Systematic review of contemporary outcomes for medical management of symptomatic patients with moderate to severe carotid stenosis

Medical therapy for secondary prevention of stroke has evolved markedly since the landmark North American Symptomatic Carotid Endarterectomy Trial (NASCET) and European Carotid Surgery Trial 1 (ECST-1) carotid surgery trials. The aim of this study was to perform a systematic review of stroke outcomes in adults with recent stroke or transient ischemic attack (TIA) with 50-99% carotid stenosis, treated with modern medical therapy over the last decade. A systematic review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, using a predefined search strategy on MEDLINE, EMBASE, Google Scholar, The Cochrane Database and clinicaltrials.gov. Inclusion criteria were studies of symptomatic patients with 50-99% carotid atherosclerotic stenosis published since 2015. Six completed studies gave original data on stroke and TIA outcomes. In general, the risk of bias was moderate to high. One-month stroke outcomes were reported as 1%, at 3 months 2%, at 1 year 10% and at 2 years 13%. Modern medical therapy, along with improvements in hyperacute stroke care, may have reduced the early risks associated with carotid plaque rupture. This in turn has implications for the role of carotid endarterectomy.