Does postsystolic motion or shortening predict recovery of myocardial function after primary percutanous coronary intervention?

Objective: The purpose of the study was to evaluate whether presence of postsystolic motion or shortening defined by Doppler tissue imaging may predict recovery of regional myocardial function in patients with ST-elevation myocardial infarction.
Methods: Echocardiography was performed a few hours after primary percutanous coronary intervention and at a 3-month follow-up visit in 83 patients with ST-elevation myocardial infarction. Based on visual assessment of wall thickening in a 16-segment model, segments were classified into those with: dyskinesia/akinesia (type A, n = 63) or hypokinesia (type B, n = 141) in the acute phase and no recovery of function at follow-up; dyskinesia/akinesia in the acute phase and partial recovery of function at follow-up (type C, n = 86); dyskinesia/akinesia/hypokinesia in the acute phase and complete recovery of function at follow-up (type D, n = 243); and normal myocardial function in the acute phase (type E, n = 759).
Results: There were no differences among type A, B, C, and D segments with regard to the proportion presenting postsystolic tissue velocity equal to or greater than 1.0 cm/s (0.52, 0.54, 0.60, and 0.47, respectively, P = .20) or with respect to postsystolic negative increase in strain (median -2.9, -1.9, -1.8, and -1.5%, respectively, P = .13) in the acute phase. However, type E segments less often presented postsystolic tissue velocity greater than 1.0 cm/s and presented lower postsystolic increase in strain (0.39 and -1.0%, respectively, P < .001 as compared with type A-D segments). In initially dysfunctional segments, presence of postsystolic contraction was not associated with improvement in strain or wall-motion score at follow-up.
Conclusion: In patients with ST-elevation myocardial infarction postsystolic motion or shortening appears more frequently in the acute phase in myocardial segments with impaired systolic function compared with normally functioning segments. However, presence of postsystolic contraction is not associated with improvement in strain or wall-motion score at follow-up, and does not seem to be a marker of viability.