Comparative Effects of Irbesartan Versus Amlodipine on Left Ventricular Mass Index in Hypertensive Patients with Left Ventricular Hypertrophy

Sex-based differences in left ventricular mass reduction across angiotensin II receptor blockers in patients with heart failure with preserved or mildly reduced ejection fraction

Although angiotensin II receptor blockers (ARBs) are more effective in women for either reduction of blood pressure or heart failure (HF), the gender disparities and the impact of class/drug effects on ARBs in relation to cardiac hypertrophy and HF remain unclear. We aimed to investigate the sex-based and drug-specific differences in left ventricular (LV) mass reduction with ARBs. We employed the cohort of 193 hypertensive patients with HF and an LV ejection fraction of ≥ 45% treated with azilsartan or candesartan once daily for 48 weeks as a sub-analysis of the J-TASTE trial. After exclusion of patients without LV mass data nor the drugs, 170 patients were finally enrolled (azilsartan: male, n = 43, female, n = 39 and candesartan: male, n = 52; female, n = 36). We investigated the sex-based differences of the primary endpoint of the change in LV mass as assessed by echocardiography from baseline to the end of the study (48 weeks), and the secondary endpoint of the incidence of the composite cardiovascular endpoint (death from cardiovascular disease or hospitalization for heart failure). In the male stratum, the ratio of patients with > 10% LV mass reduction at 48 weeks was higher in the azilsartan group than candesartan group (40 vs. 19%, p = 0.029). There was no significant difference in LV mass reduction between two groups in the female stratum. There were no differences of the onset of the secondary endpoints between male and female groups, and azilsartan and candesartan groups. The event-free survival rate of the composite cardiovascular endpoints tended to be lower in patients with ≤ 10% than > 10% LV mass reduction (95.3 vs. 100% at 48 weeks, log-rank p = 0.11). In patients with HF, the effectiveness of either azilsartan or candesartan in achieving > 10% LV mass reduction depends on sex. Male is more sensitive to azilsartan than candesartan to achieve cardiac hypertrophy in HF patients.

Comparative efficacy of different types of antihypertensive drugs in reversing left ventricular hypertrophy as determined with echocardiography in hypertensive patients: A network meta-analysis of randomized controlled trials

Reversing left ventricular hypertrophy (LVH) can reduce the incidence of adverse cardiovascular events. However, there is no clear superiority-inferiority differentiation between angiotensin-converting enzyme inhibitors (ACEI), angiotensin receptor blockers (ARB), beta-blockers (BB), calcium channel blockers (CCB), and diuretics in reversing LVH in hypertensive patients. To provide further evidence for choosing the optimal antihypertensive drug for improving LVH, we performed a network meta-analysis of randomized controlled trials (RCTs) based on the Cochrane library database, Embase, and Pubmed, and identified 49 studies involving 5402 patients that were eligible for inclusion. It was found that ARB could improve LVH in hypertensive patients more effectively than CCB (MD -4.07, 95%CI -8.03 to -0.24) and BB (MD -4.57, 95%CI -8.07 to -1.12). Matched comparison of renin-angiotensin system inhibitors (RASi) showed that the effect of ACEI in reducing left ventricular mass index (LVMi) was not effective as that of ARB (MD -3.72, 95%CI -7.52 to -0.11). The surface under the cumulative ranking for each intervention indicated that the use of ARB was more effective among the different types of antihypertensive drugs (97%). This network meta-analysis revealed that the use of ARB in antihypertensive therapy could achieve better efficacy in reversing LVH in hypertensive patients.

Regression of the Left Ventricular Hypertrophy in Patients with Essential Hypertension on Standard Drug Therapy

