Recommendations for Hypertension Management in relation to STROKE

Background Stroke should be conceptualized as a syndrome. The term ‘stroke’ is a rubric that includes ischemic stroke and transient ischemic attack, intracerebral hemorrhage, atraumatic or aneurysmal subarachnoid hemorrhage and cerebral venous sinus thrombosis. Each of these stroke types has very different prognoses, treatment and outcomes. Hypertension is quantitatively the most important risk factor for stroke. It is relevant as a risk factor for all stroke types except cerebral venous sinus thrombosis (which will not be discussed further). Ischemia is the most common stroke type comprising 65‐85% of strokes depending upon geographical location in the world (relatively more ischemia in the west and more hemorrhage in the east). Both TIA and ischemic stroke should be thought of as ischemic stroke syndromes since the mechanisms and risk factors are identical. Hemorrhagic stroke syndromes comprise 15‐35% of all strokes and are roughly evenly divided between intracerebral hemorrhage and atraumatic sub‐ arachnoid hemorrhage. It is clinically impossible to reliably distinguish between ischemia and hemorrhage based upon clinical factors alone; imaging is required. Thus, all patients presenting with an acute stroke syndrome require urgent brain imaging. A majority (~70%) of stroke patients have a known prior history of hypertension. However, hypertension is of variable importance depending upon stroke type. Hypertension is most important as a risk factor for intracerebral hemorrhage. Its effect size as a risk factor for subarachnoid hemorrhage is much smaller where tobacco smoking and family history are more important. Because ischemic stroke has a myriad of causes, hypertension is variably important in ischemic stroke, depending upon mechanism. Classically, the subtypes of ischemic stroke are defined by mechanism; broad categories include cardioembolism, large artery atherosclerotic disease, lacunar stroke and undetermined causes. For example, as a precursor to atrial fibrillation, to atherosclerotic disease and to small vessel lipohyalinosis, hypertension is an important underlying cause respectively of cardioembolic, arteroembolic and lacunar stroke. By contrast, hypertension is less relevant when the cause of stroke is cardioembolic due to endocarditis. However, broadly, because the major mechanisms of stroke (lacunar, cardioembolic, large artery) are commonly preceded by longstanding hypertension, hypertension is the most important risk factor for ischemic stroke. Most stroke patients present to hospital with elevated blood pressures. Management of hypertension among stroke patients can be naturally divided into the acute phase (first 72h) and the chronic phase. In general, there is a dearth of available data to guide therapeutic decision‐making around blood pressure management in the acute phase, and much better data to guide therapy in the chronic, stable phase.