Impact of transfusion of packed red blood cells on mid-term outcomes after transcatheter aortic valve implantation

Purpose: The adverse impact of bleeding and transfusion of packed red blood cells (PRBC) on outcome after PCI is well documented. Same holds true for bleeding and access site complications after TAVI. However, data on the impact of anemia and PRBC transfusions on outcome after TAVI are scarce. We sought to evaluate these aspects in a retrospective single-center analysis. Methods: TAVI was performed in 500 consecutive patients at high risk for surgery employing 1st and 2nd generation devices via transfemoral or transapical access. Outcomes were analysed according to the Valve Academic Research Consortium definitions with emphasis on anemia, PRBC transfusion, and its impact on survival. 12.0% of TAVI patients suffered from major/life-threatening bleeding or access site complications and were excluded from analysis. Median follow-up duration was 351 days. Patients who received PRBC transfusions (PRBC) were compared to those who did not (noPRBC). Results: Overall, 41.8% of patients received PRBC transfusions during the postoperative course after TAVI (19.4% 1-2 PRBC, 12.6% 3-4 PRBC, 9.8% > 4 PRBC), irrespective of access (transapical: 43.4% vs. transfemoral: 40.6%, p=n.s.). Variables at baseline differed significantly between PRBC and noPRBC patients with regard to risk profile (STS-PROM 8.8±6.1% vs. 6.8±4.9%, p=0.020), anemia (84.5% vs. 47.2%, p<0.001), and atrial fibrillation (39.1% vs. 29.6%, p=0.045). The incidence of stage-3 kidney injury (5.1% vs. 0.7%, p<0.001) and major stroke (5.1% vs. 1.1%, p=0.044) was higher in the PRBC group. Survival was impaired in PRBC patients (log-rank p<0.001) and correlated with the number of PRBC transfusions. Adjusted Cox regression identified PRBC transfusion as predictor of 30-day (HR 4.7, 95% CI 1.6-13.4, p=0.004) and 1-year (HR 1.7, 95% CI 1.1-2.7, p=0.030) mortality. Body-mass-index (HR 0.9, 95% CI 0.9-1.0, p=0.005), atrial fibrillation (HR 1.5, 95% CI 1.0-2.3, p=0.048), estimated GFR (HR 0.99, 95% CI 0.98-1.0, p=0.004), baseline hemoglobin (HR 0.9, 95% CI 0.7-1.2, p<0.001), and peripheral vascular disease (HR 1.6, 95% CI 1.1-12.5, p=0.025) were found as predictors for PRBC transfusion. Conclusions: PRBC transfusions were frequently required after TAVI but only in part driven by access site complications and independent of access route. However, patients requiring transfusion of PRBC displayed poorer short- and mid-term outcomes. Anemia at baseline was a strong predictor for transfusion, underscoring the need for valid risk stratification tools to identify patients at risk for transfusion during the preprocedural assessment before TAVI.