A New Ratio for Better Predicting Future Death/Myocardial Infarction than Standard Lipids in Women >50 Years Undergoing Coronary Angiography: The Apo A1 Remnant Ratio (Apo A1/[VLDL3+IDL])*

Abstract

Synopsis: Women often lag behind men in their cardiovascular (CV) disease risk. However, with age and the onset of menopause, a women’s CV risk eventually becomes similar to that of men. This change in risk may, in part, be attributable to a shift in a more atherogenic lipid profile, in particular remnant lipoproteins (VLDL3 + IDL). Therefore, determining lipid parameters that predict risk is essential. Thus, we evaluated standard lipid parameters, apolipoprotein (apo) A1, and the apo A1 remnant ratio: (apo A1/ [VLDL3 + IDL]) for their associations to death (D) or myocardial infarction (MI) among periand post-menopausal women. Purpose: To evaluate the clinical utility of the new apo A1 remnant ratio compare with standard lipid measurements in predicting future D/MI in women older than 50 years undergoing coronary angiography. Methods: Women (n 5 711) older than 50 years of age from the Intermountain Heart Collaborative Study who were undergoing coronary angiography were evaluated. Baseline clinical and angiographic characteristics, lipid levels (determined by hospital’s clinical laboratory), and sublipid particles (determined with the Vertical Auto Profile method) were collected. Lipid and sublipid parameters were evaluated as tertiles (see supplemental material). Cox regression analysis, adjusted by standard CV risk factors, was used to determine associations of lipid and sublipid particles with D/MI at 1 and 3 years (average length of follow-up: 3.9 6 2.1 years). Results: Patients averaged 67.76 9.4 years and 53.6%had underlying severe (.70% stenosis) coronary artery disease.Mean lipid measurements (mg/dL) were high-density lipoprotein: 48.3 6 15.6, low-density lipoprotein: 106.7 6 37.3, nonhigh-density lipoprotein: 136.5 6 41.3, apo A1: 119.7 6 20.3, and apoA1/(VLDL3+IDL): 6.66 3.6. Because triglycerides were non-normally distributed, median level is reported: 133.0mg/dL. Sublipidparticleswere the best predictors of short (1 year) and intermediate (3 year)D/MI risk. These associations persisted evenafter adjustment.The strongest predictor ofD/MI risk at both time-points was the apo A1 remnant ratio: apo A1/ (VLDL3+IDL). Conclusions: The newparameter, the apoA1 remnant ratio, is a strong predictor of short-term and intermediate D/MI risk amongwomenolder than 50years of age. Furthermore, this ratio has a greater predictive ability than traditional lipid parameters and apo A1. This apo A1 remnant ratio represents a potential new measurement of risk and treatment target and should be tested in a larger cohort among this population, periand postmenopausal women, and other populations.