Format

Send to

Choose Destination
Clin Cardiol. 2015 Nov;38(11):660-7. doi: 10.1002/clc.22470. Epub 2015 Oct 13.

Remnant Lipoprotein Cholesterol and Mortality After Acute Myocardial Infarction: Further Evidence for a Hypercholesterolemia Paradox From the TRIUMPH Registry.

Author information

1
Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, Maryland.
2
Atherotech Diagnostics Laboratory, Birmingham, Alabama.
3
Northwest London Hospitals NHS Trust, London, United Kingdom.
4
VA Eastern Colorado Health Care System, Denver, Colorado.
5
University of Colorado School of Medicine, Aurora, Colorado.
6
Department of Preventive Cardiology, CGH Medical Center, Sterling, Illinois.
7
University of Illinois School of Medicine, Peoria, Illinois.
8
Saint Luke's Mid America Heart Institute, University of Missouri-Kansas City, Kansas City, Missouri.

Abstract

BACKGROUND:

Remnants are partially hydrolyzed, triglyceride-rich lipoproteins that, like other apolipoprotein B-containing lipoproteins, are atherogenic. Prior observational studies suggest paradoxically better outcomes in hypercholesterolemic patients who sustain an acute myocardial infarction (AMI), one of several known recurrent risk paradoxes. To date, the association of directly measured remnant lipoprotein cholesterol (RLP-C) with survival after an AMI has not been examined.

HYPOTHESIS:

Higher RLP-C levels may be paradoxically associated with lower mortality.

METHODS:

We examined 2465 AMI survivors in a prospective, 24-center US study of AMI outcomes. Lipoprotein cholesterol subfractions were directly measured by ultracentrifugation. RLP-C was defined as intermediate-density lipoprotein cholesterol (IDL-C) + very-low-density lipoprotein cholesterol subfraction 3 (VLDL3 -C). Given a linear relationship between RLP-C and mortality, we examined RLP-C by tertiles and continuously. Cox regression hazard ratios (HRs) were adjusted for the Global Registry of Acute Coronary Events (GRACE) score and 23 other covariates.

RESULTS:

Participants were age 58 ± 12 years (mean ± SD), and 68% were men. After 2 years of follow-up, 226 (9%) participants died. The mortality proportion was 12.4% in the lowest tertile of RLP-C (0-15 mg/dL), 8.5% in the middle tertile (16-23 mg/dL), and 6.8% in the highest tertile (24-120 mg/dL; P < 0.001). A 1-SD increase in RLP-C (11 mg/dL) predicted a 24% lower adjusted risk of 2-year mortality (HR: 0.76, 95% confidence interval [CI]: 0.64-0.91). Similar results were found for a 1-SD increase in IDL-C (HR per 8 mg/dL: 0.80, 95% CI: 0.67-0.96), VLDL3 -C (HR per 4 mg/dL: 0.74, 95% CI: 0.61-0.89), and very-low-density lipoprotein cholesterol (VLDL-C; HR per 8 mg/dL: 0.69, 95% CI: 0.55-0.85).

CONCLUSIONS:

Higher RLP-C levels were associated with lower mortality 2 years after AMI despite rigorous adjustment for known confounders. Unknown protective factors or a lead-time bias likely explains the paradox.

PMID:
26459191
PMCID:
PMC4715617
DOI:
10.1002/clc.22470
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wiley Icon for PubMed Central
Loading ...
Support Center