Primary intracerebral hemorrhage (ICH) causes substantial morbidity and mortality, with only about 50 percent of patients surviving for one year. Only half of those who do survive are functionally independent. ICH caused by structural vascular lesions is associated with better outcomes than primary ICH, but why this is so has been poorly understood. Recently, Santosh B. Murthy, MD, MPH, Medical Director of the Neurosciences Intensive Care Unit at NewYork-Presbyterian/
Dr. Santosh Murthy
Most research on ICH focuses on primary causes, such as chronic hypertension, cerebral amyloid angiopathy, or secondary to anticoagulation use. According to Dr. Murthy, who served as principal investigator on the current study, ICH due to structural vascular lesions is less common and current knowledge of acute hematoma dynamics and management has been inferred from studies on primary ICH. However, emerging data suggest that ICH due to vascular lesions, particularly arteriovenous malformations, have lower mortality and better functional outcomes. The Weill Cornell Medicine investigators sought to compare initial hematoma volumes and hematoma expansion in primary versus vascular lesion-associated ICH, postulating that more favorable hematoma characteristics in vascular lesion-associated ICH may contribute to improved outcomes.
The study, funded by the NIH, included adult patients with ICH from the Cornell Acute Stroke Academic Registry from 2011 through 2017. The analysis focused on patients with primary ICH resulting from hypertension or amyloid angiopathy and those with ICH from a structural vascular lesion, such as an arteriovenous malformation, a cavernous malformation, a dural arteriovenous malformation, or an aneurysm. A panel of neurologists determined the cause of ICH using SMASH-U criteria – Structural vascular lesion, Medication-related, Amyloid angiopathy, Systemic disease, Hypertension, Unknown.
The Weill Cornell Medicine researchers concluded that patients with ICH due to a vascular lesion had smaller hematomas than patients with primary ICH and that smaller baseline hematoma volumes may partly explain favorable outcomes in this patient population.
A total of 231 patients were included in the study, of whom 42 (18 percent) had a vascular lesion. Compared to primary ICH patients, those with structural vascular lesions:
- Were younger (49 versus 68 years)
- Less likely to have hypertension (29 percent versus 74 percent)
- Had lower mean admission systolic blood pressure (140 ± 23 versus 164 ± 35)
- Had intraventricular hemorrhage less frequently (26 percent versus 44 percent)
- Had a smaller median admission hematoma volume with vascular lesions (5.9 mL versus 9.7 mL)
The Weill Cornell Medicine research team noted there was no important association between
ICH etiology and hematoma expansion, which may be due to the small sample size since fewer patients in the study had comparable 24-hour neuroimaging. Another explanation may be
that ICH from structural vascular lesions tend to have lower mean systolic blood pressures in
the first 72 hours after admission, which is the most significant factor accompanying hematoma expansion.
The investigators noted that other reasons for better outcomes in ICH from vascular lesions may be attributed to:
- Younger age and fewer comorbid medical conditions
- Limited tissue injury as most of the hematoma is within the lesion nidus
- Bleeding occurring from lower pressure system such as venous structures that might curtail the initial hematoma size or subsequent expansion
Dr. Murthy and his colleagues concluded that patients with ICH due to a vascular lesion had smaller hematomas than patients with primary ICH and that smaller baseline hematoma volumes may partly explain favorable outcomes in this patient population.
