PurposeThe American Heart Association recently issued a substantial update to the definition and scoring of cardiovascular health (CVH), now called “Life's Essential 8” (LE8). We aimed to assess the trends in overall and individual LE8 CVH metrics among adolescents in the United States. MethodsA total of 6,999 United States adolescents aged 12–19 years from six cycles of the National Health and Nutrition Examination Survey from 2007–2008 to 2017–2018 were included in this study. The individual LE8 metrics included diet, physical activity, nicotine exposure, sleep health, body mass index (BMI), blood lipids, blood glucose, and blood pressure (BP). A higher CVH score indicates better CVH health. ResultsThe mean score of overall CVH significantly increased from 72.8 (95% confidence interval: 71.2–74.3) in 2007–2008 to 77.3 (76.1–78.5) in 2017–2018 in US adolescents (p-trend < .001). From 2007–2008 to 2017–2018, the mean scores increased from 75.5 (72.0–79.1) to 90.0 (88.0–91.9) for nicotine exposure, from 65.2 (61.6–68.8) to 73.3 (69.9–76.8) for sleep health, from 69.9 (67.1–72.8) to 73.0 (69.1–76.9) for blood lipids, and from 94.4 (93.0–95.9) to 96.2 (95.2–97.3) for BP (all p-trend < .05). However, the mean scores for diet, physical activity, and blood glucose did not significantly change (all p-trend > .05), whereas the mean score decreased from 81.4 (78.9-84.0) to 78.6 (76.4–80.8) for BMI (p-trend = .023). DiscussionIn United States adolescents, the overall CVH and four components (nicotine exposure, sleep health, blood lipids, and BP) significantly improved over time, diet, physical activity, and blood glucose remained unchanged, whereas BMI worsened.