271 Meredith G, Rudd A. Postgrad Med J 2019;95:271–278. doi:10.1136/postgradmedj-2018-136157 Review Reducing the severity of stroke Georgina Meredith, Anthony Rudd To cite: Meredith G, Rudd A. Postgrad Med J 2019;95:271–278. Stroke Unit, St Thomas Hospital, London, UK Correspondence to Dr Anthony Rudd, Stroke Unit, St Thomas Hospital, London SE1 7EH, UK; anthony.rudd@kcl.ac.uk Received 2 February 2019 Revised 3 April 2019 Accepted 8 April 2019 Published Online First 25 May 2019 © Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ. ABSTRACT Stroke remains one of the most important causes of death and disability worldwide. Effective prevention could reduce the burden of stroke dramatically. The management of stroke has undergone a revolution over the last few decades, particularly with the development of techniques for revascularisation of patients with ischaemic stroke. Advanced imaging able to identify potentially salvageable brain is further increasing the potential for effective acute treatment. However, the majority of stroke patients won’t benefit from these treatments and will need effective specialist stroke care and ongoing rehabilitation to overcome impairments and adapt to living with a disability. There are still many unanswered questions about the most effective way of delivering rehabilitation. Likewise, research into how to manage primary intracerebral haemorrhage has yet to transform care. INTRODUCTION Up until the 1990s stroke was widely believed to be a largely untreatable condition with no major advances in management having been found since William Osler wrote at the beginning of the 20th century that ‘it is the duty of the physician to explain to the patient or to his friends, that the condition is past relief, that medicines and electricity will do no good and there is no possible hope of cure’. 1 The last 30 years have seen a dramatic change in that view. Not only is it recognised that stroke is largely preventable but for many patients who suffer a stroke, there are treatments that can transform them from having a life of long-term disability to one of independence. Nevertheless, there are unfortunately still many patients left, after the acute phase of the illness, with impairments requiring skilled rehabilitation and there is a dearth of high-quality evidence to show how they should be managed. This article highlights the important advances that have been made and where more research is needed. The burden of stroke It is estimated that there are 4.5 million deaths from stroke a year worldwide and over 9 million survi- vors. 2 The estimated global lifetime risk of stroke for the population aged over 25 is about 25% for both men and women, with the risk of ischaemic stroke being about 18% and about 8% for haem- orrhage. However, there are big regional variations with the risk being about 39% in East Asia and only 12% in east sub-Saharan Africa. 3 Even though in high-income countries incidence and case fatality have fallen dramatically over the last 20 years, because of an ageing population it is estimated that over the next 20 years in Europe and there- fore, likely to be mirrored in other high-income countries, there will be 45% more deaths caused by stroke, an extra 1 million stroke survivors and 32% more disability-adjusted life years lost. 4 Costs to society resulting from stroke are huge. In the UK alone, it is estimated that stroke costs about £7 billion per year. 5 Stroke is an expensive disease because over half of the survivors will have a signif- icant disability resulting in long-term health and social care costs, loss of earnings and costs to the family. So, for everyone, the risk of stroke is high and the impact on society substantial highlighting the importance of effective prevention, good acute care and rehabilitation. Prevention of stroke Stroke is not a single disease but rather an all-en- compassing term for focal vascular disease in the brain. It is, therefore, vital that the diagnostic process does not stop at stroke but rather identifies the type of stroke and therefore, its likely aetiology. The Trial of Org 10 172 in Acute Stroke Treatment (TOAST) classification is the most widely used system for defining the likely underlying cause. 6 7 TOAST classifies stroke as being due to: ► thrombosis or embolism due to atherosclerosis of a large artery (15.3% of cases in European populations), ► embolism of cardiac origin (30.2% of cases in European populations), ► occlusion of a small blood vessel (25.8% of cases in European populations), ► other determined cause (2.1% of cases in Euro- pean populations) and ► undetermined cause (two possible causes, no cause identified or incomplete investigation) (39.3% of cases in European populations). The most effective means available for reducing the burden of stroke involve modification and treatment of vascular risk factors. 8 Hypertension is the most prevalent vascular risk factor for stroke at about 30% in the UK and the USA in people aged over 16 years. 9 The risk of death from stroke increases progressively and linearly with systolic blood pres- sure levels as low as 115 mm Hg and diastolic 75 mm Hg upwards. 10 For every 20 mm Hg systolic or 10 mm Hg diastolic increase in blood pressure, there is a doubling of mortality from stroke. Atrial fibrillation (AF) increases the relative risk of stroke 2.6–4.5-fold. In patients with AF, treated with adjusted-dose warfarin or a direct oral anti- coagulant (DOAC), the relative risk reduction of stroke is 68% (95% CI, 50 to 79) and the absolute annual risk is reduced from 4.5% to 1.4%. 11 Diabetes increases the relative risk of stroke from 1.8 to 6.0. 12 The UK Prospective Diabetes Study has on June 4, 2020 by guest. 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