Timo Baks, Presenter: Nothing to Disclose

Robert Jan Van Geuns MD, Abstract Co-Author: Nothing to Disclose

Elena Biagini MD, Abstract Co-Author: Nothing to Disclose

Filippo Cademartiri MD, Abstract Co-Author: Nothing to Disclose

Gabriel Paul Krestin MD, Abstract Co-Author: Nothing to Disclose

Pim J de Feyter MD, Abstract Co-Author: Nothing to Disclose

To study the effects of early successful primary angioplasty for ST-segment elevation acute myocardial infarction (AMI) on early and late infarct size and left ventricular wall characteristics. Early reperfusion treatment for AMI preserves left ventricular function, but the effects on early and late infarct size, end-diastolic wall thickness and wall thickening are not well known.

In 22 patients with successful primary angioplasty for first AMI, cine-MRI, perfusion and delayed enhancement (DE) imaging was performed at 5 days and 5 months. Cine-imaging was performed with a steady-state free-precession sequence. Perfusion imaging was performed during infusion of 0.1 mmol/kg Gadolinium-DTPA using a notched excitation followed by a segmented gradient-echo/echo-planar readout. Delayed enhancement images were acquired 10-20 minutes after administration of another 0.1 mmol/kg Gadolinium-DTPA with an inversion-recovery gradient echo sequence. Infarct shrinkage was defined as the difference between the volume of DE at 5 days and 5 months. End-diastolic wall thickness (EDWT) and segmental wall thickening (SWT) were quantified on cine-MRI.

Infarct shrinkage occurred with the same extent in small and large infarctions (R=0.92; p<0.001) with a mean decrease of 31% (35±21 to 24±17gram). Dysfunctional segments with restored perfusion had an increased EDWT at 5 days compared to remote myocardium (9.2±1.7 versus 8.4±1.7mm;p=0.003). At 5 months, EDWT in these segments became comparable to the thickness of remote myocardium (7.8±1.6 versus 7.6±1.4mm;p=0.24) and SWT improved (21±15 to 40±24%;p<0.001) but remained impaired (40±24 versus 71±29%;p<0.001). Segments with early perfusion defects despite a stented and patent epicardial coronary artery demonstrated wall thinning at 5 months (6.4±1.3 versus 7.6±1.4mm;p<0.001) and no significant recovery in SWT (12±14 to 17±20%;p=0.36).

Infarct size decreased with 31%. Segments with restored perfusion had early increased wall thickness and late partial functional recovery. Segments with perfusion defects showed late wall thinning and no functional recovery at 5 months.

Baks, T, Van Geuns, R, Biagini, E, Cademartiri, F, Krestin, G, de Feyter, P, Effects of Primary Angioplasty for Acute Myocardial Infarction on Early and Late Infarct Size and Left Ventricular Wall Characteristics: A Magnetic Resonance Imaging Study.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4413671.html