Abstract
Background:
While left atrial (LA) enlargement increases incident stroke risk, the association with recurrent stroke is unclear. Our aim was to determine the association of LA enlargement (LAE) with stroke recurrence risk and recurrent stroke subtypes likely related to embolism (cryptogenic or cardioembolic).
Methods:
We enrolled 655 first ischemic stroke patients in the Northern Manhattan Stroke Study. LA size was measured by two-dimensional echocardiogram as part of the clinical evaluation and patients were followed annually for up to 5 years. LA size adjusted for sex and body surface area was categorized into three groups: normal (52.7%), mild LAE (31.6%), and moderate to severe LAE (15.7%). The outcomes were total recurrent stroke, and recurrent combined cryptogenic or cardioembolic stroke. Cox proportional hazard models assessed the association between LA size and risk of stroke recurrence.
Results:
Of 655 patients, LA size data was present in 529 (81%). Mean age was 69 ± 13 years; 46% were male and 18% had atrial fibrillation. Over a median of 4 years, recurrent stroke occurred in 83 patients (16%), 29 were cardioembolic or cryptogenic stroke. After adjusting for baseline demographics and risk factors including atrial fibrillation and congestive heart failure, compared to normal LA size, moderate to severe LAE was associated with greater risk of recurrent combined cardioembolic or cryptogenic stroke (adjusted HR 2. 99, 95% CI 1. 10 to 8.13), but not with risk of total stroke recurrence (adjusted HR 1.18, 95% CI 0.60 to 2.32). Mild LAE was not associated with either total stroke recurrence or the combined recurrent cryptogenic or cardioembolic stroke subtypes.
Conclusion:
Moderate to severe LAE is an independent marker of recurrent cardioembolic or cryptogenic stroke in a multiethnic cohort of ischemic stroke patients. Future research is needed to determine if anticoagulant use reduces the risk of recurrence in ischemic stroke patients with moderate to severe LAE.