P136
Objective:
Silent infarcts seen on cranial MRI scans are a risk factor for subsequent clinical stroke in the elderly. This study examines the type of clinical strokes seen in those with silent infarcts.
Methods:
Cranial MRI examination was completed on 3324 Cardiovascular Health Study (CHS) participants aged 65+ who were without a prior history of clinical stroke. Incident strokes were identified over an average follow-up of 4 years and classified as hemorrhagic or ischemic. Ischemic strokes were further subdivided into lacunar, cardioembolic, atherosclerotic or other/unknown.
Results:
Silent MRI infarcts >3mm were found in approximately 28% (n=923). Of these, 7% (n=67) subsequently had a clinically evident stroke. The characteristics of the silent MRI infarcts in those who sustained an incident stroke were as folows: 56 had only subcortical infarcts, of which 55 were <20mm; 4 had only cortical infarcts; and 7 had both cortical and subcortical infarcts. Of those with only subcortical silent MRI infarcts, 16% (n=9) went on to a hemorrhagic stroke and 84% (n=47) sustained an ischemic stroke. The ischemic strokes were subtyped as 12 cardioembolic, 3 lacunar, 2 atherosclerotic and 30 unknown/other. Considering only those with cortical silent infarcts, either alone or in combination with subcortical infarcts, there was 1 hemorrhagic stroke and 10 ischemic strokes. Half of the ischemic strokes were cardioembolic and half were unknown type.
Conclusion:
Elderly individuals with silent subcortical infarcts who go onto subsequent stroke may be at risk not only for lacunar infarcts but also cardioembolic or hemorrhagic strokes.
Use of sonography to evaluate carotid atherosclerosis in the elderly. The Cardiovascular Health Study. CHS Collaborative Research Group.