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1.
Effect of Patiromer in Hyperkalemic Patients Taking and Not Taking RAAS Inhibitors.
Kloner, RA, Gross, C, Yuan, J, Conrad, A, Pergola, PE
Journal of cardiovascular pharmacology and therapeutics. 2018;(6):524-531
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Abstract
INTRODUCTION Hyperkalemia (potassium >5.0 mEq/L) affects heart failure patients with renal disease regardless of the use of renin-angiotensin-aldosterone system inhibitors (RAASi). The open-label TOURMALINE study showed that patiromer, a sodium-free, nonabsorbed potassium binder, lowers serum potassium of hyperkalemic patients similarly when given with or without food; unlike prior studies, patients were not required to be taking RAASi. We conducted post hoc analyses to provide the first report of patiromer in patients not taking RAASi. METHODS Hyperkalemic patients received patiromer, 8.4 g/d to start, adjusted to achieve and maintain serum potassium of 3.8 to 5.0 mEq/L. If taking RAASi, stable doses were required. The primary end point was the proportion of patients with serum potassium 3.8 to 5.0 mEq/L at week 3 or 4. This analysis presents data by patients taking or not taking RAASi. RESULTS Demographics and baseline characteristics were similar in patients taking (n = 67) and not taking RAASi (n = 45). Baseline mean (SD) serum potassium was 5.37 (0.37) mEq/L and 5.42 (0.43) mEq/L in patients taking and not taking RAASi, respectively. Mean (SD) daily patiromer doses were similar (10.7 [3.2] and 11.5 [4.0] g, respectively). The primary end point was achieved in 85% (95% confidence interval [CI]: 74-93) of patients taking RAASi and in 84% (95% CI: 71-94) of patients not taking RAASi. From baseline to week 4, the mean (SE) change in serum potassium was -0.67 (0.08) mEq/L in patients taking RAASi and -0.56 (0.10) mEq/L in patients not taking RAASi (both P < .0001 vs baseline, P = nonsignificant between groups). Adverse events were reported in 26 (39%) patients taking RAASi and 25 (54%) not taking RAASi; the most common adverse event was diarrhea (2% and 11%, respectively; no cases were severe). Five patients (2 taking RAASi) reported 6 serious adverse events; none considered related to patiromer. CONCLUSIONS Patiromer was effective and generally well-tolerated for hyperkalemia treatment, whether or not patients were taking RAAS inhibitors.
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Recombinant erythropoietin acutely decreases renal perfusion and decouples the renin-angiotensin-aldosterone system.
Aachmann-Andersen, NJ, Christensen, SJ, Lisbjerg, K, Oturai, P, Johansson, PI, Holstein-Rathlou, NH, Olsen, NV
Physiological reports. 2018;(5)
Abstract
The effect of recombinant erythropoietin (rhEPO) on renal and systemic hemodynamics was evaluated in a randomized double-blinded, cross-over study. Sixteen healthy subjects were tested with placebo, or low-dose rhEPO for 2 weeks, or high-dose rhEPO for 3 days. Subjects refrained from excessive salt intake, according to instructions from a dietitian. Renal clearance studies were done for measurements of renal plasma flow, glomerular filtration rate (GFR) and the segmentel tubular handling of sodium and water (lithium clearance). rhEPO increased arterial blood pressure, total peripheral resistance, and renal vascular resistance, and decreased renal plasma flow in the high-dose rhEPO intervention and tended to decrease GFR. In spite of the decrease in renal perfusion, rhEPO tended to decrease reabsorption of sodium and water in the proximal tubule and induced a prompt decrease in circulating levels of renin and aldosterone, independent of changes in red blood cell mass, blood volumes, and blood pressure. We also found changes in biomarkers showing evidence that rhEPO induced a prothrombotic state. Our results suggest that rhEPO causes a direct downregulation in proximal tubular reabsorption that seems to decouple the activity of the renin-angiotensin-aldosterone system from changes in renal hemodynamics. This may serve as a negative feed-back mechanism on endogenous synthesis of EPO when circulating levels of EPO are high. These results demonstrates for the first time in humans a direct effect of rhEPO on renal hemodynamics and a decoupling of the renin-angiotensin-aldosterone system.
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Neurohormonal Imbalance: A Neglected Problem-And Potential Therapeutic Target-In Acute Heart Failure.
