Comparison of the effects on 24-h ambulatory blood pressure of valsartan and amlodipine, alone or in combination with a low-dose diuretic, in elderly patients with isolated systolic hypertension (Val-syst Study)

Time of administration important? Morning versus evening dosing of valsartan

Objective:

Studies suggest that bedtime dosing of an angiotensin-converting enzyme (ACE)-inhibitor or angiotensin receptor blocker shows a more sustained and consistent 24-h antihypertensive profile, including greater night-time blood pressure (BP) reduction. We compared the antihypertensive effects of morning (a.m.) and evening (p.m.) dosing of valsartan on 24-h BP.

Methods:

This 26-week, multicentre, randomized, double-blind study evaluated the efficacy and safety of valsartan 320 mg, dosed a.m. or p.m., versus lisinopril 40 mg (a.m.), a long-acting ACE-inhibitor, in patients with grade 1–2 hypertension and at least one additional cardiovascular risk factor. Patients (n = 1093; BP = 156 ± 11/91 ± 8 mmHg; 62 years, 56% male, 99% white) received (1 : 1 : 1) valsartan 160 mg a.m. or p.m. or lisinopril 20 mg a.m. for 4 weeks, then force-titrated to double the initial dose for 8 weeks. At Week 12, hydrochlorothiazide (HCTZ) 12.5 mg was added for 14 weeks if office BP was more than 140/90 mmHg and/or ambulatory BP more than 130/80 mmHg.

Results:

Mean 24-h ambulatory SBP change from baseline to Weeks 12 and 26 was comparable between valsartan a.m. (–10.6 and –13.3 mmHg) and p.m. (–9.8 and –12.3 mmHg) and lisinopril (–10.7 and –13.7 mmHg). There was no benefit of valsartan p.m. versus a.m. on night-time BP, early morning BP and morning BP surge. Evening dosing also did not improve BP lowering in patients requiring add-on HCTZ or in nondippers at baseline. All treatments were well tolerated.

Conclusion:

Once-daily dosing of valsartan 320 mg results in equally effective 24-h BP efficacy, regardless of dosing time.

Trial Registration:

ClinicalTrials.gov Identifier: NCT00241124.

Effectiveness of hydrochlorothiazide in combination with telmisartan and olmesartan in adults with moderate hypertension not controlled with monotherapy: a prospective, randomized, open-label, blinded end point (PROBE), parallel-arm study

BACKGROUND

The potential combinations of antihypertensive agents are many, and making rational choices depends on the characteristics of each drug and on their complementary mechanisms of action.

OBJECTIVE

The aim of this study was to evaluate the effectiveness of adding hydrochlorothiazide (HCTZ) 12.5 mg to olmesartan 20 mg or telmisartan 80 mg on blood pressure (BP) in patients with moderate hypertension.

METHODS

Consecutive outpatients at the Centro per l'Ipertensione e la Fisiopatologia Cardiovascolare, University of Pavia, Pavia, Italy, of both sexes aged 39 to 75 years were considered eligible for enrollment if they had a sitting diastolic BP (DBP) ->99 mm Hg and <110 mm Hg at the end of an initial 2-week washout period. Patients were random- ized to olmesartan 20 mg QD or telmisartan 80 mg QD according to a prospective, open-label, blinded end point, parallel-arm design. After 8 weeks of monotherapy, patients whose BP was not controlled (DBP ->90 mm Hg) received HCTZ 12.5 mg QD for 8 additional weeks. Clinical and ambulatory BPs were measured at the end of the washout period and at the end of both treatment periods. Adverse events (AEs) were recorded from spontaneous reports and direct inquiry from investigators.

