Normalization of ejection fraction in subjects with systolic heart failure. Is it really normal? A myocardial deformation study

Abstract

Left ventricular ejection fraction (LVEF) has been the main parameter used to guide pharmacological and device based treatment for systolic heart failure (SHF). With advancement of medical treatment for SHF, normalisation of LVEF is not infrequently seen [ 1 Binkley P.F. Lesinski A. Ferguson J.P. et al. Recovery of normal ventricular function in patients with dilated cardiomyopathy: predictors of an increasingly prevalent clinical event. Am Heart J. 2008 Jan; 155: 69-74 Google Scholar , 2 Cicoira M. Zanolla L. Latina L. et al. Frequency, prognosis and predictors of improvement of systolic left ventricular function in patients with ‘classical’ clinical diagnosis of idiopathic dilated cardiomyopathy. Eur J Heart Fail. 2001 Jun; 3: 323-330 Google Scholar , 3 Murphy N.F. O'Loughlin C. Ledwidge M. McCaffrey D. McDonald K. Improvement but no cure of left ventricular systolic dysfunction in treated heart failure patients. Eur J Heart Fail. 2007 Dec; 9: 1196-1204 Google Scholar ]. As normalised LVEF may occur even in the presence of histological irreversible myocyte damage [ [4] Dec Jr., G.W. Fallon J.T. Southern J.F. Palacios I.F. Relation between histological findings on early repeat right ventricular biopsy and ventricular function in patients with myocarditis. Br Heart J. 1988 Oct; 60: 332-337 Google Scholar ], it remains unclear if heart failure medications can be safely reduced or even ceased in these patients. However, whilst LVEF is typically used for assessment of global ventricular function it is not a sensitive measure of left ventricular (LV) systolic function. Direct measurement of myocardial contraction with strain and strain rate enables quantification of the amount and rate of myocardial deformation and is seen as a more sensitive marker of myocardial systolic function [ [5] Thomas J.D. Popovic Z.B. Assessment of left ventricular function by cardiac ultrasound. J Am Coll Cardiol. 2006 Nov 21; 48: 2012-2025 Google Scholar ]. Systolic strain is expressed as the percentage change in myocardial deformation during systole. Segmental shortening is represented by negative strain (longitudinal and circumferential) and segmental thickening by positive strain (radial strain). Strain rate measures the rate of segmental deformation over time. In this study we aimed to investigate for the presence of abnormal myocardial deformation with speckle tracking echocardiography in patients with systolic heart failure who had normalised their LV ejection fraction.