Reference Ranges and Regional Patterns of Left Ventricular Strain and Strain Rate Using Two-Dimensional Speckle-Tracking Echocardiography in a Healthy Middle-Aged Black and White Population: The CARDIA Study.

BACKGROUND: Strain and strain rate are sensitive markers of left ventricular (LV) myocardial function. The aim of this study was to assess reference ranges and regional patterns of LV strain and strain rate using two-dimensional speckle-tracking echocardiography in a large population of black and white subjects. METHODS: This study involved a retrospective review of prospectively collected images in 557 participants in the Coronary Artery Risk Development in Young Adults study who remained healthy at the year 25 examination. LV deformation parameters were measured in apical four-chamber, apical two-chamber, and parasternal short-axis views in 509, 391, and 521 subjects, respectively. RESULTS: Patients' mean age was 49.6 ± 3.6 years, 61.6% were women, and 69.5% were white. White women showed the highest LV systolic and diastolic deformation values, reflected by a more negative reference range for apical four-chamber longitudinal strain (-16.4%; 95% prediction interval [PI], -20.8% to -12.0%) and a higher positive reference range for early diastolic strain rate (0.93 1/sec; 95% PI, 0.41 to 1.46 1/sec), respectively. The lowest LV systolic and diastolic deformation values were found in black men, with apical four-chamber longitudinal strain (14.7%; 95% PI, -19.1% to -10.3%) and early diastolic strain rate (0.79 1/sec; 95% PI, 0.42 to 1.16 1/sec). Absolute strain increased from the epicardium toward the endocardium. A base-to-apex gradient of longitudinal strain toward the apex was exhibited in inferior and inferoseptal regions and, in contrast, in the opposite direction in anterior and anterolateral walls. Sex had the strongest influence on LV deformation variability. CONCLUSIONS: Strain and strain rate reference values were sex and race related. White women showed the highest reference ranges for LV deformation, while the lowest values were found in black men. Significant layer- and level-specific patterns in regional LV deformation were identified.

Age at Menarche and Cardiometabolic Risk in Adulthood: The Coronary Artery Risk Development in Young Adults Study.

OBJECTIVE: To examine the association of menarche timing with cardiometabolic risk factors into early to mid-adulthood, comparing African American and White women. STUDY DESIGN: Analyses included 2583 women (African American = 1333; White = 1250) from the Coronary Artery Risk Development in Young Adults cohort study over 25 years of follow-up (1985-2011). Outcomes included type 2 diabetes, metabolic syndrome, adiposity, glucose, insulin, blood pressure, and blood lipids. Cox models or repeated measures linear regression models estimated the association between age at menarche and the outcomes. RESULTS: Each 1-year earlier age at menarche was associated with higher mean body mass index among African American (0.88 ± 0.12 kg/m(2), P < .0001) and White (0.89 ± 0.10 kg/m(2), P < .0001) women. After body mass index adjustment, each 1-year earlier age at menarche was associated with higher triglycerides (2.26 ± 0.68 mg/dL, P = .001) and glucose (0.34 ± 0.11 mg/dL, P = .002), and greater risk for incident impaired fasting glucose (hazard ratio = 1.13, 95% CI 1.04-1.20) and metabolic syndrome (hazard ratio 1.19, 95% CI 1.11-1.26) among White women only. CONCLUSIONS: Excess adiposity associated with earlier menarche is sustained through mid-adulthood, and primarily drives higher cardiometabolic risk factor levels. However, White women with earlier menarche had increased risk of a number of insulin-resistance related conditions independent of adiposity. The cardiometabolic impact of earlier menarche was weaker in African American women despite higher average adiposity. Weight maintenance would likely reduce but may not completely eliminate the elevated cardiometabolic risk of earlier menarche.

Framingham score and LV mass predict events in young adults: CARDIA study.

BACKGROUND: Framingham risk score (FRS) underestimates risk in young adults. Left ventricular mass (LVM) relates to cardiovascular disease (CVD), with unclear value in youth. In a young biracial cohort, we investigate how FRS predicts CVD over 20 years and the incremental value of LVM. We also explore the predictive ability of different cut-points for hypertrophy. METHODS: We assessed FRS and echocardiography-derived LVM (indexed by body surface area or height2.7) from 3980 African-American and white Coronary Artery Risk Development in Young Adults (CARDIA) participants (1990-1991); and followed over 20 years for a combined endpoint: cardiovascular death; nonfatal myocardial infarction, heart failure, cerebrovascular disease, and peripheral artery disease. We assessed the predictive ability of FRS for CVD and also calibration, discrimination, and net reclassification improvement for adding LVM to FRS. RESULTS: Mean age was 30±4 years, 46% males, and 52% white. Event incidence (n=118) across FRS groups was, respectively, 1.3%, 5.4%, and 23.1% (p<0.001); and was 1.4%, 1.3%, 3.7%, and 5.4% (p<0.001) across quartiles of LVM (cut-points 117 g, 144 g, and 176 g). LVM predicted CVD independently of FRS, with the best performance in normal weight participants. Adding LVM to FRS modestly increased discrimination and had a statistically significant reclassification. The 85th percentile (≥116 g/m2 for men; ≥96 g/m2 for women) showed event prediction more robust than currently recommended cut-points for hypertrophy. CONCLUSION: In a biracial cohort of young adults, FRS and LVM are helpful independent predictors of CVD. LVM can modestly improve discrimination and reclassify participants beyond FRS. Currently recommended cut-points for hypertrophy may be too high for young adults.