Persistent Risk of Severe Covid-19 in Heart Transplant Recipients: A National Cohort Study

PURPOSE: Vaccination and therapeutic monoclonal antibodies (mAb) provide high protection against severe forms of SARS-CoV-2 infection (COVID-19) in the general population. In France, vaccination campaign started on December 2020 and the first mAb was approved on August 2021. This national cohort study aimed to evaluate the persistent risk of hospitalization and death in heart transplant (HT) recipients who develop COVID-19. METHODS: All HT recipients entered into the national registry CRISTAL between January 2020 and December 2021 were included in this study. Incidence rates of COVID-19 during the years 2020 and 2021 were calculated. Outcomes were intensive care unit (ICU) admission and case fatality rate in COVID-19 patients. Association of clinical characteristics, laboratory data, immunosuppressive regimen and year of infection with outcomes was assessed using multivariable logistic model. RESULTS: Among 5 898 HT recipients, 647 (195 aged ≥65 years, 170 females, 176 with coronary artery disease as HT indication, 68 with BMI >30 Kg/m², 228 with time since HT >10 years, 332 with glomerular filtration rate (GFR) <60 mL/min/m(²), 426 with calcineurin inhibitor-based, 175 mTOR inhibitor-based and 7 belatacept-based immunosuppression) developed COVID-19. COVID-19 incidence rate was 4.98 [4.37; 5.59] and 7.61 [6.86; 8.37] per 100 person-years in 2020 and 2021, respectively. ICU admission and case fatality rates were 8.4% vs 10.2% and 13.0% vs 14.1%, in 2021 vs 2020 respectively. Age, coronary artery disease as HT indication, time since HT, GFR <60 mL/min/m(²) and belatacept-based or mTOR inhibitor-based immunosuppression were associated with case fatality rate while year of infection was not (Figure). CONCLUSION: While incidence rate of COVID-19 increased in 2021 compared to 2020 in HT recipients in France, the risk of ICU hospitalization and death did not decrease. Our findings highlight the reduced efficacy of mAb and vaccination in this population and the need for new prophylactic treatments.