All that follows is from the above.
Cardiac embolism accounts for an increasing proportion of ischemic strokes, and might multiply several-fold over the next decades. However, research points to several potential strategies to stem this expected rise in cardioembolic stroke. First, although one-third of strokes are of unclear cause, it is increasingly accepted that many of these cryptogenic strokes arise from a distant embolism rather than in-situ cerebrovascular disease, leading to the recent formulation of “embolic stroke of undetermined source” (ESUS) as a distinct target for investigation. Second, recent clinical trials have indicated that ESUS may often stem from subclinical atrial fibrillation (AF) which can be diagnosed with prolonged heart-rhythm monitoring. Third, emerging evidence indicates that a thrombogenic atrial substrate can lead to atrial thromboembolism even in the absence of AF. Such an atrial cardiopathy may explain many cases of ESUS, and oral anticoagulant drugs may prove to reduce stroke risk from atrial cardiopathy given its parallels to AF. Non-vitamin K antagonist oral anticoagulant (NOAC) drugs have recently expanded therapeutic options for preventing cardioembolic stroke and are currently being tested for stroke prevention in patients with ESUS, including specifically those with atrial cardiopathy. Fourth, increasing appreciation of thrombogenic atrial substrate and the common co-existence of cardiac and extra-cardiac stroke risk factors suggests benefits from global vascular risk factor management in addition to anticoagulation. Finally, improved imaging of ventricular thrombus plus the availability of NOAC drugs may lead to better prevention of stroke from acute myocardial infarction and heart failure.Subject Terms: Atrial fibrillation, Embolism, Cerebrovascular Disease/StrokeKeywords: Atrial fibrillation, atrium, embolic stroke, embolism, stroke
Twenty-six million people worldwide experience a stroke each year, making it the secondleading cause of mortality and a leading cause of long-term disability.1 One-third of strokes
represent intracerebral or subarachnoid hemorrhage while two-thirds represent cerebral ischemia.1 Ischemic stroke can result from a variety of causes such as atherosclerosis of the cerebral circulation, occlusion of cerebral small vessels, and cardiac embolism.2 Of these causes, cardioembolic stroke has significance for two reasons. First, cardiac embolism causes more severe strokes than other ischemic stroke subtypes.3
Second, as treatment ofhypertension and dyslipidemia improves, cardiac embolism has accounted for an increasing
share of strokes in high-income countries such as Canada.4
Despite a decrease in the overall incidence of stroke, cardioembolic strokes have tripled during the past few decades and may triple again by 2050 based on projections from the United Kingdom.5 Given demographic changes and increasing life expectancy, risk factors for cardiac embolism may become more common in low- and middle-income countries as well.6
Conversely, oral anticoagulant therapy can prevent up to 70% of strokes in patients with the most common cardioembolic
risk factor, namely atrial fibrillation (AF).7 This leads to hope that randomized trials and translational research of therapies for other forms of cardioembolic stroke may substantially reduce stroke incidence worldwide.