title: Prevalence of regional myocardial thinning and relationship with myocardial scarring in patients with coronary artery disease.
abstract: OBJECTIVE
  Regional left ventricular (LV) wall thinning is believed to represent chronic transmural myocardial infarction and scar tissue. However, recent case reports using delayed-enhancement cardiovascular magnetic resonance (CMR) imaging raise the possibility that thinning may occur with little or no scarring.
  
  
  OBJECTIVE
  To evaluate patients with regional myocardial wall thinning and to determine scar burden and potential for functional improvement.
  
  
  METHODS
  Investigator-initiated, prospective, 3-center study conducted from August 2000 through January 2008 in 3 parts to determine (1) in patients with known coronary artery disease (CAD) undergoing CMR viability assessment, the prevalence of regional wall thinning (end-diastolic wall thickness ≤5.5 mm), (2) in patients with thinning, the presence and extent of scar burden, and (3) in patients with thinning undergoing coronary revascularization, any changes in myocardial morphology and contractility.
  
  
  METHODS
  Scar burden in thinned regions assessed using delayed-enhancement CMR and changes in myocardial morphology and function assessed using cine-CMR after revascularization.
  
  
  RESULTS
  Of 1055 consecutive patients with CAD screened, 201 (19% [95% CI, 17% to 21%]) had regional wall thinning. Wall thinning spanned a mean of 34% (95% CI, 32% to 37% [SD, 15%]) of LV surface area. Within these regions, the extent of scarring was 72% (95% CI, 69% to 76% [SD, 25%]); however, 18% (95% CI, 13% to 24%) of thinned regions had limited scar burden (≤50% of total extent). Among patients with thinning undergoing revascularization and follow-up cine-CMR (n = 42), scar extent within the thinned region was inversely related to regional (r = -0.72, P < .001) and global (r = -0.53, P < .001) contractile improvement. End-diastolic wall thickness in thinned regions with limited scar burden increased from 4.4 mm (95% CI, 4.1 to 4.7) to 7.5 mm (95% CI, 6.9 to 8.1) after revascularization (P < .001), resulting in resolution of wall thinning. On multivariable analysis, scar extent had the strongest association with contractile improvement (slope coefficient, -0.03 [95% CI, -0.04 to -0.02]; P < .001) and reversal of thinning (slope coefficient, -0.05 [95% CI, -0.06 to -0.04]; P < .001).
  
  
  CONCLUSIONS
  Among patients with CAD referred for CMR and found to have regional wall thinning, limited scar burden was present in 18% and was associated with improved contractility and resolution of wall thinning after revascularization. These findings, which are not consistent with common assumptions, warrant further investigation.
authors: Duke Cardiovascular MRI Center, DUMC 3934, Durham, NC 27710, USA.
authors: Dipan J
authors: DJ
authors: Shah
authors: Han W
authors: HW
authors: Kim
authors: Olga
authors: O
authors: James
authors: Michele
authors: M
authors: Parker
authors: Edwin
authors: E
authors: Wu
authors: Robert O
authors: RO
authors: Bonow
authors: Robert M
authors: RM
authors: Judd
authors: Raymond J
authors: RJ
authors: Kim
mesh_terms: D000368:Aged; D002921:Cicatrix / Q000473:pathology*; D003324:Coronary Artery Disease / Q000473:pathology* / Q000601:surgery; D003971:Diastole; D005260:Female; D006352:Heart Ventricles / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000473:pathology; D009204:Myocardial Revascularization; D015995:Prevalence; D011446:Prospective Studies; D020127:Recovery of Function