Abstract P333: Post-Stroke Outcomes Vary by Etiologic Stroke Subtype in the Atherosclerosis Risk in Communities Study
Background: Early risk of recurrent stroke and mortality after stroke differ by subtype, but less is known about long-term outcomes and all-cause hospital readmission. Understanding these differences may have implications for secondary prevention and treatment of stroke. We examined rates of recurrent stroke, all-cause hospital readmission, and mortality by index stroke etiologic subtype.
Methods: Atherosclerosis Risk in Communities Study cohort participants with a definite/probable first-ever stroke were identified and followed until death or 12/31/2008. The association between index and recurrent stroke subtype and median times to first recurrent stroke and first hospital admission were assessed according to index stroke subtype (infarction: thrombotic, cardioembolic [CE], and lacunar; hemorrhagic: subarachnoid [SAH] and intraparenchymal [IPH]). Incidence rates of recurrent stroke, all-cause hospitalization, and death were calculated by index subtype. Reasons for hospitalization were identified using primary ICD-9 codes. Recurrent stroke outcomes for hemorrhagic subtypes are not reported here due to small numbers of events.
Results: A total of 987 persons with first-ever stroke were identified and followed for an average 5.3±5.0 years post-stroke (48.7% thrombotic, 20.0% CE, 18.5% lacunar, 8.6% IPH, and 4.2% SAH). During follow-up, there were 183 recurrent strokes among 147 participants, 3234 hospitalizations among 746 participants, and 529 deaths. Only 139 (14.1%) participants had none of these events during follow up. Roughly 70% of recurrent strokes were of the same subtype as the index stroke; however, only a third were the same when the index stroke was lacunar. Time to first recurrent stroke varied by subtype (median days [range]; thrombotic, 930.5[2-4692]; CE, 271[2-5566]; lacunar, 789[5-4361]) while time to first hospitalization was more similar, ranging from 102.5[4-3634] among CE to 370[6-6506] among IPH. Incidence rates of recurrent stroke (per 100 person-years) were highest after lacunar stroke (4.4) followed by thrombotic (3.7), and CE (2.7). All-cause hospital readmission rates were: thrombotic (58.8), CE (88.9), lacunar (60.1), IPH (59.4), and SAH (35.3); and mortality rates were: thrombotic (9.0), CE (15.1), lacunar (7.4), IPH (22.3), and SAH (7.3). Non-stroke related hospitalizations, including heart failure, ischemic heart disease, and diabetes were not uncommon after stroke, particularly after thrombotic and CE strokes.
Conclusion: While the highest mortality was observed for IPH, there was significant burden of recurrent stroke and all-cause hospitalization for other stroke subtypes, especially lacunar and CE. Hospital readmission rates were high for all subtypes, suggesting there may be opportunities to reduce post-stroke readmissions. Prevention efforts tailored according to etiologic stroke subtype may be warranted.
- © 2012 by American Heart Association, Inc.