| Several of your claims are inaccurate, which I'll attempt to correct. tl;dr - its way more complicated LDL particles are not (at least directly) a part of the immune system. They are lipoproteins, generated primarily in the liver, that are implicated in the pathogenesis of atherosclerosis (buildup of plaques in the blood vessels). The immune system, however, plays an important role in atherosclerosis, as it is thought that inflammation in the vasculature contributes to atherosclerosis. Statins (contrary to your assertion) have in fact been conclusively shown to improve mortality from cardiovascular events. You can find many studies in the last 20 years that have demonstrated this with high statistical significance (do a pubmed search or look for articles in the New England Journal of Medicine). Perhaps most interestingly, the latest research suggests that statins may improve cardiovascular outcomes not solely from LDL reduction (which has been the classically accepted hypothesis, as statins target the enzyme in the liver that regulates LDL reuptake), but also through anti-inflammatory mechanisms. This idea has been further strengthened by research suggesting that LDL reduction alone (as with a newer agent of drugs called anti PCSK9) may not provide as strong of a mortality benefit, weakening what is known as the "LDL hypothesis". In addition, another recent trial (called CANTOS) found that an anti-inflammatory agent targeting IL-1, an inflammatory cytokine, improved cardiovascular outcomes (such as heart attacks), further strengthening the notion that the immune system plays a key role in cardiovascular disease. |