Abstract
BACKGROUND AND OBJECTIVES: Dual renin-angiotensin-aldosterone system (RAAS) blockade involves dual therapy with a combination of angiotensin-converting enzyme inhibitors (ACEis), angiotensin-receptor blockers (ARBs), direct renin inhibitors (DRIs), or mineralocorticoid receptor antagonists (MRAs). It is hypothesized that dual RAAS blockade would result in a more complete inhibition of the RAAS cascade. However, large clinical trials on dual RAAS inhibition have shown increased risk of acute kidney injury (AKI) and hyperkalemia without additional benefit on mortality, cardiovascular events, or chronic kidney disease (CKD) progression compared to RAAS inhibitor monotherapy in patients with diabetic kidney disease (DKD). The development of newer, more selective non-steroidal MRAs as cardiorenal protective therapies has created a new opportunity for dual RAAS inhibition. We conducted a systematic review and meta-analysis of the risks of AKI and hyperkalemia with dual RAAS blockade in patients with DKD. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: This is a systematic review and meta-analysis of the randomized controlled trials (RCT) published from 1 January 2006 to 30 May 2022. The study population included adult patients with DKD receiving dual RAAS blockade. A total of 31 RCTs and 33 048 patients were included in the systematic review. Pooled risk ratios (RRs) and 95% confidence intervals (CIs) were calculated using random effects. RESULTS: There were 208 AKI events in 2690 patients on ACEi + ARB versus 170 in 4264 patients with ACEi or ARB monotherapy (pooled RR 1.48, 95% CI: 1.23-1.39). There were 304 hyperkalemia events in 2818 patients on ACEi + ARB versus 208 in 4396 patients with ACEi or ARB monotherapy (pooled RR 1.97, 95% CI: 1.32-2.94). A non-steroidal MRA + ACEi or ARB showed no increase in the risk of AKI (pooled RR 0.97, 95% CI: 0.81-1.16) compared to ACEi or ARB monotherapy but had a 2-fold higher risk of hyperkalemia with 953 events in 7837 patients in dual therapy versus 454 events in 6895 patients in monotherapy (pooled RR 2.05, 95% CI: 1.84-2.28). A steroidal MRA + ACEi or ARB had a 5-fold higher risk of hyperkalemia with 28 events in 245 at risk in dual therapy versus five events in 248 at risk in monotherapy (pooled RR 5.42 95% CI: 2.15-13.67). CONCLUSION: Dual therapy with RAASi is associated with an increased risk of AKI and hyperkalemia compared to RAASi monotherapy. Conversely, dual therapy with RAAS inhibitors and non-steroidal MRAs have no additional risk of AKI but a similar risk of hyperkalemia, which is lower than dual therapy with RAAS inhibitors and steroidal MRAs.