Infarct Timing and Predictors of Infarct-Free Survival in Patients with Aneurysmal Subarachnoid Hemorrhage

Background/Objectives: Cerebral infarction significantly worsens outcomes after aneurysmal subarachnoid hemorrhage (SAH). This retrospective study analyzed early predictors of infarct-free survival and the impact of infarct timing on clinical outcomes. Methods: We reviewed 988 consecutive SAH patients treated from 2003 to 2016, all with follow-up CT scans. Baseline clinical and SAH characteristics were recorded to identify predictors of infarct-free survival and assess the relationship between infarct timing and outcomes. Results: Cerebral infarctions occurred in 475 patients (48.1%) at a median of 3.4 days post-SAH; 70.9% happened within the first week. Earlier infarctions were associated with higher in-hospital mortality (odds ratio [OR] = 0.91 per day increase, p < 0.0001) and poor 6-month outcomes (modified Rankin Scale > 3; OR = 0.96 per day increase, p = 0.012), especially within 48 h. Independent predictors of infarct-free survival included poor initial condition (WFNS ≥ 4, adjusted hazard ratio [aHR] = 1.82, p < 0.0001), intraventricular hemorrhage (aHR = 1.25, p = 0.041), aneurysm rebleeding (aHR = 1.76, p < 0.0001), acute hydrocephalus (aHR = 1.38, p = 0.020), and daily aspirin intake (aHR = 0.68, p = 0.002). The number of baseline risk factors (0–5) strongly influenced both infarction likelihood and timing (p < 0.0001). Conclusions: Cerebral infarctions predominantly occur within the first week after SAH, with earlier infarctions having a more severe impact on outcomes. Initial risk factor-adapted SAH management may improve functional outcomes.