 PURPOSE: The American College of Cardiology/ American Heart Association 2017 and European Society of Cardiology/European Society of Hypertension 2018 guidelines were a paradigm shift in hypertension management in contemporary medicine. Lowering of blood pressure to less than 130 (systolic) and 80 (diastolic) mm of Hg irrespective of cardiovascular risk is recommended. While intensive blood pressure control is commonly achievable with rational pharmacotherapy, the magnitude of left ventricular hypertrophy regression is an independent factor in improvement in cardiovascular health. The regression of left ventricular hypertrophy has been adjudged as a clinically useful surrogate marker that reflects the efficacy of hypertension treatment. Though angiotensin converting enzyme inhibitors/ angiotensin receptor blockers (ACEI/ARB) are the preferred initial drug for greater regression of left ventricular mass, the choice of add-on therapy, if required, is still debatable. Therefore, in our observational study, we sought to compare the reduction in left ventricular mass index in hypertensives with left ventricular hypertrophy on standard ACEI/ARB based drug therapy.  MATERIALS AND METHODS: The cohort (n=217) comprised of patients with uncontrolled hypertension (blood pressure>140/90 mm of Hg) and left ventricular hypertrophy (left ventricular mass index>115 and 95 gram/square meter in males and females respectively). The add-on drug in ACEI/ARB therapy was either thiazide diuretics (TD) or calcium channel blockers (CCB). Four sub-cohorts were constituted: mono-therapy - group A (n=70, ACEI/ARB), dual-therapy - group B (n=48, ACEI/ARB+TD) and  group C (n=51, ACEI/ ARB+CCB), triple therapy - group D (n=48, ACEI/ ARB+TD+CCB). Left ventricular mass index was determined using echocardiography at baseline and after 24 weeks of therapy.  RESULTS: There was no significant difference in baseline clinical or demographic variables between group B and group C. Baseline blood pressure and duration of hypertension was greater in group D compared to group A (P<0.001). The reduction in left ventricular mass index (mean ±SD) in the four groups (A to D) was 16.7±18.7, 21.0±20.8, 20.5±15.5  and 29.1±21.5 g/m2  respectively (D>A, P=0.011, B versus C, P=1.00). The corresponding change in blood pressure (systolic/diastolic) was 18.5±13.6/8.9±11.2, 27.5±19.2/12.2±9.3, 23.4±16.7/ 5.4±10.1, 26.6±19.5/10.7±12.8 mm of Hg respectively (systolic, B>A, P=0.027, D>A, P=0.048) (diastolic, B>C, P=0.013).  CONCLUSION: Anti-hypertensive treatment with angiotensin converting enzyme inhibitors/angiotensin receptor blockers-based therapy produced graded regression of left ventricular hypertrophy with monotherapy, dual therapy and triple therapy.  In dual therapy, add-on of either thiazide diuretics or calcium channel blockers to angiotensin converting enzyme inhibitors/angiotensin receptor blockers showed equal efficacy in regression of left ventricular hypertrophy independent of blood pressure reduction.

Prediction of Left Ventricular Mass Index Using Electrocardiography in Essential Hypertension - A Multiple Linear Regression Model

Background

Current electrocardiography (ECG) criteria indicate only the presence or absence of left ventricular hypertrophy (LVH). LVH is a continuum and a direct relationship exists between left ventricular mass (LVM) and cardiovascular event rate. We developed a mathematical model predictive of LVM index (LVMI) using ECG and non-ECG variables by correlating them with echocardiography determined LVMI.

Patients and Methods

The model was developed in a cohort of patients on treatment for essential hypertension (BP>140/90 mm of Hg) who underwent concurrent ECG and echocardiography. One hundred and forty-seven subjects were included in the study (56.38±11.84 years, 66% males). LVMI was determined by echocardiography (113.76±33.06 gm/m²). A set of ECG and non-ECG variables were correlated with LVMI for inclusion in the multiple linear regression model. The model was checked for multicollinearity, normality and homogeneity of variances.

Results

The final regression equation formulated with the help of unstandardized coefficients and constant was LVMI=18.494+ 1.704 (aLL) + 0.969 (RaVL+SV3) + 0.295 (MBP) + 15.406 (IHD) (aLL – sum of deflections in augmented limb leads; RaVL+SV3 – sum of deflection of (R wave in aVL + S wave in V3); MBP – mean blood pressure; IHD=1 for the presence of the disease, IHD=0 for the absence of the disease).

Conclusion

In the model, 50.4% of the variability in LV mass is explained by the variables used. The findings warrant further studies for the development of better and validated models that can be incorporated in microprocessor-based ECG devices. The determination of LVMI with ECG only will be a cost-effective and readily accessible tool in patient care.

