Poor long-term functional outcomes after a TIA or minor ischaemic stroke suggest more needs to be done in terms of primary and secondary prevention.
An international TIAregistry.org study followed 3,847 adult patients with an mRS score of 0–1 at baseline for a median of five years.
The study, which included Australian contributors, found that although not initially disabling, TIAs or minor ischaemic strokes were associated with an increased risk of long-term functional disability or death.
At five years, almost a quarter of patients (22.9%) had a poorer functional outcome (mRS score >1) or had died due to recurrent events or comorbidities.
“Overall, 345 (9 ·5%) patients had a recurrent ischaemic stroke by 5 years after baseline, of whom 141 (4·2%) had a disabling stroke and 204 (4·7%) had a non disabling stroke,” the study authors said in Lancet Neurology [link here].
The study found worse functional outcome (mRS score of >1) at 5 years in older patients (per 10 year increase, odds ratio [OR] 2·18, 95% CI 1·93–2·46; p<0·0001), diabetes of any type (1·45, 1·18–1·78; p=0·0001), hypertension (1·38, 1·00–1·92; p=0·050), congestive heart failure (1·73, 1·22–2·46; p=0·0024), coronary artery disease (1·32, 1·00–1·74; p=0·049), and atrial fibrillation or flutter (1·52, 1·04–1·94; p=0·030) than in patients with a five-year mRS score of 0–1.
A history of stroke or transient ischaemic attack before the index event was associated with an mRS score of greater than 1 at 5 years (OR 1·74, 95% CI 1·37–2·22; p<0·0001) while regular physical activity before the index event was strongly inversely associated with an mRS score of greater than 1 at 5 years (0·52, 0·42–0·66; p<0·0001).
“Recurrent ischaemic stroke during follow up was strongly associated with increased risk of having an mRS score of greater than 1 at 5 years (OR 3·52, 95% CI 2·37–5·22; p<0·0001).”
Factors associated with recurrent disabling or fatal ischaemic stroke (mRS score of >1) within 5 years were intracranial haemorrhage during follow up (HR 17 ·15; p<0·0001), NIHSS score of >5 at discharge (HR 5·11; p=0·0013), diabetes of any type (HR 2·23; p<0·0001), older age (per 10 year increase, HR 1·61; p<0·0001), mRS score of greater than 1 at discharge (HR 2·49; p=0·0083), history of coronary artery disease (HR 1 ·76; p=0·0063), history of stroke or TIA before the qualifying event (HR 1·54; p=0·035), congestive heart failure (HR 1·86; p=0·044), and stroke as qualifying event (HR 1·73; p=0·0024).
The investigators said the findings confirm the role of comorbidities as a predictor of long term disability after TIA and minor ischaemic stroke.
“A remarkable and novel finding from this study is that regular physical exercise before the index event was strongly inversely associated with disability or death at 5 years of follow up in all three categories, including overall disability, disability following a recurrent ischaemic stroke, and disability in patients without a recurrent ischaemic stroke.”
“As physical activity is protective against cerebrovascular events, whether it is leisure time or more intense activity, clinicians should focus as much on encouraging regular physical activity as they do with checking blood pressure and LDL cholesterol and glycaemia concentrations.”
“Because modifiable risk factors were independently associated with overall disability and recurrent disabling stroke, there might be room for improvement in secondary prevention strategies,” they concluded.
“Tackling disabling stroke or death after transient ischaemic attack or minor ischaemic stroke with the use of new preventive strategies and enhancing adherence to recommendations should be our main objectives.”
A Comment article in the journal [link here] said improvements in drug treatment alone were 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.”
“The findings … 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.”
“Implementation of primary and secondary prevention with a population-wide strategy are urgently needed and would be highly cost-effective for societies,” the authors concluded.