Modifiable risk factors and risk of myocardial infarction in offspring with parental disease

AIMS: Children of patients with early-onset myocardial infarction (MI) are at increased risk, but the importance of concordant vs. discordant parent-offspring risk factor profiles on MI risk is largely unknown. We quantified the long-term absolute risk of MI according to shared risk factors in adulthood.

METHODS AND RESULTS: We sampled data on familial predisposed offspring and their parents from the Framingham Heart Study. Early MI was defined as a history of parental MI onset before age 55 in men or 65 in women. Individuals were matched 3:1 with non-predisposed offspring. Cardiovascular risk factors included obesity, smoking, hypertension, high cholesterol, and diabetes. We estimated the absolute 20-year incidence of MI using the Aalen-Johansen estimator. At age 40, the 20-year risk of MI varied by cholesterol level [high cholesterol 25.7% (95% confidence interval 11.2-40.2%) vs. non-high cholesterol 3.4% (0.5-6.4)] among predisposed individuals, and this difference was greater than in controls [high cholesterol 9.3% (1.5-17.0) vs. non-high cholesterol 2.5% (1.1-3.8)]. Similar results were observed for prevalent hypertension [26.7% (10.8-42.5) vs. 4.0% (0.9-7.1) in predisposed vs. 10.8% (3.2-18.3) and 2.1% (0.8-3.4) in controls]. Among offspring without risk factors, parental risk factors carried a residual impact on 20-year MI risk in offspring [0% (0-11.6) for 0-1 parental risk factors vs. 3.3% (0-9.8) for ≥2 parent risk factors at age 40, vs. 2.9% (0-8.4) and 8.5% (0-19.8) at age 50 years].

CONCLUSION: Children of patients with early-onset MI have low absolute risks of MI in the absence of midlife cardiovascular risk factors, especially if the parent also had a low risk factor burden prior to MI.