The cost-effectiveness of irbesartan for hypertension

High blood pressure is a very common problem in the adult and elderly population, both in developed and developing countries. A relatively large number of drug classes are available to treat this condition and prevent its complications, which are not only more frequent in the aforementioned patients but also those affected by metabolic syndrome and/or Type 2 diabetes. Irbesartan is an angiotensin-receptor blocker class drug with good antihypertensive efficacy and specific pharmacological characteristics, whose efficacy has been more deeply evaluated in metabolically complex hypertensive patients. In this review, the authors will analyze its effectiveness in preventing or delaying organ damage in hypertensive patients, with a closer look at the economic implications of treating hypertension with irbesartan in the context of available antihypertensive drugs.

Comprehensive overview: efficacy, tolerability, and cost-effectiveness of irbesartan

Background

Hypertension represents a major health problem, affecting more than one billion adults worldwide. Irbesartan, an angiotensin II receptor blocker, is considered to be a highly effective treatment in the management of hypertension. The purpose of this review is to evaluate the efficacy, safety and tolerability profile , and cost-effectiveness of treatment with irbesartan in hypertension.

Methods

A review of the literature was conducted using the electronic PubMed and Cochrane Library databases and the Health Economic Evaluations Database of search terms relating to irbesartan efficacy, tolerability, and cost-effectiveness, and the results were utilized.

Results

Findings from the present analysis show that irbesartan either as monotherapy or in combination with other antihypertensive agents can achieve significant reductions in blood pressure, both systolic and diastolic, compared with alternative treatment options. Irbesartan was also found to have a renoprotective effect independent of its blood pressure-lowering in patients with type 2 diabetes and nephropathy. Furthermore, irbesartan demonstrated an excellent safety and tolerability profile , with either lower or equal adverse events compared with placebo and other alternative treatments. In terms of economic analyses, compared with other antihypertensive therapy alternatives, irbesartan was found to be a preferred option, that is less costly and more effective.

Conclusion

The evidence indicates that treating patients with hypertension alone or with type 2 diabetes and nephropathy using irbesartan can control hypertension, prolong life, and reduce costs in relation to existing alternatives.

The role of irbesartan in the treatment of patients with hypertension: a comprehensive and practical review

Irbesartan is an orally active angiotensin II type 1 receptor antagonist (angiotensin receptor blocker [ARB]) whose pharmacological profile differs significantly from those of many other compounds of the same class. In particular, according to its pharmacokinetic and pharmacodynamic profile, irbesartan has a high bioavailability, a long duration of action and a small potential for pharmacological interactions due to the nature of the enzymatic pathway involved in its metabolic process. Morbidity data with irbesartan have been mainly accumulated in patients with renal impairment where the drug has demonstrated the most remarkable evidence of efficacy among the ARBs class, regardless of the stage of the renal disease (from early to late) and the length of the observational period. The efficacy of irbesartan has also been demonstrated in patients with left ventricular hypertrophy and congestive heart failure. The drug is indicated for the treatment of hypertension and renal impairment in patients with type 2 diabetes mellitus (T2D) and hypertension, and its tolerability and safety profile have been extensively investigated and reported to be similar to placebo. From the pharmacoeconomic point of view, treating patients with T2D, hypertension and overt nephropathy using irbesartan was both a cost- and life-saving procedure compared with the use of amlodipine and standard antihypertensive treatment in an Italian setting. The role of irbesartan in the management of hypertension with or without T2D and renal impairment is clearly recognized by national and international guidelines and largely acknowledged by the medical community according to the efficacy of the drug in the prevention of cardiovascular risk in addition to and beyond kidney prevention.

