The common apolipoprotein A-1 polymorphism -75A>G is associated with ethnic differences in recurrent coronary events after recovery from an acute myocardial infarction

Overview

Since data regarding the relationship
between a common polymorphism (SNP) of the
apoA1 gene with apoA1 levels and risk of coronary
artery disease are inconsistent, we
hypothesized that its association with recurrent
coronary events differs for White and Black
individuals with diagnosed coronary heart disease.
The apoA1 -75G>A SNP was genotyped in
a cohort of 834 Black (n=129) and White
(n=705) post-myocardial infarction patients.
Recurrent coronary events (coronary-related
death, non-fatal myocardial infarction, or
unstable angina) were documented during an
average follow-up of 28 months. Thirty percent
of White and 21% of Black patients carried the
SNP. Cox proportional-hazards regression
analysis, adjusting for clinical and laboratory
covariates, demonstrated that the SNP was not
associated with recurrent events in the total
cohort (HR=1.37, 95% CI 0.95-1.97; p=0.09) but
was the only variable associated with an
increased risk of recurrent cardiac events in
Blacks (HR=2.40, 95% CI 1.07-5.40; p= 0.034).
Conversely in Whites, the SNP was not associated
with recurrent events (HR=1.12, 95% CI
0.75-1.67; p= 0.59) whereas apoB (HR=1.78,
95% CI 1.20 -2.65; p=0.0042) and calcium channel
blocker use (HR=2.53, 95% CI 1.72-3.72;
p<0.001) were associated; p=0.0024 for interaction between ethnicity and the SNP. A common apoA1 SNP is associated with a significantly increased risk of recurrent cardiac events among Black, but not White, postmyocardial infarction patients. Relationships with lipoproteins may help explain this finding.

Keywords

Apolipoprotein A1, high density lipoprotein, African-American, recurrent coronary event, myocardial infarction.

Correspondence

Robert C. Block, MD, MPH Box 644, 601 Elmwood Avenue Rochester, NY 14642 Email: robert_block@urmc.rochester.edu

Acknowledgements

We thank Paul Winters for his
assistance with the creation of the figure.
This study was supported by Research Grant
HL048259 from the National Institutes of Health,
Bethesda, Maryland, and by a contract from
Millennium Pharmaceuticals, Inc., Cambridge,
Massachusetts, USA.
This research was carried out at the University
of Rochester.
This publication was made possible by Grant
Number KL2 RR 024136 from the National Center
for Research Resources (NCRR), a component of
the National Institutes of Health (NIH), and the
NIH Roadmap for Medical Research. Its contents
are solely the responsibility of the authors and do
not necessarily represent the official view of
NCRR or NIH. Information on NCRR is available
at http://www.ncrr.nih.gov/. Information on Reengineering
the Clinical Research Enterprise can
be obtained from http://nihroadmap.nih.gov/clinicalresearch/
overview-translational.asp

Received

2009-06-26T00:00:00