Long-term management and secondary prevention

From the moment a person has a stroke or TIA they are at substantial increased risk of further events; 26% within 5 years of a first stroke and 39% by 10 years (Mohan et al, 2011). There are additional risks of about the same magnitude for other vascular events such as acute coronary syndrome. Stroke is not a single disease entity and in some cases (e.g. arterial dissection) the underlying pathology is associated with a relatively low risk of recurrence. Clinicians should seek to identify and reduce the risks that are specific to each individual. [2016]

The greatest risk of a vascular event is early after stroke or TIA and may be as high as 25% within three months, half of which is within the first four days (Johnston et al, 2000). Secondary prevention should therefore be commenced as soon as possible, and recent registry evidence suggests these measures can substantially reduce the risk of recurrent events (Amarenco & Steering Committee Investigators of the TIAregistry.org, 2016). Some of the recommendations for management in the acute phase, such as starting aspirin immediately after ischaemic stroke, are part of secondary prevention. This chapter assumes that all the recommendations made in Chapter 3 have been implemented, and the recommendations concerning early risk reduction are not repeated here. However, it is important that attention to secondary prevention is continued throughout the rehabilitation and recovery phase, as persistence with treatment is vital to long-term risk reduction. [2016]

Diet and lifestyle issues such as smoking, exercise and alcohol intake contribute significantly to cardiovascular risk, including the risk of first and recurrent stroke; their modification provides an important mechanism for influencing recurrent events. Much of the evidence here comes from primary prevention studies or from patients with coronary artery disease, with the presumption that the evidence translates to the secondary prevention of stroke based on the two conditions often sharing the same underlying pathology. Given the different causes of stroke, this will not always be the case. [2016]

People with stroke and their family/carers often face substantial challenges returning to life in the home, community and workplace. The huge variety of individual circumstances and the complex nature of the outcomes concerned complicate the design, conduct and interpretation of research into living with the long-term effects of stroke. As a consequence, the evidence to guide recommendations here is more difficult to interpret; this does not diminish the importance of the topics under consideration nor the need for expert guidance on best practice. [2016]

5.1 A comprehensive and personalised approach

Ensuring the identification and modification of all risk factors, including lifestyle issues, should lead to more effective secondary prevention of stroke and other vascular events . Show more

Ensuring the identification and modification of all risk factors, including lifestyle issues, should lead to more effective secondary prevention of stroke and other vascular events. This section covers advice and general principles of management ‒ specific interventions are covered in subsequent sections. The clinician’s approach to the modification of risk factors through lifestyle changes or medication should observe the principles of shared decision making recommended in NICE guidance (NICE, 2021c) and these principles apply to all the following sections. [2023]

People with stroke or TIA should receive a comprehensive and personalised strategy for vascular prevention including medication and lifestyle factors, which should be implemented as soon as possible and should continue long-term. [2016]

People with stroke or TIA should receive information, advice and treatment for stroke, TIA and vascular risk factors which is:

• given first in the hospital or clinic setting;
• reinforced by all health professionals involved in their care;
• provided in an appropriate format. [2016]

People with stroke or TIA should have their risk factors and secondary prevention reviewed and monitored at least once a year in primary care. [2016]

People with stroke or TIA who are receiving medication for secondary prevention should:

• receive information about the reason for the medication, how and when to take it and common side effects;
• receive verbal and written information about their medicines in an appropriate format;
• be offered compliance aids such as large-print labels, non-childproof tops and dosette boxes according to their level of manual dexterity, cognitive impairment, personal preference and compatibility with safety in the home;
• be aware of how to obtain further supplies of medication;
• have their medication regularly reviewed;
• have their capacity to take full responsibility for self-medication assessed (including cognition, manual dexterity and ability to swallow) by the multidisciplinary team as part of their rehabilitation prior to the transfer of their care out of hospital. [2016]

Working Party consensus

Ovbiagele et al, 2004; Maasland et al, 2007; Sit et al, 2007

Working Party consensus

5.2 Identifying risk factors

The risk of recurrent vascular events may vary significantly between individuals according to underlying pathology, co-morbidities and lifestyle factors. This guideline applies to . Show more