RESULTS

One hundred forty-five patients, all of whom were white, were recruited for the study. After the initial washout period, 13 patients did not meet the inclusion criteria and 6 refused to continue. A total of 126 white patients (69 men, 57 women; mean [SD] age, 60.2 [11.6] years) were randomized to receive monotherapy. Of these, 35 patients (56%) in the olmesartan group and 33 (52%) in the telmisartan group had previously received antihypertensive therapy. At the end of monotherapy, the 52 patients in the olmesartan group and the 49 patients in the telmisartan treatment group who were still in the study and had their BP inadequately controlled by treatment had HCTZ 12.5 mg QD added to their treatment regimen. Both combinations induced a greater ambulatory mean (SD) systolic BP (SBP) and DBP reduction than monothera- py (SBP: 145.3 [6.1] in the olmesartan group and 140.1 [6.4] in the telmisartan group, P < 0.05; DBP: 88.1 [5.1] in the olmesartan group and 84.9 [4.9] in the telmisartan group, P < 0.05). The mean (SD) reduction from baseline in the telmisartan/HCTZ-treated patients (21.5 [10.1]/14.6 [5.2] mm Hg for 24 hours, 21.8 [10.2]/14.9 [5.2] mm Hg for daytime, and 20.4 [10.3]/13.7 [5.9] mm Hg for nighttime; all, P < 0.001 vs baseline) was significantly greater than that observed in the olmesartan/HCTZ-treated patients (18.8 [9.8]/12.3 [4.9] mm Hg for 24 hours, 19.3 [9.8]/12.8 [4.9] mm Hg for daytime, and 17.4 [10.2]/10.6 [5.5] mm Hg for nighttime; all, P < 0.001 vs baseline), with a significant difference between the 2 treatment groups (P < 0.01). Compared with mono- therapy, the add-on effect of HCTZ 12.5 mg QD administration was significantly greater in the telmisartan group than in the olmesartan group (P < 0.05); the differ- ence being more evident for nighttime BP values (SBP, P 0.031; DBP, P 0.025). Reported AEs were similar in the olmesartan/HCTZ and the telmisartan/HCTZ groups (4 patients [7%] vs 3 patients [6%]).

CONCLUSION

The addition of HCTZ 12.5 mg to telmisartan 80 mg monothera- py was associated with greater BP reduction than the addition of the same dose of HCTZ to olmesartan 20 nag monotherapy in these patients previously uncontrolled on monotherapy.

Office and ambulatory blood pressure-lowering effects of combination valsartan/hydrochlorothiazide vs. hydrochlorothiazide-based therapy in obese, hypertensive patients

The authors evaluated the blood pressure (BP)-lowering effects of combination valsartan/hydrochlorothiazide (HCTZ) vs. amlodipine/HCTZ in a 16-week, double-blind, randomized, forced-titration study and ambulatory BP monitoring (ABPM) substudy involving centrally obese hypertensive patients 40 years and older. Patients were started on valsartan/HCTZ 160/12.5 mg or HCTZ 12.5 mg monotherapy, force-titrated at week 4 to valsartan/HCTZ 320/25 mg and HCTZ 25 mg, respectively. The HCTZ group initiated amlodipine 5 mg at week 8 and 10 mg at week 12. A subset of patients had 24-hour ABPM at baseline and weeks 8 and 16. At week 16 in the intent-to-treat population (n=401), valsartan/HCTZ and amlodipine/HCTZ lowered office systolic BP (-30.6 vs. -28.3 mm Hg; P=.14). In the ABPM subgroup (n=111), valsartan/HCTZ was more effective than amlodipine/HCTZ in reducing 24-hour systolic BP (-20.6 vs. -14.5 mm Hg; P=.011). In obese hypertensive patients, valsartan/HCTZ reduced office BP similar to amlodipine/HCTZ but lowered 24-hour systolic BP more.

