How Heart Disease Develops Over Decades

Atherosclerosis, the plaque buildup behind most heart attacks and strokes, starts decades before symptoms. ApoB-containing particles (mostly LDL) enter the artery wall, get trapped, and trigger an inflammatory response. Over years, the trapped particles and inflammation grow into plaque.

The longer cholesterol stays high, the more plaque builds. Two people with the same LDL-C at age 55 can carry very different amounts of plaque, depending on how long their levels have run high.

As early as the teens. In the PDAY study, which examined arteries of young people who died of other causes, early lesions were present in every aorta and more than half of the right coronary arteries of 15 to 19 year olds. They grew more common and more extensive through age 34.

The benefit adds up over time. A Mendelian randomization study, which uses inherited gene variants as a natural experiment, found that people with genetically lower LDL-C from birth had about a three-fold greater reduction in coronary heart disease risk per unit of LDL-C lowering than people who started a statin later in life.

Partly. Lowering LDL hard can shrink plaque a little and make it more stable. In the GLAGOV trial, adding evolocumab to a statin shrank coronary plaque in 64% of patients, compared with 47% on a statin alone. Calcium already in plaque stays, and the risk of a heart attack still falls.

If you have high cholesterol in your 30s, 40s, or 50s, each year you spend at a lower LDL before a cardiac event means less plaque and less risk. That does not mean everyone needs medicine right away. For some people, diet and lifestyle changes are enough.

For others, particularly those with a strong family history, a high ApoB, or a high Lp(a), earlier prescription treatment lowers long-term risk more. Advanced testing such as ApoB and Lp(a) fills in what a basic panel leaves out. Talk it through with your clinician.