Level of education and risk of heart failure: a prospective cohort study with echocardiography evaluation

Abstract

With increasing socioeconomic disparity in cardiovascular risk factors, there is a need to assess the role of socioeconomic factors in chronic heart failure (CHF) and to what extent this is caused by modifiable risk factors. In a prospective cohort of 18 616 men and women without known myocardial infarction or CHF examined in 1976-78, 1981-83, 1991-94, and 2001-03 in the Copenhagen City Heart Study, we studied the effect of education on CHF incidence. During a median follow-up of 21 years (range 0-31), 2190 participants were admitted to hospital for CHF. Age-adjusted hazard ratio (HR) for intermediary (8-10 years) and high level of education (>10 years) with low (< 8 years) as reference was 0.69 (0.62-0.78) and 0.52 (0.43-0.63), respectively, with similar associations in men and women. After adjusting for updated cardiovascular risk factors, corresponding HRs were 0.75 (0.67-0.85) and 0.61 (0.50-0.73). In a random subset of the population examined with echocardiography in 2001-03 (n = 3589), education was associated with left ventricular (LV) hypertrophy, LV dilatation, reduced LV ejection fraction, and severe diastolic dysfunction (P for trend, all <0.05), whereas no association was found for mild diastolic dysfunction (P for trend, 0.61). With the exception of LV hypertrophy, significant associations persisted after adjustment for potential mediating factors. In this cohort study, the level of education was associated with cardiac dysfunction and predicted future hospital admission for CHF. Only a minor part of the excess risk was mediated through traditional cardiovascular risk factors. Strategies to reduce this inequality should be strengthened.