NIHR Signal Transient ischaemic attacks may have greater long-term impact than previously thought

Published on 7 February 2017

People are more likely to go to their GP about fatigue, psychological and cognitive impairment after a transient ischaemic attack (TIA) than similar people who have not had a TIA. Following a TIA people also go to their GP with these health problems sooner than those who haven’t had a TIA.

A TIA, sometimes called a “warning stroke”, is caused by a blockage in the blood vessels leading to the brain. The symptoms are similar to a stroke but last less than 24 hours unlike a stroke which, by definition, is longer lasting.

This study used a large database of anonymised GP records to compare fatigue, psychological and cognitive impairment amongst similar people who either had or hadn’t experienced a TIA over a five year period.

The findings suggest that professionals involved in TIA management and follow-up should be aware of potential long-term health consequences of TIA in order to offer appropriate support and treatment.

Why was this study needed?

In the UK, 46,000 people have a TIA each year. One in 12 people who have a TIA go on to have a stroke within a week. This high risk of a full stroke means that there is a focus on rapid diagnosis and early treatments to prevent it.

Strokes can have a significant long-term impact on people’s health and independence. However, a recent systematic review highlighted that the long-term impact of TIA is less well-known. The review suggested that there was a high rate of fatigue, psychological and cognitive impairment following a TIA. However, it was unclear whether this was higher than in the general population.

This study compared rates of fatigue, psychological and cognitive impairment amongst people in the UK who had experienced a TIA to similar people who had not had a TIA. Psychological impairment included symptoms or a diagnosis of depression, anxiety or post-traumatic stress disorder. Cognitive impairment included memory loss, difficulty with attention, spatial awareness and perception, but not dementia.

What did this study do?

This case-control study used The Health Improvement Network database, which covers a broadly representative sample of around 6% of the UK population. Data from 9,419 people aged 18 years and over who had a first TIA between 2009 and 2013 was compared to 46,511 similar people who had not had a TIA. The researchers picked these people without a TIA from the same practice and matched them for age and sex to those who had had one.

The observational study was well designed and analysed. It took into account BMI, deprivation, smoking, alcohol and other illnesses. The main limitations are the potential lack of accuracy and completeness of the routine collected data and that it was conducted retrospectively. It relies on correct diagnosis of TIA to ensure that all eligible people are included. The recording of outcomes relied on people visiting their GP and talking to them about their on-going symptoms.

What did it find?

  • After a TIA, 9.8% of people went to their GP with fatigue, compared to 5.9% of similar people who had not had a TIA (controls). This represents a 43% increased chance of reporting fatigue after a TIA (hazard ratio [HR] 1.43, 95% confidence interval [CI] 1.33 to 1.54). People who had experienced a TIA consulted for fatigue sooner (20.7 months, 95% CI 18.6 to 23.5) on average than controls (42.4 months, 95% CI 40.6 to 44.8).
  • Psychological impairment was diagnosed in 34.1% of people seeing their doctor after a TIA, compared to 24.1% amongst controls. This means that following TIA people were 26% more likely to have psychological impairment (HR 1.26, 95% CI 1.20 to 1.31). Following a TIA people consulted for psychological impairment sooner (7.1 months, 95% CI 6.2 to 8.2) on average compared to controls (23.5 months, 95% CI 22.5 to 24.6).
  • Following a TIA, people were more likely to have cognitive impairment compared to controls (3.9% versus 2.3%). Therefore people who had a TIA were 45% more likely to consult their doctor for cognitive impairment (HR 1.45, 95% CI 1.28 to 1.65). After a TIA, people consulted for cognitive impairment on average sooner (31.1 months, 95% CI 25.9 to 35.6) than controls (52.7, 95% CI 48.6 to 56.4).
  • An exploratory analysis found that excluding people who had a past history of fatigue, psychological or cognitive impairment before the start date of the study increased the hazard ratios for all outcomes, suggesting that the main analysis may be an under‑estimate.

What does current guidance say on this issue?

The Royal College of Physicians published NICE accredited guidelines on stroke management, including TIA, in 2016. It recommends that patients with acute neurological symptoms that resolve completely within 24 hours (i.e. suspected TIA) should be given aspirin 300 mg immediately and assessed urgently within 24 hours by a specialist physician in a neurovascular clinic or an acute stroke unit.

