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

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.

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].

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.