Hypertension and Stroke: Pathophysiology and Management (Clinical Hypertension and Vascular Diseases)

HYPERTENSION AND STROKE

CLINICAL HYPERTENSION AND VASCULAR DISEASES WILLIAM B. WHITE, MD SERIES EDITOR

Hypertension and Stroke, edited by Venkatesh Aiyagari, MBBS, DM, and Philip B. Gorelick, MD, MPH, FACP, 2011 Blood Pressure Monitoring in Cardiovascular Medicine and Therapeutics, Second Edition, edited by William B. White, MD, 2007 Hypertension in the Elderly, edited by L. Michael Prisant, MD, 2005 Lower Extremity Arterial Disease, edited by Dennis G. Caralis, MD, PhD, MPH, and George L. Bakris, MD, 2005 Secondary Hypertension, Clinical Presentation, Diagnosis, and Treatment, edited by George A. Mansoor, MD, 2004 Pediatric Hypertension, edited by Ronald J. Portman, MD, Jonathan M. Sorof, MD, and Julie R. Ingelfinger, MD, 2004

For further volumes, go to http://www.springer.com/series/7673

HYPERTENSION AND STROKE Pathophysiology and Management Edited by

VENKATESH AIYAGARI, MBBS, DM College of Medicine at Chicago University of Illinois, Chicago, IL, USA

PHILIP B. GORELICK, MD, MPH, FACP College of Medicine at Chicago University of Illinois, Chicago, IL, USA

Editors Venkatesh Aiyagari, MBBS, DM Department of Neurology and Rehabilitation College of Medicine at Chicago University of Illinois Chicago, IL, USA [email protected]

Philip B. Gorelick, MD, MPH, FACP Department of Neurology and Rehabilitation College of Medicine at Chicago University of Illinois Chicago, IL, USA [email protected]

ISBN 978-1-60761-009-0 e-ISBN 978-1-60761-010-6 DOI 10.1007/978-1-60761-010-6 Springer New York Dordrecht Heidelberg London Library of Congress Control Number: 2010938514 © Springer Science+Business Media, LLC 2011 All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Humana Press, c/o Springer Science+Business Media, LLC, 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. While the advice and information in this book are believed to be true and accurate at the date of going to press, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein. Printed on acid-free paper Humana Press is part of Springer Science+Business Media (www.springer.com)

This book is dedicated to the memory of my father. Venkatesh Aiyagari, MBBS, DM To my parents, Ruth and Harold Gorelick, dedicated in honor of your sense of family and unwavering support during life’s journey. Philip B. Gorelick, MD, MPH, FACP

Foreword The importance of hypertension as it relates to cerebrovascular disease and events has been greatly appreciated by physicians and scientists since the results of the earliest Veterans Administration Cooperative Trials in the 1960s and the isolated systolic hypertension trials in the United States (SHEP) and Europe (Syst-Eur) that followed in the 1980s and 1990s. This appreciation of the severity of the complications of this common disorder particularly in advanced age has led to substantial reductions in stroke over the past 50 years. Nevertheless, there is always room for improvement and cognitive decline associated with hypertension and vascular disorders remains an elusive problem in clinical medicine. Drs. Aiyagari and Gorelick’s volume on Stroke and Hypertension is therefore a most clinically relevant contribution in the area of stroke neurology – this book brings together the basic pathophysiologic, epidemiologic, diagnostic, and therapeutic advances in the evaluation of hypertension in patients with stroke or who are at great risk of stroke. The editors have nicely organized this volume into sections that cover the general pathophysiology and epidemiology of hypertension, overviews of the epidemiology of stroke and its relationship to hypertension, clinical evaluation that covers a variety of topics such as neuroimaging, diagnostic evaluation, and cognitive assessment, and nonpharmacologic and pharmacologic approaches to the management of high blood pressure in primary and secondary stroke prevention. There are very comprehensive chapters on the evidence supporting various strategies for stroke prevention including blood pressure-lowering therapies, anticoagulation, and management of other cerebrovascular risk factors. Substantial coverage has been appropriately given to the impact of pharmacologic treatments on stroke prevention based on clinical trials in older hypertensive people in Chapters 10, 11, and 12 of the volume. There are also interesting chapters devoted to special problems in cerebrovascular disorders that highlight problems which are of particular concern in our patients, including progression of white matter disease, cognitive dysfunction, and hypertensive encephalopathy. These sections contribute to the novelty of this book since the chapters are grounded in clinical investigations that have led to enhanced understanding of the evaluation and treatment of hypertension in these special populations. The prevention of dementia in older patients is complex and clinically challenging with advances targeted toward better modalities of early clinical evaluation and improved neuroimaging modalities as outlined in Chapters 14 and 15. The chapters in Stroke and Hypertension have been written by a number of well-known, expert authors who have provided comprehensive, scientifically sound, and clinically appropriate information. As series editor of Clinical Hypertension and Vascular Diseases, I am pleased by the publication of this timely, well-organized book and know that Stroke

