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.
Academic Article
Overview
abstract
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.
