Background: There is scant information on the prevalence and factors associated with preoperative anemia in patients undergoing transcatheter aortic valve implantation (TAVI) and whether it is associated with mortality. We sought to determine the prevalence and factors associated with preoperative anemia in addition to the prognostic effects of the various levels of preoperative hemoglobin level on mortality in patients undergoing TAVI.
Methods and results: Ten-center observational study encompassing 1696 patients with aortic stenosis who underwent TAVI was conducted. Anemia was defined by the World Health Organization criteria (hemoglobin <12.0 g/dL in women and <13.0 g/dL in men). The prevalence of preoperative anemia was 57%. Patient-related factors associated with preoperative anemia were (descending order of odds ratio [95% confidence interval]) as follows: anemia-related medication (4.90 [3.08-7.80]), history of heart failure (1.77 [1.43-2.20]), male sex (1.69 [1.32-2.16]), mitral regurgitation grade ≥III (1.61 [1.15-2.25]), history of malignancy (1.44 [1.03-2.09]), and peripheral vascular disease (1.33 [1.04-1.70]). The creatinine clearance was inversely associated with preoperative anemia (odds ratio, 0.92 [0.87-0.97]). In multivariable analyses, preoperative anemia was not associated with 30-day mortality (1.72 [0.96-3.12]; P=0.073) but showed the strongest association with 1-year mortality with a hazard ratio (95% confidence interval) of 2.78 (1.60-4.82) in patients with hemoglobin <10 g/dL. Patients with anemia received ≥1 blood transfusion 2× more often, but the indication of transfusion was unrelated to overt bleeding in 60%. Blood transfusion was associated with mortality at 30 days (odds ratio, 1.25 [95% confidence interval, 1.08-3.67]) and during follow-up (hazard ratio, 1.09 [95% confidence interval, 1.03-1.14]).
Conclusions: Preoperative anemia is prevalent in >50% of patients undergoing TAVI. Various baseline factors were related to anemia, which in turn was associated with 1-year mortality. Patients with anemia received more transfusions but mostly for indications unrelated to overt bleeding, whereas transfusion was independently associated with both early and 1-year mortality. These findings indicate that optimization of baseline factors related to preoperative anemia, in addition to more strict criteria of the use of blood products, may improve outcome after TAVI.
Keywords: anemia; blood transfusion; hemoglobin.