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and Hypertension will become a highly utilized textbook for all specialists in neurology and cardiovascular medicine as well as any physician who takes care of older adults. William B. White, MD Pat and Jim Calhoun Cardiology Center University of Connecticut School of Medicine Farmington, CT, USA

Preface Hypertension and Stroke: Pathophysiology and Management reviews the pathophysiologic relationship between hypertension and cerebrovascular disease and the management of blood pressure in a variety of settings such as primary stroke prevention, acute ischemic and hemorrhagic stroke, secondary stroke prevention, and vascular cognitive impairment. Hypertension is one of the most important global public health challenges, and there is a close linkage between hypertension and cerebrovascular disease. Hypertension is the most significant modifiable risk factor for cerebrovascular disease. The importance of adequately treating elevated blood pressure in the primary prevention of stroke and management of cerebrovascular disease is widely accepted. It is estimated that about 25% and up to 50% of strokes could be prevented by blood pressure control. In the course of clinical practice, however, questions arise about the management of blood pressure in the acute, subacute, and chronic phases of stroke. For example, when is it safe to initiate blood pressure-lowering therapy after acute ischemic stroke? Is it dangerous to lower blood pressure in elderly persons who have had a stroke? What is the blood pressure-lowering target after a stroke has occurred to maximize recurrent stroke prevention? Which blood pressure-lowering agents are most efficacious and safe for persons who have had a stroke or for those in the general population to prevent a first stroke? In this book we explore answers to these and many more important aspects of hypertension and stroke. In recent years, several large clinical trials which address blood pressure management for cerebrovascular disease have been published. In this book we have attempted to collate and synthesize this rapidly expanding knowledge base in a form that can be easily accessed and utilized by treating physicians. Hypertension and Stroke provides a broad approach to the understanding of this topic from the perspectives of leading experts in the fields of vascular neurology, preventive medicine, nephrology and other cardiovascular diseases, epidemiology, pharmacology, neuropsychology and cognitive function, brain imaging, and nursing. In addition, we have recruited international experts who are well-versed in the area of stroke management, and who provide a unique clinical and epidemiological viewpoint from geographic regions where stroke risk is high. The book consists of five sections and corresponding chapters which provide insights about the following: (1) epidemiology of blood pressure and hypertension in relation to measurement, definition, diagnosis, and observational epidemiological studies and clinical trials in relation to stroke; (2) mechanisms of hypertension and how hypertension may cause stroke; (3) acute management of blood pressure after hemorrhagic and ischemic stroke, hypertensive encephalopathy, management of blood pressure to prevent recurrent stroke, non-blood-pressure-lowering effects of some antihypertensive agents, and a guide to overall cardiovascular risk factor assessment and management for prevention of recurrent stroke; (4) importance of blood pressure in cognitive function, newer brain imaging modalities

