Acute ischaemic stroke in the absence of established vascular risk factors: Patient characteristics, stroke mechanism and long-term outcome

Stefania Nannoni; Ali Scherz-Moussa Youma; Michael Amiguet; Ashraf Eskandari; Davide Strambo; Patrik Michel

doi:10.1111/ene.14667

Acute ischaemic stroke in the absence of established vascular risk factors: Patient characteristics, stroke mechanism and long-term outcome

Eur J Neurol. 2021 Apr;28(4):1275-1283. doi: 10.1111/ene.14667. Epub 2020 Dec 7.

Authors

Stefania Nannoni¹, Ali Scherz-Moussa Youma², Michael Amiguet³, Ashraf Eskandari¹, Davide Strambo¹, Patrik Michel¹

Affiliations

¹ Stroke Center, Neurology Service, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
² Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
³ Center for Primary Care and Public Health (Unisanté), University of Lausanne, Lausanne, Switzerland.

PMID: 33284528
DOI: 10.1111/ene.14667

Abstract

Background and purpose: Some acute ischaemic stroke (AIS) patients do not display established vascular risk factors (EVRFs). The aim was to assess their clinical characteristics, stroke subtype etiological classification and long-term outcome.

Methods: All consecutive AIS patients from the Acute Stroke Registry of Lausanne (2003-2018) were retrospectively analyzed with complete assessment of the following EVRFs: hypertension, diabetes, major cardioembolic sources, dyslipidemia, smoking, obesity, alcohol abuse, previous stroke/transient ischaemic attack and depression/psychosis. Patients without EVRFs were compared to patients with one or more EVRFs using appropriate statistical models.

Results: Of 4889 included patients, 103 (2.1%) had no EVRFs. In multiple regression analysis, patients without EVRFs were significantly younger (odds ratio [OR] 0.13; 95% confidence interval [CI] 0.08-0.20) and had more multiterritorial strokes (OR 3.38; 95% CI 1.26-9.05). Strokes were more often related to patent foramen ovale (PFO) (OR 3.02; 95% CI 1.44-6.32) and less to atherosclerosis, cardioembolism or small vessel disease. In patients <55 years old, PFO (OR 2.76; 95% CI 1.50-5.08) and contraceptive use in females (OR 2.75; 95% CI 1.40-5.41) were more frequent, whereas sleep apnea syndrome (OR 0.09; 95% CI 0.01-0.63) was less. In patients ≥55 years, female sex (OR 2.84; 95% CI 1.43-5.65) and active cancer (OR 3.27; 95% CI 1.34-7.94) were more prevalent. At 12 months, patients without EVRFs had worse adjusted functional outcome (Rankin shift OR_adj 0.63; 95% CI 0.42-0.95) and higher rate of recurrence and death (adjusted hazard ratio 2.11; 95% CI 1.19-3.74).

Conclusions: In a consecutive cohort of AIS patients, only 2% showed no EVRFs. PFO and contraceptive use exhibited a strong association with the absence of EVRFs in younger patients and female sex and active cancer in elderly patients. Our findings highlight the importance of searching for previously unknown risk factors and/or unusual stroke mechanisms in patients without EVRFs.

Keywords: acute ischaemic stroke; stroke etiology; stroke in the young; vascular risk factor.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Aged
Brain Ischemia* / epidemiology
Female
Foramen Ovale, Patent*
Humans
Ischemic Attack, Transient*
Ischemic Stroke*
Middle Aged
Retrospective Studies
Risk Factors
Stroke* / epidemiology