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 versus 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: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. RESULTS: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 versus 3.3% [0; 9.8] for ≥2 parent risk factors at age 40, versus 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.