Sex-specific differences in white matter microvascular integrity after ischaemic stroke.

BACKGROUND AND PURPOSE

Functional outcomes after ischaemic stroke are worse in women, despite adjusting for differences in comorbidities and treatment approaches. White matter microvascular integrity represents one risk factor for poor long-term functional outcomes after ischaemic stroke. The aim of the study is to characterise sex-specific differences in microvascular integrity in individuals with acute ischaemic stroke.

METHODS

A retrospective analysis of subjects with acute ischaemic stroke and brain MRI with diffusion-weighted (DWI) and dynamic-susceptibility contrast-enhanced (DSC) perfusion-weighted imaging obtained within 9 hours of last known well was performed. In the hemisphere contralateral to the acute infarct, normal-appearing white matter (NAWM) microvascular integrity was measured using the coefficient and apparent diffusion coefficient (ADC) values. Regression analyses for predictors of coefficient, DWI volume and good outcome (90-day modified Rankin scale (mRS) score <2) were performed.

RESULTS

105 men and 79 women met inclusion criteria for analysis. Despite no difference in age, women had increased NAWM coefficient (1027.4 vs 692.7×10/s; p=0.006). In women, atrial fibrillation (β=583.6; p=0.04) and increasing NAWM ADC (β=4.4; p=0.02) were associated with increased NAWM coefficient. In multivariable regression analysis, the coefficient was an independent predictor of DWI volume in women (β=0.007; p=0.01) but not men.

CONCLUSIONS

In women with acute ischaemic stroke, increased NAWM coefficient is associated with increased infarct volume and chronic white matter structural integrity. Prospective studies investigating sex-specific differences in white matter microvascular integrity are needed.