How much does HDL cholesterol add to risk estimation? A report from the SCORE Investigators.
BACKGROUND
Systematic COronary Risk Evaluation (SCORE), the risk estimation system recommended by the European guidelines on cardiovascular disease prevention, estimates 10-year risk of cardiovascular disease mortality based on age, sex, country of origin, systolic blood pressure, smoking status and either total cholesterol (TC) or TC/high-density lipoprotein cholesterol (HDL-C) ratio. As, counterintuitively, these two systems perform very similarly, we have investigated whether incorporating HDL-C and TC as separate variables improves risk estimation.


METHODS
The study consisted of 57,302 men and 47,659 women. Cox proportional hazards method was used to derive the function including HDL-C and an identical function without HDL-C for comparison. Risk charts were developed to illustrate the results.


RESULTS
Inclusion of HDL-C resulted in a modest but statistically significant improvement in risk estimation, based on the area under receiver operating characteristic curve (AUROC); 0.814 versus 0.808, P value less than 0.0001, for the functions with and without HDL-C, respectively. Addition of HDL-C also resulted in a significant and important improvement in risk estimation as measured by net reclassification index, which is highly clinically relevant. Improvement in risk estimation was greatest in women from high-risk countries, in terms of both AUROC and net reclassification index.


CONCLUSIONS
For the general population, the inclusion of HDL-C in risk estimation results in only a modest improvement in overall risk estimation based on AUROC. However, when using the more clinically that examines reclassification of individuals, clinically useful improvements occur. Inclusion of HDL may be particularly useful in women from high-risk countries and individuals with unusually high or low HDL-C levels. Addition of HDL-C is particularly applicable to electronic, interactive risk estimation systems such as HeartScore.
Cooney
Marie Therese
MT
Department of Cardiology Adelaide Meath Hospital, Tallaght, Dublin 24, Ireland.
Dudina
Alexandra
A
De Bacquer
Dirk
D
Fitzgerald
Anthony
A
Conroy
Ronan
R
Sans
Susana
S
Menotti
Alessandro
A
De Backer
Guy
G
Jousilahti
Pekka
P
Keil
Ulrich
U
Thomsen
Troels
T
Whincup
Peter
P
Graham
Ian
I
D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology* / Q000401:mortality; D002784:Cholesterol / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood*; D050171:Dyslipidemias / Q000097:blood / Q000150:complications* / Q000401:mortality; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D016016:Proportional Hazards Models; D012372:ROC Curve; D018570:Risk Assessment; D012307:Risk Factors
D015415:Biomarkers; D008076:Cholesterol, HDL; D002784:Cholesterol