Ung, Steven

Aortic stenosis (AS) requires repeat assessments to optimally time intervention. The utility of laboratory tests to complement clinical and hemodynamic assessments has not been established. We assessed clinical, echocardiographic, and laboratory data in 76 patients with AS or heart valve replacement (HVR), age 77 years, 37% women. Laboratory assessments included von Willebrand factor (VWF) antigen, activity, (Act/Ag, normal > 0.8), VWF multimer distribution (abnormal=loss of highest molecular weight multimers=Mult+), brain natriuretic peptide (BNP, abnormal > 155 pg/ml=BNP+), and platelet function analyzer 100 collagen-ADP closure time (PFA, normal < 121 seconds). Table: Coefficients of correlation, r, and F statistic. Chi-square, and probability. Correlation of BNP to mean gradient in patients with GFR>60 remained poor, r=0.29, while for PFA r = 0.65. Median (IQR) for PFA and BNP for mild, moderate, and severe AS and HVR are shown below. VWF multimers were abnormal in 3/14 mild AS, 6/14 moderate AS, 22/25 severe AS and 4/23 HVR patients. The severity of AS was most strongly associated with VWF multimer abnormality and prolonged PFA closure time, weakly with BNP, and not with VWF Act/Ag. Conclusion: Among various laboratory measures, PFA and VWF multimers are strongly associated with AS severity, and may merit assessment as complementary diagnostic and prognostic biomarkers in AS.