Valsartan: more than a decade of experience

Valsartan is a nonpeptide angiotensin receptor antagonist that selectively blocks the binding of angiotensin II to the angiotensin II type 1 receptor. The efficacy, tolerability and safety of valsartan have been demonstrated in large-scale studies in hypertension, heart failure (HF) and post-myocardial infarction (MI). This review focuses on what was learned from the valsartan clinical research programme and other comparative trials published from 1997 to the present. Many studies have demonstrated the efficacy of valsartan in lowering blood pressure (BP) in a variety of patient populations (including elderly, women, children, obese patients, patients with diabetes mellitus, patients with chronic kidney disease [CKD], patients at high risk of cardiovascular [CV] disease, African Americans, Hispanic Americans and Asians) and in improving outcomes in CV disease and CKD. In hypertension, valsartan exhibits dose-dependent efficacy in reducing both systolic and diastolic BP over the once-daily dose range of 80-320 mg; doses as high as 640 mg/day have been studied and found to be efficacious and safe. BP control can be enhanced with a more consistent 24-hour BP-lowering profile by using single-pill, fixed-dose combination therapy with valsartan plus hydrochlorothiazide (HCTZ). The cardioprotective benefits of valsartan have been demonstrated in large-scale outcome trials and include significant reductions in CV morbidity and mortality in HF, following MI, and in patients with co-morbid hypertension and coronary artery disease and/or HF; reductions in HF hospitalizations; and reductions in the incidence of stroke. The magnitude of these effects is comparable with that demonstrated with angiotensin-converting enzyme (ACE) inhibitors; however, valsartan has a more favourable tolerability profile, with a significantly lower incidence of cough and only rare reports of angio-oedema, both class effects of ACE inhibitor use. Consistent with its angiotensin receptor-blocking effects, valsartan also reduces circulating levels of biochemical markers that are associated with angiotensin II-mediated endothelial dysfunction and CV risk (e.g. high-sensitivity C-reactive protein or oxidized low-density lipoprotein). Improvements in CKD with valsartan include statistically and clinically meaningful reductions in urinary albumin and protein excretion in patients with type 2 diabetes and in nondiabetic patients with CKD. In short-term studies, valsartan has improved or stabilized various indices of metabolic function in at-risk patients, including those with co-morbid hypertension, obesity and/or metabolic syndrome. Because of this, valsartan is being prospectively investigated for its ability to reduce the incidence of new-onset diabetes and provide cardioprotection in patients with impaired glucose tolerance. Valsartan and valsartan/HCTZ are well tolerated. In clinical trials, adverse events during valsartan treatment were similar to those occurring with placebo. The combination of valsartan/HCTZ was better tolerated than HCTZ alone. Valsartan is administered once daily for hypertension; doses are usually taken upon awakening. In patients with HF or MI, valsartan is administered twice daily.

Randomized study to compare valsartan +/- HCTZ versus amlodipine +/- HCTZ strategies to maximize blood pressure control

OBJECTIVE

Delays in achieving blood pressure (BP) control may increase morbidity and mortality in patients with hypertension. Thus, deciding which antihypertensive agent to use and at what dosage, in addition to determining when to initiate combination therapy and which agents to combine, is important for achieving BP control.

METHODS

This randomized, double-blind, 14-week study was conducted to compare the efficacy and tolerability of various doses of valsartan +/- hydrochlorothiazide (HCTZ) versus amlodipine +/- HCTZ for maximizing BP control in 1,285 patients with uncontrolled hypertension. Patients with stage 1 hypertension and naïve to antihypertensive therapy (33.9%) started valsartan 160 mg or amlodipine 5 mg. Treatment-naïve patients with stage 2 hypertension (13.5%) or those uncontrolled on current antihypertensive monotherapy (52.6%) started valsartan 160 mg/HCTZ 12.5 mg or amlodipine 10 mg. At weeks 4, 8, and 11, patients not achieving BP control were up-titrated (maximum: valsartan 320 mg/HCTZ 25 mg, amlodipine 10 mg/HCTZ 25 mg).

RESULTS

At study end, 78.8% of patients on valsartan +/- HCTZ were controlled (BP <140/90 mmHg) and still on study medication versus 67.8% on amlodipine +/- HCTZ (P < 0.0001). Amlodipine-treated patients had a higher incidence of peripheral edema (22.4% vs 2.2%) and associated discontinuations (7.3% vs <1%). Initiating therapy earlier with valsartan/HCTZ, rather than titrating monotherapy to its maximum dose before adding a second agent, was superior to amlodipine monotherapy or amlodipine +/- HCTZ for achieving BP control, and avoided excessive treatment adjustments and maintained tolerability.