There is specific advice for managing fatigue and cognitive impairments after stroke but little recognition of the long-term impact of TIAs or advice on management of these symptoms after a TIA.

What are the implications?

The findings of this study suggest that all health professionals supporting people following a TIA should be aware of fatigue and cognitive impairment as potential long-term consequences and ask patients specifically about them in order to provide appropriate treatment and support.

The data here was routinely collected in general practice and relies on a standardised recording of these symptoms it therefore may under-estimate the exact rates of these long-term consequences.

Citation and Funding

Turner GM, Calvert M, Feltham M, et al. Ongoing impairments following transient ischaemic attack: retrospective cohort study.  European Journal of Neurology. 2016;23(11):1642-1650.

This project was funded by the National Institute for Health Research School for Primary Care Research.

Bibliography

NHS Choices. Transient ischaemic attack (TIA). London: Department of Health; 2016.

NICE. Stroke and transient ischaemic attack in over 16s: diagnosis and initial management. CG68. London: National Institute for Health and Care Excellence; 2008.

NICE. Stroke rehabilitation in adults. CG162. London: National Institute for Health and Care Excellence; 2008.

RCP. National clinical guideline for stroke. London: Royal College of Physicians; 2016.

Stroke association. Transient ischaemic attack (TIA). London: Stroke association; 2014.

Why was this study needed?

In the UK, 46,000 people have a TIA each year. One in 12 people who have a TIA go on to have a stroke within a week. This high risk of a full stroke means that there is a focus on rapid diagnosis and early treatments to prevent it.

Strokes can have a significant long-term impact on people’s health and independence. However, a recent systematic review highlighted that the long-term impact of TIA is less well-known. The review suggested that there was a high rate of fatigue, psychological and cognitive impairment following a TIA. However, it was unclear whether this was higher than in the general population.

This study compared rates of fatigue, psychological and cognitive impairment amongst people in the UK who had experienced a TIA to similar people who had not had a TIA. Psychological impairment included symptoms or a diagnosis of depression, anxiety or post-traumatic stress disorder. Cognitive impairment included memory loss, difficulty with attention, spatial awareness and perception, but not dementia.

What did this study do?

This case-control study used The Health Improvement Network database, which covers a broadly representative sample of around 6% of the UK population. Data from 9,419 people aged 18 years and over who had a first TIA between 2009 and 2013 was compared to 46,511 similar people who had not had a TIA. The researchers picked these people without a TIA from the same practice and matched them for age and sex to those who had had one.

The observational study was well designed and analysed. It took into account BMI, deprivation, smoking, alcohol and other illnesses. The main limitations are the potential lack of accuracy and completeness of the routine collected data and that it was conducted retrospectively. It relies on correct diagnosis of TIA to ensure that all eligible people are included. The recording of outcomes relied on people visiting their GP and talking to them about their on-going symptoms.

What did it find?

  • After a TIA, 9.8% of people went to their GP with fatigue, compared to 5.9% of similar people who had not had a TIA (controls). This represents a 43% increased chance of reporting fatigue after a TIA (hazard ratio [HR] 1.43, 95% confidence interval [CI] 1.33 to 1.54). People who had experienced a TIA consulted for fatigue sooner (20.7 months, 95% CI 18.6 to 23.5) on average than controls (42.4 months, 95% CI 40.6 to 44.8).
  • Psychological impairment was diagnosed in 34.1% of people seeing their doctor after a TIA, compared to 24.1% amongst controls. This means that following TIA people were 26% more likely to have psychological impairment (HR 1.26, 95% CI 1.20 to 1.31). Following a TIA people consulted for psychological impairment sooner (7.1 months, 95% CI 6.2 to 8.2) on average compared to controls (23.5 months, 95% CI 22.5 to 24.6).
  • Following a TIA, people were more likely to have cognitive impairment compared to controls (3.9% versus 2.3%). Therefore people who had a TIA were 45% more likely to consult their doctor for cognitive impairment (HR 1.45, 95% CI 1.28 to 1.65). After a TIA, people consulted for cognitive impairment on average sooner (31.1 months, 95% CI 25.9 to 35.6) than controls (52.7, 95% CI 48.6 to 56.4).
  • An exploratory analysis found that excluding people who had a past history of fatigue, psychological or cognitive impairment before the start date of the study increased the hazard ratios for all outcomes, suggesting that the main analysis may be an under‑estimate.

