Following reperfused STEMI, normal myocardial segments demonstrating deterioration in wall thickening at 3-month follow-up showed significantly increased extracellular volume expansion compared to segments with preserved function.
Observational (n=50)
No
Does extracellular volume expansion in normal myocardium associate with worsening regional myocardial function after acute STEMI?
Following reperfused STEMI, normal non-infarcted myocardium undergoes subtle extracellular volume expansion at 3 months, which is associated with worsening regional contractile function.
Absolute Event Rate: 1.82% vs -0.1%
p-value: p=<0.05
BACKGROUND: Expansion of the myocardial extracellular volume (ECV) is a surrogate measure of focal/diffuse fibrosis and is an independent marker of prognosis in chronic heart disease. Changes in ECV may also occur after myocardial infarction, acutely because of oedema and in convalescence as part of ventricular remodelling. The objective of this study was to investigate changes in the pattern of distribution of regional (normal, infarcted and oedematous segments) and global left ventricular (LV) ECV using semi-automated methods early and late after reperfused ST-elevation myocardial infarction (STEMI). METHODS: Fifty patients underwent cardiovascular magnetic resonance (CMR) imaging acutely (24 h-72 h) and at convalescence (3 months). The CMR protocol included: cines, T2-weighted (T2 W) imaging, pre-/post-contrast T1-maps and LGE-imaging. Using T2 W and LGE imaging on acute scans, 16-segments of the LV were categorised as normal, oedema and infarct. 800 segments (16 per-patient) were analysed for changes in ECV and wall thickening (WT). RESULTS: From the acute studies, 325 (40.6%) segments were classified as normal, 246 (30.8%) segments as oedema and 229 (28.6%) segments as infarct. Segmental change in ECV between acute and follow-up studies (Δ ECV) was significantly different for normal, oedema and infarct segments (0.8 ± 6.5%, -1.78 ± 9%, -2.9 ± 10.9%, respectively; P < 0.001). Normal segments which demonstrated deterioration in wall thickening at follow-up showed significantly increased Δ ECV compared with normal segments with preserved wall thickening at follow up (1.82 ± 6.05% versus -0.10 ± 6.88%, P < 0.05). CONCLUSION: Following reperfused STEMI, normal myocardium demonstrates subtle expansion of the extracellular volume at 3-month follow up. Segmental ECV expansion of normal myocardium is associated with worsening of contractile function.
Garg et al. (2016) conducted an observational in ST-elevation myocardial infarction (STEMI) (n=50). Myocardial infarction (STEMI) vs. Baseline (acute) vs 3-month follow-up was evaluated on Change in extracellular volume (Δ ECV) in normal segments with deteriorated wall thickening versus preserved wall thickening at follow-up (p=<0.05). Following reperfused STEMI, normal myocardial segments demonstrating deterioration in wall thickening at 3-month follow-up showed significantly increased extracellular volume expansion compared to segments with preserved function.