Role of angiotensin II type 1 receptor antagonists in the treatment of hypertension in patients aged >or=65 years

Systolic blood pressure (SBP) increases with age, and hypertension affects approximately two-thirds of adults in the US aged >60 years. Blood pressure (BP) increases as a consequence of age-related structural changes in large arteries, which lead to loss of elasticity and reduced vascular compliance. Increased pulse wave velocity augments SBP, resulting in a high prevalence of isolated systolic hypertension. Because age itself elevates cardiovascular risk, effective treatment of hypertension in an older (aged >or=65 years) patient population prevents many more events per 1000 patients treated than treatment of younger hypertensive patients. Recommendations for treating hypertension are similar in older patients compared with the general population. The Seventh Report of the Joint National Committee on Detection, Prevention, Evaluation, and Treatment of High Blood Pressure recommends target BP goals of <140/90 mmHg for patients with uncomplicated hypertension, and <130/80 mmHg for those with diabetes mellitus or renal disease. Recent guidelines and position papers have extended these aggressive treatment goals to include patients with coronary artery disease, other types of vascular disease and heart failure. Randomized clinical trials have demonstrated the efficacy of calcium channel antagonists (calcium channel blockers [CCBs]), low-dose diuretics, ACE inhibitors and angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) in reducing the risk of stroke and other adverse cardiovascular outcomes in older patients; beta-adrenoceptor antagonists are less effective in terms of endpoint reduction. The majority of older patients require two or more drugs to achieve BP goals. Despite active treatment, half of these patients do not achieve target BP, in part because of the reluctance of physicians to intensify treatment, a phenomenon referred to as 'clinical inertia'. ARBs are effective antihypertensive agents in older patients and have been shown to reduce cardiovascular endpoints in patients with hypertension, diabetic nephropathy, cerebrovascular disease and heart failure. ARBs produce additive BP reduction when combined with diuretics or CCBs. They also have the advantage of placebo-like tolerability, and this contributes favourably to patient compliance with long-term treatment, which is a prerequisite for reducing morbidity and mortality.

Clinical utility and applicability of smoothness index, normalized smoothness index and individualized RDH index during treatment of essential hypertension

The purpose of this study was to assess the clinical utility of the smoothness index (SI) and normalized SI (SIn), measures of duration and homogeneity of blood pressure (BP) reduction, during an observation period without antihypertensive therapy followed by a treatment period using dihydropyridines (DHP) in 54 newly diagnosed and previously untreated subjects (age 46.9 +/- 9.1 years) with essential hypertension. In addition, we aimed to describe the reduction-duration-homogeneity (RDH) index for statistical assessment of the BP reduction in the individual patient. Twenty-four-hour BP was lowered during treatment (139.2 +/- 13.9/ 91.0 +/- 7.6 mmHg vs 130.9 +/- 11.3/85.2 +/- 5.2 mmHg, p < 0.001/p = 0.001). SI showed great interindividual variation, and increased from zero to 0.9 +/- 0.8 (systolic BP) and 0.8 +/- 0.7 (diastolic BP) after treatment (p < 0.001 for both), similar results were obtained for SI(n). The RDH index revealed BP reduction in agreement with the change in individual 24-h, daytime and night-time BP. Although SI and SI(n) may add important information regarding the homogeneity of the antihypertensive effect in a group of patients, and the RDH index for the individual patient, conclusions regarding antihypertensive efficacy can be obtained from assessment of the 24-h, daytime and night-time BP changes and ambulatory BP profiles. Based on our findings, we do not recommend the use of SI or RDH index in the clinical practice.

Antihypertensive efficacy and safety of manidipine versus amlodipine in elderly subjects with isolated systolic hypertension: MAISH study

BACKGROUND AND OBJECTIVE

Isolated systolic hypertension (ISH) affects 10-20% of the elderly population and is strongly related to the risk of cardiovascular events. Elevated systolic BP values are primarily caused by reduced large vessel compliance with a consequent increase in total peripheral resistance. Vasodilating drugs, such as calcium channel antagonists, have proven to be effective in controlling ISH in elderly patients. This study set out to compare the antihypertensive efficacy and safety of two different calcium channel antagonists, manidipine and amlodipine, administered once daily in elderly subjects with ISH.

METHODS

In a European, randomised, double-blind, multicentre, parallel-group study, after a 2-week placebo run-in period, 195 patients aged >or=60 years with ISH received manidipine 10-20 mg once daily or amlodipine 5-10 mg once daily. Chlortalidone 25mg once daily could be added to the high dose of test drug in the event of insufficient antihypertensive control. The primary efficacy parameter was the proportion of patients with a reduction in office sitting systolic BP (SBP) >or=15 mm Hg, measured at trough, at the final visit. Secondary efficacy parameters included: the proportion of patients with a normal sitting SBP value (<140 mm Hg) at the final visit; a change from baseline to the final visit in mean office trough sitting SBP; a change from baseline to the final visit in the cardiovascular risk score as measured by the INDANA (INdividual Data ANalysis of Antihypertensive intervention trials) project score; the proportion of patients with at least a two-point reduction in the cardiovascular risk score; the percentage of patients requiring upward dose titration and diuretic add-on treatment and the investigator's final judgement. Safety and tolerability evaluations were based on adverse events, ECG and laboratory tests, and clinically relevant reports of abnormalities.

