Chapter 73
Cardiovascular Disease — 12
Like coronary artery disease, atrial fibrillation is largely asymptomatic, and about 10 to 20 percent is undiagnosed. However, the ease of detection has been markedly enhanced with AI algorithms embedded in some smartwatches and fingertip sensors that can be used to record one lead of the electrocardiogram when a person feels they may have an abnormal heart rhythm.
We can’t change our age or height or genetics. But we can determine our genetic risk with a polygenic risk score. Over one hundred genetic loci have been identified to associate with risk of developing atrial fibrillation. The Mass General Brigham study found over 8 percent of their patient population assessed had a high polygenic risk score, with a doubling of risk across white, Black, and Asian ancestries. In a large study of twenty-five thousand adults, high polygenic risk in the top 3 percent was associated with a doubling of the odds ratio for multiple ancestries. A polygenic risk score can also help predict the risk of stroke associated with atrial fibrillation. Reflecting the higher risk noted with gum disease, inflammation blood markers such as hs-CRP, interleukin-6, and tumor necrosis factor are associated with increased risk, as is brain natriuretic peptide. The heart organ proteomic aging clock reviewed earlier also is predictive. Not unexpectedly, with their anti-inflammatory and marked weight loss effects, the GLP-1 drugs tested in multiple randomized trials have shown substantial reduction of atrial fibrillation. And finally, epigenetic markers by DNA methylation can help identify people at increased risk for atrial fibrillation. But the sad fact is that none of these omic tests are used in mainstream clinical practice.
Using AI, the 12-lead electrocardiogram in people who have never had this kind of heart arrhythmia can be used to help accurately gauge risk of subsequently developing AF and stroke. Blood thinners for people with atrial fibrillation at increased risk for stroke are highly effective.
Acommon thread runs through these two major age-related cardiovascular conditions that pose serious risks of heart attack, stroke, and death. The conditions are both often subclinical—a large proportion of the population are incubating the disease or are sitting at high risk. Using genetic and inflammatory markers, we can do far better at detecting who they are and then taking steps to prevent these conditions from developing. In short, we know how to suppress the most important age-related cardiovascular diseases now—expand health span—but we’re not doing it.
Let’s turn to cancer. We’ll see many parallels.