
Methods: CNICS is an 8-site HIV cohort with >27,000 patients, a centralized data repository with comprehensive clinical data such as lipids, and centralized MI adjudication facilitating comparisons using a definitive, well-defined outcome. We formed a convenience sample using 731 patients who required MI adjudication based on diagnoses or elevated cardiac enzymes. This group represents a high-risk population that may be challenging for risk scores and thus illuminate potential challenges in prediction of high-risk patients. Of the 731 patients, 200 had an adjudicated MI. Using risk status prior to event dates, we compared 4 scores (estimated by Cox models) using area under the curves (AUCs): Framingham NCEP III (FRS), Framingham refit (using HIV-specific calibration), Framingham + (Framingham refit + HIV factors predictive in CNICS: time on indinavir, tenofovir use, current CD4 count, ex-smoker), and the Data Collection on Adverse events of Anti-HIV Drugs (DAD) score (HIV-specific).
Results: DAD and FRS did not have significantly different AUCs for risk discrimination in this key population. Using re-calibration (Framingham refit) resulted in a higher AUC (0.604 vs. 0.538, p=0.03) compared with the FRS. However adding additional HIV-specific risk factors (Framingham refit + HIV) had no influence on the AUC (also 0.604).
|
Adjudicated MIs |
|
Score |
AUC |
95% CI |
FRS |
0.538 |
0.49-0.59 |
Framingham refit |
0.604 |
0.56-0.65 |
Framingham refit + HIV |
0.604 |
0.56-0.65 |
DAD |
0.511 |
0.46-0.56 |
Conclusion: We found adding HIV-specific risk factors did not substantially improve a FRS refit model in this difficult to stratify population. This high-risk population results in lower AUC because these individuals are hard to stratify in advance using baseline risk factors. However, performance in these populations does illustrate how robust these scores are in homogenous sub-populations. Future studies will focus on primary MIs rather than all adjudicated MIs and extend our risk score validation in the entire cohort.

R. Nance,
None
S. Heckbert, None
M. Budoff, None
P. Paramsothy, None
C. Grunfeld, None
G. A. Burkholder, None
J. H. Willig, None
M. J. Mugavero, None
W. C. Mathews, None
C. V. Rodriguez, None
R. Moore, None
J. Eron, Jr., Janssen Services, LLC: Consultant, Consulting fee
Gilead Sciences, Inc.: Consultant, Consulting fee
S. Napravnik, None
P. Crane, None
P. Hunt, None
P. Hsue, None
W. Lober, None
M. Kitahata, None
M. S. Saag, None
H. M. Crane, None