title: 31P magnetic resonance spectroscopy in dilated cardiomyopathy and coronary artery disease. Altered cardiac high-energy phosphate metabolism in heart failure.
abstract: BACKGROUND
  The purpose of this work was to further define the value of cardiac 31P magnetic resonance (MR) spectroscopy for patients with coronary artery disease and dilated cardiomyopathy.
  
  
  RESULTS
  Blood-corrected and T1-corrected 31P MR spectra of anteroseptal myocardium were obtained at rest using image-selected in vivo spectroscopy localization, a selected volume of 85 +/- 12 cm3, and a field strength of 1.5 T. Nineteen volunteers had a creatine phosphate (CP)/ATP ratio of 1.95 +/- 0.45 (mean +/- SD) and a PDE/ATP ratio of 1.06 +/- 0.53; in four patients with left anterior descending coronary artery (LAD) stenosis, six patients with chronic anterior wall infarction, and four patients with chronic posterior wall infarction, CP/ATP and phosphodiester (PDE)/ATP ratios did not differ from those in volunteers. Twenty-five measurements of 19 patients with dilated cardiomyopathy yielded a CP/ATP of 1.78 +/- 0.51 and a PDE/ATP of 0.98 +/- 0.56 (p = NS versus volunteers). When these patients were grouped according to the severity of heart failure, however, CP/ATP was 1.94 +/- 0.43 in mild (p = NS versus volunteers) and 1.44 +/- 0.52 in severe DCM (p < 0.05), respectively. No correlation was found between CP/ATP and left ventricular ejection fraction or fractional shortening, but correlation of CP/ATP with the New York Heart Association (NYHA) class was significant (r = 0.60, p < 0.005). Six patients with dilated cardiomyopathy were studied repeatedly before and after 12 +/- 6 weeks of drug treatment leading to clinical recompensation with improvement of the NYHA status by 0.8 +/- 0.3 classes. Concomitantly, CP/ATP increased from 1.51 +/- 0.32 to 2.15 +/- 0.27 (p < 0.01), whereas PDE/ATP did not change significantly.
  
  
  CONCLUSIONS
  Cardiac high-energy phosphate metabolism at rest is normal in LAD stenosis and chronic myocardial infarction in the absence of heart failure. The CP/ATP ratio has low specificity for the diagnosis of dilated cardiomyopathy. However, CP/ATP correlated with the clinical severity of heart failure and may improve during clinical recompensation.
authors.affiliation: Department of Medicine, Würzburg University, FRG.
authors.forename: S
authors.initials: S
authors.lastname: Neubauer
authors.forename: T
authors.initials: T
authors.lastname: Krahe
authors.forename: R
authors.initials: R
authors.lastname: Schindler
authors.forename: M
authors.initials: M
authors.lastname: Horn
authors.forename: H
authors.initials: H
authors.lastname: Hillenbrand
authors.forename: C
authors.initials: C
authors.lastname: Entzeroth
authors.forename: H
authors.initials: H
authors.lastname: Mader
authors.forename: E P
authors.initials: EP
authors.lastname: Kromer
authors.forename: G A
authors.initials: GA
authors.lastname: Riegger
authors.forename: K
authors.initials: K
authors.lastname: Lackner
mesh_terms: D000328:Adult; D000368:Aged; D002303:Cardiac Output, Low / Q000378:metabolism*; D002311:Cardiomyopathy, Dilated / Q000175:diagnosis* / Q000378:metabolism; D003327:Coronary Disease / Q000175:diagnosis* / Q000378:metabolism; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D010710:Phosphates / Q000378:metabolism; D010758:Phosphorus; D012016:Reference Values
chemical_list: D010710:Phosphates; D010758:Phosphorus