Aliskiren, a novel oral renin inhibitor, provides dose-dependent efficacy and placebo-like tolerability in Japanese patients with hypertension.

Aliskiren is a novel orally active renin inhibitor for the treatment of hypertension. This study evaluated the antihypertensive efficacy, safety and tolerability of aliskiren in Japanese patients with hypertension. Forty hundred and fifty-five Japanese men and women with a mean sitting diastolic blood pressure of 95-110 mmHg were randomized to receive once-daily double-blind treatment for 8 weeks with aliskiren 75, 150 or 300 mg or placebo. Aliskiren produced significant, dose-dependent reductions in mean sitting diastolic blood pressure (p<0.0005 vs. placebo for each dose) and mean sitting systolic blood pressure (p<0.001 vs. placebo for each dose). The placebo-corrected reductions in mean sitting systolic/diastolic blood pressure were 5.7/4.0, 5.9/4.5 and 11.2/7.5 mmHg in the aliskiren 75, 150 and 300 mg groups, respectively. After 8 weeks' treatment, 27.8%, 47.8%, 48.2% and 63.7% of patients in the placebo and aliskiren 75, 150 and 300 mg groups, respectively, achieved a successful treatment response (diastolic blood pressure <90 mmHg and/or reduced by > or =10 mmHg from baseline; p<0.005 vs. placebo for each dose). Aliskiren treatment was well tolerated, with the incidence of adverse events reported in the active treatment groups (53-55%) being similar to that in the placebo group (50%). This study, which is the first to assess the antihypertensive efficacy and safety of aliskiren in Japanese patients with hypertension, demonstrates that the once-daily oral renin inhibitor aliskiren provides significant, dose-dependent reductions in blood pressure with placebo-like tolerability.     

Aliskiren, an orally effective renin inhibitor, provides antihypertensive efficacy alone and in combination with valsartan

BACKGROUND: By blocking the renin-angiotensin-aldosterone system (RAAS) at its rate-limiting step, renin inhibition may provide improved RAAS suppression. We investigated the blood pressure (BP)-lowering effects of the oral direct renin inhibitor aliskiren, alone or in combination with the angiotensin receptor blocker valsartan. METHODS: In this multicenter, randomized, placebo-controlled, 8-week trial, 1123 patients with mild-to-moderate hypertension underwent a 3 to 4 week single-blind placebo run-in and were then randomized in a modified factorial study design to receive once-daily, double-blind oral treatment with placebo, aliskiren monotherapy (75, 150, or 300 mg), valsartan monotherapy (80, 160, or 320 mg), aliskiren and valsartan in combination, or valsartan/hydrochlorothiazide (160/12.5 mg). The primary efficacy variable was the change from baseline in mean sitting diastolic BP (DBP) at endpoint. RESULTS: Once-daily oral treatment with aliskiren 300 mg significantly (P < .0001) lowered mean sitting DBP and systolic BP (SBP) compared with placebo; aliskiren monotherapy demonstrated a safety and tolerability profile comparable to placebo. Changes in DBP and SBP were fitted to a first-order dose-response surface (lack-of-fit test, P = .65), which showed that aliskiren and valsartan alone and in combination produced dose-related reductions in DBP and SBP. Coadministration of aliskiren and valsartan produced a greater antihypertensive effect than either drug alone, comparable in magnitude to the effect of valsartan/hydrochlorothiazide, with similar tolerability to the component monotherapies and to placebo. CONCLUSIONS: Aliskiren monotherapy provides antihypertensive efficacy and placebo-like tolerability in patients with hypertension. Aliskiren and valsartan in combination may provide additive BP-lowering effects with maintained tolerability.     

