Abstract Body (Do not enter title and authors here): Background
Pulse pressure (PP), the difference between systolic and diastolic blood pressure, reflects arterial stiffness and vascular aging. Its role in predicting gastrointestinal (GI) bleeding risk among anticoagulated atrial fibrillation (AF) patients remains poorly defined.

Objective
To assess whether elevated pulse pressure independently predicts GI bleeding in anticoagulated patients with atrial fibrillation.

Methods
This retrospective cohort study used the REACHnet database. Adult patients diagnosed with AF and receiving blood thinners were included. PP was derived from outpatient systolic and diastolic measurements and categorized into tertiles: T1 (<46 mmHg), T2 (46–62 mmHg), and T3 (>62 mmHg). The primary outcome was GI bleeding requiring hospitalization. Demographic and clinical variables were compared across tertiles using Wilcoxon tests, t-tests, and Chi-square tests as needed. Kaplan-Meier analysis assessed time to GI bleeding. Cox proportional hazards models were adjusted for confounders, including systolic blood pressure (SBP).

Results
Among 3,142 patients (mean age 74 ± 8.9 years; 47% female), 9.9% experienced GI bleeding over a median follow-up of 4.1 years. Patients in the highest PP tertile (T3) had significantly greater prevalence of hypertension, diabetes, peripheral artery disease, history of stroke, and anticoagulant use (all p<0.01) (Table 1). Despite this higher burden of comorbidity, elevated PP remained an independent predictor of GI bleeding. Adjusted analysis showed that patients in T3 had a 48% increased risk of GI bleeding compared to T1 (HR: 1.48; 95% CI: 1.19–1.84; p<0.001), independent of SBP and other clinical factors. Kaplan-Meier curves demonstrated significantly lower bleeding-free survival in T3 (log-rank p=0.003) (Figure 1).

Conclusion
High pulse pressure, especially >62 mmHg, is independently associated with GI bleeding in anticoagulated AF patients. This association persists after adjustment for SBP and other comorbidities. PP should be considered in bleeding risk assessment models in clinical practice.