RESULTS

In the intention-to-treat population (n = 189), 76% and 72% of patients in the manidipine and amlodipine groups, respectively, had a reduction in sitting SBP of >or=15 mm Hg (p-value not significant for between-group comparison). The percentage of patients with a normal sitting SBP value was 52% in the manidipine group and 51% in the amlodipine group (p-value not significant for between-group comparison). Sitting SBP reductions at the end of treatment were -19.5 +/- 11.8 mm Hg in patients receiving manidipine and -18.4 +/- 11.1 mm Hg in patients receiving amlodipine. Both treatments induced a small reduction in cardiovascular risk score, with 45% of patients in both treatment groups having a two-point reduction in the final score. At the final visit, approximately half of the patients in both treatment groups were still being treated with the low dose of one of the test drugs (manidipine 10mg or amlodipine 5mg). Chlortalidone was added to the high dose of test drugs in 7% and 11% of patients in the amlodipine and manidipine groups, respectively. Both drugs were well tolerated, with a higher incidence of oedema in the amlodipine group (9% vs 4%). No clinically relevant changes in heart rate were induced by either treatment.

CONCLUSION

In elderly patients with ISH, treatment with manidipine for 12 weeks was well tolerated and effective and the antihypertensive effects obtained with manidipine were the same as those obtained with amlodipine.

Antihypertensive activity of angiotensin II AT1 receptor antagonists: a systematic review of studies with 24 h ambulatory blood pressure monitoring

OBJECTIVE

To perform a systematic review of the antihypertensive activity of the angiotensin II AT1 receptor antagonists (ARB).

METHODS

Studies in which blood pressure (BP) was measured using ambulatory BP monitoring for at least 24 h were collected from MEDLINE. Data for each treatment group, ARB, placebo or the drug used for its comparison were obtained from the selected studies. Only studies with a minimum of quality criteria were selected. The final study group contained 36 publications, with a total of 47 patient cohorts receiving ARB in monotherapy, 10 with placebo, 10 with amlodipine, and five with enalapril. The reduction in clinical and ambulatory BP during 24 h, day, night and the last 4-h period for each of the drugs analysed were calculated and adjusted by age, sex, number of participants and by the initial BP level.

RESULTS

The global antihypertensive activity of ARB differs from that observed with amlodipine in the sense that the magnitude of the reduction in the BP values does not essentially depend on the initial BP values nor on the dose used. When only ARB were considered, the drug used was a determinant for systolic BP reduction, whereas for diastolic BP the influence was on the BP reduction and the duration of the antihypertensive activity. The dose used had a particular influence on the duration of the antihypertensive activity for both systolic and diastolic BP.

CONCLUSION

Among the ARB, the influence is on duration more than on the magnitude of BP reduction. Dose, therefore, is an important factor in the duration of antihypertensive activity.

Ambulatory blood pressure monitoring after 1 year on valsartan or amlodipine-based treatment: a VALUE substudy

OBJECTIVE

The ambulatory blood pressure (ABP) monitoring substudy of the Valsartan Antihypertensive Long-term Use Evaluation (VALUE) trial was carried out in a subset of patients from USA, Italy and Denmark. ABP was measured after 1 year in the trial, with the aim of evaluating comparability of ABP levels on valsartan (VAL) and amlodipine (AML)-based regimens.

METHODS

ABP was measured every 20 min during a 25-h period after morning administration of medicine; 659 patients were available for intention-to-treat analysis.

