Introduction
It has been estimated that there are at least 23 million people with heart failure (HF), making it one the most common cardiovascular disorders in the contemporary age [1]. Despite the advances in the screening, diagnosis and management of HF; mortality rates remain high, with a rate of 121 per 1000 patient years for patients with preserved ejection fraction (HFpEF) and 141 per 1000 patients for patients with a reduced ejection fraction (HFrEF) [2]. While clinical judgement and individual parameters are commonly employed for prognostication, multiple risk models are also available to estimate mortality and to guide management decisions [3-7]. A common issue with these risk models is that they generally suffer from “overfitting” of multiple redundant variables that are not useful in estimating prognosis in other HF cohorts where mortality rate is different from the original derivation cohort [8]. Moreover, the necessity of using numerous (and sometimes laborious to obtain) variables to calculate a single risk score for each HF patient usually renders these scores impractical for clinical use in a busy clinic. Age, creatinine and ejection fraction (ACEF) score was initially developed to predict postoperative mortality after cardiovascular surgery, while keeping the “law of parsimony” in mind [8]. However, later studies have found the ACEF score or its simple modifications - such as the ACEF-MDRD score - were useful to predict mortality or complications following percutaneous coronary or structural interventions, as well as those who had acute coronary syndromes [9-12]. Individual variables used to calculate ACEF score have already been shown as predictors of hospitalizations and mortality in patients with HF, and it is reasonable to consider that a score calculated using these variables would have better usefulness to predict mortality in HF [13-16]. In the present analysis, we sought to investigate whether ACEF-MDRD score could predict one-year mortality in HF patients, and to understand how ACEF-MDRD score compares to other established but more complex models, such as the Get With The Guidelines - Heart Failure (GWTG-HF) score.