Univariable Cox regression for future ischemic stroke
| Stroke Predictor | Future Stroke (−) (n = 29) | Future Stroke (+) (n = 21) | Univariable HR (95% CI) | P Value |
|---|---|---|---|---|
| Initial stroke, n (%) | 17 (58.6) | 18 (85.7) | 4.2 (1.2–14.3) | .023 |
| VWE, n (%) | 13 (44.8) | 16 (76.2) | 3.1 (1.1–8.6) | .027 |
| Maximum percent stenosis, mean (SD) | 17.1 (22.5) | 11.9 (18.3) | 0.7 (0.1–6.4) | .723 |
| Age, mean (SD) | 72.6 (8.2) | 71.0 (7.1) | 1.0 (0.9–1.0) | .651 |
| Female, n (%) | 13 (44.8) | 14 (66.7) | 1.5 (0.6–3.7) | .397 |
| Hypertension, n (%) | 24 (82.8) | 18 (90.5) | 1.7 (0.4–7.1) | .499 |
| Hyperlipidemia, n (%) | 17 (58.6) | 15 (71.4) | 1.3 (0.5–3.5) | .552 |
| Diabetes, n (%) | 7 (24.1) | 7 (33.3) | 1.3 (0.5–3.3) | .571 |
| Smoking, n (%) | 14 (48.3) | 6 (28.6) | 0.5 (0.2–1.3) | .135 |
| (interval) Antiplatelet, n (%) | 9 (31.0) | 6 (28.6) | 0.8 (0.3–2.1) | .649 |
| (interval) Anticoagulation, n (%) | 3 (10.3) | 1 (4.8) | 0.4 (0.05–2.8) | .336 |
| (interval) Antihypertension, n (%) | 23 (79.3) | 17 (81.0) | 1.3 (0.4–3.8) | .662 |
| (interval) Statin, n (%) | 22 (75.9) | 14 (66.7) | 0.7 (0.3–1.6) | .372 |
| (interval) Immunosuppression, n (%) | 7 (24.1) | 10 (47.6) | 1.5 (0.7–3.7) | .322 |
| Elevated inflammatory markers, n (%), n = 30 available | 5 (33.3) n = 15 | 5 (33.3) n = 15 | 1.1 (0.4–3.1) | .928 |
Note:—Interval indicates interval treatment with the listed medication as a potential confounder.
Univariable Cox regression was initially performed with HR values, with 95% CI and P values below. All potential confounding variables with P < .20 from the univariable analysis were placed in an initial multivariable Cox regression model for future ischemic stroke; then variables were eliminated in a backward fashion to the threshold P < .20. Two factors remained in the final multivariable regression model for future ischemic stroke: initial ischemic stroke (HR = 3.4; 95% CI, 1.0–12.0; P = .053) and VWE (HR = 2.5; 95% CI, 0.9–7.0; P = .080)