Introduction: Little is known of the long-term prognosis of patients with acute ischaemic stroke in the absence of standard modifiable stroke risk factors (SMoRFs). In acute coronary syndromes, patients without modifiable risk factors have a higher mortality rate. We analysed data from the Swedish Stroke Register to determine survival of patients without SMoRFs following an ischaemic stroke.
Patients and methods: We identified adult patients with first-presentation acute ischaemic stroke between 2010 and 2020. Patients were considered to possess a SMoRF if they had one of: hypertension, diabetes, hyperlipidaemia, atrial fibrillation or an active smoking history. We compared mortality in patients with and without SMoRFs following first-presentation ischaemic stroke using cox regression models. We also assessed the combined endpoint death and dependency (mRS 3-6) at 3 months via logistic regression models.
Results: Of 152,588 patients with ischaemic stroke, hypertension (58.7%) and atrial fibrillation (27.3%) were the most common risk factors. 34,019 patients (22.3%) had no SMoRFs. After a first-presentation ischaemic stroke, patients without SMoRFs had a lower risk of death than patients with one or more SMoRFs (HR 0.58 [95% CI 0.57-0.59]). The absence of SMoRFs was associated with lower odds of death and dependency at 3 months in logistic regression models (OR 0·60 [95% CI 0.58-0.62]).
Conclusion: One in five patients with acute ischaemic stroke had no standard modifiable stroke risk factors. These patients have lower risk of death compared to patients with one or more SMoRFs.
Keywords: Stroke; death; dependency; mortality; risk factors.