Family history in patients with transient ischemic attacks.

To determine the influence of family history on vascular disease, we surveyed hospital patients discharged with a diagnosis of transient ischemic attack. Of 117 respondents, 81 knew their family history for myocardial infarction and 81 knew their family history for stroke. Of 83 responding 43 reported a personal history of myocardial infarction, and of 85 responding 66 reported a personal history of stroke. As expected, there was an association between positive family and personal histories of myocardial infarction in younger (aged less than 70 years) patients (Fisher's two-tailed exact test, p = 0.014). This association was reversed for stroke (Fisher's two-tailed exact test, p = 0.017). Older (aged greater than or equal to 70 years) patients had a stronger association between positive family and personal histories of stroke; 14 (74%) of 19 older patients with a positive personal history of stroke had a positive family history of stroke. The reason for this reversal in the relation between family and personal histories of stroke compared with myocardial infarction may relate to the older age at onset of most strokes, differing stroke subtypes in older age groups, or lower rates of fatal myocardial infarction. This study suggests that familial factors may be important in some subtypes of cerebrovascular disease. Familial effects may be different in vascular diseases of the heart and brain.