Eur Radiol (2010) 20: 2572–2578 DOI 10.1007/s00330-010-1849-9 C A R D I A C Sebastiaan C. A. M. Bekkers Martijn W. Smulders Valéria Lima Passos Tim Leiner Johannes Waltenberger Anton P. M. Gorgels Simon Schalla Clinical implications of microvascular obstruction and intramyocardial haemorrhage in acute myocardial infarction using cardiovascular magnetic resonance imaging Received: 10 February 2010 Revised: 14 April 2010 Accepted: 23 April 2010 Published online: 26 June 2010 # The Author(s) 2010. This article is published with open access at Springerlink.com S. C. A. M. Bekkers ()) : M. W. Smulders : J. Waltenberger : A. P. M. Gorgels : S. Schalla Department of Cardiology, Maastricht University Medical Center, P. Debyelaan 25, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands e-mail: s.bekkers@mumc.nl V. L. Passos Department of Methodology and Statistics, Maastricht University Medical Center, P. Debyelaan 25, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands T. Leiner Department of Radiology, Maastricht University Medical Center, P. Debyelaan 25, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands Abstract Objectives To investigate the clinical implications of microvascular obstruction (MVO) and intramyocardial haemorrhage (IMH) in acute myocardial infarction (AMI). Methods Ninety patients with a ﬁrst AMI undergoing primary percuta- neous coronary intervention (PCI) were studied. T2-weighted, cine and late gadolinium-enhanced cardiovascular magnetic resonance imaging was performed at 5±2 and 103±11days. Patients were categorised into three groups based on the presence or absence of MVO and IMH. Results MVO was observed in 54% and IMH in 43% of patients, and correlated signiﬁcantly (r=0.8, p<0.001). Pre-PCI thrombolysis in myocardial infarction 3 ﬂow was only observed in MVO(−)/IMH(−) patients. Infarct size and impairment of systolic function were largest in MVO(+)/IMH(+) patients (n=39, 23±9% and 47±7%), smallest in MVO(−)/IMH(−) patients (n=41, 8±8% and 55±8%) and intermediate in MVO(+)/IMH(−) patients (n=10, 16±7% and 51±6%, p<0.001). LVEF increased in all three subgroups at follow-up, but remained intermediate in MVO(+)/IMH(−) and was lowest in MVO(+)/IMH(+) patients. Using random intercept model analysis, only infarct size was an independent predictor for adverse LV remodelling. Conclusions Intramyocar- dial haemorrhage and microvascular obstruction are strongly related. Pre-PCI TIMI 3 ﬂow is less frequently observed in patients with MVO and IMH. Only infarct size was an independent predictor of LV remodelling. Keywords Myocardial infarction . Intramyocardial haemorrhage . Microvascular obstruction . Magnetic resonance imaging . Ventricular remodelling Introduction myocyte hypercontraction, microvascular obstruction (MVO) and intramyocardial haemorrhage (IMH) [2, 3]. Coronary occlusion that persists for more than 40 min Both MVO and IMH occur exclusively in myocardium leads to irreversible myocardial damage that starts in the that sustains the most severe ischaemia and are therefore endocardium and progresses towards the epicardium as a conﬁned to the central portions of infarcted myocardium wavefront phenomenon [1]. Although timely reperfusion [3]. As IMH is caused by extravasation of blood into the salvages myocardium and reduces mortality, successful extravascular space as a consequence of ischaemic micro- restoration of epicardial artery patency after prolonged vascular damage, it only occurs in reperfused AMI [4, 5]. occlusion does not always lead to adequate reperfusion at IMH does not depend on the magnitude of early reﬂow the microvascular level. Reperfused acute myocardial but, similar to MVO, on the severity of ischaemia as infarction (AMI) is characterised by myocyte swelling reﬂected by a longer duration of coronary occlusion and due to osmotic overload, intracellular calcium overload, low collateral ﬂow [6, 7].