Aliskiren: an oral renin inhibitor for the treatment of hypertension

Hypertension is a common chronic disease that leads to significant cardiovascular morbidity and mortality worldwide. Blood pressure control is critical in reducing the end-organ complications, such as stroke, myocardial infarction, heart failure, or kidney disease. Currently available antihypertensive agents work by different mechanisms to reduce blood pressure. Aliskiren, a novel direct renin inhibitor, lowers blood pressure by decreasing renin activity, and angiotensin I and II levels. At the approved dosage (150-300 mg once daily), it reduces systolic blood pressure by 12-16 mm Hg and diastolic blood pressure by 2-12 mm Hg. In studies its efficacy was comparable to losartan 100 mg, irbesartan 150 mg, and valsartan 80-320 mg. When used adjunctively with ramipril, an angiotensin-converting enzyme (ACE) inhibitor, valsartan, an angiotensin II receptor blocker (ARB), or hydrochlorothiazide, a diuretic, it provides additional blood pressure reduction compared with placebo or monotherapy. Aliskiren is well tolerated, with the most common side effects being gastrointestinal symptoms, fatigue, weakness, and headache. In short-term clinical trials, aliskiren caused fewer disturbances in potassium levels when compared with hydrochlorothiazide, ACE inhibitors and ARBs. Long-term data on morbidity and mortality outcomes are not currently available, thus it is unknown whether aliskiren would join ACE inhibitors and ARBs as the preferred hypertensive agents for end organ protection. At this time, aliskiren should be considered as an alternative agent for mild-to-moderate hypertension, or as an adjunctive therapy when preferred agents fail to maintain optimal blood pressure control. It is also an option for those patients who have contraindications or intolerability to other antihypertensive agents, including dry cough induced by ACE inhibitors.     

Ambulatory 24-hour blood pressure monitoring in patients with resistant hypertension

The aim of the study was to assess the usefulness of 24-hour blood pressure (BP) and heart rate (HR) monitoring in patients with "resistant" hypertension. 30 patients (44.1 +/- 9.9 years) with diastolic BP 100 mm Hg or more in spite of treatment with three or more antihypertensive drugs were studied. Ambulatory recording of BP and HR was performed by means of Del Mar Avionics monitoring system 9000. Mean recording time was 21.5 hours and mean number of measurements during one recording--56.7. Mean ambulatory systolic and diastolic BP values were significantly lower than mean value of three casual measurements (146.0 +/- 24.6 vs 171.5 +/- 21.2 mm Hg for systolic and 97.2 +/- 11.3 vs 110.4 +/- 7.5 mm Hg for diastolic BP p less than 0.01) In 14 (46.6%) systolic BP and in 10 patients (33.3%) diastolic BP were normal. The patients with normal and abnormal ambulatory BP recordings did not differ in regard to age and mean clinic BP levels. However, patients with abnormal ambulatory BP recordings were more often overweight and showed a greater frequency of left ventricular hypertrophy and family history of hypertension and its complications. The results of the study show that ambulatory BP monitoring may be of value in assessing the response to antihypertensive treatment in patients with so called resistant hypertension as judged on the basis of clinic pressure.     

Blood pressure lowering in essential hypertension with an oral renin inhibitor, aliskiren

Inhibition of the first and rate-limiting step of the renin-angiotensin system has long been an elusive therapeutic goal. Aliskiren, the first known representative of a new class of completely nonpeptide, orally active, renin inhibitors, has been shown to inhibit the production of angiotensin I and II in healthy volunteers and to reduce blood pressure (BP) in sodium-depleted marmosets. The aim of this randomized, double-blind, active comparator trial study was to assess the BP-lowering efficacy and safety of aliskiren. Two hundred twenty-six patients, 21 to 70 years of age, with mild to moderate hypertension, were randomly assigned to receive 37.5 mg, 75 mg, 150 mg, or 300 mg aliskiren or 100 mg losartan daily for 4 weeks. Dose-dependent reductions in daytime ambulatory systolic pressure (mean change, mm Hg [SD of change]; -0.4 [11.7], -5.3 [11.3], -8.0 [11.0], and -11.0 [11.0], P=0.0002) and in plasma renin activity (median change % [interquartile range]; -55 [-64, -11], -60 [-82, -46], -77 [-86, -72], and -83 [-92, -71], P=0.0008) were observed with 37.5, 75, 150, and 300 mg aliskiren. The change in daytime systolic pressure with 100 mg losartan (-10.9 [13.8]) was not significantly different from the changes seen with 75, 150, and 300 mg aliskiren. Aliskiren was well tolerated at all doses studied. This study demonstrates that aliskiren, through inhibition of renin, is an effective and safe orally active BP-lowering agent. Whether renin inhibition results in protection from heart attack, stroke, and nephropathy, similar to angiotensin-converting enzyme inhibition and angiotensin receptor blockade, needs to be researched.     

Comparative efficacy of two different beta-blockers on 24-hour blood pressure control.

