Aortic stenosis severity gradient and gastrointestinal bleeding: Pathophysiological mechanisms, epidemiological evidence, and rationale for a gradient-stratified retrospective study

BACKGROUND: Aortic stenosis (AS) is the most prevalent valvular heart disease in aging Western populations and is pathophysiologically linked to gastrointestinal (GI) bleeding through acquired von Willebrand syndrome (aVWS). This relationship, termed Heyde syndrome, encompasses severe AS, aVWS type 2 A, and GI bleeding from angiodysplasia. Despite over six decades of recognition, the quantitative relationship between transvalvular gradient as a continuous hemodynamic variable and GI bleeding incidence remains incompletely characterized. METHODS: We conducted a narrative synthesis of peer-reviewed literature from PubMed, Embase, and Cochrane databases examining AS severity, von Willebrand factor (VWF) abnormalities, GI bleeding outcomes, and reversibility after valve replacement. RESULTS: High shear stress at the stenotic valve cleaves high-molecular-weight (HMW) VWF multimers via ADAMTS-13, creating hemostatic deficiency compounded by GI angiodysplasia. A consistent inverse correlation between transvalvular gradient and HMW multimer levels is demonstrated across multiple cohorts (r = -0.40 to -0.64). Severe AS confers a hazard ratio of 3.59 (95% CI 1.56-8.29) for major bleeding versus mild AS. GI bleeding cessation occurs in 73% and aVWS recovery in 86-92% of patients after valve replacement. CONCLUSION: Direct quantification of GI bleeding incidence across the full transvalvular gradient spectrum as a continuous variable remains an important evidence gap. A gradient-stratified retrospective cohort study is warranted, with implications for risk stratification, timing of valve intervention, and bleeding prophylaxis.