Goldsmith, SR, Bart, BA, Pin A, IL
Current problems in cardiology. 2018;(7):294-304
Abstract
Decompensated or acute heart failure (AHF) is characterized by increased ventricular and atrial pressures which may lead to and be caused by circulatory congestion. Unless due to a primary decrease in cardiac function, congestion arises from volume expansion or vasoconstriction. In turn, volume expansion and vasoconstriction are due to neurohormonal imbalance since both result from activation of the sympathetic nervous system, the renin-angiotensin-aldosterone axis and excess secretion of arginine vasopressin. Outcomes in AHF remain dismal. Loop diuretics are the mainstay of therapy for AHF and may themselves aggravate neurohormonal imbalance. No adjunctive pharmacotherapy has yielded improvement in outcomes in AHF despite many attempts with various vasodilators and inotropes. We, therefore, propose that insufficient attention has been paid to neurohormonal imbalance in AHF. As in chronic HF, rectifying the effects of neurohormonal imbalance may lead to better outcomes. The use of alternative decongestive strategies or adjunctive pharmacotherapy directed at neurohormonal activation could yield benefit.
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Dual RAAS Blockade with Aliskiren in Patients with Severely Impaired Chronic Kidney Disease.
Rasche, FM, Joel, C, Ebert, T, Frese, T, Barinka, F, Busch, V, Rasche, WG, Lindner, TH, Schneider, J, Schiekofer, S
Experimental and clinical endocrinology & diabetes : official journal, German Society of Endocrinology [and] German Diabetes Association. 2018;(1):39-52
Abstract
Dual renin-angiotensin-aldosterone blockade (dRAASb) is purposed in the prevention of the cardiorenal syndrome (CRS). However, all attempts with dRAASb even in patients with moderate impaired chronic kidney disease (CKD) were terminated due to the typical severe adverse events (SAE), e. g., hyperkalemia and rise of serum creatinine. The aim of our study with the direct renin inhibitor aliskiren was to evaluate the effect of dRAASb with a washout phase in patients with severely advanced CKD. We have studied 45 patients (G3b to 4, A2 and >A3; median glomerular filtration rate (GFR) CKD-EPI 31 (23-40) ml/min per 1.73 m² BSA (body surface area), albumin-creatinine-ratio in urine (UACR) (0.413 (0.164 to 1.39) g/g) and proteinuria (0.5 (0.2 to 0.9) g/l) before, with and without aliskiren (150 respectively 300 mg per day) added to an angiotensin-converting enzyme inhibitor (ACEi) or an AT1-receptor blocker (ARB) over 4 ½ years. The dRAASb with aliskiren showed a significant decrease of proteinuria (0.5 to 0.38 g/l), especially in patients with an UACR≥350 mg/g and in the subgroup analysis e. g., in patients with diabetes, but proteinuria increased in the washout phase again. The blood pressure (130/80 mm Hg), serum potassium (4.9 to 5.0 mmol/l) and GFR remained nearly constant (31 to 29.5 ml/min per 1.73 m2 BSA). A more than 30% increase in serum creatinine was associated with an UACR>300 mg/g. The dRAASb has beneficial effects on proteinuria and is safe in patients with severely advanced CKD. However, in patients with high UACR (>300 mg/g) raise of creatinine and potassium have to be controlled.
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Four decades of ocular renin-angiotensin and kallikrein-kinin systems (1977-2017).
Igić, R
Experimental eye research. 2018;:74-83
Abstract
This review offers a contemporary history of the renin-angiotensin (RAS) and kallikrein-kinin (KKS) systems with emphasis on how these complex systems affect the eye. It describes the types of communication (cross-talk) between the two systems and evaluates their potential role in the development of diabetic retinopathy, diabetic macular edema, age-related macular degeneration, glaucoma, and uveitis. In addition to detailing the important physiological actions of components of the RAS and KKS, possibilities are suggested for new therapeutic avenues in the treatment of common ocular diseases. Historical notes indicate the major events in this research area, marking four decades from the first publication on the discovery of renin and angiotensin converting enzyme in the eye to the present time.
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6.
Combination therapies for hypertension - why we need to look beyond RAS blockers.
