What is a coronary risk factor ?
Right from the days of Framingham study we have conferred a privileged place to few cardiac risk factors.
- Diabetes mellites
They are referred to as conventional risk factors . What is the convention ? Do they deserve the cult status they enjoy ?
Today we also have a cluster of non conventional risk factors like , Lip (a) , low HDL, Homocystenemia , CRP , Apo B etc . Currently , in any large cohort of CAD up to 30 % do not exhibit even a single conventional risk factor . This is a huge number .Hence we tend to give more importance to genetic make up and mental stress etc .The search is still on for newer risk factors .
Why some research findings are difficult to comprehend ?
It is because we are yet to decode the intricacies of human biology fully . Our knowledge is so superficial , as we chase a pseudo scientific proofs for a presumed hypothesis. The classical example is the concept called good cholesterol (HDL) and reverse cholesterol transport which is never based on solid scientific foundations.
Take the sorry story of Torcetrapib
Many consider low HDL as an independent CAD risk factor to be a myth or else why should we miserably fail to have any positive effect of increasing the HDL levels by pharmacological means . (One argument is physiological and natural elevation of HDL would still be beneficial . But the issue is still wrapped in a statistical mystery
This paper from JAMA adds further insight into our ignorance about the genesis of CAD .
The data is from NRMI registry.
The statistics reveal a stunning fact .In the overall CAD cohort , patients with no major risk factors experience highest mortality and the ones with maximum risk factors have least mortality ! What a shocker of a study ?
This paper would bring jitters to the population , but in the real sense it sends an important message .
A significant population develop CAD without any known risk factors.(14.5% in NRMI registry )
If a person develops a CAD without any major risk factor , it seems . . . it is not at all a good news ! rather we need to introspect , why without any risk factor he or she has suffered CAD ,
One inference is their vascular system is more vulnerable ! Some hidden factors are operating . How to manage such patients without any target to intervene ? A diabetic dyslipidemic smoker has a definite therapeutic target .
What about these lesser humans who develop CAD without any known risk factors ? They tend to suffer more !
Is CAD due to DM/SHT is better than others ? This study seems to say so ” Known devils are better than unknown ones “
Unlearning is an “essential and fundamental” component of scientific learning . In this progressive scientific world , this applies most to medical profession than any other field !