Association of coronary heart disease risk factors with microscopic qualities of coronary atherosclerosis in youth

Background - This study examined whether atherosclerosis in young people is associated with the risk factors for clinical coronary heart disease (CHD). Methods and Results - Histological sections of left anterior descending coronary arteries (LADs) from 760 autopsied 15-to 34-year-old victims of accidents, homicides, and suicides were graded according to the American Heart Association (AHA) system and computerized morphometry. Risk factors (dyslipoproteinemia, smoking, hypertension, obesity, impaired glucose tolerance) were assessed by postmortem measurements. Approximately 2% of 15- to 19-year-old men and 20% of 30- to 34-year-old men had AHA grade 4 or 5 (advanced) lesions. No 15- to 19-year-old women had grade 4 or 5 lesions; 8% of 30- to 34-year-old women had such lesions. Approximately 19% of 30- to 34- year-old men and 8% of 30- to 34-year-old women had atherosclerotic stenosis ≥40% in the LAD. AHA grade 2 or 3 lesions (fatty streaks), grade 4 or 5 lesions, and stenosis ≥40% were associated with non-HDL cholesterol ≥4.14 mmol/L (160 mg/dL). AHA grade 2 or 3 lesions were associated with HDL cholesterol <0.91 mmol/L (35 mg/dL) and smoking. AHA grade 4 or 5 lesions were associated with obesity (body mass index ≥30kg/m²) and hypertension (mean arterial pressure ≥110 mm Hg). Conclusions - Young Americans have a high prevalence of advanced atherosclerotic coronary artery plaques with qualities indicating vulnerability to rapture. Early atherosclerosis is influenced by the risk factors for clinical CHD. Long-range prevention of CHD must begin in adolescence or young adulthood.