Gorostidi, M, de la Sierra, A
Expert review of clinical pharmacology. 2018;(9):841-853
Abstract
Hypertension is the leading cause of mortality and disability worldwide. Despite the proven benefits of blood pressure (BP) reduction, lack of BP pressure control continues to be the most important clinical problem in hypertension management. Areas covered: Factors involved in the lack of BP control and strategies to improve such control have been reviewed, with special focus on the usefulness of combination therapies, those types of combination which include a renin-angiotensin system (RAS) blocker, with diuretics, calcium channel blockers, or both. Expert commentary: Combination therapy is required for BP control in most hypertensive patients. RAS blockers should be included in such combinations, except contraindicated. Diuretics, and especially calcium channel blockers are the drugs of choice for double or triple combinations. Diuretics stimulate RAS and enhance the effect of RAS blockers, while minimizing the undesirable metabolic effects of diuretics. RAS blockers and calcium channel blockers have synergistic protective effects on the vascular wall and have demonstrated to be superior to other types of combinations, thus becoming the preferred initial treatment for most hypertensive patients. The use of single-pill combinations is associated with better treatment adherence, thus facilitating the achievement of adequate BP control.
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Hydrochlorothiazide and alternative diuretics versus renin-angiotensin system inhibitors for the regression of left ventricular hypertrophy: a head-to-head meta-analysis.
Roush, GC, Abdelfattah, R, Song, S, Kostis, JB, Ernst, ME, Sica, DA
Journal of hypertension. 2018;(6):1247-1255
Abstract
BACKGROUND Found in 36-41% of hypertension, elevated left ventricular mass (LVM) independently predicts cardiovascular events and total mortality. Conversely, drug-induced regression of LVM predicts improved outcomes. Previous studies have favored renin-angiotensin system inhibitors (RASIs) over other antihypertensives for reducing LVM but ignored differences among thiazide-type diuretics. From evidence regarding potency, cardiovascular events, and electrolytes, we hypothesized a priori that 'CHIP' diuretics [CHlorthalidone, Indapamide and Potassium-sparing Diuretic/hydrochlorothiazide (PSD/HCTZ)] would rival RASIs for reducing LVM. METHOD AND RESULTS Systematic review yielded 12 relevant double-blind randomized trials. CHIPs were more closely associated with reduced LVM than HCTZ (P = 0.004), indicating that RASIs must be compared with each diuretic separately. Publication bias favoring RASIs was corrected by cumulative analysis. For reducing LVM, HCTZ tended to be less effective than RASIs. However, the following surpassed RASIs: chlorthalidone Hedge's G: -0.37 (95% CI -0.72 to -0.02), P = 0.036; indapamide -0.20 (-0.39 to -0.01), P = 0.035; all CHIPs combined (with 61% of patients in one trial) -0.25 (-0.41to -0.09), P = 0.002. Statistical significance (P < 0.05) did not depend on any one trial. CHIPs reduction in LVM was 37% greater than that from RASIs. CHIPs superiority tended to increase with trial duration, from a negligible effect at 0.5 year to a maximal effect at 0.9-1.0 years: -0.26 (-0.43 to -0.09), P = 0.003. Fifty-eight percent of patients had information on echocardiographic components of LVM: relative to RASIs, CHIPs significantly reduced end-diastolic LV internal dimension (EDLVID): -0.18 (-0.36 to -0.00), P = 0.046. Strength of evidence favoring CHIPs over RASIs was at least moderate. CONCLUSION In these novel results in patients with hypertension, CHIPs surpassed RASIs for reducing LVM and EDLVID.
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Resistant Hypertension On Treatment (ResHypOT): sequential nephron blockade compared to dual blockade of the renin-angiotensin-aldosterone system plus bisoprolol in the treatment of resistant arterial hypertension - study protocol for a randomized controlled trial.
