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Although often ascribed to the Latin icere — ‘to strike’, as in the term ictus cerebri (previously in common use as a medical term for stroke), the true origin of the word ‘stroke’ probably has its derivation from Hippocrates’s use of ‘apoplexy’ (apopleissen — ‘to cripple by striking’). As a descriptive medical term, though, it is likely that it referred to many different ailments at the time. Hippocrates wrote of stroke, “that apoplexy was difficult to treat and impossible to cure”.
When I last wrote an article of this nature in 2008, we had about 10,000 acute strokes occurring in Ireland every year, causing approximately 2,100 deaths, our third-leading cause of death. It was then, and still is, our leading cause of adult disability, with about 30,000 people living with a disability post-stroke. However, the Irish National Audit of Stroke Care (INASC) demonstrates that with improvement in care, both mortality and disability from stroke have lessened and more people are going home after stroke than before, with improved survival not merely reflecting a survival with severe disability.
The article I wrote in 2008 was titled Stroke: An age-old disease with new challenges, as it reflected on the four main challenges to us in the stroke community at the time: 1) stroke unit care; 2) provision of acute thrombolysis and rapid assessment transient ischaemic attack (TIA) services; 3) stroke prevention through education, lifestyle and screening; and 4) an integrated holistic rehabilitation and health maintenance programme for all stroke patients in hospital, at home and in continuing care.
At that time, we had perhaps one true acute stroke unit in the country, whereas in the 2015 audit some 78 per cent of sites had an acute stroke unit. We had very limited and patchy thrombolysis services in 2008, where now at least 11 per cent of all cases of acute stroke receive this treatment, even out-of-hours, which compares very well internationally. We had little public recognition of stroke and its risk factors and this has improved, and we have started screening for important conditions like atrial fibrillation.
We had a limited number of stroke specialists and stroke rehabilitation staff and while staffing difficulties in MDTs still exist, organised teams are now widespread, clinical nurse specialists in stroke are the ‘norm’ and there are several early supported discharge programmes.
While fortunate to have inherited an organised stroke service from the Meath Hospital in 1995, like many other institutions, Tallaght Hospital, Dublin, has developed in tandem with these developments. Our stroke mortality has dropped from 15 per cent in 1997 to 7.5 per cent; we had <1 per cent thrombolysis rates in 2005, whereas now 33 per cent of patients presenting within window are treated. We had no clot retrieval thrombectomy service, whereas now 5.1 per cent of patients are referred for this treatment. Since 2008, we have an acute stroke unit and a better-resourced stroke MDT.
Much happened to cause this change. The first Irish national audit of stroke care in 2008 highlighted our deficits in stroke care; a new national cardiovascular strategy published in 2009 recognised for the first time the importance of stroke as a target for improved cardiovascular health; the first standards of care, services and staffing for stroke were formulated and agreed in Irish Heart (previously Irish Heart Foundation) guidelines; and the National Stroke Programme was launched to organise our stroke services and reduce death and disability. Behind this effort was a committed multidisciplinary and interdisciplinary team of doctors, nurses and allied health professionals and advocacy bodies from across the spectrum of stroke care. The success has been remarkable and gives life to the expression, ‘ní neart go cur le chéile’.
Significant challenges remain, however, and our local catchment area is a leading example of the challenges we face. While incidence of stroke has been declining, the prevalence of stroke has been increasing as it is largely an age-related condition and more people are thankfully surviving stroke.
This demographic challenge is stark in Tallaght, Dublin. Over the next 15 years, some suburbs of Tallaght will see a remarkable 700-1,500 per cent increase in the numbers of over-75s and the catchment area of the hospital as a whole will experience a 250 per cent increase in that population. The demographic shift in Tallaght to a ‘Florida without the sun’ has potentially far reaching implications for the community and the hospital and for the incidence and prevalence of stroke over the coming years.
In addition, while the television FAST adverts greatly improved public knowledge of stroke and the importance of presenting quickly, this has demonstrably disimproved since the end of the campaign and over half our stroke patients do not present within the three-and-a-half hours needed to allow access to thrombolysis treatment.
To return to Hippocrates’s observation that “a stroke can be difficult to treat and impossible to cure”, prevention will be an important goal and modifiable risk factors, among which atrial fibrillation will be number one in this ageing population, is a key target for stroke services at Tallaght Hospital, as elsewhere.
Atrial fibrillation is the commonest cardiac arrhythmia, occurring in anywhere from 5-to-13 per cent of people aged over 65 years. It is usually asymptomatic and often intermittent. It is associated with one-in-three strokes in Ireland. The strokes caused by atrial fibrillation are more likely to be severe, recurrent and fatal. It is perhaps the greatest public health issue for older people and as such fulfils many of the World Health Organisation original Wilson-Jungner Criteria for screening.