Long-Term Tolerability and Efficacy of Single-Pill Combinations of Telmisartan 40-80 mg Plus Amlodipine 5 or 10 mg in Patients Whose Blood Pressure Was Not Initially Controlled by Amlodipine 5-10 mg: Open-Label, Long-Term Follow-Ups of the TEAMSTA-5 and TEAMSTA-10 Studies

BACKGROUND

Two 8-week, randomized, double-blind, controlled studies previously evaluated the efficacy and tolerability of single-pill combinations of telmisartan 40-80 mg/amlodipine 5-10 mg (T40-80/A5-10) in patients with hypertension not at diastolic blood pressure (DBP) goal (DBP <90 mm Hg) after 6 weeks of amlodipine 5 mg monotherapy (A5) (TEAMSTA-5) or amlodipine 10 mg monotherapy (A10) (TEAMSTA-10). The long-term (≥6 months) tolerability and efficacy of single-pill combinations of T40-T80/A5-A10 have now been evaluated in 2 open-label studies in patients who had successfully completed either TEAMSTA-5 or TEAMSTA-10 (TEAMSTA-5 and TEAMSTA-10 Follow-Ups).

METHODS

In the TEAMSTA-5 Follow-Up, 976 patients whose blood pressure was not initially controlled by taking A5 received T40/A5 for 4 or 8 weeks, with consecutive uptitration to T80/A5 if DBP was ≥90 mm Hg. In TEAMSTA-10 Follow-Up, 838 patients not initially achieving blood pressure control using A10 received T40/A10 for 4 weeks before randomization to T40/A10 or T80/A10; after 4 weeks, patients randomized to T40/A10 with DBP ≥90 mm Hg were uptitrated to T80/A10. In both studies, add-on antihypertensive medication was allowed if DBP was not at goal.

RESULTS

Treatment compliance in both follow-up studies was ≥98.4%. Single-pill combinations of T40-T80/A5-A10 resulted in additional clinically relevant blood pressure reductions and 67% to 93% of patients achieved DBP goal (<90 mm Hg); only 1% to 19% of patients received additional medication for hypertension, of whom 29% to 76% achieved DBP goal. Long-term treatment with T40-T80/A5-A10 was well tolerated, with comparable adverse event profiles for all telmisartan/amlodipine combinations. The most common drug-related adverse events were peripheral edema (1.9%-3.9%) and dizziness (1.5% in the T80/A5 group only); these were consistent with the known tolerability profiles of telmisartan/amlodipine combinations. Overall treatment discontinuation rates due to adverse events were low (0.7%-1.5%).

CONCLUSIONS

In patients not achieving DBP goal with either A5 or A10 monotherapy, the vast majority achieved DBP goal with single-pill combinations of T40-T80/A5-A10. Long-term treatment was well tolerated with high compliance, promoting treatment adherence regardless of telmisartan/amlodipine dose. ClinicalTrials.gov identifiers: NCT00614380 (TEAMSTA-5 Follow-up) and NCT00624052 (TEAMSTA-10 Follow-up).

Effects of the combinations of amlodipine/valsartan versus losartan/hydrochlorothiazide on left ventricular hypertrophy as determined with magnetic resonance imaging in patients with hypertension

BACKGROUND

Left ventricular hypertrophy (LVH), a marker of cardiac end-organ damage, is frequently found in patients with arterial hypertension and is associated with cardiovascular and cerebrovascular morbidity and mortality. Therefore, LVH regression is an important treatment goal. For amlodipine plus valsartan (A/V) no specific study on LVH has been reported to date.

METHODS

Prospective, open-label, randomized parallel-group study. Patients with essential hypertension and LVH were randomized to 52-week treatment with A/V 10/160 mg (n = 43) or the active comparator losartan/HCT 100/25 mg (L/H, n = 47). Add-on medication was allowed in case of inadequate blood pressure control. LV parameters were measured by cardiovascular magnetic resonance imaging (MRI), and adjudicated in a blinded manner. Study identifiers were NCT00446563 and EudraCT 2006-001977-17.

RESULTS

In addition to the study treatment, 35% of patients in the A/V group and 49% in the L/H group received additional antihypertensive medication. Compared to baseline, both treatments reduced measures of LVH significantly after 52 weeks (e.g. LV mass index in the A/V group from 64.7 g/m(2) by -3.5 g/m(2), in the L/H group from 69.1 g/m(2) by -4.4 g/m(2), p < 0.01 for both). LV ejection fraction and LV volumes were not significantly changed by any regimen. A/V and L/H treatments were well tolerated.

CONCLUSIONS

Both regimen were effective in reducing LV mass compared to baseline and were well tolerated.

