Data from: Association of white matter hyperintensity markers on MRI and long-term risk of mortality and ischemic stroke: The SMART-MR study

Objective To determine whether white matter hyperintensity (WMH) markers
on MRI are associated with long-term risk of mortality and ischemic
stroke. Methods We included consecutive patients with manifest arterial
disease enrolled in the SMART-MR study. We obtained WMH markers (volume,
type and shape) from brain MRI scans performed at baseline using an
automated algorithm. During follow-up, occurrence of death and ischemic
stroke was recorded. Using Cox regression, we investigated associations of
WMH markers with risk of mortality and ischemic stroke, adjusting for
demographics, cardiovascular risk factors and cerebrovascular disease.
Results We included 999 patients (59±10 years; 79% male) with a median
follow-up of 12.5 years (range 0.2-16.0 years). A greater periventricular
or confluent WMH volume was independently associated with a greater risk
of vascular death (hazard ratio (HR) 1.29, 95% CI 1.13-1.47 for a 1 unit
increase in natural log-transformed WMH volume) and ischemic stroke
(HR=1.53, 95% CI 1.26-1.86). A confluent WMH type was independently
associated with a greater risk of vascular (HR=1.89, 95% CI 1.15-3.11) and
nonvascular death (HR=1.65, 95% CI 1.01-2.73), and ischemic stroke
(HR=2.83, 95% CI 1.36-5.87). A more irregular shape of periventricular or
confluent WMH, as expressed by an increase in concavity index, was
independently associated with a greater risk of vascular (HR=1.20, 95% CI
1.05-1.38 per standard deviation increase) and nonvascular death (HR=1.21,
95% CI 1.03-1.42), and ischemic stroke (HR=1.28, 95% CI 1.05-1.55).
Conclusions WMH volume, type and shape are associated with long-term risk
of mortality and ischemic stroke in patients with manifest arterial
disease.