Influence of angiotensin converting enzyme inhibition and angiotensin II type 1 receptor antagonism on renal sodium and water handling and albuminuria during infusion of atrial natriuretic factor into healthy volunteers

Progress and prospects of Sacubitril/Valsartan: Based on heart failure with preserved ejection fraction

Heart failure with preserved ejection fraction (HFpEF) is present in nearly half of patients with heart failure. The prevalence of heart failure with normal or near-normal ejection fractions increases more rapidly than in patients with reduced ejection fractions. Angiotensin-converting enzyme inhibitor (ACEI), angiotensin receptor blocker (ARB), aldosterone antagonist, β-blocker, and calcium channel blocker have not shown significant efficacy in HFpEF clinical trials. Sacubitril/Valsartan, combined angiotensin receptor blocker (Valsartan) with neprilysin inhibitor (Sacubitril), was the first-of-its-kind angiotensin receptor-neprilysin inhibitor (ARNI) to be developed. It has shown significant efficacy on HFpEF in recent studies. It is considered that most of the current Sacubitril/Valsartan studies are still concentrated in the field of heart failure, especially heart failure with reduced ejection fraction (HFrEF). This review discusses the latest advances in cardiovascular, renal, and metabolic aspects of Sacubitril/Valsartan, mainly in HFpEF, providing more evidence for further future research on Sacubitril/Valsartan and raising issues that should be paid attention. At the same time, this review will introduce the academic consensus on Sacubitril/Valsartan in treating HFpEF in China.

Effect of Sacubitril/Valsartan on renal function in patients with chronic kidney disease and heart failure with preserved ejection fraction: A real-world 12-week study

Patients with chronic kidney disease (CKD) are often complicated with heart failure with preserved ejection fraction (HFpEF). However, several drugs, including angiotensin-converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB), have not shown apparent benefits in terms of morbidity and mortality of HFpEF. PARAMOUNT and other studies have shown the potential benefits of Sacubitril/Valsartan on patients with HFpEF, but its effects on renal function and the effect of low-dose Sacubitril/Valsartan in actual clinical conditions have not been thoroughly evaluated. In our longitudinal and observational research, 353 patients were followed up for 12 weeks. We evaluated renal function [urinary protein, serum creatinine and estimated glomerular filtration rate (eGFR)] and cardiac function [NT-proBNP (brain natriuretic peptide), New York Heart Association (NYHA) classification, left ventricular ejection fraction (LVEF), left atrial width and left ventricular end-diastolic width] at baseline and during follow-up. Worsening renal function (WRF) was defined as an increased serum creatinine≥26.5umol/L or decreased eGFR≥20%. The decline of eGFR in the Sacubitril/Valsartan group was slower than that in the control group (p = 0.021). The outcome of proteinuria in the ACEI/ARB group was significantly better than that in the Sacubitril/Valsartan group (p = 0.001). In terms of echocardiogram, the average left atrial width in Sacubitril/Valsartan group decreased by 1.38 ± 3.02 mm, which was significantly lower than that in the ACEI/ARB group (p = 0.02). The increase of urine protein class in the ACEI/ARB group increased the risk of WRF with statistical significance (OR = 2.36, 95%CI 1.01-5.49, p = 0.047), but no statistical significance was found in all the patients or Sacubitril/Valsartan group. In conclusion, Sacubitril/Valsartan could more effectively slow down renal function decline and reverse myocardial remodeling in patients with CKD and HFpEF than ACEI/ARB, even at low doses, though its protective effect on urinary protein is not as good as that of ACEI/ARB.

Renal effects of the angiotensin receptor neprilysin inhibitor LCZ696 in patients with heart failure and preserved ejection fraction

BACKGROUND

Increases in serum creatinine with renin-angiotensin-aldosterone system (RAAS) inhibitors can lead to unnecessary discontinuation of these agents. The dual-acting angiotensin receptor neprilysin inhibitor LCZ696 improves clinical outcome patients with heart failure with reduced ejection fraction, and pilot data suggest potential benefit in heart failure with preserved ejection fraction (HFpEF). The effects of LCZ696 on renal function have not been assessed.

