MECHANISMS OF LATE STROKE AFTER MYOCARDIAL INFARCT - THE LAUSANNE STROKE REGISTRY

To assess the potential mechanisms and patterns of late stroke after myocardial infarct, 94 consecutive patients with first ever stroke at least three months after myocardial infarction (anterior 67%; inferior 12%; widespread 12%) were studied. Systematic investigations were those of the Lausanne Stroke Registry and included brain CT, extra/transcranial Doppler ultrasound, 12-lead ECG, three-lead continuous ECG monitoring for at least 24 hours after admission, and transthoracic two dimensional echocardiography. All patients had an akinetic left ventricular segment, but only 11 (12%) had a visible thrombus. Eleven (12%) of the patients had long standing hypertension and a small deep infarct so that lacunar infarction due to small artery disease was as likely to be the cause as cardioembolic stroke. There was severe internal carotid artery disease (greater-than-or-equal-to 50% stenosis or occlusion) ipsilateral to the infarct in 20 (21%) of the patients with anterior circulation stroke. A potential cardiac source of embolism other than akinetic left ventricular segment was found in 14 (15%) patients, atrial fibrillation (12%) being the commonest. Only 13 (14%) patients had no potential cause for stroke other than akinetic left ventricular segment. The study group was compared with 466 patients with first stroke but no akinetic left ventricular segment on two dimensional echocardiography, and with 94 patients with first stroke and a potential cardiac source of embolism but no akinetic left ventricular segment and no history of ischaemic heart disease. Logistic regression analysis showed that older age, male sex, hypercholesterolaemia, and vascular claudication were significantly and independently associated with stroke after myocardial infarction. The findings suggest that late stroke after myocardial infarction may often be a direct consequence of the sequelae of myocardial infarction, but other potential cardiac causes of stroke, large artery disease, and lacunar stroke must also be considered.