Long-term use and tolerability of irbesartan for control of hypertension

In this review, we discuss the pharmacological and clinical properties of irbesartan, a noncompetitive angiotensin II receptor type 1 antagonist, successfully used for more than a decade in the treatment of essential hypertension. Irbesartan exerts its antihypertensive effect through an inhibitory effect on the pressure response to angiotensin II. Irbesartan 150-300 mg once daily confers a lasting effect over 24 hours, and its antihypertensive efficacy is further enhanced by the coadministration of hydrochlorothiazide. Additionally and partially beyond its blood pressure-lowering effect, irbesartan reduces left ventricular hypertrophy, favors right atrial remodeling in atrial fibrillation, and increases the likelihood of maintenance of sinus rhythm after cardioversion in atrial fibrillation. In addition, the renoprotective effects of irbesartan are well documented in the early and later stages of renal disease in type 2 diabetics. Furthermore, both the therapeutic effectiveness and the placebo-like side effect profile contribute to a high adherence rate to the drug. Currently, irbesartan in monotherapy or combination therapy with hydrochlorothiazide represent a rationale pharmacologic approach for arterial hypertension and early-stage and late-stage diabetic nephropathy in hypertensive type II diabetics.

Regression of Left Ventricular Mass by Antihypertensive Treatment

Blood pressure–lowering therapy reduces left ventricular mass, but the question of whether differences exist among drug classes has not been fully resolved. Our aim was to compare the effects of diuretics, β-blockers, calcium channel blockers, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers on left ventricular mass regression in patients with hypertension on the basis of prospective, randomized comparative studies. We performed meta-analyses, involving pooled pairwise comparisons of the drug classes and of each class versus other classes statistically combined, and meta-regression analyses to identify the determinants of the regression. The 75 relevant publications involved 84 pairwise comparisons and 6001 patients. Regression of left ventricular mass was significantly less ( P =0.01) with β-blockers (9.8%) than with angiotensin receptor blockers (12.5%), but none of the other analyzable pairwise comparisons between drug classes revealed significant differences ( P >0.10). In addition, β-blockers showed less regression than the other 4 classes statistically combined ( P <0.01), and regression was more pronounced with angiotensin receptor blockers versus the others ( P <0.01). In multivariable meta-regression analysis on all of the treatment arms, β-blocker treatment was a significant and negative predictor of the regression (−3.6%; P <0.01), but this was not the case for the other drug classes, including angiotensin receptor blockers. In conclusion, β-blockers show less regression of left ventricular mass, whereas angiotensin receptor blockers may induce larger regression. The inferiority of β-blockers appears to be more convincing than the superiority of angiotensin receptor blockers.

Comparison of olmesartan medoxomil versus amlodipine besylate on regression of ventricular and vascular hypertrophy

Reversal of left ventricular (LV) hypertrophy is an important goal of antihypertensive therapy. This phase 3b study compared the ability of the angiotensin receptor blocker olmesartan medoxomil with the calcium channel blocker amlodipine besylate to induce regression of LV hypertrophy and vascular hypertrophy after achieving blood pressure (BP) goal. After a washout phase, 102 patients with hypertension and LV hypertrophy were randomized to olmesartan medoxomil 20 mg/day, up titrated to 40 mg/day, or amlodipine 5 mg/day, up titrated to 10 mg/day, for up to 4 weeks until a BP goal of <140/90 mm Hg (<130/85 mm Hg for diabetes) was achieved (hydrochlorothiazide 25 mg/day and terazosin 1 to 5 mg/day 2 times/day could be added if needed). Upon achieving the BP goal or by week 8, and again at weeks 26 and 52, assessments of LV mass and compliance and arterial structure and function were performed by echocardiography, Doppler flow, and arterial ultrasonography, respectively. There was no statistically significant percent change in LV mass at 52 weeks in either treatment group (11.6% with olmesartan medoxomil vs 2.9% with amlodipine) and no statistically significant difference between treatment groups. There were no significant changes in LV compliance or carotid or femoral artery wall-to-lumen ratios in either treatment group at 52 weeks. In conclusion, there did not appear to be a clinically significant BP-independent effect with olmesartan medoxomil or amlodipine on LV mass decrease, diastolic function or vascular structure, and compliance in patients with hypertension and LV hypertrophy.

