Risk of stroke in noninvasively treated asymptomatic and symptomatic patients with carotid stenosis.

We assessed the average annual rate of ipsilateral stroke and the quality of care, with respect to asymptomatic and symptomatic individuals with advanced (50% to 99%) carotid stenosis given noninvasive arterial care alone in studies published since 2013. We conducted a systematic search for quality studies using previously published criteria (principally, prospective with >100 patients stratified by symptomatic status and followed for ≥12 months) with sufficient data to calculate the average annual rate of ipsilateral stroke with noninvasive care alone. We assessed the quality of noninvasive care using our novel "BRAINIAC" scoring system and our analyses on how to best define and manage stroke risk factors. Only four studies satisfied our search criteria in relation to asymptomatic carotid stenosis (two randomized and two nonrandomized), and only one in relation to symptomatic individuals (a nonrandomized study). The range in average annual raw data-derived rate of ipsilateral stroke in relation to asymptomatic carotid stenosis was 0.47% to 1.24%, and it was 3.00% in the single study related to symptomatic patients. In all five studies, despite noninvasive care being poorly described, there were opportunities for improvement using the current evidence-based. Average annual ipsilateral stroke rates in relation to advanced carotid stenosis in the identified studies were low relative to likely routine practice procedural risks. The current priority is to properly define and administer current best practice noninvasive arterial care and produce quality studies of its effectiveness in different populations. We anticipate that outcomes will improve further with noninvasive arterial care alone.