Coronary Artery Disease (CAD)

Coronary Artery Disease (CAD)

APOE4 is risk factor for myocardial infarction and death from CAD. The risk is most apparent in younger patients and most evident when look at fatal cases. 

In Song (59) a meta-analysis that looked at 48 relevant studies APOE4 was a significant risk factor for Coronary heart disease (CHD) wirh 42% higher risk for CHD. (OR 1.42).

In Framingham Offspring Study (60) the odds ratio was 1.53 in men and 1.99 in women. In women APOE4 carrier status associated with moderately elevated LDL cholesterol. In men APOE4 associated with moderately elevated triglycerides. 

In Finnish study (61) of men 65 to 84, during 5 year follow-up, APOE4 positive men had double the rate of death from CHD.

In Helsinki sudden Death Study (62) of 700 male autopsy cases average age 53, range 33 to 70; E4 allele was significant genetic risk factor for coronary atherosclerosis in early middle age. Men with E4 allele had 61% larger total atherosclerotic lesion in RCA (right coronary artery) and 26% larger area in LAD (left coronary artery than E3 men.

In another study (63), patients who had a prior myocardial infarction were followed 5 years. The death rate in control group with E4 was nearly double the death rate in control group with E3. The treatment group was given Simvastin (statin) and E4 carriers completely abolished increased risk of death compared to non-APOE4 group [HR 0.33 for E4 compared to HR 0.66 for non-E4. 

The above study (63) showed Simvastin (Zocor) was especially beneficial for APOE4 group as regards secondary protection, after prior heart attack. 

In angiographic studies APOE4 carriers have more lesions with HR 1.4 for men and HR 1.8 for women. Another angiographic studies showed APOE4 carriers having more severe lesions and more frequent triple vessel disease. 

In summary, APOE4 carriers have more severe CAD at younger age and higher risk of death from CAD; however, they did exceptionally well on Simvastin follwing a hear attack.  

Accordingly, proper treatment in APOE4 carriers should also include measures to also lower risk of death from CAD.