RESULTS

Office blood pressure (BP) differences were smaller than in the main study and mean ABP levels also showed only minor differences between the two regimens (VAL, 132.5/74.8 mmHg; AML, 131.5/75.2 mmHg). However, during the first 7 h after dosing, ABP was lower on VAL, whereas AML exerted a significantly stronger effect during the last 4 h of the dosing interval--possibly influencing the differences in office BP found in the main study. Mean heart rate (HR) was higher on AML (72.3 bpm) than on VAL (70.5 bpm) (P = 0.013), suggesting a sustained difference in sympathetic activation. Correlation analysis showed a close relationship between treated ABP levels and the occurrence of combined cardiovascular endpoints--superior to the relationship to office BP.

CONCLUSIONS

In these elderly high-risk patients, diastolic ABP levels tended to be less predictive than systolic, and daytime less predictive than night-time for all cardiovascular endpoints. The findings underline the importance of ABP substudies in comparative trials for elucidating significant differences in pharmacodynamics, and stresses the superior predictive power of ABP.

Hydrochlorothiazide added to valsartan is more effective than when added to olmesartan in reducing blood pressure in moderately hypertensive patients inadequately controlled by monotherapy

This study was undertaken to evaluate the effects on blood pressure of hydrochlorothiazide (HCTZ) 12.5 mg added to valsartan 160 mg or to olmesartan 20 mg in hypertensive patients. After a 2-wk placebo period, 130 patients, aged 35 to 75 y, with diastolic blood pressure (DBP) >or=99 and 110 mm Hg were randomly assigned to olmesartan 20 mg once daily or to valsartan 160 mg once daily according to a prospective, parallel-arm study design. After 4 wk of monotherapy, patients whose BP was not controlled (DBP >or=90 mm Hg) were given combination treatment with HCTZ 12.5 mg for an additional 4 wk. At the end of the placebo period and at the end of each treatment period, clinical and ambulatory BP measurements were recorded. At the end of the combination therapy period, venous blood samples were drawn 2, 4, and 24 h after drug intake for evaluation of HCTZ plasma concentrations. Both combinations induced a greater ambulatory BP reduction than monotherapy. However, mean reduction from baseline in the valsartan/HCTZ-treated patients (-21.5)-14.6 mm Hg for 24 h, -21.8/-14.9 mm Hg for daytime, and -20.4/-13.7 mm Hg for nighttime systolic blood pressure [SBP]/DBP) was greater than in the olmesartan/HCTZ-treated patients )-18.8/-12.3 mm Hg for 24 h, -19.3/-12.8 mm Hg for daytime, and 17.4/-10.6 mm Hg for nighttime SBP/DBP). The difference between the effects of the 2 treatments was significant (P<.01). In particular, compared with monotherapy, the add-on effect of HCTZ 12.5 mg was significantly greater in the valsartan group than in those treated with olmesartan; the difference was more evident for nighttime BP values. Plasma concentrations of HCTZ were significantly greater with valsartan than with olmesartan at each determination time (P<.05). These findings suggest that the addition of HCTZ 12.5 mg to valsartan 160 mg monotherapy produces a greater BP reduction than the addition of the same dose of HCTZ to olmesartan 20 mg monotherapy.

The population RDH index: a novel vector index and graphical method for statistical assessment of antihypertensive treatment reduction, duration, and homogeneity

Current indices used in the evaluation of antihypertensive treatment duration and homogeneity such as the trough-peak, smoothness index, and normalized smoothness index were designed to be applied to ambulatory blood pressure monitoring recordings from individual participants. Evaluation of antihypertensive treatment in populations is often carried out by calculating these individual indices for each of the participants and providing summarizing statistics about the population, such as the mean and median. We describe a new population vector index and graphical method for the statistical assessment of antihypertensive treatment reduction, duration, and homogeneity (RDH) from ambulatory blood pressure monitoring. The population (RDH) was specifically designed as a tool to evaluate and compare blood pressure coverage offered by antihypertensive drugs over 24 h in populations. The population RDH is a three-component vector index that incorporates information about the reduction, duration, and homogeneity of antihypertensive treatment, as well as their statistical significance over the 24 h period. In addition to defining the RDH index, in this paper we also demonstrate its usefulness and advantages as an index and graphical method for antihypertensive treatment duration and homogeneity assessment by using it to analyze two data sets.

