Abstract 18541: Prevalence of Systolic Dysfunction Despite Normal or Supernormal Ejection Fraction in African-Americans with Hypertensive Kidney Disease: the AASK study.
Background: Left ventricular hypertrophy (LVH), highly prevalent in pts with chronic renal insufficiency (CRI), is thought to maintain ejection fraction (EF) despite adverse loading conditions. However LVH can be associated with LV myocardial dysfunction (reduced midwall shortening--FSmw) and high cardiovascular risk, despite normal EF. We sought to investigate this discrepancy between EF and FSmw among African-Americans enrolled in AASK a group with high prevalence of concentric LVH--high relative wall thickness (RWT).
Methods: Data from 594 pts (age 60.1±10.1years, 38 % women, GFR 44.2±16 mL/min/1.73 m2) with hypertensive CRI and normal EF were analysed. We repeated the analysis in those with supranormal EF (>75%). Sublinical LV sysunction was defined as FSmw < 14.7% (a prognostically validated partition value).
Results: 220 of 594 pts (37%) had low FSmw. Compared with normal FSmw pts, they had larger LA (4.2±1 vs 3.9±1cm), LV mass (293±81 vs 221±105g) and RWT 0.62±0.7 vs 0.46±0.14; all p<0.001). However (Figure), when limiting the analysis to pts with supranormal EF (n=229) a peculiar cardiac phenotype was found in pts with low FSmw (n=60 or 26%): low tissue Doppler velocity (e′; 8.5±3 cm/s vs 10.3±4cm/s), paired with a higher Doppler E/e′ ratio (8.7±4 vs 7.9±3: both p<0.05), indicative of higher LV filling pressures.
Conclusions: Impaired myocardial systolic dysfunction (low FSmw) is common in African Americans with CRI likely due to the advanced abnormalities in cardiac geometry. Moreover one in four CRI patients with supranormal EF also had low FSmw, as well as associated significant abnormalities in diastolic function, and increased filling pressure. This phenotype highlights the dissociation between myocardial function and EF and argues that FSmw is the preferred systolic function index among hypertensive African-Americans, especially with CRI. In these pts, moreover, diastolic dysfunction and low FSmw appear to be coupled.
- © 2010 by American Heart Association, Inc.