Abstract P347: The Impact of the Length of the Follow-up on the the Strengths of the Associations Between Cardiovascular Risk Factors and Future Myocardial Infarction, Stroke and Heart Failure
Objective: The aim of this study was to investigate how the length of the follow-up period influences the strength of the associations between major cardiovascular risk factors and different cardiovascular outcomes (myocardial infarction [MI], stroke and heart failure).
Methods: We examined 1826 men aged 50 regarding cardiovascular risk factors in 1970-74. The follow-up time was 33 years. The hazard ratio (HR) was calculated yearly for each risk factor and outcome. During follow-up, 571 cases of MI, 381 cases of stroke and 384 cases of heart failure occurred.
Results: Two major patterns were found regarding influence of the follow-up time on the associations between risk factors and the different cardiovascular outcomes. First, a gradual decline in the HR over time was seen for blood pressure in relation to all three outcomes, with the most rapid decline for heart failure and stroke. This pattern was also seen for BMI in relation to MI and heart failure, and for smoking regarding MI and stroke. Second, we observed a gradual increase in HRs to a maximum at 20-25 years, and thereafter a slight decline. This pattern was seen for the apoB/A1 ratio, HDL, and triglycerides, mainly in relation to MI and heart failure.
Conclusion: The length of follow-up influenced the associations between traditional risk factors and cardiovascular outcomes in different ways. The collective influence of the risk factors did however show a substantial decline in discrimination over time for the outcomes stroke and heart failure, but not regarding myocardial infarction.
- © 2012 by American Heart Association, Inc.