Abstract 15466: Echo Assessment of Ventricular Stiffness Based on Epicardial Movement: Insights from Analysis of Changes after Antihypertensive Treatment in the Untreated Hypertensive Patients
Background: Left ventricular (LV) epicardial movement reflects LV stiffness, and its M-mode echo quantitation is likely to provide an estimate of LV stiffness. Specifically, diastolic wall strain (DWS), determined as (LV posterior wall thickness at end-systole - LV posterior wall thickness at end-diastole)/ (LV posterior wall thickness at end-systole), was proposed as an estimate of LV stiffness. Objectives: We attempted to explore changes in LV stiffness with DWS, following antihypertensive medication in hypertensive patients, and to correlate the change in DWS to those in serum markers of collagen turnover.
Methods: We enrolled 44 untreated hypertensives without LV systolic dysfunction. They were randomly assigned to one of the followings: calcium channel blocker (CCB; amlodipine) group (n=22) or angiotensin II type1 receptor blocker (ARB; losartan) group (n=22). Target blood pressure was less than140/90mmHg, and if blood pressure reduction was not achieved, alpha blocker and/or diuretics were added. DWS was measured before and after antihypertensive treatment for 6 months along with peak early diastolic mitral annular velocity (E'), and serum procollagene type I C- terminal peptides (P1CP) and matrix metalloproteinase 2 (MMP2) levels that reflect production and degradation of collagen, respectively.
Results: Regression of LV hypertrophy was comparable in both groups. There was no significant improvement in diastolic parameters such as E' and DWS, or serum collagen turnover markers in CCB group. On the other hand, both E' and DWS increased in ARB group (6.8±1.6 vs. 5.9±1.3, p<0.01, 0.37±0.07 vs. 0.33±0.05, p<0.05, respectively), however there was no significant correlation between changes in DWS and changes in E' (r=0.23, p=0.33). The changes in DWS were associated with increases in MMP2 (856±144 vs. 782±122, p<0.05), but not with changes in P1CP. There was a significant correlation between changes in DWS and in MMP2 in ARB group (r= 0.55, p=0.01) but not E'.
Conclusions: ARB administration but not CCB improved DWS along with a facilitation of collagen degradation as assessed with serum MMP2. Increased DWS may reflect LV fibrosis but not hypertrophy in hypertensive patients. DWS and collagen turnover may provide a new insight into LV stiffness.
- © 2010 by American Heart Association, Inc.