Familial aggregation of early-onset myocardial infarction.
BACKGROUND
An inherited predisposition is an important factor in the etiology of myocardial infarction (MI) at a young age. However, the extent of the risk for early-onset MI in relatives of young patients is still unclear, due to the paucity of family history data. Hence familial aggregation of early-onset MI was investigated in a cohort of relatives of Italian patients who had survived MI who occurred at the age of 45 or earlier.


METHODS
In the framework of a case-control study, lifetime data and early-onset MI status for 11,696 relatives of cases and 8897 relatives of controls were collected using a standardized questionnaire.


RESULTS
Occurrence of early-onset MI in females was very uncommon (Kaplan-Meier risk=0.6%, 95% confidence interval (CI): 0.38-0.82%, for female case relatives), and significantly lower than that for male case relatives (5.0%, 95% CI: 4.41-5.56%). The hazard ratio (HR) for case relatives was approximately 3-fold greater than that for control aunts (taken as reference category). Risk for early-onset MI to siblings (HR=1.7, 95% CI: 1.33-2.18) was significantly different from that to parents (HR=0.9, 95% CI: 0.71-1.16). The familial risk ratio λ(R) was 2.6 (95% CI: 2.30-2.89) for case relatives, using control parents as reference population for early-onset MI risk estimates (i.e. 37 per 100,000 in fathers and 7 per 100,000 in mothers).


CONCLUSIONS
We evaluated the risk of early-onset MI by category of relatives, obtaining evidence for familial aggregation of the disease in this Italian sample and providing figures for genetic counselling and planning genetic epidemiological studies.
Department of Applied Health Sciences, Division of Epidemiology and Medical Statistics, University of Pavia, via Bassi 21, 27100, Pavia, Italy. v.cipriani@ucl.ac.uk
Valentina
V
Cipriani
Pier M
PM
Mannucci
Diego
D
Ardissino
Maurizio
M
Ferrario
Giancarlo
G
Corsini
Piera Angelica
PA
Merlini
Francesca
F
Notarangelo
Daniela
D
Lina
Luisa
L
Bernardinelli
D017668:Age of Onset; D016022:Case-Control Studies; D005190:Family; D005192:Family Health; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology* / Q000235:genetics*; D012307:Risk Factors; D011795:Surveys and Questionnaires