#2183 Does thrombotic microangiopathy drive the occurrence and pattern of cerebrovascular disease in malignant hypertension?

Abstract Background and Aims Malignant hypertension (MHT) is characterized by diffuse microvascular damage caused by severe hypertension, often presenting with multiple organ involvement. Cerebrovascular injury, occurring in both acute and chronic forms, stands as a hallmark of the disease, being identified in up to half of patients. Thrombotic microangiopathy (TMA), defined as the association of mechanical hemolytic anemia with thrombocytopenia, also emerges as a frequent complication in MHT patients. However, the potential contribution of TMA to cerebrovascular disease remains unexplored. The secondary objective of this study was to provide a comprehensive description of the patterns of cerebrovascular injury occurring in MHT, with a focus on acute ischemic strokes (AIS). Method We retrospectively assessed the brain MRI of patients admitted to the kidney intensive care unit at Tenon hospital for malignant hypertension during the 2017-2023 period. Brain MRIs were performed on a systematic basis regardless of neurological symptoms and were independently reviewed by two trained specialists in a blinded fashion. Patterns of acute cerebrovascular disease, defined as AIS, intracerebral hematoma (ICH) or posterior reversible encephalopathy syndrome (PRES), were systematically assessed. Number of AIS lesions, their size and localization were recorded. Underlying chronic cerebral small vessel disease (CSVD) was defined as presence of lacunes, white matter hyperintensities, cerebral microbleeds or perivascular spaces. Severity of the chronic cerebrovascular disease was measured using a validated CSVD score. Results A total of 60 patients were admitted for malignant hypertension, with a mean age of 42.9 years. 40 patients (66.7%) presented with severe acute kidney injury. Cerebrovascular disease, either acute or chronic, was found in 42 patients (70.0%). Underlying chronic CSVD was present in 33 patients (55.0%). Acute patterns of injury occurred in 27 patients (45.0%). AIS was the most frequent (33.3%), followed by PRES (21.7%). Only one patient presented with ICH. Among patients with AIS, 14 (70%) presented with multiple simultaneous lesions. Of note, most patients with AIS exhibited diffuse encephalopathy syndrome (60.0%) rather than focal deficit (40.0%). Systemic TMA was present at admission in 34 patients (56.7%). In an exploratory data analysis, presence of AIS on brain MRI was associated with the presence of underlying CVSD (p = 0.013), but not with the presence of TMA at admission (p = 0.79). No association was found between TMA and PRES (p = 0.22). Conclusion Our study confirmed the high incidence of cerebrovascular disease during MHT. Most notably, 1 in 3 patients presented with AIS. TMA did not appear to increase the incidence nor to influence the pattern of brain injury.