July 26th, 2011
Coronary and Cerebrovascular Disease May Differ in Their Heritability
Larry Husten, PHD
Although coronary and cerebrovascular disease usually receive equal weight when family history is assessed as a risk factor, a new study suggests that family history may play a more important role in MI and ACS than in stroke or TIA.
In an article published in Circulation: Cardiovascular Genetics, Amitava Banerjee and colleagues report the results of a population-based study in which they assessed the relative heritability of cerebral and coronary events in 906 patients with ACS and 1015 patients with cerebrovascular disease. For the ACS patients, parental MI was strongly associated with MI in one or more siblings:
- 1 parent with MI: odds ratio, 1.48; 95% CI, 1.04-2.10; P=0.03
- 2 parents with MI: OR, 5.97; 95% CI, 3.23-11.03; P<0.0001
For the stroke and TIA patients, the association of parental stroke with sibling stroke did not achieve statistical significance:
- 1 parent with stroke: OR, 0.88; 95% CI, 0.50-1.56; P=0.67
- 2 parents with stroke: OR, 1.19; 95% CI, 0.27-5.29; P=0.81
In all, 142 ACS cases (15.7%) occurred in families in which 2 or more first-degree relatives were also affected. By contrast, only 56 (5.1%) of patients with TIA or stroke occurred in families in which 2 or more first-degree relatives were also affected.
In an AHA press release, senior author Peter Rothwell said that “the way physicians predict the odds of a healthy person suffering a heart attack or stroke needs refining. Currently, most risk models lump a patient’s family history of stroke and heart attack together. We probably should model family history of stroke and heart attack separately in the future.”
For now family history is an ill-defined risk. Framingham is of little help. The age at which the events occur must be relevant (did the above trial only count premature MI…or are all MIs premature?). Very frequently, the parent smoked. This must mitigate risk..but how much? So…I will often do a CAC score, if results will affect preventive approach.