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to elucidate brain structure and function in hypertension, and the role of cerebral amyloid angiopathy and brain microhemorrhages on cognitive function; and (5) organization of stroke care to improve blood pressure control and overall stroke prevention. We believe that this text will provide the most up-to-date and expert information on a myriad of important aspects relating to hypertension and stroke. We anticipate that primary care physicians, neurologists, physician extenders, residents and medical students, and epidemiologists, stroke and other cardiovascular researchers, and public health specialists will benefit from this treatise. The global public health challenge of elevated blood pressure will continue to increase. Hypertension and Stroke is designed to help meet these challenges. Venkatesh Aiyagari, MBBS, DM Philip B. Gorelick, MD, MPH, FACP

Contents

Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii

PART I. B LOOD P RESSURE AND H YPERTENSION AS A NTECEDENTS OF S TROKE 1. Blood Pressure: Definition, Diagnosis, and Management . . . . . . . . . Raymond R. Townsend and Susan P. Steigerwalt

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2. The Link Between Hypertension and Stroke: Summary of Observational Epidemiological Studies . . . . . . . . . . . . . . . . 21 Youji Soga and Dilip K. Pandey 3. Blood Pressure Control and Primary Prevention of Stroke: Summary of Clinical Trial Data . . . . . . . . . . . . . . . . . . . . . 41 William J. Elliott

PART II. M ECHANISMS OF H YPERTENSION AND H YPERTENSION -R ELATED S TROKE 4. Mechanisms Underlying Essential Hypertension: Neurogenic and Nonneurogenic Contributors . . . . . . . . . . . . . . . . . . . . . 63 Scott H.Carlson and J. Michael Wyss 5. Pathophysiology and Mechanisms Whereby Hypertension May Cause Stroke . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 Jinhao Han, Hee-Joon Bae, and Lawrence K.S. Wong

PART III. M ANAGEMENT OF B LOOD P RESSURE FOR F IRST S TROKE P REVENTION , I MMEDIATELY AFTER ACUTE S TROKE , AND FOR R ECURRENT S TROKE P REVENTION 6. Cardiovascular Risk Assessment and Summary of Guidelines for the Management of Hypertension . . . . . . . . . . . . . . . . . . 97 Tamar Polonsky and George Bakris 7. Acute Blood Pressure Management After Ischemic Stroke . . . . . . . . 115 Venkatesh Aiyagari xi

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8. Hypertensive Encephalopathy and Acute Blood Pressure Management After Hemorrhagic Stroke . . . . . . . . . . . . . . . . . 127 Rebbeca A. Grysiewicz and Sean D. Ruland 9. Recurrent Stroke Prevention I: Diuretic and AngiotensinConverting Enzyme Inhibitors (ACEIs) – The PROGRESS Trial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 Thomas K.A. Linden and Geoffrey A. Donnan 10. Recurrent Stroke Prevention II: Angiotensin Receptor Blockers—The LIFE, MOSES, PRoFESS, and Other Trials . . . . . . 159 Venkatesh Aiyagari and Philip B. Gorelick 11. A Practical Guide to Recurrent Stroke Prevention . . . . . . . . . . . . . 173 Laura Pedelty

PART IV. M ECHANISMS AND S EQUELAE OF E LEVATED B LOOD P RESSURE ON B RAIN F UNCTION AND C OGNITION 12. Vascular Cognitive Impairment and Alzheimer Disease: Are These Disorders Linked to Hypertension and Other Cardiovascular Risk Factors? . . . . . . . . . . . . . . . . . . . . . . . 195 Fernando D. Testai and Philip B. Gorelick 13. Cerebral Small Vessel Disease, Hypertension, and Cognitive Function . . 211 Elizabeth K. Geary and David L. Nyenhuis 14. Cerebral Microbleeds, Small-Vessel Disease of the Brain, Hypertension, and Cognition . . . . . . . . . . . . . . . . . . . . . . . 225 Anand Viswanathan, Hugues Chabriat, and Steven M. Greenberg 15. Imaging Effects of Hypertension on the Brain: A Focus on New Imaging Modalities and Options . . . . . . . . . . . . . . . . . . . . . 237 Deborah M. Little, Evan Schulze, Nilay Shah, and Shanele McGowan