What does current guidance say on this issue?

The Royal College of Physicians published NICE accredited guidelines on stroke management, including TIA, in 2016. It recommends that patients with acute neurological symptoms that resolve completely within 24 hours (i.e. suspected TIA) should be given aspirin 300 mg immediately and assessed urgently within 24 hours by a specialist physician in a neurovascular clinic or an acute stroke unit.

There is specific advice for managing fatigue and cognitive impairments after stroke but little recognition of the long-term impact of TIAs or advice on management of these symptoms after a TIA.

What are the implications?

The findings of this study suggest that all health professionals supporting people following a TIA should be aware of fatigue and cognitive impairment as potential long-term consequences and ask patients specifically about them in order to provide appropriate treatment and support.

The data here was routinely collected in general practice and relies on a standardised recording of these symptoms it therefore may under-estimate the exact rates of these long-term consequences.

Citation and Funding

Turner GM, Calvert M, Feltham M, et al. Ongoing impairments following transient ischaemic attack: retrospective cohort study.  European Journal of Neurology. 2016;23(11):1642-1650.

This project was funded by the National Institute for Health Research School for Primary Care Research.

Bibliography

NHS Choices. Transient ischaemic attack (TIA). London: Department of Health; 2016.

NICE. Stroke and transient ischaemic attack in over 16s: diagnosis and initial management. CG68. London: National Institute for Health and Care Excellence; 2008.

NICE. Stroke rehabilitation in adults. CG162. London: National Institute for Health and Care Excellence; 2008.

RCP. National clinical guideline for stroke. London: Royal College of Physicians; 2016.

Stroke association. Transient ischaemic attack (TIA). London: Stroke association; 2014.

Ongoing impairments following transient ischaemic attack: retrospective cohort study

Published on 19 July 2016

G. Turner,M. Calvert, M. Feltham, R. Ryan, T. Marshall

European Journal of Neurology , 2016

Background and purpose Clinical management after transient ischaemic attack (TIA) is focused on stroke prevention; however, a number of small studies suggest that patients may experience ongoing residual impairments. Methods This was a retrospective matched-cohort study using anonymized electronic primary care records from The Health Improvement Network database, which covers approximately 6% of the UK population. Adults (≥ 18 years old) who experienced a first TIA between 2009 and 2013 were matched in a ratio of 1:5 to controls by age, sex and general practice. The time to first consultation for fatigue, psychological impairment or cognitive impairment was estimated by Kaplan–Meier survivor functions and adjusted hazard ratios. Results A total of 9419 TIA patients and 46 511 controls were included. The Kaplan–Meier curves showed that TIA patients were more likely than controls to consult for all three impairments (P < 0.0001). Within 7.1 months (95% confidence interval (CI), 6.2–8.2), 25% of TIA patients consulted for psychological impairment compared with 23.5 months (95% CI, 22.5–24.6) for controls. Hazard ratios for TIA patients were 1.43 (95% CI, 1.33–1.54) for consulting for fatigue, 1.26 (95% CI, 1.20–1.31) for psychological impairment and 1.45 (95% CI, 1.28–1.65) for cognitive impairment. Conclusions Transient ischaemic attack is associated with significantly increased subsequent consultation for fatigue, psychological impairment and cognitive impairment. These findings suggest that impairments exist after initial symptoms of TIA have resolved, which should be considered by clinicians when treating TIA patients.

Expert commentary

TIA is an important diagnosis to make. The definition is an arbitrary one based on full resolution within 24 hours. Sensitive brain imaging has shown that many patients have infarction. Further, the diagnosis of TIA is one of the more difficult clinical decisions and is subject to wide variation between clinicians. So a retrospective study using routine primary care data must always be treated with caution. Nevertheless these findings fit with those found in stroke patients and therefore have face validity. They further highlight that TIA is not a benign condition and support the case for getting rid of the diagnosis altogether and calling all cerebral ischemia ‘stroke’.

Tony Rudd, Professor of Stroke Medicine, Kings College London; Consultant Stroke Physician, Guy's and St Thomas' NHS Foundation Trust; National Clinical Director for Stroke NHS England; London Stroke Clinical Director; Stroke Programme Director, Royal College of Physicians

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