Incidence and risk factors of hemolysis after transcatheter aortic valve implantation with a balloon-expandable valve

Abstract

There are currently no data evaluating the hematologic and biocompatibility profile of transcatheter aortic valves in vivo. We evaluated the incidence, predictive factors, and clinical consequences associated with hemolysis post-transcatheter aortic valve implantation (TAVI). A total of 122 patients who underwent TAVI with a balloon-expandable valve were included. Baseline blood sampling and echocardiography, followed by early post-TAVI echocardiography and repeat blood sampling, at 6 to 12 months post-TAVI were performed. Hemolysis post-TAVI was defined according to the established criteria. The incidence of hemolysis post-TAVI was 14.8% yet no patient experienced severe hemolytic anemia requiring transfusion. Compared with the nonhemolysis group, those with hemolysis demonstrated significant reductions in hemoglobin (p = 0.012), were more frequently women (67% vs 34%, p = 0.016), and had a higher incidence of post-TAVI severe prosthesis-patient mismatch (PPM) (44% vs 17%, p = 0.026). The rate of mild or more prosthetic valve regurgitation did not significantly differ between those patients with and without hemolysis (56% vs 37%, p = 0.44). Wall shear rate (WSR) and energy loss index (ELI), both indirect measures of shear stress, were higher (p = 0.039) and lower (p = 0.004), respectively, in those patients with hemolysis. Increasing PPM severity was also associated with significant stepwise WSR increments and ELI decrements (p <0.01 for both). In conclusion, subclinical hemolysis occurred in 15% of patients following TAVI. Although prosthetic valve regurgitation had no impact on hemolysis, a novel association between PPM and hemolysis was found, likely driven by higher shear stress as determined by WSR and ELI. These hematologic and biomechanical findings may have long-term clinical implications and could affect future transcatheter aortic valve design.