METHODS AND RESULTS

A total of 301 HFpEF patients were randomly assigned to LCZ696 or valsartan in the PARAMOUNT trial. We studied renal function [creatinine, estimated glomerular filtration rate (eGFR), cystatin C, and urinary albumin to creatinine ratio (UACR)] at baseline, 12 weeks, and after 36 weeks of treatment. Worsening renal function (WRF) was determined as an serum creatinine increase of >0.3 mg/dL and/or >25% between two time-points. Mean eGFR at baseline was 65.4 ± 20.4 mL/min per 1.73 m(2) . The eGFR declined less in the LCZ696 group than in the valsartan group (-1.5 vs. -5.2 mL/min per 1.73 m(2) ; P = 0.002). The incidence of WRF was lower in the LCZ696 group (12%) than in the valsartan group (18%) at any time-point, but this difference was not statistically significant (P = 0.18). Over 36 weeks, the geometric mean of UACR increased in the LCZ696 group (2.4-2.9 mg/mmol), whereas it remained stable in the valsartan group (2.1-2.0 mg/mmol; P for difference between groups = 0.016).

CONCLUSION

In patients with HFpEF, therapy with LCZ696 for 36 weeks was associated with preservation of eGFR compared with valsartan therapy, but an increase in UACR.

Renal effects of urodilatin in healthy subjects are independent of blockade of the cyclooxygenase and angiotensin II receptor

OBJECTIVE

Little is known about the role of the renin-angiotensin-aldosterone system and the renal prostaglandins in modulating the renal vasoconstrictive and natriuretic effects of synthetic urodilatin (URO) in healthy humans.

MATERIAL AND METHODS

Twelve volunteers were pretreated in a randomized, single-blind, crossover study with losartan 50 mg a day or placebo for 5 days. Another 12 healthy subjects received indomethacin 25 mg three times a day or placebo for 4 days and a single dose on day 5. All subjects received a URO infusion (15 ng kg(-1) min(-1)) on day 5. Radioactive tracers and the lithium clearance technique were used.

RESULTS

The effective renal plasma flow (ERPF) decreased significantly during URO infusion: losartan pretreatment 573+/-63 to 461+/-76 mL/min versus placebo 540+/-89 to 432+/-90 mL/min. The urinary sodium excretion rate (UNa) increased significantly during URO infusion: losartan 335+/-115 to 502+/-134 umol/min (micromol/min) (UNa) versus placebo 386+/-142 to 476+/-137 umol/min (micromol/min) (UNa). In the indomethacin pretreated subjects, ERPF decreased significantly from 530+/-109 to 446+/-55 mL/min versus 533+/-89 to 449+/-69 mL/min in the placebo group. UNa increased significantly from 395+/-142 to 768+/-254 umol/min (micromol/min) (UNa) in the indomethacin group versus 282+/-117 to 552+/-242 umol/min (micromol/min) (UNa) in placebo.

CONCLUSION

The renal vasoconstrictive and natriuretic effects of synthetic URO are not modified by sustained inhibition of the angiotensin II receptor or the cyclooxygenase in man in a sodium replete state.

Fibrosis rather than blood pressure determines cardiac BNP expression in mice

BACKGROUND

Since first reports demonstrated interactions between the natriuretic peptide (NPS) and renin-angiotensin system (RAS), our experiments should clarify whether cardiac brain natriuretic peptide (BNP) is regulated in mice genetically altered for components of the RAS.

METHODS AND RESULTS

The study was carried out in hypotensive AT1- and angiotensinogen (ANG)-, and normotensive AT2-knockout mice, and in hypertensive animals overexpressing ANG and wildtype controls of each genotype. Ventricular BNP expression was analyzed by RNase-protection assay (RPA) (n=6). Cardiac fibrosis was visualized by Sirius red staining. While ANG overexpression increases cardiac BNP-mRNA expression (1035+/-210 vs. wildtype: 405+/-95 in PSL/mm(2), P<0.01), its deficiency had no influence. Both AT1- and AT2-knockouts showed significantly decreased BNP-mRNA concentrations (AT1: 21+/-6 vs. wildtype: 139+/-28 in PSL/mm(2), P<0.001; AT2: 8+/-2 vs. 19+/-3 in PSL/mm(2), P<0.05). These alterations correlate to reduced cardiac fibrosis in AT2-deficient animals, and an unchanged matrix content in ANG knockouts.

