Family history of premature death and risk of early onset cardiovascular disease.

OBJECTIVES

The purpose of this study was to examine the effect of a family history of premature death, cardiovascular death in particular, on the risk of early cardiovascular disease.

BACKGROUND

Studies suggest that fatal cardiovascular events and less severe cardiovascular diseases may co-occur in families. Consequently, a family history of premature death may indicate a familial cardiac frailty that predisposes to early cardiovascular disease.

METHODS

We ascertained family history of premature death (age <60 years) in all individuals born in Denmark from 1950 to 2008 and followed this cohort for early cardiovascular disease (age <50 years). Using Poisson regression, we estimated incidence rate ratios (IRRs) reflecting the effect of premature death in the family on early cardiovascular disease risk.

RESULTS

Among 3,985,301 persons followed up for 89,294,258 person-years, 129,825, 31,172, and 5,214 were diagnosed with any early cardiovascular disease, ischemic heart disease, and ventricular arrhythmia, respectively. IRRs for these conditions given a history of premature cardiovascular death in first-degree relatives were 1.72 (95% confidence interval [CI]: 1.68 to 1.77), 2.21 (95% CI: 2.11 to 2.31), and 1.94 (95% CI: 1.70 to 2.20), respectively. With ≥2 cardiovascular deaths in a family, corresponding IRRs were 3.30 (95% CI: 2.77 to 3.94), 5.00 (95% CI: 3.87 to 6.45), and 6.18 (95% CI: 3.32 to 11.50). The IRR for any early cardiovascular disease given a family history of premature noncardiovascular death was significantly lower, 1.12 (95% CI: 1.10 to 1.14) (p(cardiac vs. noncardiac) < 0.0001).

CONCLUSIONS

Family history of premature cardiovascular death was consistently and significantly associated with a risk of early cardiovascular disease, suggesting an inherited cardiac vulnerability. These results should be kept in mind when assessing cardiovascular disease risk in persons with a family history of premature cardiovascular death.