Nonselective β-blockers may induce development of portal vein thrombosis in cirrhosis

Currently, nonselective β-blockers (NSBBs) are commonly used for the prevention of variceal bleeding in liver cirrhosis. The beneficial effects of NSBBs are primarily attributed to the reduction in cardiac output by blockade of β1 receptors and vasoconstriction of the splanchnic circulation by the blockade of β2 receptors. The prognostic value of occlusive portal vein thrombosis (PVT) in cirrhotic patients has been increasingly recognized. The most important risk factor for the development of PVT in liver cirrhosis is the decreased portal vein inflow velocity. Collectively, we propose that the use of NSBBs potentially increases the development of portal vein thrombosis by reducing portal vein inflow velocity. The hypothesis should be confirmed by prospective cohort studies, in which cirrhotic patients without prior PVT treated with and without NSBBs are enrolled, and the development of PVT during follow-up is compared between the two groups. Additionally, subgroup analyses should be performed according to the dosage of NSBBs and the reduction of portal inflow velocity after use of NSBBs.