The Ratio of Mitral Deceleration Time to E-wave Velocity and Mitral Deceleration Slope Outperform Deceleration Time Alone in Predicting Cardiovascular Outcomes: The Strong Heart Study

Abstract

The deceleration time of early mitral inflow (E) is shortened by left ventricular chamber stiffening and prolonged by impaired relaxation. For any given rate of deceleration of early mitral inflow, a higher E-wave velocity (E) is associated with a longer deceleration time. It is not known whether deceleration time normalized for E-velocity or its inverse (deceleration slope) better predicts cardiovascular (CV) events compared with deceleration time or E-velocity alone. We compared the prognostic value of deceleration time, E-velocity, deceleration time/E-velocity, and deceleration slope in 3102 American Indian participants in the Strong Heart Study, free of clinical CV disease and documented atrial fibrillation, in predicting fatal and nonfatal CV events. During a mean of 8.5 +/- 2.4 years, there were 637 fatal and nonfatal CV events. After adjustment for traditional CV risk factors, deceleration time/E-velocity (adjusted hazard ratio [HR], 1.09; 95% confidence interval [CI], 1.00-1.18; P = .04 for every 0.89 msec/[cm/s] [1 + standard deviation {SD}] increase) and deceleration slope (HR, 0.91; 95% CI, 0.82-1.00; P = .01 for every 91 msec [1 + SD] increase) predicted CV events, whereas deceleration time and E-velocity did not. When participants with restrictive-type filling (n = 74) were removed from the analysis, deceleration time/E-velocity (HR, 1.10; 95% CI, 1.01-1.20; P = .03 for every 0.89 msec/[cm/s] [1 + SD] increase) and deceleration slope (HR, 0.64; 95% CI, 0.36-0.91; P = .01 for every 91 msec [1 + SD] increase) predicted CV events even more strongly. In a large population-based sample with high prevalences of hypertension and diabetes, free of prevalent CV disease, deceleration time/E-velocity and deceleration slope predict CV events, whereas their components (deceleration time and E-velocity) do not. This suggests normalization of deceleration time for E-velocity or using its inverse (deceleration slope) more precisely captures prognostically significant prolongation of deceleration than does deceleration time alone.