A total of 13 randomized controlled trials with 12,222 patients indicated that aliskiren in combination therapy with angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers had remarkable effects in reducing both systolic and diastolic blood pressure when compared with angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers monotherapy, but with significantly increased risk of hyperkalaemia and kidney injury. Here, ACE is linked to kidney injury.