BackgroundBlood products are commonly transfused in patients with acute upper gastrointestinal bleeding (UGIB). There exists considerable practice variation and less evidence to guide fresh frozen plasma transfusion in patients with UGIB. The aim of this study was to explore any association between fresh frozen plasma transfusion following acute UGIB and clinical outcomes.MethodsThis was a prospective, observational, multicenter study conducted at 20 tertiary hospitals in China. Patients with acute UGIB with an international normalized ratio ≤ 2.0 at emergency department admission were included. Multivariate logistic regression models were used to examine and quantify any clinical associations.ResultsA total of 976 patients (61.57 ± 15.79 years old, 73.05% male) were included, of whom 17.42% received fresh frozen plasma transfusion. The overall 90-day mortality and rebleeding rates were 10.20 and 12.19%, respectively. After adjusting for confounding factors, transfusion of fresh frozen plasma during hospitalization was associated with higher 90-day mortality [odd ratio (OR), 2.36; 95% confidence interval (CI), 1.36–4.09; p = 0.002] but not rebleeding (OR, 1.5; 95% CI; 0.94-2.54; p = 0.085). In a subgroup analysis, patients with an international normalized ratio <1.5 who were treated with fresh frozen plasma were associated with both significantly higher 90-day mortality (OR, 2.78; 95% CI, 1.49–5.21; p = 0.001) and rebleeding (OR, 2.02; 95% CI, 1.16–3.52; p = 0.013), whereas in patients with an international normalized ratio between 1.5 and 2, we did not find any significant correlation.ConclusionThis study found an association between fresh frozen plasma transfusion following acute UGIB and elevated 90-day mortality. Both 90-day mortality and rebleeding risk were significantly higher in patients with an international normalized ratio < 1.5. Fresh frozen plasma transfusion in acute UGIB does not improve the poor outcomes (Chinese Clinical Trial registry, Number ChiCTR1900028676).