Table 2:
Comparison of Demographics, Echo Characteristics, and Outcomes Stratified by Test Cohort
| Boston Children’s Hospital | Mount Sinai Hospital | ||
|---|---|---|---|
| Internal Testing | Emergency Department | External Validation | |
| Demographics | |||
| Patients | 12,631 | 2,830 | 5,088 |
| ECG-echo Pairs | 12,631 | 2,830 | 5,088 |
| Sex | |||
| Female | 5,859 (46%) | 1,217 (43%) | 2,696 (53%) |
| Male | 6,772 (54%) | 1,613 (57%) | 2,376 (47%) |
| Missing | — | — | 16 (0.3%) |
| Age at ECG (years) | 8.8 (2.8, 14.4) | 7.7 (1.2, 14.5) | 4.3 (0.3, 12.2) |
| Echo Characteristics | |||
| LVEF (%) | 63.0 (59.0, 66.0) | 62.0 (58.0, 66.0) | 62.1 (58.6, 65.8) |
| LVEF (z-score) | −0.1 (−0.9, 0.6) | −0.3 (−1.2, 0.6) | −0.3 (−1.0, 0.5) |
| LV mass (g) | 62.7 (32.5, 102.4) | 59.9 (25.3, 105.0) | 36.9 (13.4, 78.3) |
| LV mass (z-score) | 0.5 (−0.2, 1.4) | 0.7 (−0.1, 1.8) | 0.0 (−0.8, 1.1) |
| LV EDV (mL) | 77.3 (39.9, 121.8) | 70.6 (29.5, 118.2) | 47.8 (15.8, 97.8) |
| LV EDV (z-score) | 0.6 (−0.2, 1.3) | 0.6 (−0.3, 1.6) | 0.4 (−0.4, 1.4) |
| Qualitative Outcomes | |||
| Composite LV outcome | 567 (4.5%) | 260 (9.2%) | — |
| LV dysfunction | 150 (1.2%) | 123 (4.3%) | — |
| LV hypertrophy | 232 (1.8%) | 94 (3.3%) | — |
| LV dilation | 254 (2.0%) | 102 (3.6%) | — |
| Quantitative Outcomes * | |||
| Composite LV outcome | 437/9,476 (4.6%) | 203/1,974 (10.0%) | 280/4,602 (6.1%) |
| LV dysfunction | 83/9,565 (0.9%) | 87/2,036 (4.3%) | 61/5,080 (1.2%) |
| LV hypertrophy | 294/9,484 (3.1%) | 128/1,980 (6.5%) | 153/4,602 (3.3%) |
| LV dilation | 253/9,576 (2.6%) | 95/2,036 (4.7%) | 206/4,747 (4.3%) |
Data presented as median (interquartile range). Note qualitative outcomes not available for the external validation site.
Abbreviations: left ventricle (LV); beats per minute (BPM); ejection fraction (EF); end-diastolic volume (EDV).
*
Outcome rates presented as number of events/number of eligible echos based on z-score availability.