Background: The number of sensitized heart failure (HF) patients on waiting lists for heart transplantation (HTx) is increasing. We investigated the prevalence and clinical impact of calculated panel-reactive antibody (cPRA) in patients undergoing HTx using the Korean Organ Transplantation Registry (KOTRY), a nation-wide multicenter database. Methods: We retrospectively reviewed 813 patients who underwent HTx between 2014 and 2021. Patients were grouped according to peak PRA level as group A, patients with cPRA <10% (n=492); group B, patients with cPRA ≥10% & <50% (n=160); group C, patients with cPRA ≥50% (n=161). Post-HTx outcomes were freedom from antibody-mediated rejection (AMR), any treated rejection, acute cellular rejection, coronary allograft vasculopathy, and all-cause mortality. Results: The median follow up duration was 44 months (range,19–72). Female sex, retransplantation, and pre-HTx renal replacement therapy were independently associated with increased risk of sensitization (cPRA ≥50%). Group C patients were more likely to have longer hospital stay and to use anti-thymocyte globulin as an induction agent compared to groups B and C. Significantly more patients in group C had positive flow-cytometric crossmatch, and had higher incidence of preformed donor-specific antibody compared to groups A and B. During follow-up, group C had significantly lower rates of freedom from AMR, but the overall survival rate was comparable with those of groups A and B. Conclusions: Patients with cPRA ≥50% had significantly higher incidence of preformed DSA and lower freedom from AMR but post-HTx survival rates were similar to those with cPRA <50%.