PART V. O RGANIZATION OF S TROKE C ARE 16. The Joint Commission’s Initiatives to Improve Stroke Care and What It Means for Acute Stroke Care and Prevention . . . . . . . . . . 259 Wende Fedder Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269

Contributors V ENKATESH A IYAGARI , MBBS , DM • Department of Neurology and Rehabilitation, College of Medicine at Chicago, University of Illinois, Chicago, IL, USA H EE -J OON BAE, MD, PhD • Seoul National University Bundang Hospital, Department of Neurology, Gyeonggi-do, South Korea G EORGE BAKRIS , MD • University of Chicago Medical Center, Chicago, IL, USA S COTT H. C ARLSON, PhD • Department of Biology, Luther College, Decorah, IA, USA H UGUES C HABRIAT, MD, PhD • Department of Neurology CHU Lariboisière, Assistance Publique des Hôpitaux de Paris, Paris, France G EOFFREY A. D ONNAN , MD , FRCP, FRACP • The Florey Neuroscience Institutes, University of Melbourne, Melbourne, VIC, Australia W ILLIAM J. E LLIOTT, MD, PhD • Department of Preventive Medicine, Rush Medical College at Rush University Medical Center, Chicago, IL, USA W ENDE F EDDER , RN , MBA , DNP - C • Neuroscience Institute, Alexian Brothers Hospital Network, Elk Grove Village, IL, USA E LIZABETH K. G EARY, PhD • Department of Neurology, University of Illinois at Chicago, Chicago, IL, USA P HILIP B. G ORELICK , MD , MPH , FACP • Department of Neurology and Rehabilitation, College of Medicine at Chicago, University of Illinois, Chicago, IL, USA S TEVEN M. G REENBERG, MD, PhD • Department of Neurology, Hemorrhagic Stroke Research Program, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA R EBBECA A. G RYSIEWICZ , DO • Department of Neurology, University of Illinois at Chicago, Chicago, IL, USA J INHAO H AN, MD, PhD • Department of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong, China T HOMAS K.A. L INDEN, MD, PhD • Institute of Neuroscience and Physiology, Gothenburg University, Gothenburg, Sweden; National Stroke Research Institute, Heidelberg Heights, VIC, Australia D EBORAH M. L ITTLE, PhD • Departments of Neurology and Rehabilitation, Anatomy and Cell Biology, Ophthalmology and Visual Sciences, and Psychology, Centers for Stroke Research and Cognitive Medicine, College of Medicine at Chicago, University of Illinois, Chicago, IL, USA S HANELE M C G OWAN , MD • Department of Neurology and Rehabilitation, Centers for Stroke Research, College of Medicine at Chicago, University of Illinois, Chicago, IL, USA DAVID L. N YENHUIS, PhD • Department of Neurology and Rehabilitation Medicine, Chicago Medical Center, University of Illinois, Chicago, IL, USA

