Abstract 12687: Intramyocardial Haemorrhage In St-elevation Myocardial Infarction. Experimental Validation. Implications on Late Left Ventricular Remodelling and Patient Outcome
Purpose: In ST elevation myocardial infarction (STEMI) intramyocardial haemorrhage (IH) reflects a severe damage secondary to the ischemia injury. Cardiovascular magnetic resonance (CMR) is the state-of-the-art technique for its evaluation. The aim of this study was to experimentally validate this finding and to analyze, in patients, its implications on late left ventricular remodelling and clinical outcome.
Methods: In a swine model of angioplasty balloon induced STEMI we evaluated the association of IH in CMR with IH in heart samples (haematoxylin-eosin). We prospectively study 348 consecutive patients who were admitted for a first reperfused STEMI. CMR was performed at pre-discharge and at 6 months. The extent (number of segments) of IH (lack of enhancement in the core of a hyperenhanced area in T2-weighted sequence), microvascular obstruction (MVO, lack of contrast arrival in the core of a hyperenhanced area in late enhancement imaging), infarct size (areas displaying late enhancement) along with traditional LV indexes were quantified. Adverse left ventricular remodelling (% enlargement of end-dyastolic and end-systolic volumes indexes) was determined. The occurrence of major adverse cardiovascular events (MACE: death, reinfarction or heart failure) was recorded
Results: In swine, IH was confirmed in all segments displaying IH in CMR and took place in the core of the MVO area. In patients, IH (>1 segment) was detected in 121 patients (35%). The presence of IH associated to a larger extent of MVO and infarct size at 1 week as well as to more dilated left ventricular volume indexes, adverse left ventricular remodelling and more depressed ejection fraction at 6 months (p <0.0001 in all cases). IH vanished in all cases at 6-months CMR. IH related to more MACE (19% vs. 12%, p=0.03). In the multivariate analysis, infarct size and the extent of MVO but not IH predicted adverse LV remodelling and MACE.
Conclusions: IH is a common finding after reperfused STEMI which is accurately detected by CMR. It is strongly associated with a higher incidence of MACE and severe structural LV damage soon and late after infarction. However it does not constitute an independent predictor.
- © 2011 by American Heart Association, Inc.