Table 4:
Hazard ratios (95% CIs) for incidence of stroke associated with progression in WMH, lacune and the combined microvascular brain disease measure from 1st brain MRI (1993-1995) to 2nd brain MRI (2004-2006).
| Level | n (%) | Number of incident strokes by end of follow-up | HR (95% CI) for incident stroke |
|---|---|---|---|
| Progression in WMH grade | |||
| 0 | 357 (39.4) | 20 | 1 (Ref.) |
| 1 | 339 (37.4) | 25 | 1.23 (0.67-2.27) |
| 2 | 152 (16.8) | 12 | 1.30 (0.63-2.72) |
| 3 | 45 (5.0) | 5 | 1.86 (0.68-5.09) |
| 4 | 10 (1.1) | 1 | 2.39 (0.29-19.34) |
| 5 | 4 (0.4) | 1 | 16.36 (1.93-138.53) |
| Progression in lacunes (additional new lacunes) | |||
| 0 | 849 (93.6) | 56 | 1 (Ref.) |
| 1 | 35 (3.9) | 5 | 2.16 (0.85-5.49) |
| 2 | 15 (1.7) | 2 | 2.26 (0.54-9.44) |
| 3 | 4 (0.4) | 1 | 4.70 (0.59-37.38) |
| 4 | 1 (0.1) | 0 | -- |
| 5 | 3 (0.3) | 0 | -- |
| Progression in the combined WMH/lacune measure | |||
| None | 344 (37.9) | 20 | 1 (Ref.) |
| Mild | 518 (57.1) | 36 | 1.10 (0.62-1.94) |
| Moderate | 45 (5.0) | 8 | 3.00 (1.30-6.94) |
Progression in WMH defined as the increase in CHS rating scale grade from 1st brain MRI (1993-1995) to 2nd brain MRI (2004-2006).
Progression in lacune defined as new lacunes in the 2nd brain MRI. The group with no progression includes 8 participants with lacunes in both visits.
Progression in the combined WMH/lacune measure categories: no progression; mild progression (increase of ≥1 unit in WMH grade or new lacune), and moderate progression (increase of ≥1 unit in WMH grade and new lacune).
Participants were followed up from 2nd brain MRI to December 31, 2017 (median [25%-75%]=12.6 [8.9-13.4] years). HR (95% CI) for incident stroke adjusted for age, sex, race, education level, time from 1st to 2nd MRI, BMI, smoking, hypertension, diabetes and CHD.