International Validation of Metabolic Exercise test data combined with Cardiac and Kidney Indexes (MECKI) Score in Heart Failure

Background: Current European heart failure (HF) Guidelines suggests the use of risk score: among them, the Metabolic Exercise test data combined with Cardiac and Kidney Indexes (MECKI) score has demonstrated to be one of the most accurate. However, the risk scores are still poorly implemented in clinical practice, also due to lack of strong evidence regarding their external validation in different populations. Thus, the current study was designed as an external validation test of the MECKI score in an international multicentre setting. Methods: The study cohort consisted of patients diagnosed with HF with reduced ejection fraction (HFrEF) across international centres (not Italian), retrospectively recruited. Collected data included demographics, HF aetiology, laboratory testing, ECG, echocardiographic findings, cardiopulmonary exercise testing (CPET) results as described in the original MECKI score publication. Results: 1042 patients across 8 international centres (7 European and 1 Asian) were included and followed up from 1998 till 2019. Patients were divided according to the calculated MECKI scores into 3 subgroups: (i) MECKI score <10%; (ii) 10-20%; (iii) ≥20%. Survival analysis comparison among the 3 MECKI score subgroups showed a worse prognosis in patients with higher MECKI score value: median event-free survival times were 4396 days for MECKI score <10%; 3457 days for 10-20%; 1022 days for ≥20% (p<0.0001). ROC curves and the AUC curves were like those reported in the original internal validation studies. Conclusion: In patients diagnosed with HFrEF, the power of the MECKI score was confirmed in terms of prognosis and risk stratification, supporting its implementation as advised by the HF Guidelines.