Best predictor for coronary artery disease
Elevated LDL cholesterol and decreased HDL cholesterol are independent predictors of coronary heart disease.
Although there is consensus regarding the benefits of lowering LDL cholesterol the value of elevating HDL
cholesterol remains controversial.
Low HDL and coronary risk
High serum HDL cholesterol is associated with a lower risk of CHD.
The incidence of CHD events in a normal population appears to be inversely related to serum HDL cholesterol with
low levels being associated with increased coronary risk.
Based upon data from the Framingham Heart study, the risk for myocardial infarction increases by about 2 5% for
every 5mg/dl (.13 mmol/l) decrement in serum HDL cholesterol.
Elevated LDL and coronary risk
Elevation in LDL cholesterol is a well-known risk factor for the development of coronary artery disease.
Association of elevated LDL with coronary artery disease has been established in various trials and studies.
There is linear reduction in cardiovascular disease with progressive lowering of the LDL cholesterol.
Traditionally LDL levels are considered to be the most important factor in the prediction of coronary artery disease.
The importance of LDL as a risk factor lies in the fact that effective therapies are available to lower it, while it is not
so in the case of HDL. So when treating dyslipidemia for reducing cardiovascular events, the first target is LDL and
not HDL.
Doubt and Controversy
What is creating doubts in our mind is a table from Braunwald 8th/e p1008 according to which ‘Low HDL’ appears to
be better marker for prediction of future cardiovascular disease than ‘High LDL’
According to this bar diagram in Braunnwald 8th/e pl008 - the adjusted hazard ratio for future cardiovascular events
for LDL is 1.62 while that of HDL is 2.32. But the text given in the book does clarify which one is better marker, (we
have given this table from Braunwald in our previous discussion on this topic in Nov 2009 Medicine).
We have tried to confirm this ‘Low HDL’ fact from various other books. But none of the texts clearly favored any one
between these 2 to be the better marker. Both LDL and HDL are mentioned to be important.
We have also consulted several cardiologist on this. All of them say that the answer should be LDL.
Well, Braunwald is text book of immense reputation, and any information or text given in the book does not need
confirmation from any other source. But what has added to the confusion is that the latest edition of Braunwald i.e.,
9th/e has eliminated that diagram from the book and in the text have not clarified which one is better marker.
Instead, the text states that Apolipo (a) and B 100 are better marker for predicting future cardiovascular events than
LDL and HDL.
We are not absolutely sure of the answer, but we would for the time being go with LDL.
Also Know
The following lipid and lipoprotein abnormalities are associated with increased coronary risk.
Elevated total cholesterol
Elevated LDL cholesterol
Low HDL cholesterol
Increased total to HDL cholesterol ratio
Increased non HDL cholesterol
Hypertriglyceridemia
Increased Lp(a)
Increased apolipoprotein B
Small dense LDL particles
HDL
LDL
VLDL
Chylomicron