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D ILIP K. PANDEY, MD, PhD • Neuroepidemiology Program, Department of Neurology and Rehabilitation, College of Medicine at Chicago, University of Illinois, Chicago, IL, USA L AURA P EDELTY, MD, PhD • Department of Neurology and Rehabilitation, College of Medicine at Chicago, University of Illinois, Chicago, IL, USA TAMAR P OLONSKY , MD • Hypertension Diseases Unit, Department of Medicine, University of Chicago Medical Center, Chicago, IL, USA S EAN D. RULAND , DO • Department of Neurology and Rehabilitation, College of Medicine at Chicago, University of Illinois, Chicago, IL, USA E VAN S CHULZE , BS • Department of Neurology and Rehabilitation, Centers for Stroke Research, College of Medicine at Chicago, University of Illinois, Chicago, IL, USA N ILAY S HAH , BS • Department of Neurology and Rehabilitation, Centers for Stroke Research, College of Medicine at Chicago, University of Illinois, Chicago, IL, USA YOUJI S OGA, MD, PhD • Neuroepidemiology Program, Department of Neurology and Rehabilitation, College of Medicine at Chicago, University of Illinois, Chicago, IL, USA S USAN P. S TEIGERWALT , MD , FASH , FACP • Division of Nephrology and Hypertension, Providence of St. John Health, Detroit, MI, USA F ERNANDO D. T ESTAI, MD, PhD • Department of Neurology and Rehabilitation, College of Medicine at Chicago, University of Illinois, Chicago, IL, USA R AYMOND R. T OWNSEND , MD • Renal Electrolyte and Hypertension Division, University of Pennsylvania, Philadelphia, PA, USA A NAND V ISWANATHAN, MD, PhD • Department of Neurology, Massachusetts General Hospital, Boston, MA, USA L AWRENCE K.S. W ONG , MD • Departments of Medicine and Therapeutics, Chinese University of Hong Kong, Hong Kong Special Administrative Region, China J. M ICHAEL W YSS, PhD • Departments of Cell Biology and Medicine, University of Alabama, Birmingham, AL, USA

I

BLOOD PRESSURE AND H YPERTENSION AS ANTECEDENTS OF STROKE

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Blood Pressure: Definition, Diagnosis, and Management Raymond R. Townsend, MD and Susan P. Steigerwalt, MD, FASH CONTENTS D EFINITION OF “H YPERTENSION ” D IAGNOSIS OF H YPERTENSION M ANAGEMENT OF H YPERTENSION B LOOD P RESSURE R EFERENCES

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DEFINITION OF “HYPERTENSION” As with many cardiovascular risk factors, a definition of what constitutes “normal” vs. “abnormal” in relation to blood pressure level is challenging as it may be with glucose, cholesterol, and other biomarkers associated with atherosclerotic end-organ disease. Based largely upon actuarial data accrued in the first half of the twentieth century, a convenient definition of blood pressure emerged with levels of 140 mmHg systolic and 90 mmHg diastolic constituting threshold values of high blood pressure. In landmark research of the natural history of untreated hypertension, Perera studied 500 untreated hypertensives, showing that the typical life span of a person diagnosed with blood pressures exceeding a value of 140/90 mmHg was less than 20 years (1). In the past, most studies showing the benefit of drug therapy in reducing blood pressure-related consequences used diastolic blood pressure (DBP) entry criteria (90–100 mmHg) to consistently show that there is substantial cardiovascular benefit of reducing blood pressure with medication (2). The Joint National Committee (JNC), the European Hypertension Societies, as well as most guideline writing bodies now generally agree on definitions of blood pressure as shown in Table 1 (3). A considerable number of patients have comorbidities which either precede or occur in conjunction with hypertension. A growing body of evidence indicates that in the case of several selected comorbidities (dubbed “compelling indications” by the JNC), there is additional benefit to the reduction of blood pressure below the threshold target values of 140/90 mmHg (3). In a population, increased cardiovascular risk begins at blood pressures as low as 115/75 mmHg. “Optimum” blood pressure is defined as less than 120/80 mmHg and “prehypertension” as a blood pressure of 120–139/80–89 mmHg by JNC 7, based on From: Clinical Hypertension and Vascular Diseases: Hypertension and Stroke Edited by: V. Aiyagari, P.B. Gorelick, DOI 10.1007/978-1-60761-010-6_1  C Springer Science+Business Media, LLC 2011

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Table 1 Classification of Hypertension (3) Blood pressure (mmHg)

Classification of hypertension

120/80 120–139/80–89 140–159/90–99 ≥160/100

Normal Prehypertension Stage 1 hypertension Stage 2 hypertension

an increased lifetime risk of developing hypertension in the USA which is estimated to be 80% (JNC 7). However, we lack interventional trials showing cardiovascular protection for treatment of initial blood pressures