CONCLUSIONS

Increased BNP-mRNA levels in hypertensive ANG-overexpressing mice and decreased BNP in hypotensive AT1-deficient animals suggest that this mRNA expression is blood pressure-dependent. However, the observed alterations of fibrosis and the unchanged BNP in hypotensive ANG knockouts and impaired BNP-mRNA expression in normotensive AT2-deficient mice demonstrate a direct interaction of the RAS and NPS that is fibrosis- rather than blood pressure-dependent.

Blood pressure independent association of microalbuminuria and left ventricular hypertrophy in hypertensive men

BACKGROUND

Rather unique amongst the prognostic predictors, microalbuminuria (MA, albuminuria: 15-200 microg min-1) is associated with several cardiovascular risk factors including left ventricular hypertrophy (LVH). The relationship, usually assumed to reflect an increased blood pressure (BP) load on the heart and the kidney, may, however, represent more than a haemodynamic correlate.

METHODS

To evaluate this possibility, we related MA to left ventricular mass index (LVMI) and other functional and structural echocardiographic parameters, office and 24-h BP, weight, lipids and smoking status in 330 never treated nondiabetic hypertensive men.

RESULTS

The risk of MA increased linearly by ascending quartiles of LVMI and was 2.3-fold higher in the presence of LVH after adjustment for age, left atrial size, mean fractional shortening. Systolic BP, either office or 24 h, and smoking status were the only additional independent predictors in multivariate logistic regression models. The BP-adjusted risk of MA was about twofold higher in patients with LVH, either concentric or eccentric, and neutral in those with concentric remodelling compared with normal geometry.

CONCLUSIONS

The association between elevated LVMI and MA independent of several other potential confounders, systolic BP in particular, is consistent with the existence of cardiac albuminuric factors, possibly of hormonal nature, which are to be identified more precisely. The extent to which LVH explains the predictive power of MA for morbid events independent of the BP load remains unknown.

Eprosartan: an angiotensin-II receptor antagonist for the management of hypertension

Eprosartan is a competitive angiotensin-II receptor antagonist with a high affinity for the angiotensin-II subtype 1 receptor. The drug has an elimination half-life of approximately 5 to 9 hours and duration of antihypertensive effect of up to 24 hours. The antihypertensive efficacy of eprosartan has been examined in a number of placebo-controlled, dose-finding, and comparative trials. Results of these clinical trials have consistently shown statistically significant differences in antihypertensive efficacy favoring eprosartan doses of 400 mg or greater per day over placebo. Eprosartan was also shown to be at least as effective as enalapril at lowering blood pressure in patients with mild to severe hypertension. The frequency of adverse events observed with eprosartan has been similar to that seen with placebo. In addition, there are no clinically significant drug interactions associated with eprosartan. Given the excellent tolerability and drug-interaction profiles of eprosartan, the use of this agent may help to improve patient compliance to a drug regimen. In addition, eprosartan may be particularly advantageous when used as a part of combination therapy for the management of hypertension.

Safety and tolerability of eprosartan

The safety and tolerability of eprosartan were extensively assessed in 17 phase IIb-III studies that included 2709 patients with hypertension. The frequency of adverse events observed with eprosartan was similar to that seen with placebo. Neither the number nor the severity of these effects increased with prolonged therapy, and their frequency was not affected by increased eprosartan dosage or dosing frequency. The drug is equally well tolerated by women and men, by younger (< 65 yrs) and older (> or = 65 yrs) individuals, and by persons of all races. There are no known drug interactions, and eprosartan is well tolerated when given in combination with other frequently prescribed antihypertensive agents, without an increase in adverse events beyond those expected of baseline antihypertensive therapy.