Relationships between lipoprotein components and risk of myocardial infarction: age, gender and short versus longer follow-up periods in the Apolipoprotein MOrtality RISk study (AMORIS).

Description

The Apolipoprotein MOrtality RISk study (AMORIS) was designed to investigate the relationship between apolipoproteins and other indices of the lipoprotein-lipid profile to acute myocardial infarction (AMI) risk. A total of 149,121 men and women free from AMI at baseline (1985) were followed up to 2002. In men, the age-adjusted hazard ratio (HR) for future AMI was 1.50 (95% CI, 1.46-1.53) for the apolipoprotein (apo) B/apo AI ratio and 1.29 (95% CI, 1.27-1.31) for the total cholesterol/HDL cholesterol (TC/HDL-C) ratio. In women, the respective HRs were 1.43 (95% CI, 1.38-1.48) and 1.28 (1.26-1.31). The apo B/apo AI ratio appeared to better predict AMI in participants less than 65 years of age whereas TC/HDL-C ratio provided a similar HR for future AMI in participants below or above 65 years of age. It was also reported that the apo B/apo AI ratio added clinically significant information to the TC/HDL-C ratio in men [net reclassification improvement = 9.4% (p<0.001)] but not in women [net reclassification improvement = 1.1% (NS)] in women. Based on these observations, the authors suggested that both apo B and apo AI should take on greater significance in the next generations of guidelines. The paper was accompanied by an editorial by Romero-Corral et al. who highlighted the important findings of AMORIS. The authors also evaluated the strengths and limitations of the investigation, noting that the study sample was very large. On the other hand, they suggested that the lack of information on other cardiovascular risk factors, such as medications and behavioural modifications, were not reported. Nevertheless, they agreed with the authors’ conclusion that measurement of apolipoproteins could be clinically useful.