Impact of Significant Hemoglobin Drop Without Bleeding in Patients Undergoing Transcatheter Aortic Valve Replacement

BACKGROUND: Hemoglobin (Hgb) drop without bleeding is common among patients undergoing transcatheter aortic valve replacement; however, the clinical implications of significant Hgb drop have not been fully evaluated. METHODS AND RESULTS: Consecutive patients undergoing transcatheter aortic valve replacement at our institution from 2011 to 2021 were retrospectively reviewed. Three groups were assessed: no Hgb drop and no bleed (NoD-NoB [reference group]), Hgb drop with bleed, and Hgb drop and no bleed (D-NoB). Hgb drop was defined as ≥3 g/dL decrease from pre-to post-transcatheter aortic valve replacement. Outcomes of interest were in-hospital death and 1-year all-cause mortality. A total of 1851 cases with complete Hgb data were included: NoD-NoB: n=1579 (85.3%); D-NoB: n=49 (2.6%); Hgb drop with bleed: n=223 (12.6%). Compared with NoD-NoB, the D-NoB group was older (81.1 versus 78.9 years of age) with higher preprocedure Hgb (12.9 versus 11.7 g/dL). In-hospital death rate was higher among patients with D-NoB versus NoD-NoB (4.5% versus 0.8%, P<0.001) and similar to Hgb drop with bleed (4.5% versus 4.1%, P=0.999). Predictors of in-hospital death were D-NoB (odds ratio [OR], 3.45 [95% CI, 1.32–8.69]) and transfusion (OR, 10.6 [95% CI, 4.25–28.2]). Landmark survival analysis found that D-NoB experienced 1-year mortality rate comparable to NoD-NoB, whereas Hgb drop with bleed had higher midterm mortality (hazard ratio [HR], 3.2 [95% CI, 1.83–5.73]), and transfusion continued to impact mortality (HR, 2.5 [95% CI, 1.79–3.63]). CONCLUSIONS: Hgb drop without bleeding is common among patients undergoing transcatheter aortic valve replacement and may represent a higher risk of periprocedural death. Blood transfusion increases short-and midterm mortality risk in patients with and without bleeding, supporting a restrictive transfusion strategy.