Abstract 2438: Reduced Left Ventricular Maximal Change Rate Of Normalized Wall Stress In Heart Failure
BACKGROUND: We recently reported a new left ventricular (LV) contractility index, dS*/dtmax, based on the maximum rate of change of pressure-normalized wall stress. dS*/dtmax is a function of the ratio of peak LV outflow and myocardial volume. It represents the capacity of LV to develop wall stress sufficient to generate pressure and kinetic energy to eject blood from the LV.
PURPOSE: We aimed to evaluate dS*/dtmax for assessment of LV performance in heart failure with normal and reduced ejection fractions (HFNEF and HFREF, respectively) compared to normal subjects.
METHODS: We performed echocardiography in 3 age- and sex-matched groups (Group 1: healthy controls; Group 2: HFNEF; Group 3: HFREF; each n=26). We measured LVEF, Doppler and tissue Doppler (early diastolic myocardial velocity, E’) indices. Patients with significant heart valve disease were excluded. dS*/dtmax was calculated as 1.5(Vmax)A/Vm [Vmax, LV outflow tract velocity; A, aortic valve area; Vm, LV myocardial volume, quotient of LV mass (from M-mode echo) and density (assumed 1.05g/ml)].
RESULTS: ANOVA revealed significantly different dS*/dtmax among all groups (table⇓). Multiple logistic regression analysis showed dS*/dtmax to be the most significant predictor of HFNEF and HFREF among all variables. On ROC analysis, dS*/dtmax cutoff values of 3.2s-1 and 2.3s-1 were able to predict HFNEF (sensitivity 0.81, specificity 0.81, AUC 0.84) and HFREF (sensitivity 0.85, specificity 0.85, AUC 0.88), respectively.
CONCLUSION: dS*/dtmax is superior to other Doppler parameters for diagnosis of HFNEF and HFREF. In heart failure, dS*/dtmax may enhance diagnostic precision, hence aiding triage and management. Echocardiographic measurements and dS*/dtmax in normals and heart failure