The risk of recurrent vascular events may vary significantly between individuals according to underlying pathology, co-morbidities and lifestyle factors. This guideline applies to the vast majority of people with TIA and stroke, including those not admitted to hospital; some of the recommendations may not be appropriate for the small minority of people with unusual stroke pathologies. [2016]

People with stroke or TIA for whom secondary prevention is appropriate should be investigated for risk factors as soon as possible within 1 week of onset. [2016]

Provided they are eligible for any resultant intervention, people with stroke or TIA should be investigated for the following risk factors:

• ipsilateral carotid artery stenosis;
• atrial fibrillation;
• structural cardiac disease. [2016]

People with evidence of non-symptomatic cerebral infarction on brain imaging (silent cerebral ischaemia) should have an individualised assessment of their vascular risk and secondary prevention. [2016]

Working Party consensus

The identification of risk factors for stroke and TIA should be part of the assessment during the acute phase. Regular review of risk factors and secondary prevention in primary care may require additional resources. [2016]

5.3 Carotid artery stenosis

Atheroma and stenosis of the carotid arteries is commonly associated with stroke and TIA, and surgical or radiological interventions (endarterectomy or stenting) have been used to

Atheroma and stenosis of the carotid arteries is commonly associated with stroke and TIA, and surgical or radiological interventions (endarterectomy or stenting) have been used to reduce the risk of recurrent ipsilateral stroke. [2016]

Following stroke or TIA, the degree of carotid artery stenosis should be reported using the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method. [2016]

People with non-disabling carotid artery territory stroke or TIA should be considered for carotid revascularisation, and if they agree with intervention:

• they should have carotid imaging (duplex ultrasound, MR or CT angiography) performed urgently to assess the degree of stenosis;
• if the initial test identifies a relevant severe stenosis (greater than or equal to 50%), a second or repeat non-invasive imaging investigation should be performed to confirm the degree of stenosis. This confirmatory test should be carried out urgently to avoid delaying any intervention. [2016]

People with non-disabling carotid artery territory stroke or TIA should be considered for carotid revascularisation if the symptomatic internal carotid artery has a stenosis of greater than or equal to 50%. The decision to offer carotid revascularisation should be:

• based on individualised risk estimates taking account of factors such as the time from the event, gender, age and the type of qualifying event;
• supported by risk tables or web-based risk calculators (e.g. the Oxford University Stroke Prevention Research Unit calculator, https://www.ndcn.ox.ac.uk/divisions/cpsd/carotid-stenosis-tool-1). [2016]

People with non-disabling carotid artery territory stroke or TIA and a carotid stenosis of less than 50% should not be offered revascularisation of the carotid artery. [2016]

Carotid endarterectomy for people with symptomatic carotid stenosis should be:

• the treatment of choice, particularly for people who are 70 years of age and over or for whom the intervention is planned within seven days of stroke or TIA;
• performed in people who are neurologically stable and who are fit for surgery using either local or general anaesthetic according to the person’s preference;
• performed as soon as possible and within 1 week of first presentation;
• deferred for 72 hours in people treated with intravenous thrombolysis;
• only undertaken by a specialist surgeon in a vascular centre where the outcomes of carotid surgery are routinely audited. [2016]

Carotid angioplasty and stenting should be considered for people with symptomatic carotid stenosis who are:

• unsuitable for open surgery (e.g. high carotid bifurcation, symptomatic re-stenosis following endarterectomy, radiotherapy-associated carotid stenosis);

• less than 70 years of age and who have a preference for carotid artery stenting.

The procedure should only be undertaken by an experienced operator in a vascular centre where the outcomes of carotid stenting are routinely audited. [2016]

People who have undergone carotid revascularisation should be reviewed post-operatively by a stroke physician to optimise medical aspects of vascular secondary prevention. [2016]

Patients with atrial fibrillation and symptomatic internal carotid artery stenosis should be managed for both conditions unless there are contraindications. [2016]

Working Party consensus

Wardlaw et al, 2006

Rothwell et al, 2004, 2005; Rerkasem and Rothwell, 2011

Rerkasem and Rothwell, 2011; Bonati et al, 2012; Vaniyapong et al, 2013; Rantner et al, 2013; Working Party consensus

