Long-term disability after transient ischaemic attack or minor stroke

Disability is not an unexpected outcome after a stroke and, in people aged 75–80 years, functional decline is a common outcome, which can be associated with other comorbidities. Whether disability is an inevitable result of normal ageing, and if the process of functional decline can be prevented or halted, are questions that remain to be answered.

In The Lancet Neurology , Cristina Hobeanu and colleagues ¹ report 5-year follow-up data from TIAregistry.org, an international, prospective observational registry that included 3105 patients with transient ischaemic attack or minor ischaemic stroke and no disability (modified Rankin Scale [mRS] score of ≤1) at baseline, ² with the aim to investigate factors associated with poor functional outcome. All study sites that provided data for the registry had dedicated care systems for people with transient ischaemic attack, with care delivered by stroke specialists. Prescription and sustained use of pharmacological secondary prevention were high in this population, probably higher than in any clinical setting.

Despite having no disability immediately after transient ischaemic attack or minor stroke, more than one in five patients (710 [22·9%] of 3105) had developed disability (mRS score of >1) by 5 years of follow-up, frequently after recurrent stroke. ¹ Patients with new disability were, on average, 11 years older (mean age 74·9 years [SD 10·8] at baseline) than those without disability (age 63·9 years [12·6]). Living alone also contributed to the risk of new disability. Recurrent stroke or intracranial haemorrhage had occurred in 184 (25·9%) of 710 patients with disability at 5 years, compared with 144 (6·0%) of 2395 patients who did not have disability. These strokes occurred despite the reported high and sustained use of pharmacological secondary prevention in the cohort. Patients with disability at 5 years had a far higher burden of risk factors, including smoking, alcohol consumption, and cardiovascular comorbidities compared with those without disability at 5 years.

Findings of the 2018 US National Health Interview Survey ³ showed that a physical difficulty (defined as respondents answering at least once “very difficult” or “can’t do at all” after performing nine physical activities) was present in 19·0% of people aged 45–64 years, in 30·0% of those aged 65–74 years, and in 48·6% of those aged 75 years or older. From this perspective, the increase in disability after transient ischaemic attack or minor stroke that was recorded by Hobeanu and colleagues ¹ is not high—most likely because only patients with an mRS score of 0–1 at baseline were included in the cohort. The aim in clinical care, however, is not to achieve average disability, but to reduce disability to a minimum in every individual presentation.

Hobeanu and colleagues ¹ also reported that the risk of long-term disability was reduced by half with regular physical activity before the index event. It is well known that physical activity after stroke reduces the risk of recurrent stroke and poor outcome in a dose-dependent manner. ⁴ However, people with stroke seem less physically active than people of the same age without stroke. ⁵ These findings therefore highlight the importance of reducing physical inactivity and identifying efficient means of doing so. ⁶

Development of new and effective drugs for prevention of stroke, including factor XIa inhibitors, ⁷ could provide better risk reduction for patients who adhere to treatment compared with available drugs. Nevertheless, improvements in drug treatment alone are unlikely to halt stroke incidence. The risk factors and causes of stroke are heterogeneous, as are outcomes after stroke, implying that the absolute benefit of a specific drug—as well as the risk–benefit ratio—will vary between patients. One approach could be to investigate secondary prevention on the basis of risk factors and cause of stroke, which could entail interventions targeting specific subgroups—eg, patients with large-vessel disease. This approach could also include provision of appropriate support for patients with risk factors (eg, living alone) and focus on non-pharmacological interventions, including regular physical activity.

The findings reported by Hobeanu and colleagues ¹ highlight that, even in people with excellent early outcome after transient ischaemic attack and who were receiving pharmacological secondary prevention, functional decline at 5 years is frequent and often related to recurrent stroke. The incidence of strokes and the number of people living with stroke are increasing and expected to rise for years to come. ⁸ Presently, it is unlikely that most stroke patients (even in high-income regions, such as Europe) receive the dedicated care that was provided for the cohort reported by Hobeanu and colleagues. Implementation of primary and secondary prevention with a population-wide strategy are urgently needed and would be highly cost-effective for societies. 910