Telmisartan Plus HCTZ vs. Amlodipine Plus HCTZ in Older Patients With Systolic Hypertension: Results From a Large Ambulatory Blood Pressure Monitoring Study

Systolic hypertension often requires combination therapy. Few data exist comparing angiotensin receptor blocker plus diuretic therapy with other combinations in older patients. In a prospective, randomized, open-label, blinded-end point trial, patients (> or =60 years of age) with predominantly systolic hypertension received telmisartan 40-80 mg or amlodipine 5-10 mg for 8 weeks, before the addition of hydrochlorothiazide (HCTZ) 12.5 mg for a further 6 weeks. Twenty-four-hour ambulatory blood pressure monitoring showed that telmisartan plus HCTZ (n=448) and amlodipine plus HCTZ (n=424) changed systolic blood pressure for the last 6 hours of the dosing interval by -18.3 and -17.4 mm Hg, respectively (p=0.2520). Over the 24-hour period, telmisartan plus HCTZ was superior (-19.3 and -17.2 mm Hg, respectively; p=0.001) and provided higher systolic control rates (65.9% and 58.3%, respectively; p=0.0175). Adverse events (41.2% and 53.7%, respectively) and discontinuations (5.0% and 11.3%, respectively) were lower (p<0.0001) with telmisartan than with amlodipine, mainly due to peripheral edema (1.2% and 24.3%, respectively).

Valsartan/Hydrochlorothiazide

Valsartan/hydrochlorothiazide is a fixed-dose (valsartan 80, 160 or 320mg plus hydrochlorothiazide 12.5 or 25mg) angiotensin II receptor blocker/diuretic drug combination indicated for the treatment of patients with essential hypertension not adequately controlled by monotherapy.There is ample evidence that valsartan/hydrochlorothiazide is an effective fixed-dose combination antihypertensive agent. However, efficacy and tolerability data pertaining to the 320mg dose of valsartan in the combination are currently relatively few. There is also some evidence of potential benefits associated with the relatively favourable tolerability profile of the combination, the low occurrence of new-onset diabetes mellitus versus amlodipine and the valsartan-associated improvements in cardiac and endothelial function.

Impact of Increased Heart Rate on Clinical Outcomes in Hypertension

Thirty-eight studies have been published to date on the association between elevated heart rate and mortality. After adjustment for other risk factors, only two studies for all-cause mortality and four studies for cardiovascular mortality reported an absence of association between heart rate and mortality in male populations. This relationship has been found to be generally weaker among females. Most of these studies investigated samples of general populations. The four studies performed in hypertensive men found a positive association between heart rate and all-cause mortality (hazard ratios ranging from 1.9 to 2.0) or cardiovascular mortality (hazard ratios ranging from 1.3 to 1.7). In spite of this evidence, elevated heart rate remains a neglected cardiovascular risk factor in both genders. The pathogenetic mechanisms connecting high heart rate, hypertension, atherosclerosis and cardiovascular events have also been explicated in many studies. Elevated heart rate is due to an increased sympathetic and decreased parasympathetic tone. This altered balance of the autonomic nervous system tone could explain the increase in events with the increased heart rate. However, it has also been proved that blood flow changes associated with high heart rate favour both the formation of the atherosclerotic lesion and the occurrence of the cardiovascular event. Reduction of heart rate in hypertensive patients with increased heart rate could be an additional goal of antihypertensive therapy. Several trials retrospectively showed the beneficial effect of cardiac-slowing drugs, such as beta-adrenoceptor antagonists (beta-blockers) and non-dihydropyridine calcium channel antagonists, on mortality, notably in patients with coronary heart disease, but no published data are available in patients with hypertension free of coronary heart disease. Other antihypertensive drugs that have been shown to reduce the heart rate are centrally acting drugs and angiotensin II receptor antagonists, but their bradycardic effect is rather weak. The f-channel antagonist ivabradine is a selective heart rate-lowering agent with no effect on blood pressure. Although it has not been proven in existing trials, it would seem reasonable to recommend antihypertensive agents that decrease the heart rate in hypertensive patients with a heart rate higher than 80-85 beats per minute. Since the fast heart rate per se causes cardiovascular damage, all drugs that lower the heart rate have the potential of further reducing cardiovascular events in patients with elevated heart rate. Unfortunately, lowering of the heart rate is not a clinically recognised goal. Prospective trials investigating whether treatment of high heart rate can prevent cardiovascular events, notably in hypertensive patients, are warranted.