Lone atrial fibrillation (LAF), that is atrial fibrillation without underlying structural heart disease, is not a life-threatening disorder and is not associated with fatal arrhythmias such as ventricular fibrillation. It is also generally agreed that LAF, on its own, is not associated with an increased risk of ischemic stroke (stroke caused by a blood clot). However, if LAF is combined with one or more established risk factors for stroke (hypertension, diabetes, heart failure, heart disease, etc.) then the stroke risk is very real and measures are needed to ensure adequate protection.
The standard medical approach to stroke prevention is pretty well confined to prescribing either aspirin or warfarin. Aspirin, as we shall see, has a negative benefit/risk ratio in preventing a first stroke. The net benefit of warfarin therapy can be substantial when underlying heart disease or a history of stroke or heart attack is present. However, when no additional risk factors for stroke are present, then warfarin therapy is not beneficial and may even be detrimental. Despite this recognized fact, warfarin is often prescribed routinely to AF patients who are unlikely to benefit from it.
There are indeed many myths and misconceptions surrounding stroke prevention in LAF. It is my hope that this book will help dispel most of them. Early in my research, I realized that an ischemic stroke suffered by a LAF patient is no different from one suffered by someone without LAF. The underlying cause and ultimate mechanism involved are exactly the same, although blood stasis may play a greater role in afibbers with heart failure. This, of course, means that stroke prevention measures known to work in the general population are equally effective for patients with LAF. Thus the whole realm of proven natural stroke prevention agents opens up for the afibber to consider – and what a treasure trove this is! Several natural antithrombotics have been found to be superior to both aspirin and warfarin and have none of their adverse effects. After several months of research I have reached the conclusion that natural antithrombotics will do just fine for me and I feel very comfortable with this decision.
Selecting a stroke prevention program is, nevertheless, an intensely personal decision and is certainly among the most important decisions that every afibber has to make early in their "career". There is no easy way to go about making this decision. A great deal of research and soul-searching is required and this is where, hopefully, my book will help.
Thrombosis and Stroke Prevention not only provides in-depth discussions of both natural and pharmaceutical stroke prevention agents, it also covers in detail the underlying causes and mechanisms of thrombosis (blood clot formation) and stroke. Blood clot formation is a very complex process involving platelet aggregation, coagulation and fibrinolysis. In order to rationally select a stroke prevention program, it is necessary to have at least a rudimentary understanding of the mechanisms and factors involved in these three stages of the thrombosis process. The first two chapters of the book are designed to provide this understanding. Chapters 3 and 4 deal with natural and pharmaceutical antithrombotics and chapter 5 provides detailed questionnaires and tables for estimating your stroke risk. Chapter 6 compares the effectiveness of all the agents discussed in previous chapters with some very surprising results. Finally, chapter 7 puts it all together by presenting a suggested, rational stroke prevention plan. This plan, of course, may not appeal to everyone and I strongly encourage readers to develop their own personal plans based on information presented in this book combined with appropriate input from a knowledgeable physician.
This Second Edition of Thrombosis and Stroke Prevention adds chapters covering the latest research on risk factors and prevention as well as a chapter on how to live with warfarin and one on warfarin interactions with other drugs and herbs. The current guidelines for stroke prevention are also reviewed in detail.
This book would not have been possible without the whole-hearted support of my wife Judi who was instrumental in seeing it come to fruition. Without her word processing skills, editing advice, and encouragement I couldn't have accomplished it. Jackie Burgess, Patrick Chambers, MD, Norman Fisher, MD, Sadja Greenwood, MD, Martin Klughaupt, MD, FACC, and Frank McCabe deserve my special, heartfelt thanks for taking the time to thoroughly review and comment on the book. Finally I would like to express my appreciation to the many enthusiastic and caring contributors to the Bulletin Board and to the subscribers to The AFIB Report without whose support my research would not have been possible.
Hans R. Larsen
Victoria, BC, Canada