Abstract W MP91: Does Recurrent Intracerebral Hemorrhage Have the Same Etiologic Subtypes According to SMASH-U Classification Method?

Background and Purpose: Etiologic classification of intracerebral hemorrhage (ICH), such as SMASH-U, is important to predict functional outcome and mortality in ICH patients. This study aimed to investigate whether recurrent ICH has the same etiologic subtypes or not. Methods: We analyzed 4,332 consecutive ICH patients treated at National Taiwan University Hospital from January 1995 to December 2012. The ICH etiology was classified in each patient according to the SMASH-U method as structural vascular lesions, medication-related, cerebral amyloid angiopathy (CAA), systemic disease, hypertensive angiopathy (HA), or undetermined. Results: Among all of the ICH patients, 3,659 patients was first-ever ICH patients (male, 62.9%; mean age, 59.8±16.8 years). The most common etiology was HA (54%), followed by systemic disease (14%), CAA (12%), undetermined (10%), structural vascular lesions (8%), and medication (3%). The interrater agreement for ICH classification was high ( κ , 0.89; 95% CI, 0.84-0.94, P <0.001). During a mean follow-up of 4.8 years, 175 (4.8%) patients had recurrent ICH. Of these patients, 32 (18%) had different etiologies between the two ICH events, mostly were CAA to HA, or vice versa. In the first ICH event, 41 patients were classified as CAA, and 88 patients as HA. Of the 41 CAA patients, 28 (68%) remained as CAA in the second ICH event, but 10 (24%) changed to HA. Of the 88 HA patients, 74 (84%) remained as HA in the second ICH event, but 8 (9%) changed to CAA. Conclusions: One-fifth of recurrent ICH patients had different etiologic subtypes in the two ICH events according to SMASH-U classification, particularly for CAA. Therefore, over-diagnosis of CAA is likely if we follow the proposed classification method of SMASH-U.