Changes in whole blood viscosity in patients undergoing percutaneous or surgical intervention for aortic stenosis

ObjectiveAortic stenosis is a common valvular disease in the elderly. This study aimed to investigate changes in whole blood viscosity (WBV), which reflects hemodynamic load and blood flow and is associated with cardiovascular diseases, after percutaneous and surgical interventions for aortic stenosis.MethodsFrom 2019 to 2022, 200 patients undergoing Transcatheter Aortic Valve Implantation (TAVI) (n = 100) or bioprosthetic Aortic Valve Replacement (bAVR) (n = 100) were analyzed. WBV at low shear rate (LSR, 0.5 s^-1) and high shear rate (HSR, 208 s^-1) was calculated from the hematocrit and total protein using the De Simone formula. Pre- and 3-month values were compared using paired and independent t-tests, and correlations and multivariable regression were performed.ResultsThe aortic valve area was negatively correlated with HSR (r = -0.340, p < 0.01) and LSR (r = -0.358, p < 0.01). At 3 months, HSR decreased by 0.95 ± 0.31 cP and LSR by 18.92 ± 6.32 cP (both p < 0.001). Reductions were significant in both groups without between-group differences and were mainly related to decreases in non-albumin protein fractions.ConclusionBoth TAVI and bAVR markedly reduced WBV, independent of the intervention type. WBV may be a useful biomarker for monitoring hemorheological and protein-based changes following valve intervention.