Economopoulos et al, 2011; Bonati et al, 2015; Working Party consensus

Working Party consensus

The principal evidence for carotid endarterectomy for people with recent symptoms is from the European Carotid Surgery Trial (ECST) and the North American Symptomatic Carotid Endarterectomy Trial (NASCET) (Rothwell et al, 2003b). Only people with non-disabling stroke or TIA were included in these trials and the benefits of surgery cannot be assumed to apply to those with more disabling strokes. People with possible cardioembolism were also excluded. When allowance is made for the different methods used to measure stenosis from angiograms, the two trials report consistent findings. To avoid confusion regarding the degree of stenosis the technique used in NASCET should be used (the ratio of the diameter of the residual lumen at the point of maximum narrowing to that of the more distal internal carotid artery, expressed as a percentage). In a pooled analysis of the individual data from 6,092 patients, carotid endarterectomy reduced the 5-year absolute risk of ipsilateral ischaemic stroke by 16.0% in patients with 70–99% stenosis, and by 4.6% in patients with 50–69%. There was no benefit for patients with 30–49% stenosis and surgery increased the risk in patients with less than 30% stenosis. There was no evidence of benefit for patients with a near-occlusion. In these trials conducted in the 1980s the operative risk of stroke (ocular or cerebral) and death within 30 days of endarterectomy was 7%. [2016]

There is evidence of considerable heterogeneity in individual risk according to age, gender, degree of stenosis, presenting symptom, time from presenting symptom and presence of plaque ulceration (Rothwell et al, 2004). Prognostic models based on these characteristics have been derived which may be useful in the decision making process (Rothwell et al, 2005). These models are based on trial data which are now over 20 years old and with improvements in other treatments these models are likely to overestimate the absolute risk of stroke. Modified prognostic models incorporating corrections to allow for improvements in ‘best medical therapy’ have been developed (e.g. the Carotid Artery Risk score – www.ecst2.com/), but await validation. [2016]

In a systematic review of operative risks in relation to timing of surgery, no statistically significant difference for early versus late surgery was identified for patients with stable stroke (Rerkasem & Rothwell, 2009). In patients undergoing emergency surgery the pooled absolute risk of stroke and death was 20.2% for those with ‘stroke-in-evolution’ (fluctuating or progressive deficit) and 11.4% for those with crescendo TIA (more than 2 episodes in a week), significantly higher than for those undergoing non-emergency surgery (odds ratio [OR] 4.6). Such patients are likely to be at increased risk if surgery is not performed, but given these risks and the effectiveness of medical management it cannot be assumed that emergency surgery is beneficial in neurologically unstable patients. The outcome from carotid endarterectomy is not significantly influenced by whether the procedure is carried out under local or general anaesthesia (Vaniyapong et al, 2013), and if the person has a particular preference, this should be taken into account. [2016]

Compared to surgical endarterectomy, endovascular therapy involving carotid angioplasty and stenting is associated with an increased risk of stroke of any severity or death (Bonati et al, 2012). This increased risk is modified by age, with no difference in stroke or death when the comparison is confined to those below 70 years of age (International Carotid Stenting Study investigators, 2010). Long-term follow-up identifies an excess of procedure-related and non-disabling strokes with endovascular therapy (Bonati et al, 2015). By contrast, carotid endarterectomy is associated with an excess of cranial nerve palsy and myocardial infarction (Bonati et al, 2012). For endovascular procedures undertaken within the first few days after symptom onset there is an excess of disabling and fatal, as well as non-disabling strokes in comparison to carotid endarterectomy (Rantner et al, 2013). [2016]

There is no high quality evidence to guide decision making regarding the timing and indications for carotid revascularisation in patients presenting with ischaemic stroke who have been treated with intravenous thrombolysis. A number of case series have been reported with small numbers and few outcome events (Naylor, 2015). Activation of the coagulation system and fibrin formation occurs following alteplase therapy with changes peaking at 1 to 3 hours but detectable for up to 72 hours (Fassbender et al, 1999). It is not clear what impact if any these changes in the coagulation system may have on the balance of risks and benefits, but in the absence of high quality data it would seem reasonable to advise caution if considering surgery within 72 hours of intravenous thrombolysis. [2016]

Vascular surgery services should offer the option to perform carotid endarterectomy surgery under local or general anaesthetic. Multidisciplinary teams should include a carotid interventionist able to advise on and deliver carotid artery angioplasty and stenting. [2016]