MECKI score thresholds for heart transplantation referral of ambulatory heart failure patients

Introduction In heart failure (HF) patients, guidelines recommend scores for assessing outcomes and heart transplant (HTX) eligibility. However, scores use remains limited and cut-off values for HTX listing not well established. Among the available tools, MECKI score is easy to calculate and likely offers the best prognostic accuracy. Compare MECKI score-based survival with that of HTX recipients and identify a MECKI threshold above which survival is inferior to that of HTX recipients at 5-year. Methods Consecutive ambulatory HF patients enrolled in MECKI score programme between January 2010 and January 2022 were evaluated. Primary endpoint was a composite of cardiovascular death, HTX, or left ventricular assist device implantation. Heart transplant survival data were obtained from the International Society of Heart and Lung Transplantation registry up-dated through 2023. To identify the MECKI score threshold beyond which prognosis is worse than that of HTX recipients, patients were stratified by deciles of MECKI score. Results We analysed 3865 HF patients (mean age 62.4 ± 12.6 years). Peak VO₂ was 58.2 ± 18.3% predicted; VE/VCO₂ slope 33.2 ± 8.2, haemoglobin 13.5 ± 1.7 g/dL, Na⁺ 139 ± 3 mmol/L, LVEF 33.7 ± 10.4%, and eGFR 73 ± 26 mL/min/1.73 m². Periodic breathing occurred in 15.8% of patients. At 5 years, mean survival was 83.7%. The average 5-year survival of HTX recipients (71.2%) lies between the eighth and ninth MECKI score deciles suggesting a MECKI score value ≥0.1368 as the proper cut-off for HTX listing. Conclusion MECKI score ≥0.1368 may warrant HTX listing, while lower scores support clinical deferral.