The Impact of Transfusions on Mortality After Transcatheter or Surgical Aortic Valve Replacement

Background: An increasing body of evidence suggests that packed red blood cell (PRBC) transfusion may be associated with increased morbidity and mortality after transcatheter and surgical aortic valve replacement. It remains unclear whether PRBC transfusion is a surrogate marker or truly an independent risk factor for mortality after aortic valve replacement in different populations. Methods: The Surgical Replacement and Transcatheter Aortic Valve Implantation (SURTAVI) trial randomized 1660 patients with symptomatic, severe aortic stenosis at intermediate risk for operative death to transcatheter aortic valve replacement or surgical aortic valve replacement. Baseline characteristics and outcomes including all-cause and cardiovascular mortality at 30 days and thereafter were compared between participants with and participants without PRBC transfusion. Cox proportional hazards models with time-varying covariates were fitted to estimate the effect of PRBC transfusion on mortality after adjustment for comorbidities and procedural complications. Results: Patients receiving PRBC were older, more commonly female and frail, with more comorbidities. The Society of Thoracic Surgeons Predicted Risk of Mortality baseline score was higher in the transfused group. After adjustment for these differences, PRBC transfusion was associated with mortality at 30 days, but not thereafter. The effect of PRBC on mortality (hazard ratio 1.04; 95% confidence interval, 0.96 to 1.11; P = .304) at 30 days was not independent of procedural complications (hazard ratio 21.04; 95% CI, 7.26 to 60.95; P < .001). Conclusions: Poor health status, procedural complications, PRBC transfusion, and mortality are correlated with each other. Transfusion of PRBC did not independently increase risk for mortality. In this intermediate-risk population, transfusion appears to be a risk marker of chronic conditions and periprocedural complications as opposed to a risk factor for postprocedural mortality. (Clinical trial registration: www.clinicaltrials.gov NCT01586910.)