The Impact of the Apolipoprotein E Genotype on Cardiovascular Disease and Cognitive Disorders

Apolipoprotein E (ApoE) plays a critical role in cholesterol transport and protection against the development of atherosclerotic cardiovascular disease (ASCVD). Humans have 3 prevalent isoforms of ApoE: apolipoprotein E2 (ApoE2), apolipoprotein E3 (ApoE3), and apolipoprotein E4 (ApoE4). The E4 allele has been associated with higher ASCVD risk. While E4 patients do have higher cholesterol levels, they do not have enough to account for the substantially elevated ASCVD risk relative to E2 and E3 patients. ASCVD risk calculators would underestimate the true effect of E4 if the difference was caused entirely by a difference in cholesterol level. This article reviews the function of ApoE in atherosclerosis, and how each isoform functions differently. We review what is known about the molecular mechanisms through which ApoE prevents endothelial dysfunction and damage, how ApoE stimulates macrophage efflux of cholesterol from atherogenic lesions, and the ways in which ApoE decreases inflammation throughout atherosclerosis. The impact of ApoE on Alzheimer's disease and a discussion of why it is possibly unrelated to ASCVD prevention are included. Clinical applications to hyperlipidemia management and ASCVD prevention in specific patient populations are discussed.

Use of the DASH Diet and Coronary Artery Disease

Initial dietary approach to stop hypertension (DASH) diet feeding trials showed blood pressure (BP)-lowering effects that corresponded to higher degrees of concordance with the diet. These results popularized the idea that adherence to a DASH diet could reduce coronary artery disease (CAD) risk for patients. Recent evidence shows that the impact of DASH on CAD incidence and risk is less clear. While many studies show that the DASH diet impacts CAD risk factors, others suggest that these effects do not remain when important confounders are controlled. Also, the evidence from meta-analyses that the DASH diet impacts incident CAD is still inconclusive. Reassessment of the DASH diet, and the search for an ideal diet to prevent CAD will require a better understanding of the mechanisms through which the DASH diet works. Proposed mechanisms for its benefit include preventing inflammation and atherosclerosis progression as well as providing a heathy balance of dietary sodium and potassium intake.

The Impact of Long COVID-19 on the Cardiovascular System

Long coronavirus disease (COVID) is the development or persistence of symptoms after an acute SARS-CoV-2 (COVID-19) infection. Fewer patients are developing acute COVID-19 infections, but patients with long COVID continue to have alarming long-term sequelae. Many cardiac magnetic resonance imaging studies show significant changes in cardiac structure after a COVID-19 infection, suggestive of an increased burden of many cardiovascular diseases, notably myocarditis. The pathophysiology of COVID-19 requires viral binding to angiotensin-converting enzyme 2 protein receptors throughout the body, which are upregulated by inflammation. Consequently, the numerous preexisting conditions that worsen or prolong inflammation enhance this binding and have differing effects on patients based on their unique immune systems. These pathophysiological changes drive long COVID cardiac sequelae such as inappropriate sinus tachycardia, postural orthostatic tachycardia, and other types of orthostatic intolerance. Increased screening for long COVID and low-risk interventions such as exercise regimens could alleviate the suffering endured by patients with long COVID. Many studies such as the Researching COVID to Enhance Recovery Initiative (RECOVER) trials at the National Institutes of Health are exploring potential treatments for long COVID patients.