Ratio of Transmitral Early Filling Velocity to Early Diastolic Strain Rate Predicts All-Cause Mortality in Heart Failure with Reduced Ejection Fraction

Aims: The ratio of early mitral inflow velocity to global diastolic strain rate (E/e'sr) has recently emerged as a novel measure of left ventricular (LV) filling pressure. This new measure has demonstrated to have prognostic value superior to E/e'. This study aimed to investigate the prognostic value of E/e'sr in a large cohort of patients with heart failure with reduced ejection fraction (HFrEF) in relation to all-cause mortality.

Methods: We retrospectively studied 897 HFrEF (mean age 66 ± 12 years, 73% male, 59% ischemic cardiomyopathy) patients who underwent speckle tracking echocardiography where E/e'sr along with novel and conventional echocardiographic parameters were obtained. The primary endpoint was defined as all-cause mortality.

Results: During follow-up (median: 40 months IQR: 22-57), 137 (15.3%) patients died. Both E/e'sr and E/e' were significantly associated with mortality (E/e'sr: HR 1.03 95%CI [1.02-1.04], p<0.001, per 0.10m increase) and (E/e': HR 1.04 95%CI [1.02-1.06], p = 0.001, per 1unit increase). E/e'sr remained an independent predictor in a multivariable model after adjusting for age, gender, mean arterial pressure, heart rate, BMI, total cholesterol, diabetes mellitus, ischemic cardiomyopathy, LVEF, LVIDd, LVMI, LAVI, TAPSE and LV-GLS (HR 1.02 95%CI [1.01-1.03], p = 0.007) whereas E/e' did not (HR 1.01 95%CI [0.98-1.04], p = 0.57). Furthermore, E/e'sr provided incremental prognostic information beyond a model including known risk factors: age, gender, total cholesterol, mean arterial pressure, heart rate, BMI, smoking status and E/e' (Harrell's C-statistics: 0.72 (0.68-0.77) vs 0.70 (0.66-0.75), p = 0.047).

Conclusions: In HFrEF patients, E/e'sr provides independent and incremental prognostic information regarding all-cause mortality superior to E/e'.