Position of fixed‐dose combinations containing an AT1‐receptor blocker and a thiazide diuretic

Treatment of hypertension remains a difficult task despite the availability of different types of medications lowering blood pressure by different mechanisms. In order to reach the target blood pressures recommended today combination therapy is required in most patients. The co-administration of two drugs with different impacts on the cardiovascular system markedly increases the antihypertensive effectiveness without altering adversely tolerability. Fixed low-dose combinations are becoming a valuable option not only as second-line, but also as first-line therapy. In this respect the co-administration of thiazide diuretic with an AT(1)-receptor blocker is particularly appealing. The diuretic-induced decrease in total body sodium activates the renin-angiotensin system, thus rendering blood pressure maintenance angiotensin II-dependent. During blockade of the renin-angiotensin system low doses of thiazides generally suffice, allowing the prevention of undesirable metabolic effects. Also, blockade of the AT(1)-receptor, particularly when angiotensin II production is enhanced in response to diuretic therapy, is expected to be beneficial, since angiotensin II seems to contribute importantly to the pathogenesis of cardiovascular and renal complications of hypertension.

Studies on left ventricular hypertrophy regression in arterial hypertension: a clear message for the clinician?

BACKGROUND

Evidence-based medicine should provide clear and unbiased information to clinicians. We conducted an analysis on published randomized trials evaluating the effects of antihypertensive therapy on left ventricular (LV) morphology assessed by echocardiography to investigate (i) the consistency of criteria used for definition of LV hypertrophy (LVH) and (ii) the consistency of the way LVH regression and blood pressure (BP) control were reported.

METHODS

Studies identified by a PubMed search were eligible for inclusion in the analysis, if they fulfilled the following criteria: (i) publication in a peer-reviewed journal within the last 12 years; (ii) double blind, randomized, controlled, parallel-group design; (iii) numerosity of at least 50 adult hypertensive subjects; (iv) follow-up duration of at least 6 months; (v) comparison between single-drugs or association regimens; (vi) LV mass (LVM) or wall thickness measured by echocardiography.

RESULTS

Thirty-nine trials, including 9,162 hypertensive subjects of both genders in 78 active treatment arms or in 6 placebo arms were identified. Definition of LVH was provided by 34 studies (87.1%) according to 19 different criteria. All trials evaluated LVH regression as the absolute or relative changes of continuous variables such as LVM index (LVMI) or LV wall thickness. Data concerning prevalence rates of LVM normalization were reported in 12 studies (30.7%). The percentage of patients reaching BP target (<140/90 mm Hg) was reported in 11 studies (28.2%).

CONCLUSIONS

Our findings indicate that (i) definition of hypertensive LVH phenotype is extremely variable, and (ii) no precise information on LVH regression rates or changes in LV geometrical patterns, as well as on target BP, is provided by the majority of papers.

Complications of hypertension and the role of angiotensin receptor blockers in hypertension trials

Hypertension is a high-prevalence disease that may affect several organs. In recent years, data have accumulated indicating that angiotensin II receptor blockers (ARBs) may have a supplementary effect beyond lowering blood pressure. The aim of this review is to evaluate the impact of ARBs on the most important complications of hypertension--heart, cerebrovascular and renal diseases, and metabolic complications--based on the findings from large clinical hypertension trials. The results may indicate that ARBs have a superior effect compared with placebo or other antihypertensive drugs in order to prevent left ventricular hypertrophy, atrial fibrillation, stroke, renal disease and diabetes mellitus, while there appears to be no blood pressure-independent superior effect of ARBs regarding prevention of myocardial infarction or heart failure.

