Heart transplantation is the best option available to treat end-stage Heart Failure (HF). There is a shortage of donor hearts in the United States even with the steady increase in the number of donors. One likely reason is the decreasing transplant wait-list mortality resulting from advancements in bridge-to-transplant (BTT) therapies in HF, which causes the candidates to be more selective of donor hearts offered. This study aims to evaluate the changes in the donor characteristics between two decades (1995--2005 and 2005--2015), separated by dramatic increase in BTT.UNOS deceased-donor data was used for the study and divided into two decades with respect to the donor date (1995--2005 and 2005--2015). Two logistic regression models of donor characteristics were derived for the above two decades and used to decide whether an organ is discarded or not. These two models are compared on the actual donor data for 2005--2015. Model 1 (1995--2005) had 5,840 fewer discards than Model 2 (2005--2015). Organs deemed transplantable from two models were simulated using Thoracic Simulated Allocation Model for organ allocation and acceptance.The transplant rate for Model 1 is significantly higher than the Transplant rate for Model 2 at the high-priority status 1A and is not significantly different in lower priorities 1B and 2. However, there was no statistical difference in the mortality rate between the two models in Status 1A.The better performance of Model 1 over Model 2 in both transplant and mortality rates implies that hearts admissible for transplantation are being discarded. The donor-heart quality preferences of transplant candidates for accepting offers are becoming stricter, and is contributing to the donor-heart shortage in the United States.