Loss of Inertia Force of Late-systolic Aortic Flow in Patients with Mid-range Left Ventricular Ejection Fraction Deterioration

Background: The upper limit of cut-off value of left ventricular ejection fraction (LVEF) for classifying heart failure with mid-range deterioration of LVEF (HFmrEF) is unclear. Methods: The cardiac functional parameters of study patients (n = 428, LVEF>&=40%) including inertia force of late systolic aortic flow (IFLAF) which was calculated from the LV pressure and dP/dt relation were obtained using a catheter-tipped micro-manometer. We determined a cut-off value of LVEF to divide the patients into 2 groups where they had different cardiac functional backgrounds. We then searched a predictor of future cardiovascular death or hospitalization for HF in each group. In addition, we determined an appropriate upper limit LVEF level of the HFmrEF based on the predictor using ROC analysis. Results: Significant differences in tau, ±dP/dt, and IFLAF were demonstrated between patients with LVEF <60% and >&=60%. In patients with LVEF <60%, a multivariate Cox proportional-hazards model revealed that a loss of IFLAF was a significant predictor of future events (HR: 0.222, 95%CI: 0.049 to 0.996, P=.049). Furthermore, an LVEF <58% was a surrogate indicator for loss of IFLAF and a time-dependent ROC analysis revealed that the IFLAF could be a strong predictor with a high accuracy among patients with LVEF up to 67%. Conclusion: Maintaining systolic function with the existence of IFLAF may be a key issue for preventing HFpEF.