Atenolol and metoprolol succinate, dosed once daily, have different pharmacokinetic profiles. This study tests the hypothesis that differences that are especially noted in the early morning period, when cardiovascular risk is highest, in 24-hour blood pressure (BP) control exist between these 2 beta-blockers. This was a small, randomized open-label study with blinded end point evaluation in 36 hypertensive patients. All participants received hydrochlorothiazide 12.5 mg for 2 weeks before randomization to either 50 mg atenolol or metoprolol succinate given every morning; both treatments were force-titrated to 100 mg/d at 4 weeks. The primary end point was the change in early morning ambulatory systolic BP. Early morning (12 AM-6 AM) systolic BP differences were 3+/-14 mm Hg with atenolol vs -7+/-8 mm Hg with metoprolol succinate (P=.03). The overall 24-hour changes in systolic BP were 1+/-15 mm Hg with atenolol vs -9+/-11 mm Hg with metoprolol (P=.03). In conclusion, metoprolol succinate was more effective in sustaining 24-hour and early morning BP reductions compared with atenolol in a small group of hypertensive patients also treated with once-daily low-dose hydrochlorothiazide. It is possible that differences in outcome between atenolol-based and other therapies may be the result of inadequate dosing of atenolol, a medication that may not be effective for the entire 24-hour period.     

Experience with 24-hour ambulatory blood pressure monitoring in hypertension

Traditional sphygmomanometric blood pressure measurements may lead to errors in the diagnosis of arterial hypertension due to a number of factors, among which are the alerting reaction and pressor response induced in patients by the doctor's visit. This phenomenon, as quantified in our laboratory by continuous intraarterial recordings, is responsible for an average rise in systolic and diastolic blood pressure of 27/15 mm Hg, a rise that does not seem to be reduced by simply desensitizing the patient by means of more frequent physician visits. Twenty-four hour ambulatory blood pressure monitoring may theoretically improve the diagnostic approach to hypertensive patients by overcoming some limitations of isolated cuff measurements. In recording intraarterial blood pressure in 108 ambulant hypertensive subjects, we have found that 24-hour blood pressure values are able to discriminate among patients with different degrees of target organ damage better than isolated sphygmomanometric readings. Moreover, these studies have indicated that 24-hour blood pressure variability may be as important as blood pressure mean values in the assessment of cardiovascular complications. In clinical practice, however, intraarterial blood pressure monitoring is not feasible, and only noninvasive recorders can be used. Use of these devices does not induce any alerting reaction in the patients and does not interfere with day-night blood pressure changes. Although it is characterized by intermittent readings, this approach is not incompatible with a precise estimate of 24-hour blood pressure mean values.(ABSTRACT TRUNCATED AT 250 WORDS)     

24-hour blood pressure in primary and secondary hypertension

The blood pressure is subject to physiological day-night fluctuations, which can be attenuated in secondary hypertension as well but not in essential hypertension. In this study, the blood pressure profile over 24 hours was determined in a large collective of patients with primary and secondary hypertension for comparison to assess the relevance of ambulatory blood pressure monitoring in secondary hypertension. There were 88 patients with essential hypertension (age 20 to 73 years) and 80 patients with secondary hypertension (age 19 to 70 years) with a mean blood pressure value from 8 a.m. to 8 p.m. greater than 135 mm Hg. Blood pressure and heart rate were monitored for 24 hours. In 58/80 patients with secondary hypertension renal parenchymal disease was present, 14 had renovascular disease, three had Cushing's syndrome, four had primary hyperaldosteronism and one had a pheochromocytoma. Of the 88 patients with essential hypertension 67, and of the 80 patients with secondary hypertension 69 were on antihypertensive treatment. The measurements were carried out with a portable automatic ambulatory monitor unit (SpaceLabs 90202) between 6 a.m. and midnight at intervals of 15 minutes and from midnight to 6 a.m. at intervals of 30 minutes. The duration of sleep was documented. In patients with secondary hypertension, as compared with patients with essential hypertension, there were higher blood pressure values during the night from 8 p.m. to 8 a.m., and during sleep (Table 1). The profile of the hourly mean values for systolic and diastolic blood pressure (Figure 1) shows that patients with secondary hypertension, as compared with patients with essential hypertension, have a clearly diminished blood pressure reduction during the night.(ABSTRACT TRUNCATED AT 250 WORDS)     

24-hour blood pressure behavior in patients with untreated and treated hypertension in comparison with normotensive patients

Blood pressure was continuously monitored over 24 h in 201 patients with mild to moderate essential hypertension using a noninvasive method. Measurements were made both before and after 6 months of antihypertensive treatment and the data were compared to results from 100 normotensive patients. The frequency with which blood pressure values above 140/90 mm Hg occurred during the 24-h period proved to be the most reliable parameter for distinguishing between hypertensive and normotensive profiles. The blood pressures of all patients could be normalized (less than 140/90 mm Hg) on single or combined drug therapy as assessed by casual measurement. However, significant differences were observed between the 24-h profiles of the treated patients and the control group. The mean 24-h blood pressure, the mean day and nighttime blood pressures, the mean hourly pressure, and the frequency of increased blood pressure values were all significantly higher in the patients on medication as compared to the normotensive controls. This would suggest that normotension, as defined by the control group, cannot be attained with antihypertensive medication. In conclusion, 24-h continuous blood pressure monitoring allows a better evaluation of blood pressure profiles and consequently, will be of greater value in assessing cardiovascular risk than occasional random measurements.     

