Systematic Review Article: New Drug Strategies for Treating Resistant Hypertension-the Importance of a Mechanistic, Personalized Approach

Resistant hypertension (RHT) is characterized by persistently high blood pressure (BP) levels above the widely recommended therapeutic targets of less than 140/90 mmHg office BP, despite life-style measures and optimal medical therapies, including at least three antihypertensive drug classes at maximum tolerated dose (one should be a diuretic). This condition is strongly related to hypertension-mediated organ damage and, mostly, high risk of hospitalization due to hypertension emergencies or acute cardiovascular events. Hypertension guidelines proposed a triple combination therapy based on renin angiotensin system blocking agent, a thiazide or thiazide-like diuretic, and a dihydropyridinic calcium-channel blocker, to almost all patients with RHT, who should also receive either a beta-blocker or a mineralocorticoid receptor antagonist, or both, depending on concomitant conditions and contraindications. Several other drugs may be attempted, when elevated BP levels persist in these RHT patients, although their added efficacy in lowering BP levels on top of optimal medical therapy is uncertain. Also, renal denervation has demonstrated to be a valid therapeutic alternative in RHT patients. More recently, novel drug classes and molecules have been tested in phase 2 randomised controlled clinical trials in patients with RHT on top of optimal medical therapy with at least 2-3 antihypertensive drugs. These novel drugs, which are orally administered and are able to antagonize different pathophysiological pathways, are represented by non-steroid mineralocorticorticoid receptor antagonists, selective aldosterone synthase inhibitors, and dual endothelin receptor antagonists, all of which have proven to reduce seated office and 24-h ambulatory systolic/diastolic BP levels. The main findings of randomized clinical trials performed with these drugs  as well as their potential indications for the clinical management of RHT patients are summarised in this systematic review article.

Relationship between the prognostic nutritional index and resistant hypertension in patients with essential hypertension

OBJECTIVES

Immune system activation plays a role in resistant hypertension (RHTN) pathogenesis. The clinical effect of the prognostic nutritional index (PNI) on patients with RHTN remains unclear. The aim of this study investigated the possible correlation between PNI and RHTN.

METHODS

In this cross-sectional study, we enrolled 180 adult subjects. In patients were classified into three groups according to their office and ambulatory blood pressure measurements (ABPM): RHTN (n = 60), controlled hypertension (CHTN, n = 60), and normotension-control (NT-C, n = 60). RHTN was defined as BP ≥140/90 mm Hg while taking ≥3 antihypertensive medications or BP <140/90 mm Hg while taking ≥4 medications. The PNI was calculated from the 10 x serum albumin (g/dL) + 0.005 x total lymphocyte count (/μL) formula.

RESULTS

Office and ABPM were significantly higher in patients with RHTN. Patients in the RHTN (46.1 ± 5.3) had significantly lower PNI than that in the CHTN (54.9 ± 6.7) (P = .032), and PNIs of both hypertensive groups were significantly lower than the NT-C group (P = .019, for both). The ROC curve analysis performed to assess the predictive value of PNI for RHTN and using 50.9 optimal cutoff value of PNI for RHTN gave a sensitivity of 77% and a specificity of 68.5% (AUC = 0.73, 95% CI 0.69-0.96).Multivariate analysis indicated diabetes, 24-h ABPM SBP, CRP, pill burden, and PNI (<51.6) as independent predictors of RHTN.

CONCLUSION

This study showed that the level of PNI was significantly lower in patients with RHTN compared to patients with CHTN. PNI is independently related to RHTN.

Triple Combination Therapies Based on Olmesartan: A Personalized Therapeutic Approach to Improve Blood Pressure Control

Recent epidemiological surveys have demonstrated that effective and sustained blood pressure (BP) control is achieved in a relatively small proportion of treated hypertensive patients. Indeed, treatment of hypertension represents a key strategy for preventing coronary artery disease, stroke, congestive heart failure and cardiovascular death. Several interventions have been proposed by international guidelines for ameliorating hypertension management and control, mostly including integrated and multi-dimensional pharmacological and non-pharmacological strategies. In particular, numerous evidence demonstrated that a more extensive use of combination therapy may represent a valid therapeutic option for treating hypertensive patients at different risk profile. This strategy has been definitely strengthened by the availability of single pill fixed-dose combinations. Among potential combination therapies, those based on the association of renin-angiotensin system antagonists, thiazide diuretics and calcium channel blockers are very effective in lowering BP levels and well tolerated. We will provide here an overview of clinical evidence supporting the use of triple combination therapy, with a focus on that based on olmesartan medoxomil, a thiazide diuretic (hydrochlorothiazide) and a calcium channel blocker (amlodipine besylate), which is available in multiple dosages. Finally, in view of the recognised importance of single-pill combination therapy for treating hypertension, we will examine the potential benefits of dual (fixed) combination therapy based on olmesartan medoxomil with either thiazide diuretic hydrochlorothiazide or calcium channel blocker amlodipine in terms of efficacy, safety and tolerability profile.

