Carvedilol is a potent non-selective β-blocker with both beta and alpha-1 blocker effect. It significantly lowers portal pressure even in propranolol non-responders. However, it is unclear weather carvedilol will play a role in the prevention of recurrent gastric variceal bleeding. The investigators conducted a randomized controlled trial to compare the efficacy of carvedilol combined with endoscopic cyanoacrylate injection with endoscopic cyanoacrylate injection alone in secondary prophylaxis of gastric variceal bleeding.