Safety and efficacy of the oral direct renin inhibitor aliskiren in elderly patients with hypertension

OBJECTIVES: To evaluate the efficacy, safety and tolerability of aliskiren in elderly patients (> or =65 years old) with essential hypertension. METHODS: In this double-blind, multicenter study, 355 elderly patients with hypertension [office mean sitting systolic blood pressure (msSBP) > or =145-<180 mmHg and mean 24-h ambulatory systolic BP (ASBP) > or =135 mmHg] were randomized to once-daily treatment for 8 weeks with aliskiren 75 mg (n = 91), 150 mg (n = 84), 300 mg (n = 94) or the comparator lisinopril 10 mg (n = 86). The primary efficacy variable was change in mean 24-h ASBP. RESULTS: At endpoint, aliskiren 75 mg, 150 mg, 300 mg and lisinopril 10 mg lowered mean 24-h ASBP (least-squares mean+/-SEM) by 8.4+/-0.8, 7.1+/-0.8, 8.7+/-0.8 and 10.2+/-0.9 mmHg, and mean 24-h ambulatory diastolic BP by 4.5+/-0.5, 3.6+/-0.5, 3.9+/-0.5 and 6.3+/-0.5 mmHg, respectively, with no significant difference between aliskiren doses. The trough-to-peak ratio for ASBP reduction with aliskiren 75 mg, 150 mg, 300 mg and lisinopril 10 mg was 0.77, 0.64, 0.79 and 0.87, respectively. All treatments lowered office msSBP and mean sitting diastolic BP (msDBP) compared with baseline. A significantly greater proportion of patients receiving aliskiren 300 mg achieved BP control (msSBP/msDBP <140/90 mmHg) compared with those receiving aliskiren 75 mg (36.2% vs 24.2%, p = 0.033). There was no evidence of dose-related increases in the rate of adverse events with aliskiren treatment. CONCLUSIONS: Aliskiren, a novel direct renin inhibitor, provides effective 24-h BP lowering with no evidence of dose-related increases in the incidence of adverse events in elderly patients with hypertension.     

Enhanced 24-hour norepinephrine and renin secretion in young patients with essential hypertension: relation with the circadian pattern of arterial blood pressure

This study examines the possibility that 24-hour differences in blood pressure (BP) regulation between hypertensive and normotensive subjects is related to changes in 24-hour secretory patterns in circulating pressor hormones. Nine young subjects with normal BP and 9 patients with essential hypertension (EH) were studied during 24-hour recumbency. Every 20 minutes samples were taken to determine plasma norepinephrine (NE) levels and plasma renin activity (PRA). BP was measured every 20 minutes by automatic recording. A distinct circadian rhythm was demonstrated for mean BP, NE and PRA in both groups. Nocturnal reductions in mean BP, NE and PRA related best to the sleep-wakefulness cycle in both groups. Circadian changes in mean BP correlated with NE levels in both normal subjects and patients with EH. The most striking difference between the 2 groups was the absolute levels of mean BP, NE and PRA, which were higher in the EH group at most time points in the 24-cycle. Differences in levels of NE and PRA between the 2 groups were most accentuated during sleep. Thus, young persons with EH show evidence of enhanced sympathetic nervous activity throughout the 24-hour cycle, which is most pronounced during sleep. The multiple sampling approach offers a more sensitive indicator of the role of pressor hormones in BP maintenance.     