Olmesartan in the treatment of hypertension in elderly patients: a review of the primary evidence

Hypertension, particularly systolic hypertension, is prevalent in the elderly and increases with advancing age, in part because of age-related endothelial dysfunction and increased arterial stiffness. There is strong evidence from randomized clinical trials that supports the use of antihypertensive treatment for effective and sustained blood pressure (BP) control in older patients to reduce the risk of vascular-related morbidity and mortality, particularly cerebrovascular accidents, including stroke. Furthermore, current evidence and guidelines suggest that all major classes of antihypertensive agents are equally effective in controlling BP and preventing cardiovascular events in older patients. Diuretics are commonly used in elderly patients, but recent outcomes data have raised doubt about their long-term benefits. Renin-angiotensin system inhibitors have a better tolerability profile than diuretics. Extensive clinical evidence has demonstrated the excellent efficacy and tolerability profile of olmesartan medoxomil (OM)--an angiotensin II receptor blocker AT1 receptor antagonist--including in elderly patients. Randomized and observational studies have shown that OM provides effective BP control across the 24 h dosing interval in the elderly. It also has a good tolerability profile, a pharmacokinetic profile unaffected by age and a low propensity for drug interactions. An additional factor is that OM once-daily regimens are simple and straightforward, which can be an important factor in maintaining adherence to therapy in elderly patients. This article provides an overview of the main recent clinical evidence supporting the use of OM-based therapy in elderly patients with hypertension.

Diagnosis and treatment of resistant hypertension

Hypertension resistant to lifestyle interventions and antihypertensive medications is a common problem encountered by physicians in everyday practice. It is most often defined as a blood pressure remaining ≥ 140/90 mmHg despite the regular intake of at least three drugs lowering blood pressure by different mechanisms, one of them being a diuretic. It now appears justified to include, unless contraindicated or not tolerated, a blocker of the renin-angiotensin system and a calcium channel blocker in this drug regimen, not only to gain antihypertensive efficacy, but also to prevent or regress target organ damage and delay the development of cardiorenal complications. A non-negligible fraction of treatment-resistant hypertension have normal "out of office" blood pressures. Ambulatory blood pressure monitoring and/or home blood pressure recording should therefore be routinely performed to identify patients with true resistant hypertension, i.e. patients who are more likely to benefit from treatment intensification.

Triple combination therapy to improve blood pressure control: experience with olmesartan-amlodipine-hydrochlorothiazide therapy

INTRODUCTION

Effective treatment of hypertension is a key strategy for preventing and reducing the burden of hypertension-related cardiovascular diseases. In spite of these well-established concepts, hypertension remains poorly controlled, worldwide. Among the different pharmacological strategies required to improve blood pressure (BP) control, a more extensive use of combination therapy is progressively emerging as a cornerstone of a more effective treatment of hypertension. Among different drug combinations currently available for the clinical management of hypertension, those based on the association of drugs inhibiting the renin-angiotensin system, thiazide diuretics and calcium channel blockers have demonstrated to be very effective in lowering both systolic and diastolic, clinic and 24-h ambulatory BP levels with a good tolerability and safety profile.

AREAS COVERED

In the present manuscript the authors provide an overview of the evidence supporting the use of triple combination therapy with different classes of antihypertensive drugs, with a particular focus on those based on olmesartan medoxomil, a thiazide diuretic (hydrochlorothiazide) and a calcium channel blocker (amlodipine besylate).

EXPERT OPINION

Available data indicate that triple combination therapy based on olmesartan provides effective and sustained clinical and 24-h BP control in a high proportion of individuals among a broad range of hypertensive patients.

Blood pressure control in resistant hypertension: new therapeutic options

Resistant hypertension, namely the hypertensive state characterized by the inability of multiple antihypertensive drug interventions to lower blood pressure to goal levels, represents a condition frequently detected in clinical practice. Its main features are represented by its heterogeneous etiology as well as its very high cardiovascular risk. This latter peculiarity has implemented the research for new approaches to the treatment of the disease. This article will focus on two of them, namely carotid baroreceptor electric stimulation and the renal denervation procedure. Clinical studies and large-scale clinical trials are presently ongoing with the aim of defining the long-term efficacy and safety profile of the two interventions.

Resistant hypertension and left ventricular hypertrophy: an overview

Available data on subclinical cardiac damage in resistant hypertension (RH) are rather scanty. Thus, we sought to review the literature focusing on the association between RH and left ventricular hypertrophy (LVH). A MEDLINE search was performed to identify relevant articles using the key words "resistant hypertension, " "refractory hypertension," "left ventricular hypertrophy," "cardiac damage," and "left ventricular dysfunction." Full articles published in the English language in the last two decades (December 1, 1989, to July 31, 2010) reporting studies in adult or elderly individuals, were considered. Checks of the reference lists of selected articles complemented the electronic search. A total of 11 cross-sectional and longitudinal studies, including 3325 patients attending outpatient hypertension clinics, were considered. Prevalence rates of echocardiographic LVH, as assessed by updated criteria, ranged from 55% to 75% of patients with RH, peaking to 91% in the subgroup with concomitant electrocardiographic (ECG) LV strain. Reduction in ECG-LVH induced by treatment showed a relevant beneficial impact on cardiovascular prognosis. These data support the view that initial and on-treatment assessment of LVH in patients with RH is important for cardiovascular risk monitoring and therapeutic strategies decision-making.