Abstract Body: Background:
Cerebral vasomotor reactivity (VMR) is crucial for regulating cerebral blood flow and neurological health. Research suggests that high-intensity statin therapy may improve VMR shortly after a stroke. This study aims to evaluate the duration of this improvement over three months and explore the association between white matter hyperintensities (WMH), cerebral micro-bleeding (CMB), and VMR as an endothelial function marker.

Methods:
We enrolled 120 ischemic stroke patients from July 2023 to June 2024 at an academic stroke center. Patients were divided retrospectively into high-intensity (40 or 80 mg Atorvastatin or equivalent) and moderate to low-intensity (10-20 mg Atorvastatin or equivalent) statin therapy groups. VMR was assessed using the Breath Holding Index (BHI) via transcranial Doppler ultrasound at two weeks and three months post-stroke. We analyzed the correlation between WMH, CMB, and VMR across different statin doses using multivariable regression, adjusting for baseline NIHSS, demographics, cerebrovascular risk factors, WMH, and CMB.

Results:
The cohort had an average age of 69.8 years, with 50.8% being male. High-intensity statins were used by 63 patients (52.5%). At baseline, the high-intensity group had a significantly higher BHI (Mean VMR: 0.9 vs. 0.7, P < 0.008), which remained higher at the three-month follow-up (Mean VMR: 0.8 vs. 0.7, P < 0.001). Baseline WMH was present in 29.2% of patients, and 18.3% had CMB. Patients with lower baseline VMR had a higher incidence of WMH (53.5% vs. 6.5%, P < 0.001), which persisted at three months (55.6% vs. 7.6%, P < 0.001). Lower baseline VMR was also associated with higher CMB rates (37.9% vs. 0%, P < 0.001), continuing at three months (40.7% vs. 0%, P < 0.001). The average baseline BHI was 0.65 in patients with WMH versus 0.81 in those without WMH (P < 0.001) and 0.64 in patients with CMB versus 0.79 in those without CMB (P < 0.001).

Conclusion: High-intensity statin therapy positively affects VMR in stroke patients over three months. Lower VMR is associated with increased WMH and CMB, suggesting that optimizing statin treatment may improve vascular health and reduce stroke recurrence risk. Future research should investigate these findings further and assess the long-term effects of statin therapy on VMR and recurrent cerebrovascular events.