Evaluation of the 24-hour blood pressure effects of eprosartan in patients with systemic hypertension

BACKGROUND: Eprosartan is a new nonphenyl angiotensin II receptor blocker, which has been approved for the treatment of hypertension. Although the drug has a relatively short plasma half-life of 5 to 9 h, clinical studies have suggested that its antihypertensive effect persists for 24 h. METHODS: We assessed both the changes in 24-h and trough blood pressure (BP) (last 4 h of the ambulatory BP while the patient was awake) of eprosartan at doses of 600 and 1,200 mg once daily in a randomized, double-blind, placebo-controlled trial. Ambulatory BP was monitored at placebo baseline and after 8 weeks of double-blind therapy. RESULTS: Two hundred patients randomized in the study with 177 patients completing the trial. The 24-h change in BP from baseline was 0.2/0.1 +/- 1.4/1.0 mm Hg, -7.9/ -5.4 +/- 1.0 mm Hg (P < .0001), and -7.4/-5.0 +/- 0.9 mm Hg (P < .0001) in the placebo, 600-mg eprosartan, and 1,200-mg eprosartan groups, respectively. Changes in trough ambulatory BP showed significant reductions of -6.3/-4.1 +/- 1.6/1.1 mm Hg and -7.7/-5.5 +/- 1.5/1.0 mm Hg for 600 mg of eprosartan and 1,200 mg of eprosartan, respectively. CONCLUSIONS: These data demonstrate that eprosartan at doses of 600 or 1200 mg significantly reduced BP throughout an entire 24-h dosing period. There were no differences between the 600- and 1,200-mg dose; thus, 600 mg once daily should be the only dose used in the treatment of hypertension with eprosartan.     

Assessment of patients with office hypertension by 24-hour noninvasive ambulatory blood pressure monitoring

To assess the discrepancy between casual (office) and home blood pressure readings in patients performing home blood pressure monitoring, we analyzed office, home, and 24-hour ambulatory blood pressure and heart rates in 19 patients in a prospective four-week study. After the month of study, the average difference between mean office and manual home blood pressures in this office hypertensive group was 30 +/- 17/20 +/- 6 mm Hg. The blood pressures taken in the office were substantially greater than the 24-hour average blood pressures and ambulatory blood pressures during work or while at home (awake). An analysis of the automatic monitor readings while in the doctor's office and at 15-minute intervals after leaving the office showed a progressive reduction in blood pressure and heart rate during the first hour after leaving the office. A mean 24-hour blood pressure of less than 130/80 mm Hg was found in 13 (68%) patients. These data suggest that patients with office hypertension are usually normotensive but may have a persistent and recurrent pressor response in a medical care setting. Ambulatory blood pressure monitoring provides confirmation of not only the office-home disparity, but also suggests that stress other than office visits fails to elicit a hypertensive response.     

24-hour blood pressure recording in patients with orthostatic hypotension

Continuous intra-arterial blood pressure measurement and electrocardiograms were obtained in two ambulatory patients with orthostatic hypotension due to autonomic dysfunction. Systolic and diastolic arterial pressure presented marked variations which took place mainly during the day and were related to several physical activities; however, marked falls in blood pressure were also observed during sleep and at the moment of arousal. A peak incidence of hypotensive events was found in the afternoon, mainly in the hours following the afternoon meal. Recording was repeated after 3 weeks of treatment with propranolol, 40 mg t.i.d. In patient 1, beta blockade drastically reduced the number and severity of hypotensive episodes, while propranolol failed to control blood pressure in patient 2, who experienced a higher number of hypotensive events during treatment. Findings of this study may be relevant to the management of patients with orthostatic hypotension and should contribute to a more accurate characterization of blood pressure profile in autonomic dysfunction.     

Early 24-hour blood pressure elevation in normotensive subjects with parental hypertension

Subjects with a family history of parental hypertension are reported to have a slightly higher office blood pressure in the prehypertensive stage. Whether this reflects a hyperreactivity to blood pressure measurement or a more permanent blood pressure elevation, however, is not known. In the present study, blood pressure was measured in 15 normotensive subjects whose parents are both hypertensive (FH++), 15 normotensive subjects with one hypertensive parent (FH(+)-), and 15 normotensive subjects whose parents are not hypertensive (FH--); among the three groups, subjects were matched for age, sex, and body mass index. The measurements were made in the office during a variety of laboratory stressors and during a prolonged resting period, and for a 24-hour period (ambulatory blood pressure monitoring). Office blood pressure was higher in the FH++ group than in the FH-- group (p less than 0.05). The pressor responses to laboratory stressors were similar in the two groups, but the FH++ group had higher prolonged resting and 24-hour blood pressure than the FH-- group; the difference was always significant (p less than 0.05) for systolic blood pressure. The FH++ group also had a greater left ventricular mass index (on echocardiographic examination) than the FH-- group (p less than 0.01). The blood pressure values and echocardiographic values of the FH(+)- group tended to be between those of the other two groups. Thus, the higher blood pressure shown by individuals in the prehypertensive stage with a family history of parental hypertension does not reflect a hyperreactivity to stress but an early permanent blood pressure elevation.(ABSTRACT TRUNCATED AT 250 WORDS)