Mechanism of Angiotensin II Type 1 Receptor Blocker Action in the Regression of Left Ventricular Hypertrophy

Left ventricular hypertrophy refers to a pathologic increase in left ventricular mass and is associated with an increased risk of subsequent cardiovascular morbidity and mortality from any cause. In the development of left ventricular hypertrophy there is growth of cardiomyocytes and accumulation of extracellular matrix and fibrosis. The actions are partly induced by angiotensin II, the principal effector of the renin-angiotensin-aldosterone system, binding to the AT1 receptor. Biochemical markers, some implicated in inflammatory changes, correlate with changes in left ventricular mass. The reduction in left ventricular mass brought about with angiotensin-converting enzyme inhibitor or angiotensin receptor blocker (ARB) therapy correlates with a reduction in these inflammatory changes, monitored by brain natriuretic peptide. Recent studies incorporating trials of ARBs have found ARBs to be more effective in reducing left ventricular mass than beta blockers and possibly more effective than calcium antagonists. Initial studies suggest that ARBs and angiotensin-converting enzyme inhibitors may have similar effects in terms of reducing left ventricular hypertrophy, and the combination of angiotensin-converting enzyme inhibitors and ARBs is thought to be synergistic due to a more complete inhibition of the renin-angiotensin-aldosterone system. In conclusion, these agents are efficacious in antihypertensive therapy and can play an important role in the prevention or regression of left ventricular hypertrophy due to hypertension.

Goals and guidelines for treating hypertension in a patient with heart failure

Hypertension promotes left ventricular (LV) hypertrophy and myocardial remodeling and is frequently present in patients with systolic or diastolic heart failure. Control of hypertension in both of these settings may attenuate progressive LV hypertrophy and remodeling and improve clinical outcomes. Guidelines for the management of heart failure recommend that hypertension should be treated in all patients with preclinical heart failure as well as in those with heart failure with reduced or preserved LV systolic function. Consistent with national hypertension guidelines, the goal for blood pressure control in hypertensive patients with heart failure is less than 140/90 mm Hg, but lower targets (< 130/80 mm Hg) may be desirable in those with concomitant diabetes mellitus or renal disease. Angiotensin-converting enzyme inhibitors, angiotensin II receptor antagonists, and beta-adrenoreceptor antagonists are first-line options for hypertension treatment in heart failure. Calcium channel antagonists and the alpha blocker doxazosin should be avoided. Episodes of recurrent pulmonary edema and hypertension may also indicate underlying severe renovascular disease that may respond to percutaneous renal artery intervention.

Targeting effective blood pressure control with angiotensin receptor blockers

Angiotensin receptor blockers (ARBs) have become established as a major class of antihypertensive on the basis of their powerful effects on blood pressure (BP), excellent tolerability and pleiotropic end-organ-protective effects. However, individual ARBs vary in antihypertensive efficacy, which may be important to clinical outcome. Several strategies are available to ensure that BP reductions with ARBs are at least as great as that which can be achieved with other antihypertensive classes. Firstly, several newer ARBs, including irbesartan, candesartan, telmisartan and olmesartan, have been reported to provide equivalent antihypertensive efficacy to amlodipine and greater efficacy than either losartan, valsartan or both. Secondly, increases in dose may improve the antihypertensive efficacy of agents such as valsartan, although clinical studies are necessary to provide characterisation of new, higher-dose monotherapies. Thirdly, fixed dose combinations with hydrochlorothiazide (HCTZ) increase the antihypertensive effect of all ARBs. It is likely that differences in efficacy between newer and older ARBs will in some cases be sustained in combination therapy, such that the most potent ARBs and HCTZ will provide another tier of control. The future use of ARBs is likely to involve a growing emphasis on compound-specific data, with regard to the antihypertensive efficacy and pleiotropic protective actions of agents.

Optimizing therapeutic strategies to achieve renal and cardiovascular risk reduction in diabetic patients with angiotensin receptor blockers

The major challenge for the treatment of hypertensive patients with type 2 diabetes is to achieve the uniformly recommended blood pressure goal of 130/80 mmHg, and 120/75 mmHg in proteinuric patients. Such low target blood pressure levels require the administration of multiple drugs. Angiotensin receptor blockers and the combination of angiotensin receptor blockers with diuretics fulfil the criteria to lower blood pressure effectively with a placebo-like side-effect profile. Beyond pressure control, clinical prospective trials have documented that it does matter what kind of antihypertensive agent is used to control blood pressure. Large-scale follow-up trials have documented blood pressure independent effects of angiotensin receptor blocker on cardiac [left-ventricular hypertrophy (LVH), congestive heart failure] and renal protection (proteinuria, chronic renal failure). Of note, in these trials, angiotensin receptor blockers have been combined with diuretics, and most of the included patients have been on combination therapy comprising two to four antihypertensive agents. In addition to the combination of an angiotensin receptor blocker with a diuretic, the combination of an angiotensin receptor blocker with an angiotensin-converting enzyme inhibitor appeared to be most effective in reducing proteinuria, attenuating chronic renal failure and treating congestive heart failure.

