Effectiveness of the direct renin inhibitor, aliskiren, in patients with resistant hypertension

When blood pressure refuses to budge: exploring the complexity of resistant hypertension

Resistant hypertension, defined as blood pressure that remains above goal despite using three or more antihypertensive medications, including a diuretic, affects a significant proportion of the hypertensive population and is associated with increased cardiovascular morbidity and mortality. Despite the availability of a wide range of pharmacological therapies, achieving optimal blood pressure control in patients with resistant hypertension remains a significant challenge. However, recent advances in the field have identified several promising treatment options, including spironolactone, mineralocorticoid receptor antagonists, and renal denervation. In addition, personalized management approaches based on genetic and other biomarkers may offer new opportunities to tailor therapy and improve outcomes. This review aims to provide an overview of the current state of knowledge regarding managing resistant hypertension, including the epidemiology, pathophysiology, and clinical implications of the condition, as well as the latest developments in therapeutic strategies and future prospects.

Renin Inhibition with Aliskiren: A Decade of Clinical Experience

The renin-angiotensin-aldosterone system (RAAS) plays a key role in the pathophysiology of arterial hypertension as well as in more complex mechanisms of cardiovascular and renal diseases. RAAS-blocking agents like angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers, have long been key components in the treatment of essential hypertension, heart failure, diabetic nephropathy, and chronic kidney disease, showing benefits well beyond blood pressure reduction. Renin blockade as the first step of the RAAS cascade finally became possible in 2007 with the approval of aliskiren, the first orally active direct renin inhibitor available for clinical use and the newest antihypertensive agent on the market. In the last decade, many clinical trials and meta-analyses have been conducted concerning the efficacy and safety of aliskiren in comparison to other antihypertensive agents, as well as the efficacy and potential clinical use of various combinations. Large trials with cardiovascular and renal endpoints attempted to show potential benefits of aliskiren beyond blood pressure lowering, as well as morbidity and mortality outcomes in specific populations such as diabetics, heart failure patients, and post-myocardial infarction individuals. The purpose of this review is to present the currently available data regarding established and future potential clinical uses of aliskiren.

Biomarkers Investigation for In-Hospital Death in Patients With Stanford Type A Acute Aortic Dissection

This retrospective study aimed to investigate the predictive value of biomarkers for in-hospital mortality of patients with Stanford type A acute aortic dissection (AAD).AAD is a life-threatening disease with an incidence of about 2.6-3.6 cases per 100,000/year.A total of 67 consecutive Stanford type A AAD patients admitted to hospital were divided into a deceased group and survival group. The baseline information of the patients between two groups was systematically compared, followed by examination of the electrocardiograms (ECG). Based on the follow-up during hospitalization, we investigated the simultaneous assessment of indexes like fragmented QRS complex (fQRS), admission systolic blood pressure (SBP), aortic diameter, surgical management, troponin I (TnI), white blood cell (WBC) count, N-terminal pro-brain natriuretic peptide (NT-proBNP), and D-dimer.The levels of TnI and NT-proBNP, WBC counts, and rate of fQRS (+) in patients of the deceased group were significantly higher than those in the survival group. The male sex (hazard ratio, 10.88; P = 0.001), admission SBP (hazard ratio, 0.98; P = 0.012), NT-proBNP (hazard ratio, 1.00; P = 0.001), and WBC count (hazard ratio, 1.10; P = 0.033) were independently related with in-hospital death. As a single marker, WBC count had the highest sensitivity at 84.6% (specificity 65.9%).Admission SBP, NT-proBNP, and WBC count were potential independent risk factors of in-hospital death in Stanford type A AAD patients. WBC count may be a more accurate predictor of type A AAD than either alone.

Antihypertensive Efficacy of the Direct Renin Inhibitor Aliskiren as Add-on Therapy in Patients with Poorly Controlled Hypertension

OBJECTIVE

A direct renin inhibitor, aliskiren, has a longer stable antihypertensive effect compared with other renin-angiotensin-aldosterone system (RAAS) inhibitors.

METHODS

This study was a 6-month, single-center, open trial conducted between December 2010 and November 2011 to assess the antihypertensive effect of adding aliskiren (300 mg) to the treatment of essential hypertension patients whose target blood pressure (BP) had not been achieved and to assess whether it was possible to reduce the amount of antihypertensive drugs used.

