Normal reference range values in adult echocardiography: Further evidence that race matters

Normal Values of Left Ventricular Size and Function on 3D Echocardiography: Results of the World Alliance of Societies of Echocardiography Study

BACKGROUND

Echocardiography remains the most widely used modality to assess left ventricular (LV) chamber size and function. Currently this assessment is most frequently performed using 2D echocardiography (2DE). Yet, 3D echocardiography (3DE) has been shown to be more accurate and reproducible than 2DE. Current normative reference values for 3D LV analysis are predominantly based on data from North America and Europe. The World Alliance of Societies of Echocardiography (WASE) study was a designed to sample normal subjects from around the world to provide more universal global reference ranges. In this study we sought to assess the world-wide feasibility of LV 3DE and report on size and function measurements.

METHODS

2262 healthy subjects were prospectively enrolled from 19 centers in 15 countries. 3D LV full-volume datasets were obtained and analyzed offline with vendor-neutral software. Measurements included end-diastolic and end-systolic volumes (EDV, ESV), ejection fraction (EF), global longitudinal and circumferential strain (GLS and GCS). Results were categorized by age (18-40, 41-65 and >65 years), sex and race.

RESULTS

1589 subjects (feasibility 70%) had adequate LV datasets for analysis. Mean normal values for indexed EDV, ESV and EF in men and women were 70 ± 15 and 65 ± 12 mL, 28 ± 7 and 25 ± 6 mL and 60 ± 5, 62 ± 5% respectively. Men had larger LV volumes and lower EF than women. GLS and GCS were higher in magnitude in women. In both sexes, LV volumes were lower and EF tended to be higher with increasing age, especially considering the differences between the youngest and oldest age groups. While GLS was similar across age groups in men, in women, the youngest and middle-age cohorts revealed higher magnitudes of GLS when compared to the oldest age group. GCS was higher in magnitude at older age in both men and women. Finally, Asians had smaller chamber sizes and higher EF and absolute strain values than both blacks and whites.

CONCLUSIONS

Age, sex, and race should be considered when defining normal reference values for LV dimension and function parameters obtained by 3DE.

Age- and Body Size-Adjusted Left Ventricular End-Diastolic Dimension in a Japanese Hospital-Based Population

BACKGROUND

Using the normal values for the East Asian population, we evaluated age- and body size-adjusted left ventricular end-diastolic dimension (LVEDD) and its prognostic impact in a hospital-based population in Japan. Methods and Results: We retrospectively analyzed data obtained from 4,444 consecutive patients who had undergone both transthoracic echocardiography and electrocardiography at Kitano Hospital in 2013. Those who presented with a history of previous episodes of myocardial infarction and severe or moderate valvular disease or with low ejection fraction (<50%) were excluded from the analysis. We calculated LVEDD adjusted by age and body surface area. A total of 3,474 patients were categorized into 3 groups: 401 with large adjusted LVEDD, 2,829 with normal adjusted LVEDD, and 244 with small adjusted LVEDD. Mean patient age in the large, normal, and small adjusted LVEDD groups was 66.6±18.4, 65.6±15.7, and 62.1±15.5 years, respectively (P<0.001). After adjusting for confounding factors, the excess adjusted 3-year risk of primary outcome of large adjusted LVEDD relative to normal LVEDD was significant (HR, 1.40; 95% CI: 1.08-1.78). The risk for primary outcomes of small adjusted LVEDD relative to normal adjusted LVEDD was significantly lower (HR, 0.55; 95% CI: 0.34-0.85).

CONCLUSIONS

Adjusted large LVEDD has a deleterious impact on long-term mortality, whereas small LVEDD carried a significantly lower risk.