Comparison of American and European Guideline Recommendations for Diagnostic Workup and Secondary Prevention of Ischemic Stroke and Transient Ischemic Attack

Guidelines help to facilitate treatment decisions based on available evidence, and also to provide recommendations in areas of uncertainty. In this paper, we compare the recommendations for stroke workup and secondary prevention of ischemic stroke and transient ischemic attack of the American Heart Association (AHA)/American Stroke Association (ASA) with the European Stroke Organization (ESO) guidelines. The primary aim of this paper is to offer clinicians guidance by identifying areas where there is consensus and where consensus is lacking, in the absence or presence of high-level evidence. We compared AHA/ASA with the ESO guideline recommendations for 7 different topics related to diagnostic stroke workup and secondary prevention. We categorized the recommendations based on class and level of evidence to determine whether there were relevant differences in the ratings of evidence that the guidelines used for its recommendations. Finally, we summarized major topics of agreement and disagreement, while also prominent knowledge gaps were identified. In total, we found 63 ESO and 82 AHA/ASA recommendations, of which 38 were on the same subject. Most recommendations are largely similar, but not all are based on high-level evidence. For many recommendations, AHA/ASA and ESO assigned different levels of evidence. For the 10 recommendations with Level A evidence (high quality) in AHA/ASA, ESO only labeled 4 of these as high quality. There are many remaining issues with either no or insufficient evidence, and some topics that are not covered by both guidelines. Most ESO and AHA/ASA Guideline recommendations for stroke workup and secondary prevention were similar. However not all were based on high-level evidence and the appointed level of evidence often differed. Clinicians should not blindly follow all guideline recommendations; the accompanying level of evidence informs which recommendations are based on robust evidence. Topics with lower levels of evidence, or those with recommendations that disagree or are missing, may be an incentive for further clinical research.