Abstract 1743: Timing and Magnitude of Infarct Resorption in Relation to Recovery of Global Left Ventricular Function in Patients with Reperfused Myocardial Infarction
Background: The timing and magnitude of myocardial infarct resorption after reperfused acute infarction and its relationship to recovery of left ventricular (LV) function has been studied in animal models. The aim of this study was to explore this relationship in patients with reperfused first-time infarction by following them at multiple points in time during the first year after admission.
Methods: Twenty-two patients with reperfused first-time myocardial infarction were prospectively enrolled. Cardiac magnetic resonance imaging (MRI), including cine imaging and delayed-contrast enhanced (DE) imaging for infarct visualization, was performed 1 day, 1 week, 6 weeks, 6 months and 1 year after admission. Left ventricular ejection fraction, end-diastolic volume and end-systolic volume were assessed from the cine images. Infarct size, transmurality and endocardial extent of infarction, expressed as a percentage of the total endocardial surface, were determined from the DE-MRI images.
Results: Infarct size decreased, especially during the first week after infarction (P < 0.001) (Fig A⇓). Both infarct transmurality and endocardial extent of infarction contributed to the decrease in infarct size (Fig B⇓). The LV ejection fraction increased gradually over time (P < 0.001) (Fig C⇓), reflected by an early increase in end-diastolic volume and a gradual decrease in end-systolic volume (Fig D⇓).
Conclusions: Infarct size decreases mostly during the first week after infarction in patients with small to moderate sized reperfused first-time infarcts. The global left ventricular, however, increases gradually during the first year after infarction.