Importance
Coronary heart disease is the most common cause of mortality in
adults in the United States. Treatment to prevent CHD events by
modifying risk factors is currently based on the Framingham risk model,
which sorts individuals into low-, intermediate-, or high-risk groups.
If the risk model could be improved, treatment might be better targeted,
thereby maximizing screening benefits and minimizing harms. The most
likely opportunity to improve the model is use of additional risk
factors to reclassify those in the intermediate-risk group to either
high- or low-risk.
Detection
There is insufficient evidence to determine the percentage of persons
with an intermediate CHD risk who would be reclassified by screening
with nontraditional risk factors other than hs-CRP and ABI.
About 11% of men with an intermediate CHD risk would be reclassified
into the high-risk category by hs-CRP screening, and about 12% of men
would be reclassified into the low-risk category. National estimates of
the number of women who would be reclassified by hs-CRP screening are
not reliable because of small study samples. The available meta-analysis
of individual data on ABI does not yield a clear picture on the
proportion of intermediate-risk men who would be reclassified but does
suggest that approximately 10% of women would be reclassified from
intermediate to high risk for CHD.
Benefits of Detection and Early Intervention
The evidence is insufficient to determine the magnitude of any
reduction in CHD events and CHD-related deaths obtained by using
nontraditional risk factors in CHD screening. This constitutes a
critical gap in the evidence for benefit from screening.
Harms of Detection and Early Treatment
Little evidence is available to determine the harms of using
nontraditional risk factors in CHD screening. Harms include lifelong use
of medications without proof of benefit but with expense and potential
side effects. Statins are the class of medication most commonly used;
these medications have been demonstrated to be safe but are associated
with the rare but serious side effect of rhabdomyolysis.1 Psychological and other harms may result from being put into a higher risk category for CHD events.
USPSTF Assessment
The USPSTF concludes that the evidence is insufficient to determine
the balance between benefits and harms of using nontraditional risk
factors in screening for CHD risk.
Although using hs-CRP and ABI to screen men and women with
intermediate Framingham CHD risk would reclassify some into the low-risk
group and others into the high-risk group, the evidence is insufficient
to determine the ultimate effect on the occurrence of CHD events and
CHD-related deaths.