title: Iron overload in polytransfused patients without heart failure is associated with subclinical alterations of systolic left ventricular function using cardiovascular magnetic resonance tagging.
abstract: BACKGROUND
  It remains incompletely understood whether patients with transfusion related cardiac iron overload without signs of heart failure exhibit already subclinical alterations of systolic left ventricular (LV) dysfunction. Therefore we performed a comprehensive evaluation of systolic and diastolic cardiac function in such patients using tagged and phase-contrast CMR.
  
  
  METHODS
  19 patients requiring regular blood transfusions for chronic anemia and 8 healthy volunteers were investigated using cine, tagged, and phase-contrast and T2* CMR. LV ejection fraction, peak filling rate, end-systolic global midventricular systolic Eulerian radial thickening and shortening strains as well as left ventricular rotation and twist, mitral E and A wave velocity, and tissue e' wave and E/e' wave velocity ratio, as well as isovolumic relaxation time and E wave deceleration time were computed and compared to cardiac T2*.
  
  
  RESULTS
  Patients without significant iron overload (T2* > 20 ms, n = 9) had similar parameters of systolic and diastolic function as normal controls, whereas patients with severe iron overload (T2* < 10 ms, n = 5), had significant reduction of LV ejection fraction (54 ± 2% vs. 62 ± 6% and 65 ± 6% respectively p < 0.05), of end-systolic radial thickening (+6 ± 4% vs. +11 ± 2 and +11 ± 4% respectively p < 0.05) and of rotational twist (1.6 ± 0.2 degrees vs. 3.0 ± 1.2 and 3.5 ± 0.7 degrees respectively, p < 0.05) than patients without iron overload (T2* > 20 ms) or normal controls. Patients with moderate iron overload (T2* 10-20 ms, n = 5), had preserved ejection fraction (59 ± 6%, p = NS vs. pts. with T2* > 20 ms and controls), but showed reduced maximal LV rotational twist (1.8 ± 0.4 degrees). The magnitude of reduction of LV twist (r = 0.64, p < 0.001), of LV ejection fraction (r = 0.44, p < 0.001), of peak radial thickening (r = 0.58, p < 0.001) and of systolic (r = 0.50, p < 0.05) and diastolic twist and untwist rate (r = -0.53, p < 0.001) in patients were directly correlated to the logarithm of cardiac T2*.
  
  
  CONCLUSIONS
  Multiple transfused patients with normal ejection fraction and without heart failure have subclinical alterations of systolic and diastolic LV function in direct relation to the severity of cardiac iron overload. Among all parameters, left ventricular twist is affected earliest, and has the highest correlation to log (T2*), suggesting that this parameter might be used to follow systolic left ventricular function in patients with iron overload.
authors.affiliation: Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Cliniques Universitaires St-Luc and Université Catholique de Louvain, Brussels, Belgium.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Seldrum
authors.forename: Sophie
authors.initials: S
authors.lastname: Pierard
authors.forename: Stéphane
authors.initials: S
authors.lastname: Moniotte
authors.forename: Christiane
authors.initials: C
authors.lastname: Vermeylen
authors.forename: David
authors.initials: D
authors.lastname: Vancraeynest
authors.forename: Agnès
authors.initials: A
authors.lastname: Pasquet
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Vanoverschelde
authors.forename: Bernhard L
authors.initials: BL
authors.lastname: Gerber
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D000740:Anemia / Q000097:blood / Q000628:therapy*; D058070:Asymptomatic Diseases; D001530:Belgium; D016022:Case-Control Studies; D002648:Child; D003971:Diastole; D005260:Female; D006801:Humans; D007502:Iron Chelating Agents / Q000627:therapeutic use; D019190:Iron Overload / Q000097:blood / Q000188:drug therapy / Q000209:etiology*; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013318:Stroke Volume; D013599:Systole; D054159:Torsion, Mechanical; D065227:Transfusion Reaction; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D016277:Ventricular Function, Left; D055815:Young Adult
chemical_list: D007502:Iron Chelating Agents