International studies have been adding to the evidence for screening, and with Irish Heart support, Tallaght and Beacon hospitals recently piloted a community-based systematic screening study for atrial fibrillation, which showed a number-needed-to-screen of seven people over the age of 60 with one-to-two risk factors to identify any atrial fibrillation.
Rolling out a national screening programme, however, will need resources and further study. While opportunistic pulse-checking with supportive ECG can identify new cases of atrial fibrillation, it is not an ideal approach for a condition that is often paroxysmal and could be falsely reassuring. In this writer’s opinion, detection of atrial fibrillation needs a more systematic approach, as anything else ‘amounts to breast cancer screening without mammography’.
Identifying atrial fibrillation is a key first step but treatment, stroke prevention and perhaps electrophysiological cure of the condition requires an interdisciplinary approach between cardiology, stroke physicians and pharmacy, a fact recognised in the latest iteration of the European Society of Cardiology guidelines. Aware of our demography, Tallaght Hospital has been running an interdisciplinary atrial fibrillation clinic for the past two years.
Much progress has been made since 2008 in trying to cure stroke when it happens. The availability of clot-busting thrombolysis has become widespread and specialist stroke assessment is now available on a 24/7 basis in most centres. One solution has been the use of telemedicine to make rotas workable and sustainable across regions. Our own telemedicine service, which started in 2010 as a pilot across Dublin Mid-Leinster, resulted in a large improvement in thrombolysis rates, from 2 per cent to almost 16 per cent. Now, 786 consultations and over 14,000 minutes of telemedicine later, there is little doubt of its value in improving stroke care.
However, a challenge remains in migrating from a pilot to a national network and what works for one network is not necessarily a solution for another.
Acute occlusion of a large artery due to cardiac embolus from atrial fibrillation and atherosclerotic plaque of aorta or carotid accounts for half of all strokes. Analogous to a blocked drain, the use of intravenous thrombolysis is likened to pouring Domestos onto the backed-up pool of water, and while often successful, recanalisation of major arterial blockages is achieved in less than 40 per cent cases.
The percutaneous coronary intervention (PCI) or ‘dyno-rod’ approach in stroke has been a slower evolution than in coronary arterial disease, not least due to lack of an existing historical experience, the vastly different environment of the thinner-walled, free-standing cerebral arteries, and the very serious repercussions of perforation.
Over the last 10 years, not only the time interval but the nature of catheter type and pre-treatment angiography criteria have been well defined so that we now have five randomised, controlled trials published (MR CLEAN, ESCAPE, SWIFT PRIME, REVASCAT, EXTEND-IA) and a meta analysis of thrombectomy in acute ischaemic stroke showing that in properly-selected patients, a number-needed-to-treat (NNT) of four results in one extra, independent from neurological disability outcome. Compared to an NNT of nine for thrombolysis and 14 for acute stroke unit care, thrombectomy has been the single greatest development in acute stroke care.
Ireland played a significant part in the development of this research base, with our network approach around a thrombectomy centre at Beaumont Hospital, Dublin, contributing the second-largest numbers to the ESCAPE trial. A challenge remains to resource this treatment at Beaumont and Cork University hospitals and optimising patient pathways to care, while anticipating future needs.
To date, there has been little in the way of acute treatment for stroke caused by intracerebral haemorrhage. The condition is often associated with hypertension and less commonly by an underlying vascular malformation or amyloid angiopathy as we age. Trials of administering clotting factors such as Factor VII have, to date, failed to show improved outcome and while control of blood pressure acutely has been well tolerated and resulted in reduced haematoma volume, this has not translated into improved outcomes to date. A novel approach has been to extrapolate from trauma data where tranexamic acid has shown improved outcomes to trialling this antifibrinolytic agent in non-traumatic intracerebral bleeding.
The large international Tranexamic In acute Intracerebral Haemorrhage (TICH-2) trial is well underway and has four participating centres in Ireland, co-ordinated by Tallaght, Naas, the Mater and Beaumont and should be reporting results in late 2018.
A recent exciting development has been the Irish Stroke Clinical Trials Network set up to help harness the infrastructure and talents of the stroke community to both contribute to existing international work and design new stroke trials from our strong Irish base.
With support from the Health Research Board and Irish Heart, Prof Peter Kelly has created a unique opportunity for Irish stroke academia and most recently the network has launched the first ‘home grown’, large, multi-centre international trial, CONVINCE, to look at the drug colchicine in the prevention of recurrent stroke.
This represents a landmark in stroke research for this country.