Angiotensin receptor blockade in the challenging era of systolic hypertension

Systolic blood pressure is a major cardiovascular risk factor which is often associated with arterial stiffness. Markers of arterial stiffness, such as pulse pressure and carotid-femoral pulse wave velocity, have been proved independent predictors of cardiovascular risk. Recent evidence suggests that the renin-angiotensin system is involved in the pathogenesis of systolic hypertension and arterial stiffness. Outcome trials have shown impressive cardiovascular protection by reducing systolic blood pressure (BP) with drug treatment. However, in clinical practice systolic hypertension remains largely uncontrolled, first, because systolic BP goal is more difficult to be reached than diastolic and, second, because physicians are often reluctant to intensify treatment in patients with systolic BP close to 150 mmHg. Recent trials have focused on the effects of antihypertensive drugs not only on blood pressure, but also on pulse pressure and pulse-wave velocity. Blockade of the renin-angiotensin-aldosterone system, using angiotensin-converting enzyme inhibitors and more recently angiotensin receptor blockers, has been shown to provide beneficial effects on arterial stiffness that appear to be independent of their antihypertensive effects. Recent outcome trials have shown significant cardiovascular protection with angiotensin receptor blockers. These drugs have an excellent placebolike profile of adverse effects which is maintained when these drugs are combined with low-dose diuretics. Therefore, an angiotensin receptor blocker-based treatment strategy appears to be an attractive and evidence-based approach for the management of systolic hypertension, the reduction of arterial stiffness and the prevention of cardiovascular disease.

Irbesartan: a review of its use in hypertension and in the management of diabetic nephropathy

Irbesartan (Avapro, Aprovel) is a potent and selective angiotensin II subtype 1 receptor antagonist indicated for use in patients with hypertension, including those with type 2 diabetes mellitus and nephropathy. Once-daily administration of irbesartan provided 24-hour control of blood pressure (BP). In patients with mild-to-moderate hypertension irbesartan was as effective as enalapril, atenolol and amlodipine, and more effective than valsartan in terms of absolute reduction in BP and response rates. Irbesartan produced a greater reduction in diastolic BP at trough than once-daily losartan, but had a smaller effect than olmesartan; the reduction in systolic BP achieved with irbesartan was similar or greater than that with losartan and similar to that seen with olmesartan. The combination of irbesartan with hydrochlorothiazide produced additive effects on BP reduction. Irbesartan also induced regression of left ventricular mass in patients with hypertension and left ventricular hypertrophy. In two large studies (IRbesartan MicroAlbuminuria type 2 diabetes mellitus in hypertensive patients [IRMA 2] and the Irbesartan Diabetic Nephropathy Trial [IDNT]) irbesartan exerted a renoprotective effect in hypertensive patients with type 2 diabetes at both the early and later stages of diabetic nephropathy. The renoprotective effect was at least partly independent of the BP-lowering effect. In the IRMA 2 trial, the proportion of patients progressing to overt nephropathy was significantly lower for recipients of irbesartan 300mg once daily than placebo. In patients with overt nephropathy in the IDNT, irbesartan 300mg once daily provided significantly greater renoprotection than amlodipine 10mg once daily or placebo. The relative risk of doubling of serum creatinine was significantly lower with irbesartan than amlodipine or placebo. Irbesartan is well tolerated in hypertensive patients, including those with type 2 diabetes and incipient or overt nephropathy. The overall incidence of adverse events with irbesartan was similar to that with placebo. Irbesartan was associated with a lower incidence of cough than enalapril and was not associated with ankle oedema or with any clinically significant drug interactions. In conclusion, irbesartan is a well tolerated and effective antihypertensive agent. It also slows the progression of renal disease in hypertensive patients with type 2 diabetes at both the early and later stages of diabetic nephropathy. Thus, irbesartan is a valuable agent in the management of patients with these indications.