Cestário, EDES, Fernandes, LAB, Giollo-Júnior, LT, Uyemura, JRR, Matarucco, CSS, Landim, MIP, Cosenso-Martin, LN, Tácito, LHB, Moreno, H, Vilela-Martin, JF, et al
Trials. 2018;(1):101
Abstract
BACKGROUND Resistant hypertension is characterized when the blood pressure (BP) remains above the recommended goal after taking three antihypertensive drugs with synergistic actions at their maximum recommended tolerated doses, preferably including a diuretic. Identifying the contribution of intravascular volume and serum renin in maintaining BP levels could help tailor more effective hypertension treatment, whether acting on the control of intravascular volume or sodium balance, or acting on the effects of the renin-angiotensin-aldosterone system (RAAS) on the kidney. METHODS/DESIGN This is a randomized, open-label, clinical trial is designed to compare sequential nephron blockade and its contribution to the intravascular volume component with dual blockade of the RAAS plus bisoprolol and the importance of serum renin in maintaining BP levels. The trial has two arms: sequential nephron blockade versus dual blockade of the RAAS (with an angiotensin converting enzyme (ACE) inhibitor plus a beta-blocker) both added-on to a thiazide diuretic, a calcium-channel blocker and an angiotensin receptor-1 blocker (ARB). Sequential nephron blockade consists in a progressive increase in sodium depletion using a thiazide diuretic, an aldosterone-receptor blocker, furosemide and, finally, amiloride. On the other hand, the dual blockade of the RAAS consists of the progressive addition of an ACE inhibitor until the maximum dose and then the administration of a beta-blocker until the maximum dose. The primary outcomes will be reductions in the systolic BP, diastolic BP, mean BP and pulse pressure (PP) after 20 weeks of treatment. The secondary outcomes will evaluate treatment safety and tolerability, biochemical changes, evaluation of renal function and recognition of hypotension (ambulatory BP monitoring (ABPM)). The sample size was calculated assuming an alpha error of 5% to reject the null hypothesis with a statistical power of 80% giving a total of 40 individuals per group. DISCUSSION In recent years, the cost of resistant hypertension (RH) treatment has increased. Thus, identifying the contribution of intravascular volume and serum renin in maintaining BP levels could help tailor more effective hypertension treatment, whether by acting on the control of intravascular volume or sodium balance, or by acting on the effects of the RAAS on the kidney. TRIAL REGISTRATION Sequential Nephron Blockade vs. Dual Blockade Renin-angiotensin System + Bisoprolol in Resistant Arterial Hypertension (ResHypOT). ClinicalTrials.gov, ID: NCT02832973 . Registered on 14 July 2016. First received: 12 June 2016. Last updated: 18 July 2016.
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New Therapeutic Approaches for the Treatment of Hyperkalemia in Patients Treated with Renin-Angiotensin-Aldosterone System Inhibitors.
Tamargo, J, Caballero, R, Delpón, E
Cardiovascular drugs and therapy. 2018;(1):99-119
Abstract
Hyperkalemia (serum potassium > 5.5 mEq/L) is a common clinical problem in patients with chronic kidney disease, hypertension, diabetes, and heart failure. It can result from increased K+ intake, impaired distribution between intracellular and extracellular spaces, and most frequently, decreased renal excretion. Patients at the highest risk of hyperkalemia are treated with renin-angiotensin-aldosterone system inhibitors (RAASIs) as they improve cardiovascular and renal outcomes and are strongly recommended in clinical guidelines. However, RAASIs cause or increase the risk of hyperkalemia, a key limitation to fully titrate RAASIs in patients who are most likely to benefit from treatment. Until recently, drugs for the treatment of hyperkalemia presented limited efficacy and/or safety concerns and there was an unmet need of new drugs to control hyperkalemia while maintaining RAASI therapy. We provide an overview of the mechanisms involved in K+ homeostasis and the epidemiology and management of hyperkalemia as a complication in cardiovascular patients and, finally, analyze the efficacy and safety of two new polymer-based, non-systemic agents, patiromer calcium and sodium zirconium cyclosilicate (ZS-9), designed to increase fecal K+ loss and to normalize elevated serum K+ levels and chronically maintain K+ homeostasis in hyperkalemic patients treated with RAASIs.
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Use of Renin-Angiotensin System Blockade in Advanced CKD: An NKF-KDOQI Controversies Report.
Weir, MR, Lakkis, JI, Jaar, B, Rocco, MV, Choi, MJ, Kramer, HJ, Ku, E
American journal of kidney diseases : the official journal of the National Kidney Foundation. 2018;(6):873-884
Abstract
Multiple clinical trials have demonstrated that renin-angiotensin system (RAS) blockade with either angiotensin-converting enzyme inhibitors or angiotensin receptor blockers effectively reduces chronic kidney disease (CKD) progression. However, most clinical trials excluded participants with advanced CKD (ie, estimated glomerular filtration rate [eGFR]<30mL/min/1.73m2). It is acknowledged that initiation of RAS blockade is often associated with an acute reduction in eGFR, which is thought to be functional, but may result in long-term preservation of kidney function through the reductions in glomerular intracapillary pressure conferred by these agents. In this National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (NKF-KDOQI) report, we discuss the controversies regarding use of RAS blockade in patients with advanced kidney disease. We review available published data on this topic and provide perspective on the impact of RAS blockade on changes in eGFRs and potassium levels. We conclude that more research is needed to evaluate the therapeutic index of RAS blockade in patients with advanced CKD.