Abstract
Recent myocardial infarction is a recognized risk factor for ischemic stroke. Patients who have a stroke in the peri-infarct period are usually in hospital and therefore well placed to access early cerebral reperfusion therapy. However, due to the risk of myocardial rupture, recent myocardial infarction is considered a contraindication to intravenous thrombolysis, which is usually the first-line therapy for the treatment of ischemic stroke. We report a case in which intravenous thrombolysis was safely and effectively used to treat acute ischemic stroke in a patient who had suffered an acute myocardial infarct within the previous 48 h. We also highlight the lack of evidence-based guidelines for the treatment of stroke in this important subgroup of patients.
1
Introduction
Patients who have an acute myocardial infarction (MI) are recognized to be at an increased risk of ischemic stroke . This risk is highest in the first 30 days after MI (approximately 1%) and decreases thereafter . The development of stroke in the peri-infarct period can have devastating consequences and has been shown to increase mortality significantly. Ischemic stroke is also a rare but well-recognized complication of cardiac catheterization and percutaneous coronary intervention (PCI) . The management of stroke occurring in the peri-infarct or periprocedural period is of particular interest as these patients are usually in hospital and therefore the neurological signs of a stroke are generally recognized early. However, there is a lack of evidence-based guidelines for the management of stroke in this subgroup of patients. We present a case of acute ischemic stroke following coronary angiography to investigate anterior MI, which was successfully treated with systemic thrombolytic therapy.
2
Case presentation
A 58-year-old gentleman with cardiovascular risk factors of hypertension and a 20-pack-year history of smoking presented after 6 h of ischemic-type chest pain, with non-ST segment elevation MI. A 12-lead electrocardiogram showed biphasic T waves across the anterior leads, in association with a high serum troponin and peak serum creatine kinase of 500 IU/l. The patient was therefore prescribed usual postinfarct medications including aspirin, atorvastatin, and perindopril, and commenced on a therapeutic dose of low-molecular-weight heparin (1 mg/kg twice daily).
A transthoracic echocardiogram (TTE) was done on the day of admission and showed a grade 2 left ventricle with an akinetic distal anterior left ventricular wall and apex, and a small apical thrombus ( Fig. 1 ). Coronary angiography performed 18 h after initial presentation revealed a completely occluded left anterior descending artery (LAD) with visible thrombus at the origin of a large first diagonal branch, which itself was free of critical disease ( Fig. 2 ). The other coronary arteries were largely free of disease, and there was excellent retrograde filling of the LAD via collaterals from the dominant right coronary artery. A left ventriculogram was not performed due to the previously reported presence of left ventricular thrombus on echocardiogram. A decision was made by the interventionalist to defer PCI to the LAD in view of the risk of jeopardizing the large diagonal branch and collateralization, and to instead optimize medical therapy first.
Approximately 30 h after the coronary angiogram, the patient was noted to have a dense right hemiparesis and global aphasia with a National Institute of Health Stroke Scale (NIHSS) score of 17. An urgent computed tomographic (CT) scan of the brain showed a hyperdense left middle cerebral artery (MCA) sign (an early CT finding of ischemic stroke) , and an intracranial bleed was excluded ( Fig. 3 ). Following consultation with the stroke care unit specialists, it was thought that there would be a significant delay to the potential initiation of intraarterial (IA) therapy in the angiography suite (event occurred out of hours). The patient was given partial-dose systemic thrombolytic therapy [intravenous recombinant tissue-type plasminogen activator (IV rt-PA) at a dose of 0.6 mg/kg] within 45 min of the onset of symptoms. The lower dose of the thrombolytic agent was chosen due to the patient’s history of recent MI and femoral artery puncture, associated with the decision to proceed with cerebral angiography. Subsequent cerebral digital subtraction angiography performed approximately 40 min later surprisingly showed a patent MCA with normal flow ( Fig. 4 ). No further thrombolysis was administered.
Within 6 h of his cerebral event, the patient made a nearly full neurological recovery apart from some minor word-finding difficulty. A magnetic resonance imaging brain scan with diffusion-weighted imaging done 24 h later showed diffusion restriction in the left head of the caudate nucleus and putamen, consistent with a recent left MCA territory ischemic stroke ( Fig. 5 ). In addition, a carotid artery ultrasound excluded any preexisting carotid artery disease. A repeat TTE showed persistence of the apical thrombus and apical akinesis, so warfarin was commenced on the day after the neurological event, before he was discharged home on day 5 of admission. Three months from the initial event, following outpatient rehabilitation therapy, he had no functional deficits, reported no angina symptoms, and had returned to full-time work as a builder. A TTE at this time showed complete resolution of the apical thrombus, with only mild left ventricular systolic dysfunction and anteroapical hypokinesis.
2
Case presentation
A 58-year-old gentleman with cardiovascular risk factors of hypertension and a 20-pack-year history of smoking presented after 6 h of ischemic-type chest pain, with non-ST segment elevation MI. A 12-lead electrocardiogram showed biphasic T waves across the anterior leads, in association with a high serum troponin and peak serum creatine kinase of 500 IU/l. The patient was therefore prescribed usual postinfarct medications including aspirin, atorvastatin, and perindopril, and commenced on a therapeutic dose of low-molecular-weight heparin (1 mg/kg twice daily).
A transthoracic echocardiogram (TTE) was done on the day of admission and showed a grade 2 left ventricle with an akinetic distal anterior left ventricular wall and apex, and a small apical thrombus ( Fig. 1 ). Coronary angiography performed 18 h after initial presentation revealed a completely occluded left anterior descending artery (LAD) with visible thrombus at the origin of a large first diagonal branch, which itself was free of critical disease ( Fig. 2 ). The other coronary arteries were largely free of disease, and there was excellent retrograde filling of the LAD via collaterals from the dominant right coronary artery. A left ventriculogram was not performed due to the previously reported presence of left ventricular thrombus on echocardiogram. A decision was made by the interventionalist to defer PCI to the LAD in view of the risk of jeopardizing the large diagonal branch and collateralization, and to instead optimize medical therapy first.
