Associations of renal function with cerebral small vessel disease and functional outcome in acute intracerebral haemorrhage: A hospital-based prospective cohort study

Background: Intracerebral haemorrhage (ICH) is a severe clinical consequence of cerebral small vessel disease (SVD), but associations between renal impairment and SVD in patients with ICH have not been fully characterised.Methods: Using data from the CROMIS-2 ICH observational study, we compared SVD neuroimaging markers and total burden (score 0-3) identified using CT brain imaging in patients with and without renal impairment (estimated glomerular filtration rate, eGFR<60). We assessed functional outcome at 6-month follow-up using the modified Rankin scale.Results: 1027 participants were included (mean age 72.8, 57.1% male); 274 with and 753 without renal impairment. 18.7% of the eGFR<60 group had moderate-to-severe SVD burden (score 2-3), compared with 14.0% of those with eGFR>60 (p = 0.039). SVD burden was associated with renal impairment after adjusting for hypertension (OR 1.36, 95% CI 1.04-1.77, p = 0.023), but not after adjusting for age. Cerebral atrophy was more prevalent in patients with eGFR<60 (81.2% vs. 72.0%, p = 0.002), as were WMH (45.6% vs. 36.6%, p = 0.026). Neither was associated with renal function after adjusting for age and vascular risk factors. Renal impairment was associated with functional outcome (OR 0.65, 95% CI 0.47-0.89, p = 0.007), but not after adjusting for age, pre-morbid function and comorbidities (OR 0.95, 95% CI 0.65-1.38, p = 0.774).Conclusion: In acute ICH, renal impairment is associated with a higher cerebral SVD burden independent of hypertension, but not age. Reduced eGFR is associated with worse functional outcome, but not independent of age and comorbidities. Since CT has limited sensitivity to detect SVD severity and distribution, further studies including MRI are needed.