Relative Familial Clustering of Cerebral Versus Coronary Ischaemic Events
Background—Few population-based studies have ascertained both cerebral and coronary events or considered their relative heritability. Differences in heritability of transient ischaemic attack (TIA) and ischaemic stroke versus acute coronary syndromes (ACS) may inform risk prediction, genetic studies, and understanding of disease mechanisms.
Methods and Results—In a population-based study of all acute vascular events, irrespective of age, we studied family history of myocardial infarction (MI), stroke and related risk factors in first degree relatives (FDR). To allow for differences in rates of affected FDRs due to differences in disease incidence, we looked at the extent to which parental history was associated with affected siblings within disease category. 906(604 males, mean age=70.0) probands with ACS and 1015(484 males,mean age=73.0) with cerebral events had complete family history data. In ACS probands, parental MI was associated with MI in ≥1 sibling: one parent with MI – OR=1.48, 1.04-2.10, p=0.03; both parents with MI - OR=5.97, 3.23-11.03; p<0.0001. In probands with cerebral events, however, parental stroke was not associated with sibling stroke. The overall frequency of ≥2 siblings with the same condition was also greater in probands with ACS than in those with cerebral events (5.43, 3.03-9.76; p<0.00001), despite similar overall incidence of MI and stroke in our study population. 142(15.7%) ACS occurred in families with ≥2 affected FDRs compared with 56(5.1%) TIA/strokes. All results were similar when analyses were confined to probands with MI only versus stroke only, and independent of smoking.
Conclusions—Heritability of coronary events was greater than that of cerebral events, such that MI was more likely to cluster in families than was stroke.
- Received November 28, 2010.
- Accepted May 27, 2011.
- Copyright © 2011, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited