Early Diastolic Strain Rate in Relation to Systolic and Diastolic Function and Prognosis in Aortic Stenosis

OBJECTIVES: This study examined the impact of early mitral inflow velocity-to-early diastolic strain rate (E/SRe) ratio on long-term outcome after aortic valve replacement (AVR) in aortic stenosis (AS).

BACKGROUND: In AS, increased filling pressures are associated with a poor prognosis and can be estimated using the early diastolic mitral inflow velocity-to-early diastolic velocity of the mitral annulus (E/e') ratio. Recent studies suggest that the E/SRe ratio surpasses the E/e' ratio in estimating outcome.

METHODS: Pre-operative evaluation was performed in 121 patients with severe AS (aortic valve area <1 cm(2)) and left ventricular ejection fraction (LVEF) of >40% who were scheduled for AVR. Patients were divided according to E/SRe median and followed for 5 years. The primary endpoint was overall mortality.

RESULTS: LVEF was lower (53 ± 7% vs. 56 ± 7%, respectively; p = 0.03) and a restrictive filling pattern more common (28% vs. 8%, respectively, p = 0.005) in patients with increased E/SRe ratio. Five-year overall mortality was increased in patients with high E/SRe (40% vs. 15%, respectively; p = 0.007). In univariate Cox regression analysis, E/SRe, age, European System for Cardiac Operative Risk Evaluation (EuroSCORE), LV mass index, left atrial volume index, LVEF, global longitudinal strain, E/e' ratio, and N-terminal pro-B-type natriuretic peptide level were univariate predictors of overall mortality, although when we adjusted for the predefined variables age, history of diabetes mellitus and LVEF, only E/SRe and left atrial volume index remained associated with overall mortality. Even when we included left atrial volume index in the multivariate model, E/SRe was significantly associated with overall mortality (hazard ratio [HR]: 2.2; 95% confidence interval [CI]: 1.1 to 4.4; p < 0.05); additionally, in a model with forward selection, E/SRe was the sole predictor (HR: 2.9; 95% CI: 1.6 to 5.5; p = 0.001. The overall log likelihood chi-square analysis of the predictive power of the multivariate model containing E/SRe was statistically superior to models based on the E/e' ratio.

CONCLUSIONS: Pre-operative E/SRe ratio was significantly associated with long-term post-operative survival and was superior to the E/e' ratio in patients with severe AS undergoing AVR. (Effect of Angiotensin II Receptor Blockers (ARB) on Left Ventricular Reverse Remodelling After Aortic Valve Replacement in Severe Valvular Aortic Stenosis; NCT00294775).