Table 4 Diagnostic Accuracy of cardiac ultrasound—Subgroup Analyses
| Â | Number of studies (Participants) | Number of patients with Myocardial Ischemia (%) | Summary sensitivity % (95% confidence interval) | P value | Summary specificity % (95% confidence interval) | P value |
|---|---|---|---|---|---|---|
Patient spectrum | ||||||
 Excludes HD | 13 (1880) | 820 (43.6) | 74.1 (58.0 to 85.5) | 0.168 | 91.0 (84.1 to 95.1) | 0.029 |
 Includes HD | 13 (2985) | 1432 (48.0) | 85.8 (73.5 to 93.0) |  | 78.0 (66.1 to 86.6) |  |
Ultrasound Operator | ||||||
 Cardiology | 6 (727) | 276 (38.0) | 90.2 (73.7 to 96.8) | 0.720 | 88.1 (71.8 to 95.5) | 0.983 |
 Emergency medicine | 6 (1790) | 1136 (63.5) | 83.1 (60.2 to 94.1) |  | 89.2 (73.4 to 96.1) |  |
 Sonographer | 3 (735) | 500 (68.0) | 83.7 (55.8 to 95.4) |  | 87.6 (59.5 to 97.1) |  |
Timing of Ultrasound | ||||||
 At admission | 9 (2700) | 1797 (66.6) | 89.5 (78.9 to 95.1) | 0.038 | 81.5 (66.2 to 90.8) | 0.389 |
 First 24 h | 4 (1025) | 229 (22.3) | 62.8 (34.6 to 84.3) |  | 89.5 (71.4 to 96.7) |  |
Type of Ultrasound Device | ||||||
 Echocardiography device | 20 (4413) | 2248 (50.9) | 81.1 (70.7 to 88.5) | 0.809 | 87.1 (77.8 to 92.9) | 0.945 |
 Cart/Tray-based or Handheld | 4 (242) | 39 (16.1) | 84.0 (53.2 to 96.0) |  | 86.5 (58.1 to 96.7) |  |
Type of Cardiac Ultrasound Protocol | ||||||
 TTE | 23 (3193) | 1186 (37.1) | 79.1 (67.5 to 87.3) | 0.827 | 88.3 (79.9 to 93.4) | 0.681 |
 POCUS | 5 (1824) | 1140 (62.5) | 76.4 (47.9 to 91.9) |  | 84.7 (59.5 to 95.4) |  |
Reference Standard | ||||||
 Cardiac enzymes only | 3 (340) | 54 (15.9) | 93.8 (73.9 to 98.8) | 0.082 | 50.7 (23.8 to 77.3) | 0.014 |
 Chart review | 11 (2968) | 1451 (48.9) | 65.8 (47.9 to 80.1) |  | 93.0 (86.7 to 96.4) |  |
 Combination of tests | 7 (609) | 186 (30.5) | 74.2 (52.3 to 88.3) |  | 85.2 (70.6 to 93.2) |  |
 Coronary angiography | 7 ( 948) | 632 (66.7) | 87.0 (73.2 to 94.3) |  | 88.7 (76.2 to 95) |  |
Target Condition | ||||||
 Myocardial infarction | 8 (2138) | 1159 (54.2) | 90.7 (78.3 to 96.3) | 0.035 | 67.4 (49.4 to 81.4) | 0.002 |
 Acute coronary syndrome | 16 (2433) | 897 (36.9) | 68.0 (53.3 to 79.8) |  | 93.2 (88.2 to 96.2) |  |
Significant coronary stenosis | 5 (472) | 274 (58.1) | 85.0 (65.4 to 94.4) | Â | 82.7 (81.5 to 91.2) | Â |