REN and liver disorder: PEP: Primary endpoint; SEP: Secondary endpoint; SCr: Serum creatinine; HRS: Hepatorenal syndrome; AE: Adverse events; CHRSR: Confirmed hepatorenal syndrome reversal; RRT: Renal replacement therapy; OS: Overall survival; LTx: Liver transplant; MELD: Model for end-stage liver disease; MAP: Mean arterial pressure; RCTs: Randomized controlled trials; SIRS: Systemic inflammatory response syndrome; PRA: Plasma renin activity