Comparative analysis of four scores to stratify patients with heart failure and reduced ejection fraction

There are several prognostic risk scores available for patients with heart failure with reduced ejection fraction (HFrEF) that can aid in the decision of listing candidates for heart transplant (HTx). A direct comparison between these scores has not been performed. Therefore, our objective was to evaluate the calibration and discriminative power of 4 contemporary HF scores. A retrospective analysis of 259 patients with HFrEF who underwent cardiopulmonary exercise test was conducted. The Heart Failure Survival Score (HFSS), Seattle Heart Failure Model (SHFM), Meta-analysis Global Group in Chronic Heart Failure (MAGGIC), and Metabolic Exercise Cardiac Kidney Index (MECKI) were compared. During the first year, 7 deaths occurred (6 cardiovascular) and 25 patients were submitted to HTx (8 urgent). Over a 2-year period, 14 deaths occurred (10 cardiovascular) and 34 patients received an HTx (8 urgent). Calibration analysis showed that SHFM and HFSS tended to underestimate event occurrence, whereas MAGGIC and MECKI tended to overestimate risk, especially in the highest risk subgroups. Interestingly, MECKI score at 1 year was well calibrated (expected similar to observed events). Overall, the MECKI score consistently showed better discrimination ability for all studied end points (areas under the curve between 0.8 and 0.9). In conclusion, along with HFSS and SHFM, the MECKI score can also be used to aid treatment decisions, such as HTx listing with the advantage of being very well calibrated at 1-year intervals, which might allow us to avoid the pitfalls of under/overestimation of risk.