The purpose of this study is to determine whether Remote Ischemic Perconditioning is effective on Acute kidney injury in adult valve replacement.

Methods: Patients meeting the requirement will be randomized into 2 groups: the treatment group consisted of three 5-minute cycles left lower limb ischemia, induced by inflating a blood pressure cuff on the lower limb to 600 mmHg with an intervening 5 minutes of reperfusion, during which time the cuff was deflate; the control group consisted of placing an uninflated cuff on the left lower limb for 30 minutes. The postconditioning protocol was applied after the aortic cross-clamping. The clinical data of inotropes requirement, drainage, ventilation and intensive care time will be recorded. Venous blood samples will be taken perioperatively for detecting concentration of troponin I (cTnI), Myocardial enzyme, Renal function, Cystatin c, and High-sensitivity c-reactive protein(HS-CRP).

Inclusion Criteria:

• rheumatic heart valve disease requiring selective aortic or double valve(aortic and mitral valve) replacement

Exclusion Criteria:

• infective endocarditis congenital valve disease previous cardiac surgery complicated with rereplace valve
• Renal dysfunction
• diabetes
• coronary artery disease
• hypertension
• peripheral vascular disease affecting the lower limb free of arteriovenous fistula
• receiving aspirin, corticosteroids, angiotensin-converting enzyme inhibitors or statin perioperatively