The 3A3B score: The simple risk score for heart failure with preserved ejection fraction - A report from the CHART-2 Study

Abstract Background Few simple risk models, without echocardiography have been developed for patients with heart failure (HF) and preserved left ventricular ejection fraction (LVEF) (HFpEF). Methods To develop a risk score to predict all-cause death for HFpEF patients, we examined 1277 HF patients with LVEF ≥50% and BNP >100 pg/ml in the CHART-2 Study, a large-scale prospective cohort study for HF in Japan. We selected the optimal subset of covariates for the score with Cox proportional hazard models and random survival forests (RSF). Results During the median 5.7-year follow-up, 576 deaths occurred. Cox models and RSF analyses consistently indicated age ≥75 years, anemia, albumin 2 , and BNP ≥300 pg/ml (or NT-proBNP ≥1400 pg/ml), as the important 6 prognostic variables. Incorporating these 6 variables, we developed a scoring system (3A3B score, with 2 points given to age ≥75 years and 1 point to other items based on the beta coefficients. The discrimination ability of the risk score was excellent (c-index 0.708). Regarding model goodness-of-fit, the overall gradient in 5-year risk was well captured by the score. The predictive accuracy of the 3A3B score was confirmed in the external validation cohorts from the TOPCAT trial (N = 835, c-index 0.652) and the ASIAN-HF registry (N = 170, c-index 0.741). Conclusions We developed a simple risk score to predict long-term prognosis of HFpEF patients in the CHART-2 Study. The 3A3B score, comprising 6 commonly available parameters in daily practice, is simple to use, and has high discriminatory capacity, potential utility in the risk stratification and management of HFpEF patients.