RESULTS

The results showed an overall improvement in the target BP achievement rate of 60% for clinic BP and 52% for home BP measurements (75 cases total). The mean number of drugs before treatment with aliskiren was 3.28±1.52, whereas at the end of the six months the mean number of drugs prescribed other than aliskiren was 2.85±1.72 (p<0.0001). Moreover, no worsening of the renal function was observed in patients with diabetes or chronic kidney disease (CKD) who were being treated with other RAAS inhibitors in combination to aliskiren.

CONCLUSION

These results showed that when aliskiren was added to the treatment of poorly controlled hypertension, the BP achievement rate increased, and it was possible to reduce the amount of antihypertensive drugs used in combination with aliskiren. Moreover, as a result of careful monitoring of the renal function or decreasing the amounts of drugs used in combination, no worsening of the renal function was observed even in the cases complicated by diabetes or CKD being treated with other RAAS inhibitors.

Drug therapy of apparent treatment-resistant hypertension: focus on mineralocorticoid receptor antagonists

Apparent treatment-resistant hypertension (aTRH) is defined as blood pressure (BP) >140/90 mmHg despite three different antihypertensive drugs including a diuretic. aTRH is associated with an increased risk of cardiovascular events, including stroke, chronic renal failure, myocardial infarction, congestive heart failure, aortic aneurysm, atrial fibrillation, and sudden death. Preliminary studies of renal nerve ablation as a therapy to control aTRH were encouraging. However, these results were not confirmed by the Symplicity 3 trial. Therefore, attention has refocused on drug therapy. Secondary forms of hypertension and associated conditions such as obesity, sleep apnea, and primary aldosteronism are common in patients with aTRH. The pivotal role of aldosterone in the pathogenesis of aTRH in many cases is well recognized. For patients with aTRH, the Joint National Committee-8, the European Society of Hypertension, and a recent consensus conference recommend that a diuretic, ACE inhibitor, or angiotensin receptor blocker and calcium channel blocker combination be used to maximally tolerated doses before starting a 'fourth-line' drug such as a mineralocorticoid receptor (MR) antagonist. Although the best fourth-line drug for aTRH has not been extensively investigated, a number of studies summarized here show that an MR antagonist is effective in reducing BP when added to the standard multi-drug regimen.

Combined Aliskiren and L-arginine treatment reverses renovascular hypertension in an animal model

Renovascular hypertension is characterized by increased renal sympathetic activity, angiotensin II and by endothelial dysfunction. The purpose of this study was to determine the role of renal sympathetic nerve activity (RSNA) in mediating the anti-hypertensive effects of aliskiren (ALSK) and L-arginine (L-ARG) in a rat renovascular hypertension model. Hypertension was induced by clipping the right renal artery, and the following five groups were divided: SHAM operated; 2-kidney, 1-clip (2K1C); 2K1C plus ALSK; 2K1C plus L-ARG; and 2K1C plus ALSK+ L-ARG. The systolic blood pressure (SBP) of 2K1C rats increased from 114.4±5.2 to 204±12.7 mm Hg (P<0.05) and was only reduced by ALSK+L-ARG treatment (138.4±4.37 mm Hg). The 2K1C hypertension increased the baseline RSNA (SHAM: 62.4±6.39 vs. 2K1C: 97.4±8.43%). L-ARG or ALSK+L-ARG treatment significantly decreased baseline RSNA (2K1C L-ARG:70.7±2.39; 2K1C ALSK+L-ARG: 69.3±4.23%), but ALSK treatment alone did not (2K1C ALSK: 84.2±2.5%). Urinary water, Na(+), Cl(-) and urea excretion were similar in the 2K1C L-ARG, 2K1C ALSK+L-ARG and SHAM groups. The combination of ALSK+L-ARG restored urine flow and increased the glomerular filtration rate. The nNOS expression in the non clipped kidney was significantly increased in 2K1C ALSK+L-ARG rats. In conclusion, combined ALSK+L-ARG treatment normalizes SBP and prevents renal dysfunction in 2K1C hypertensive rats.