Table 3.
Intention-to-Treat Analysis
| Surgical Group (n=97) | Nonsurgical Group (n=98) | |||||
|---|---|---|---|---|---|---|
| Number of Events | Estimated Rate (95% CI) | Number of Events | Estimated Rate (95% CI) | Difference (95% CI) | P Value | |
| Primary Endpoint | 20 | 21.0 (12.8, 29.2) | 20 | 22.7 (13.9, 31.6) | 1.7 (−10.4, 13.8) | .78 |
| Secondary Endpoints | ||||||
| Any Stroke | 22 | 23.4 (14.8, 32.0) | 24 | 26.9 (17.6, 36.2) | 3.5 (−9.2, 16.1) | .59 |
| Fatal Stroke | 1 | 1.0 (0, 3.1) | 2 | 2.4 (0, 5.6) | 1.3 (−2.5, 5.2) | .50 |
| Disabling Stroke | 5 | 5.9 (0.8,10.4) | 2 | 2.4 (0, 5.6) | −3.2 (−9.0, 2.6) | .27 |
| Deaths | 1 | 1.0 (0, 3.1) | 5 | 5.1 (0.2, 9.9) | 4.0 (−1.2, 9.7) | .13 |
| Any Stroke or Death | 22 | 23.4 (14.8, 32.0) | 26 | 29.9 (20.1, 39.8) | 6.5 (−6.5, 19.6) | .33 |
| Modified Rankin score 0–1 | 48 | 49.5 (39.5, 59.4) | 42 | 42.9 (33.1, 52.7) | −6.6 (−20.6, 7.3) | .41 |
| Modified Rankin score 0–2 | 68 | 70.1 (61.0, 79.2) | 73 | 74.5 (65.9, 83.1) | 4.4 (−8.2, 16.9) | .70 |
| Modified Barthel scale 19–20 | 68 | 70.1 (61.0, 79.2) | 70 | 71.4 (62.5, 80.4) | 1.3 (−11.4, 14.1) | .85 |
| Summary SSQoL, mean | 3.82 (3.60, 4.04) | 3.58 (3.37, 3.79) | −.24 (−.54,. 07) | .13 | ||
The primary endpoint for all participants who were assigned to surgery and received surgery was the combination of: (1) all stroke and death from surgery through 30 days post surgery and (2) ipsilateral ischemic stroke within two years of randomization. The primary endpoint in the nonsurgical group and for those participants assigned to surgery who did not receive surgery was the combination of (1) all stroke and death from randomization to randomization plus 30 days and (2) ipsilateral ischemic stroke within two years of randomization. Ipsilateral ischemic stroke was defined as the clinical diagnosis of a focal neurological deficit due to cerebral ischemia clinically localizable within the territory of the symptomatic occluded internal carotid artery that lasted for more than 24 hours.
All stroke endpoints are two-year Kaplan-Meier estimates of the proportions (95% confidence intervals) based on 195 randomized participants. Deaths were of any cause within 2 years of randomization for all 195 randomized participants. There was 1 death (fatal stroke) in the surgical group on the day of surgery (day 7 after randomization). There were 5 deaths in nonsurgical group: 2 fatal strokes (days 67 and 657 after randomization) and 3 non-stroke deaths due to pneumonia (day 564), sudden death (day 597), and stage IV lymphoma (day 725).
Rankin and Barthel endpoints (proportions) and the SSQoL (stroke specific quality of life) have worst case imputed for deaths and missing values. All values are given with 95% confidence intervals. The p-values are for Fisher exact tests.