Future stroke risk analysis. Kaplan-Meier survival curves are shown for patients with CAA with versus without VWE, vwMRI (+) versus (-). In the 50 participants, the total time at risk was 37.5 person-years, and incidence event rate of ischemic stroke was 49.7% (95% CI, 34.5%–67.2%) per year. Patients with CAA with VWE demonstrated significantly shorter stroke-free survival with an event rate of 63.9% (95% CI, 43.2%–84.0%) per year compared with 32.2% (95% CI, 14.4%–62.3%), chi-square = 4.9, P = .027. As discussed in Table 3, multivariable Cox regression followed by backward elimination to a threshold P value of 0.20 showed that VWE was 1 of 2 factors remaining in the final future stroke prediction model (VWE HR = 2.5; 95% CI, 0.9–7.0; P = .080 and initial ischemic stroke HR = 3.4; 95% CI, 1.0–12.0; P = .053).