Two or More Ischaemic Events Within Seven Days Before Carotid Endarterectomy Increases the Risk of Peri-operative Stroke or Death

Abstract

The aim of this study was to determine how many pre-operative ischaemic events occurring within a specific timeframe before carotid endarterectomy (CEA) are needed to increase the peri-operative 30 day risk of stroke or death. This was a secondary exploratory analysis based on pooled data from three observational studies sourced from a single centre. Patients with recently symptomatic conventional ≥ 50% carotid stenosis were included. The principal analysis was limited to patients presenting with stroke or transient ischaemic attack (TIA). The primary outcome was 30 day risk of peri-operative stroke or death. Whether one, two, three, or four or more ipsilateral pre-operative ischaemic events within 3, 7, 14, or 30 days before CEA were associated with the primary outcome was assessed. The study included 382 patients who underwent CEA with symptomatic conventional ≥ 50% carotid stenosis with stroke or TIA as the presenting event. Mean patient age ± standard deviation was 72 ± 7 years, 117 (30.6%) were female, and 6% were treated with dual antiplatelet therapy. The primary outcome occurred in 21 patients (5.5%). Two or more events within 7 days before CEA was the most discriminative definition of repeated events, with a 14.3% (8/56) risk of the primary outcome. Those who fell outside this definition of two or more events within 7 days before CEA had a 4.0% (13 of 326; p = .006) risk of experiencing the primary outcome (adjusted odds ratio 4.1, 95% confidence interval 1.6 - 10.5). Several alternative definitions were assessed, but patients with two or more events within 7 days before CEA and negative for these alternatives still had a > 10% risk of the primary outcome. Two or more ipsilateral ischaemic events within 7 days before CEA are associated with an increased risk of peri-operative stroke or death in cases with symptomatic conventional ≥ 50% carotid stenosis and TIA or stroke as the presenting event. Studies assessing whether delayed or immediate CEA is preferable for this patient group are warranted.