Evidence-Based Management of Stroke
Evidence-based medicine is the mantra of modern-day practice, the bedrock of today's clinical care. We feel justified, and to a certain degree protected, when we build our daily patient care decisions with randomized clinical trial data as the substratum for our house of informed management. When our patient happens to stray from this foundation slightly by not meeting the criteria of the original studies, we generalize with a mild degree of reticence. When the issue ventures out into unsupported territory, we rely on the joists of our own clinical judgment and experience, our understanding of the pathophysiology, and the expert opinion and guidelines put together by our professional organizations. Perhaps we, collectively, rest uneasy as we venture out into those areas. When examining the current state of our medical architecture, we might find it at once impressive in its scope but perhaps lacking in solidity.
Today's practitioner of stroke medicine is constantly presented with patients and situations that challenge one's level and depth of understanding of the literature. The diagnosis and management of acute stroke involves a series of difficult decisions that must be rapidly executed. Some rest on solid experimental and theoretical ground, others do not. Guidelines for Food and Drug Administration–approved intravenous tissue-type plasminogen activator within 3 hours of stroke onset are straightforward, but many patients fall outside the recommendations. How does one calculate the risk-benefit ratio? How should these decisions be made? How should one manage blood pressure and glucose in this setting? How strong is the evidence on which we base these decisions?
A similar, but no less taxing, set of decisions revolve around management of high-grade carotid stenosis. Although we have excellent randomized, controlled trial data to support the use of carotid endarterectomy for symptomatic stenosis of >50%, these are derived from data on patients from the late 1980s and early 1990s, when best medical therapy (the control) consisted mainly of aspirin and unclearly delineated blood pressure and diabetes mellitus management. Statins, thiazolidinediones, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers had not yet made their marks. Is it fair to assume that the risk-benefit ratio of carotid endarterectomy plus best medical management over best medical management alone would be the same for today's patients? Similar issues pervade other areas of vascular neurology. Therein lies our daily difficulty.
Intellectual honesty and a consistent evaluation of our depth of information are crucial to state-of-the-art care. Evidence-Based Management of Stroke combines standard-fare reviews of the accumulated relevant data on topics in stroke medicine with a rating system that assigns levels and grades of evidence to assist us in understanding the degree to which we can rely on the information that is available to plan patient care. It seeks to combine succinct writing with supported conclusions.
The forward introduces the theme of the book and lists both the levels and grades of evidence on which the authors of the chapters relied. Unfortunately, there is currently no universal grading system accepted in clinical medicine. The system used in this book is somewhat arbitrary, and it was unclear how studies were evaluated according to rating level (for example, all of the levels II and III included only “well-designed” studies; what about those not so “well-designed,” and how would one judge?). The grades more or less simply repeat the levels and appear to have no independent meaning. Additionally, they are not applied uniformly throughout the volume (for example, the second chapter uses an entirely different schema of levels and recommendations). Rather than clarifying, this served to confuse this reviewer's interpretation of what was written.
The text consists of 15 chapters and covers the gamut of problems encountered in daily practice (acute management of infarction, subarachnoid and intracerebral hemorrhage, prevention topics), as well as a selection of less frequently encountered issues (vascular malformations, venous sinus thrombosis, stroke during pregnancy and in children). The organization of the book is a bit haphazard, weaving back and forth between acute management and secondary prevention. Many of the chapters are written or coauthored by acknowledged leaders in the field. Both the writing styles and the range of subject matter differ between chapters, with some incorporating clinical approaches to their topics and others seemingly content with summarizing and discussing the accumulated evidence. Choice of focus and the conclusions drawn seemed rather idiosyncratic in places. For example, the chapter on interventions for carotid artery disease devotes nearly half of its space to issues revolving around the timing of endarterectomy, while completely neglecting the medical preparation of the patient for surgery and appropriate postsurgical management, such as antiplatelet agents and hypertension-related issues.
The variations in the writing styles of the chapters left this reviewer feeling a bit disjointed. Overall, the text made little attempt to place the findings from the literature in a context of pathophysiology that would give the reader a framework to help in understanding how all these pieces fit together. One is left perhaps trying to memorize the data rather than improving one's understanding of stroke medicine and the reliability of the information on which it is based. I found the key points at the end of each chapter, along with their respective evidence-level designations, helpful. These take-home points serve to help us focus—and to help us realize how spare is our collective knowledge base. Some of the chapters were a good read, and helpful, but overall, I found the book difficult to digest, poorly edited, and not as useful as I had hoped. Two of the chapters (thrombolysis in ischemic stroke and interventions for acute ischemic stroke) in fact are largely redundant and at times presented different interpretations of the same data.
This book may be most useful to emergency-based physicians, family practitioners, and internists who encounter stroke as part of their general practice. Its scope of information is appropriate; its structure will facilitate focus and a rapid understanding of where the practice lies today. General neurologists will find this book helpful in organizing their thinking and understanding the level of what is supported in the literature, but the text is mainly limited to general overviews of the subject and sometimes neglects practical advice. Vascular neurologists may find interest in the approach and use its basis of rating pieces of information to spur a conscious realization of how limited is our collective understanding.
Although the goal of elucidating the solidity of our decision making is laudable and much needed in our routine practice, this volume falls a bit short in this attempt. The text lacks cohesiveness, and the context of underlying pathophysiology that is so important for the achievement of a deeper understanding of stroke is largely absent. In sum, as we continually renovate, upgrade, and reconstruct our daily practice of the melding of medical literature with patient care, we increasingly rely on data to support our clinical decision making. How we as individuals accomplish this varies. Having expert reviews along with grading of evidence simplifies and enhances our synthetic ability. Evidence-Based Management of Stroke sets the appropriate foundation for this process but does not quite mortar it solid. As frequently occurs in the building trades, the plan may have been sound, but when the execution falls short, the structure is less than secure.
Mark Gorman, MD
Associate Professor of Neurology
University of Vermont
- © 2012 American Heart Association, Inc.