Abstract 11730: A New Index to Characterize Asymptomatic Patients with Essential Hypertension, a Wave to Mitral Flow Propagation Velocity Ratio
Introduction: Changes of peak flow velocity during atrial contraction (A wave) are known to be related with diastolic abnormalities in left ventricular hypertrophy (LVH). Mitral flow propagation velocity (Vp) represents a non-invasive index for assessing LV relaxation. Whether the A/Vp ratio could be useful to characterize asymptomatic patients with essential hypertension (HT) remains unknown.
Methods: We have studied 270 patients without arrhythmia or heart failure, age 60±13, diagnosed with HT. NT-proBNP (pg/ml) was determined. Vp (cm/s) and A wave (cm/s) were calculated. We also measured systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), E/A, left atrial size (LAS, mm), deceleration time (DT, ms), IVRT (ms), ejection fraction (EF), body mass index (BMI) and left ventricular mass index (LVMI).
Results: For the whole population NT-proBNP levels were 147±266, A/Vp 1.8±0.85, SBP 148±20, DBP 87±11, PP 61±18, A wave 78±21, E/A 0.9±0.25, Vp 48±11, LAS 33.7±0.42, DT 200±38, IVRT 95±7, E/Vp 1.5±0.55, EF 59±5 and LVMI 52.4±17. Interobserver variability (IV) for A/Vp was 6.2±6%. When we correlated A/Vp with LVMI and with NT-proBNP, we found for both r=0.6, p<0.0001. When we correlated A/Vp with E/A, DT, IVRT, LAS and E/Vp we found p<0.0001. When we divided A/Vp in quartiles (1.0±0.14, 1.4±0.12, 1.9±0.15, 2.9±0.86) and we compared with the correspondent LVMI values (42±8, 47±14, 54±14, 66±19), we found p<0.0001. The ROC curve of A/Vp for detection of LV hypertrophy (LVH) yielded an AUC of 0.80±0.03 (p<0.0001). From the ROC of A/Vp, the optimal cut-off value (1.71) had a specificity and sensitivity of 83% and 61% for detection of LVH higher than any other diastolic function parameter. Furthermore, multivariate linear regression was performed using LVMI as dependent variable. When the multivariate model was applied, BMI (p<0.0001), NT-proBNP (p<0.0001), A/Vp (p<0.0001), age (p<0.05) and known hypertension duration (p<0.05) were independent predictors of LVMI (r²=0.72, p<0.0001).
Conclusions: In conclusion, A/Vp is significantly correlated with left ventricular mass index and all diastolic parameters in HT. A/Vp is the best echo-Doppler diagnostic and predictor factor of LVH in asymptomatic patients with HT.
- © 2011 by American Heart Association, Inc.