Mortality in ischaemic stroke patients without standard modifiable risk factors: An analysis of the Riksstroke registry.

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.