Why Is Infarct Expansion Such an Elusive Therapeut

Authors: William J Richardson Jeffrey W Holmes

Publish Date: 2015/09/21

Volume: 8, Issue: 7, Pages: 421-430

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Abstract

Myocardial infarct expansion has been associated with an increased risk of infarct rupture and progression to heart failure motivating therapies such as infarct restraint and polymer injection that aim to limit infarct expansion However an exhaustive review of quantitative studies of infarct remodeling reveals that only half found chronic inplane expansion and many reported inplane compaction Using a finite element model we demonstrate that the balance between scar stiffening due to collagen accumulation and increased wall stresses due to infarct thinning can produce either expansion or compaction in the pressurized heart—potentially explaining variability in the literature—and that loaded dimensions are much more sensitive to changes in thickness than in stiffness Our analysis challenges the concept that inplane expansion is a central feature of postinfarction remodeling rather available data suggest that radial thinning is the dominant process during infarct healing and may be an attractive therapeutic target

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