Summary of high-risk features in patients with asymptomatic carotid artery stenosis
| Microembolic detection38* | |||
| Study | Ipsilateral strokes with embolic signals | Without embolic signals | OR (95% CI) |
| ACES38 | 5/77 (6.5%) | 5/390 (1.3%) | 5.35 (1.51 to 18.94) |
| Abbott et al78 | 2/60 (3.3%) | 4/171 (2.3%) | 1.44 (0.26 to 8.07) |
| Molloy and Markus79 | 1/12 (8.3%) | 0/30 (0%) | 7.96 (0.30 to 209.7) |
| Orlandi et al80 | 3/6 (50.0%) | 0/15 (0%) | 31.00 (1.29 to 747.03) |
| Slebler et al81 | 1/8 (12.5%) | 1/56 (1.8%) | 7.86 (0.44 to 140.14) |
| Spence et al82 | 5/32 (15.6%) | 3/287 (1.0%) | 17.53 (3.97 to 77.38) |
| Total | 17/195 (8.7%) | 13/949 (1.4) | 6.63 (2.85 to 15.44) |
| Plaque echolucency43* | |||
| Study | Ipsilateral strokes with echolucent plaque | With echogenic plaque | RR (95% CI) |
| Grønholdt et al83 | 8/63 (12.7%) | 7/48 (14.6%) | 0.87 (0.34 to 2.23) |
| Mathiesen et al84 | 5/100 (5.0%) | 1/77 (1.3%) | 3.85 (0.46 to 32.28) |
| Nicolaides et al85 | 28/409 (6.8%) | 21/677 (3.1%) | 2.23 (1.28 to 3.87) |
| O'Holleran et al86 | 13/88 (14.8%) | 6/205 (2.9%) | 5.12 (2.01 to 13.04) |
| Polak et al87 | 30/856 (3.5%) | 73/4030 (1.8%) | 1.96 (1.25 to 2.90 |
| Silvestrini et al88 | 8/61 (13.1%) | 31/560 (5.5%) | 2.58 (1.13 to 5.89) |
| Topakian et al89 | 8/164 (4.9%) | 2/271 (0.7%) | 6.61 (1.42 to 30.75) |
| Total | 100/1741 (5.7%) | 141/5868 (2.4%) | 2.48 (1.90 to 3.22) |
| Progression of stenosis | |||
| Study | Ipsilateral strokes with progression | Without progression | RR (95% CI) |
| Conrad et al55* | 36/262 (13.7%) | 54/638 (8.5%) | 1.62 (1.09 to 2.41) |
| Kakkos et al57 | 19/222 (8.6%) | 40/899 (4.5%) | 1.92 (1.14 to 3.25) |
| Total† | 55/484 (11.4%) | 94/1537 (6.1%) | 1.86 (1.35 to 2.55) |
| Reduced cerebrovascular reserve (CVR) | |||
| Study | Ipsilateral strokes in normal CVR | Impaired CVR | OR (95% CI) |
| Gur et al90 | 0/23 (0.0%) | 2/21 (9.5%) | 6.03 (0.27 to 133.11) |
| Silvestrini et al43 | 4/54 (7.4%) | 8/40 (20.0%) | 3.13 (0.87 to 11.24) |
| Kimiagar et al91 | 0/14 (0.0%) | 6/21 (28.6%) | 12.16 (0.63 to 235.70) |
| Total† | 4/91 (4.4%) | 16/82 (19.5%) | 5.27 (1.68 to 16.51) |
| Intraplaque hemorrhage (IPH) | |||
| Study | Ipsilateral strokes with IPH | Without IPH | HR (95% CI) |
| Schindler et al70 | 8/40 (20.0%) | 2/96 (2.1%) | 14.5 (2.9 to 7.25) |
| Ipsilateral silent brain infarction (SBI) | |||
| Study | Annual stroke rate with prior ipsilateral SBI | Without prior ipsilateral SBI | HR (95% CI) |
| Kakkos et al54 | 3.6% | 1.0% | 3.0 (1.46 to 6.29) |
*This study used ipsilateral neurologic symptom as outcome measure, including ipsilateral stroke, transient ischemic attack, or amaurosis fugax rather than solely ipsilateral strokes.
†Calculation derived from authors.
‡The list of studies obtained these meta-analyses.38 43