Among patients with CAD and regional wall thinning, limited scar burden was present in 18% and was strongly associated with improved contractility and resolution of thinning after revascularization.
Observational (n=1,055)
Yes
Does coronary revascularization improve contractility and reverse wall thinning in CAD patients with regional myocardial thinning and limited scar burden?
Regional myocardial wall thinning in CAD patients does not always represent irreversible transmural scar, as 18% have limited scar burden and can experience functional improvement and reversal of thinning after revascularization.
Effect estimate: slope coefficient -0.03 (95% CI -0.04 to -0.02)
p-value: p=<.001
IMPORTANCE: 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. DESIGN, SETTING, AND PATIENTS: 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. MAIN OUTCOMES AND MEASURES: 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 AND RELEVANCE: 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.
Shah et al. (Wed,) conducted a observational in Coronary artery disease (n=1,055). Scar extent within thinned myocardial regions was evaluated on Contractile improvement after revascularization (slope coefficient -0.03, 95% CI -0.04 to -0.02, p=<.001). Among patients with CAD and regional wall thinning, limited scar burden was present in 18% and was strongly associated with improved contractility and resolution of thinning after revascularization.