely to prolong the quality and duration of life. In real terms, this means that the primary goal of treatment is the prevention of the major vascular sequelae of hypertension (heart attack, ventricular remodeling, hypertrophy, heart failure, and stroke) that shorten useful life. There are a number of effective hypertensive treatments, which can be selected based on individual patient requirements. However, many consensus guidelines do not allow the flexibility required to optimize individual patient treatment. As a result, health care providers should not feel compelled to regard the preferences of "official" guidelines as the best, modern, state-of-the-art therapy for an individual patient. All seven experts who are deeply involved in the daily care of patients preferred drugs other than beta-blockers and diuretics (the Joint National Committee [JNC] choices) for first-line therapy of hypertension.

Lower dose diuretic therapy in the treatment of patients with mild to moderate hypertension

Indapamide (Lozol), an indoline antihypertensive drug with diuretic and vasodilating activities, was evaluated in 195 patients with mild to moderate essential hypertension (sitting DBP between 95 and 110 mmHg) in a multicentre, randomised, double-blind, parallel-group design trial. A four week single-blind placebo wash-out period was followed by an eight week double-blind period. Patients were randomised to indapamide 1.25 mg/day or to placebo. The primary efficacy endpoint was the mean change in sitting DBP from baseline to week 8. Ninety patients in the placebo group (93%) and 82 patients (84%) in the indapamide group completed the eight weeks of double-blind therapy. Indapamide produced a mean (SE) decrease in sitting DBP of 7.4 (0.63) mmHg (from 100.1 to 92.8 mmHg) compared with a decrease of 3.6 (0.75) mmHg (from 99.6 to 95.8 mmHg) produced by placebo (p < 0.0001). Indapamide and placebo also produced mean decreases in standing DBP of 6.8 (0.75) and 2.8 (0.77) mmHg, respectively (p = 0.0002), in sitting SBP of 11.1 (1.18) and 3.2 (1.35) mmHg, respectively (p = 0.0001) and in standing SBP of 11.4 (1.29) and 4.0 (1.43) mmHg, respectively (P = 0.0002). Reduction in BP of > or = 10 mmHg or to a DBP of < or = 90 mmHg was more frequent (P = 0.0005) among indapamide (46.6%) compared with placebo (23.7%) treated patients. During the eight week double-blind treatment period, incidence rates for all adverse experiences and for drug-related adverse experiences were similar between the two treatment groups.(ABSTRACT TRUNCATED AT 250 WORDS)

A repressive coping style protecting from emotional distress in low-renin essential hypertensives

OBJECTIVE

To investigate the relationship between the behavioural characteristics and specified subgroups of patients with essential hypertension.

DESIGN AND METHODS

Fifty-four patients were classified into groups with a high (n = 9), normal (n = 35) or low plasma renin activity (n = 10), and were compared with 20 normotensive subjects by psychological tests. Standardized tests were used to measure anger expression, defensiveness and the subjects' psychological status (e.g. anxiety, depression).

RESULTS

A repressive coping style, defined by a high defensiveness and low anxiety levels, was found significantly more often in patients with low than in patients with high plasma renin activity and normotensive subjects. The patients with high plasma renin activity scored significantly higher on suppressed anger, anxiety and interpersonal sensitivity than did those with low plasma renin activity. The scores of the normal plasma renin activity group were similar to those of the normotensive group.

CONCLUSIONS

The results underline that there is not one hypertensive 'personality'. Whereas the patients with a high plasma renin activity appear to be more susceptible to emotional conflicts, the patients with low plasma renin activity report low emotional distress and maintain an apparently well-adjusted facade.

Prostaglandin E2 and prostacyclin inhibit the production and secretion of endothelin from cultured endothelial cells

Endothelin-1 (ET-1) is the most potent endogenous vasoconstrictor yet identified. This peptide plays an important role in the regulation of arterial tone, in part through its interaction with endogenous vasodilator compounds. To understand the interactions of endothelin with the vasoactive prostaglandins (PGs), we determined the effects of prostaglandin E2 (PGE2), prostacyclin (PGI2), and thromboxane A2 on ET-1 synthesis and secretion from cultured bovine aortic endothelial cells and on ET-1 action in aortic smooth muscle cells. Both PGE2 and PGI2 (vasodilator prostaglandins) caused an approximately 40% inhibition of basal ET-1 secretion and a 50% inhibition of serum-stimulated ET-1 secretion in a dose-related and time course fashion. In contrast, the vasoconstrictor prostaglandin, thromboxane A2, had no effect on ET-1 secretion. PGE2 and PGI2 similarly inhibited the basal production of new ET-1 protein (translation) by 40-50% and inhibited the basal steady-state mRNA expression of ET-1 in bovine aortic endothelial cells by 60-70%. Both prostaglandins also caused an approximately 55% inhibition of ET-1 transcription, as shown by chloramphenicol acetyltransferase reporter studies. PGE2 and PGI2 strongly stimulated cGMP generation; both the PG stimulation of cGMP and the inhibition of ET-1 secretion and translation were reversed by LY83583, a general inhibitor of cGMP generation. The PG-induced inhibition of ET-1 secretion and translation was also reversed by KT5823, an inhibitor of cGMP-dependent protein kinase, but not by (Rp)-adenosine cyclic 3':5'-monophosphate, an inhibitor of protein kinase A activation. PGE2 and PGI2 also inhibited both basal and ET-1-stimulated DNA synthesis in aortic smooth muscle cells by approximately 45% through a cGMP-dependent mechanism. Therefore, two endogenous PGs, known to be important vasodilators in vivo, significantly inhibit the transcription, translation, secretion, and action of ET-1. We propose that the vasodilator action of the PGs results, in part, from their ability to inhibit the production of this potent vasoconstrictor.

Effect of chelation treatment with dimercaptosuccinic acid (DMSA) on lead-related blood pressure changes

An elevation in mean blood pressure was found in rats treated with low lead (0.01%) for 6 months and then only water for an additional 6 months (discontinuous low lead). No change in blood pressure was found in rats similarly treated with high lead (0.5%) (discontinuous high lead). Administration of DMSA (0.5% in drinking water), for 5 days every 2 months following cessation of lead administration, resulted in a significant lowering of blood pressure in both groups of animals. In the low-lead but not the high-lead group, this was associated with an increase in plasma cyclic GMP (acting as a second messenger for endothelium-derived relaxing factor, EDRF) and a decrease in the plasma concentration of a 12-kDa hypertension-associated protein. Plasma endothelin-3 (ET-3) levels were decreased in discontinuous high-lead rats, increased in discontinuous low-lead rats, but were unaltered by DMSA treatment. We infer that the elevated blood pressure in the discontinuous low-lead rats is related to an increase in the putative vasoconstrictors, ET-3 and the hypertension-associated protein, without a change in the vasodilator, EDRF. With DMSA treatment, plasma cyclic GMP in low-lead rats increased above normal, and the hypertension-associated protein decreased, resulting in lowered blood pressure. DMSA was shown to act as an antioxidant in vitro. Thus the DMSA effect on plasma cGMP (EDRF) may occur via a scavenging effect on EDRF-inactivating reactive oxygen species.