A novel predictor of clinical outcomes in patients with heart failure with preserved left-ventricular ejection fraction: a pilot study

Predictors of outcomes in patients with heart failure with preserved left-ventricular ejection fraction (HFpEF) remain unclear. The ratio of early diastolic transmitral flow velocity to early diastolic myocardial velocity (E/e′) has been proposed, but the predictive accuracy remains unsatisfactory. We hypothesized that E/e′ normalized by the stroke volume (SV), E/e′/SV, could be a good predictor of outcome in HFpEF patients by reflecting the terminal slope of the end-diastolic pressure–volume relation, i.e., stiffness of the left ventricle. This pilot study was conducted to propose a novel echocardiographic index for predicting the outcomes of patients with HFpEF. Echocardiography including E/e′/SV measurement was performed in consecutive 80 HFpEF patients at discharge in index hospitalization due to HF. The end points included the readmission for heart failure and cardiovascular death at 1 year after discharge. 19 patients (24%) met the end points. Receiver-operating characteristic analysis showed that E/e′′/SV was a strong predictive factor (AUC = 0.78) compared to E/e′ (AUC = 0.74). Kaplan–Meier analysis showed that patients with E/e′/SV > 0.40 had a poorer prognosis than those with E/e′/SV < 0.40 (p < 0.01). By Cox regression multi-variate analysis, a high E/e′/SV was an independent predictor of event-free survival [adjusted hazard ratio (95% CI) 14.26 (3.18, 63.93) (p = 0.01)]. E/e′/SV has potential to predict clinical outcomes in patients with HFpEF.