Time course of antiproteinuric effect of aliskiren in arterial hypertension associated with type 2 diabetes and microalbuminuria

Renin inhibitors versus angiotensin converting enzyme (ACE) inhibitors for primary hypertension

BACKGROUND

Renin inhibitors (RIs) reduce blood pressure more than placebo, with the magnitude of this effect thought to be similar to that for angiotensin converting enzyme (ACE) inhibitors. However, a drug's efficacy in lowering blood pressure cannot be considered as a definitive indicator of its effectiveness in reducing mortality and morbidity. The effectiveness and safety of RIs compared to ACE inhibitors in treating hypertension is unknown.

OBJECTIVES

To evaluate the benefits and harms of renin inhibitors compared to ACE inhibitors in people with primary hypertension.

SEARCH METHODS

The Cochrane Hypertension Group Information Specialist searched the following databases for randomized controlled trials up to August 2020: the Cochrane Hypertension Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1946), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We also contacted authors of relevant papers about further published and unpublished work. The searches had no language restrictions.

SELECTION CRITERIA

We included randomized, active-controlled, double-blinded studies (RCTs) with at least four weeks follow-up in people with primary hypertension, which compared renin inhibitors with ACE inhibitors and reported morbidity, mortality, adverse events or blood pressure outcomes. We excluded people with proven secondary hypertension.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the included trials, evaluated the risks of bias and entered the data for analysis.

MAIN RESULTS

We include 11 RCTs involving 13,627 participants, with a mean baseline age from 51.5 to 74.2 years. Follow-up duration ranged from four weeks to 36.6 months. There was no difference between RIs and ACE inhibitors for the outcomes: all-cause mortality: risk ratio (RR) 1.05, 95% confidence interval (CI) 0.93 to 1.18; 5 RCTs, 5962 participants; low-certainty evidence; total myocardial infarction: RR 0.86, 95% CI 0.22 to 3.39; 2 RCTs, 957 participants; very low-certainty evidence; adverse events: RR 0.98, 95% CI 0.93 to 1.03; 10 RTCs, 6007 participants;  moderate-certainty evidence; serious adverse events: RR 1.21, 95% CI 0.89 to 1.64; 10 RTCs, 6007 participants; low-certainty evidence; and withdrawal due to adverse effects: RR 0.85, 95% CI 0.68 to 1.06; 10 RTCs, 6008 participants; low-certainty evidence. No data were available for total cardiovascular events, heart failure, stroke, end-stage renal disease or change in heart rate. Low-certainty evidence suggested that RIs reduced systolic blood pressure: mean difference (MD) -1.72, 95% CI -2.47 to -0.97; 9 RCTs, 5001 participants;  and diastolic blood pressure: MD -1.18, 95% CI -1.65 to -0.72; 9 RCTs, 5001 participants,  to a greater extent than ACE inhibitors, but we judged this to be more likely due to bias than a true effect.  AUTHORS' CONCLUSIONS: For the treatment of hypertension, we have low certainty that renin inhibitors (RI) and angiotensin converting enzyme (ACE) inhibitors do not differ for all-cause mortality and myocardial infarction. We have low to moderate certainty that they do not differ for adverse events. Small reductions in blood pressure with renin inhibitors compared to ACE inhibitors are of low certainty.  More independent, large, long-term trials are needed to compare RIs with ACE inhibitors, particularly assessing morbidity and mortality outcomes, but also on blood pressure-lowering effect.

Efficacy and Safety of Imarikiren in Patients with Type 2 Diabetes and Microalbuminuria: A Randomized, Controlled Trial

BACKGROUND AND OBJECTIVES

Imarikiren is a novel, potent, and selective direct renin inhibitor that has shown high oral availability during clinical development for the treatment of diabetic nephropathy. We evaluated the efficacy and safety of imarikiren in patients with type 2 diabetes mellitus and microalbuminuria.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a randomized, multicenter, placebo-controlled, double-blind, phase 2, dose-finding trial. A total of 415 patients were randomized to imarikiren 5, 20, 40, or 80 mg; placebo; or candesartan cilexetil 8 mg treatment for 12 weeks. The primary end point was change in log-transformed urine albumin-to-creatinine ratio from baseline to the end of treatment analyzed using analysis of covariance and a fixed sequence testing procedure. Secondary efficacy end points included urine albumin-to-creatinine ratio at each assessment point and remission and progression rates. Exploratory efficacy end points included eGFR and sitting BP before dosing.

RESULTS

Changes in the urine albumin-to-creatinine ratio from baseline to the end of treatment were 16% (placebo), -16% (imarikiren 5 mg), -27% (imarikiren 20 mg), -38% (imarikiren 40 mg), -39% (imarikiren 80 mg), and -31% (candesartan cilexetil 8 mg). Urine albumin-to-creatinine ratio reductions from baseline were statistically significant in all imarikiren groups versus placebo (P<0.001 each) as well as for candesartan cilexetil 8 mg versus placebo (P<0.001). Remission rates (urine albumin-to-creatinine ratio <30 mg/g creatinine and decreased ≥30% from baseline) were higher in all imarikiren groups versus the placebo group. Incidence of adverse events was higher in the imarikiren 80-mg group (52%) versus placebo (42%) and candesartan cilexetil (43%) groups. Incidence of adverse events for the other imarikiren groups ranged from 33% to 42%. Adverse events were mild or moderate in severity. All imarikiren doses were well tolerated.

CONCLUSIONS

Imarikiren resulted in a dose-dependent improvement in albuminuria compared with placebo, and it was well tolerated in patients with type 2 diabetes mellitus and microalbuminuria.