Impact of white matter hyperintensities on the prognosis of cryptogenic stroke patients

Background To our knowledge, little is known regarding whether white matter hyperintensities (WMH) affect the prognosis of cryptogenic stroke (CS) patients. Understanding this association may be helpful with expecting the prognosis of CS patients. Methods This retrospective observational study enrolled consecutive CS patients who underwent brain MRI and comprehensive cardiac evaluation. Severe WMH was defined as Fazekas' score >= 3. We defined poor functional outcome as modified Rankin Scale score >= 3 at 3 months. Long-term mortality and causes of death were identified using national death certificates and assessed by Kaplan-Meier method and regression analysis model. Results Among 2732 patients with first-ever ischemic stroke, 599 (21.9%) patients were classified as having CS. After exclusions, 235 patients were enrolled and followed up for a median of 7.7 years (IQR, 6.7-9.0). Severe WMH were found in 81 (34.5%) patients. After adjustments, severe WMH were an independent predictor for poor functional outcomes at 3 months (OR 5.25, 95% CI, 2.07-13.31). Subgroup analysis showed that severe WMH were an independent predictor for long-term mortality only in younger patients (age < 65) (HR 3.11, 95% CI, 1.29-7.50), but not in older patients (HR 1.19, 95% CI, 0.63-2.23). Conclusions Severe WMH were independently associated with short-term functional outcomes in CS patients and independently associated with long-term mortality in younger CS patients. Grading WMH is of value in predicting prognosis of CS patients with young age.