Steven Dymarkowski MD, PhD, Presenter: Nothing to Disclose

Maria Kalantzi MD, Abstract Co-Author: Nothing to Disclose

Stefaan Janssens MD, PhD, Abstract Co-Author: Nothing to Disclose

Frans Van De Werf MD, PhD, Abstract Co-Author: Nothing to Disclose

Jan Bogaert MD, PhD, Abstract Co-Author: Nothing to Disclose

Intramyocardial hemorrhage (IMH) is a complication after revascularization for acute myocardial infarction (AMI). At present it is unknown whether these infarcts behave different than infarcts without IMH. The paramagnetic properties of blood breakdown-products can be exploited to non-invasively detect IMH by using T2-weighted MRI.

Fifty-two patients with AMI, receiving PCI 2-12 hours after onset were studied at 1week(1W) and after 4months(4M). T2weighted STIR-TSE MRI was used to detect myocardial edema (hyperintense) and IMH (central hypointense core with peripheral hyperintense rim). Early (ie, 2-5 min) contrast-enhanced MRI was used to visualize microvascular obstruction (MVO) while late imaging (ie, 10-25 min) was used for infarct imaging.

The majority (43/52) of patients showed homogeneous hyperintense signal on T2w MRI, 9 patients showed a distinct IMH pattern. All 9 IMH patients showed MVO on early CE-MRI, while MVO was found in 23/43 of the edema group. Comparing both groups, IMH showed a trend towards longer time of onset to PCI (380±272 vs 266±122 min, p = 0.07) and higher troponin I (p= 0.086). Without differences in infarct volume (p=0.5) between groups, IMH showed a trend towards larger MVO volume (48.7±29.3% vs 31.5±21.8%, p=0.079). Normalized LV myocardial mass and mean LV wall thickness were larger in IMH (72.4±16.0 vs 57.5±9.1 g, p=0006, and 8.0±1.9 vs 6.7±1.4 mm, p = 0.02). At 4M, there was a trend towards larger loss in LV mass (-10.6±8.2 vs 5.3±9.4g, p=0.1) and reduction in LV wall thickness in IMH (infarcted area: p= 0.07, remote area: p=0.026). Global and regional LV function were similar between IMH and non-IMH infarcts 1W and 4M after the acute event.

Intramyocardial hemorrhage is a frequent finding after coronary reperfusion for AMI, detectable by a typical appearance on T2w MRI. Our results suggest a pattern and behavior that is similar but likely more severe than in MVO infarctions. IMH seems to occur preferentially in patients with pre-existing LV hypertrophy. Although IMH MVO and non-IMH MVO infarctions behave functionally similar, IMH infarcts seem to be prone to more LV remodelling.

Dymarkowski, S, Kalantzi, M, Janssens, S, Van De Werf, F, Bogaert, J, Intramyocardial Hemorrhage in Acute Myocardial Infarction: Use of Comprehensive MRI Techniques to Assess Morphological and Functional Behavior Early and at Short-term after the Acute Event.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4412566.html