Improving long-term prediction of first cardiovascular event: the contribution of family history of coronary heart disease and social status

Abstract

Objective: The aim of this study is to assess whether family history of coronary heart disease (CHD) and education as proxy of social status improve long-term cardiovascular disease risk prediction in a low-incidence European population.

Methods: The 20-year risk of first coronary or ischemic stroke events was estimated using sex-specific Cox models in 3956 participants of three population-based surveys in northern Italy, aged 35-69 years and free of cardiovascular disease at enrollment. The additional contribution of education and positive family history of CHD was defined as change in discrimination and Net Reclassification Improvement (NRI) over the model including 7 traditional risk factors.

Results: Kaplan-Meier 20-year risk was 16.8% in men (254 events) and 6.4% in women (102 events). Low education (hazard ratio=1.35, 95%CI 0.98-1.85) and family history of CHD (1.55; 1.19-2.03) were associated with the endpoint in men, but not in women. In men, the addition of education and family history significantly improved discrimination by 1%; NRI was 6% (95%CI: 0.2%-15.2%), raising to 20% (0.5%-44%) in those at intermediate risk. NRI in women at intermediate risk was 7%.

Conclusion: In low-incidence populations, family history of CHD and education, easily assessed in clinical practice, should be included in long-term cardiovascular disease risk scores, at least in men.

Keywords: Cardiovascular disease; Family history of CHD; Improvement; Italy; Long-term risk prediction; Risk stratification; Social status.