According to a recent study at the European Academy of Neurology (EAN) Congress 2022, the majority of people who get ischemic strokes and have no known risk factors have underlying diseases.

Overall, the study identified that 67.7 per cent of stroke patients with previously undiagnosed major risk factors (UMRF) were found to have one major risk factor. Researchers from the Centre Vaudois, Lausanne, Switzerland, analysed health records of 4,354 stroke patients from the ASTRAL registry from 2003 to 2018, 1,125 of whom had UMRF.

The most common detected vascular risk factor was dyslipidaemia, an imbalance of blood fats such as high cholesterol or raised levels of triglycerides (61.4 per cent of patients). The second most common risk factor was high blood pressure (23.7 per cent of patients), and one in 10 (10.2 per cent of patients) patients had atrial fibrillation, a condition which causes a fast and often irregular heartbeat.

Using multivariate analyses, the research found a positive association between UMRF patients and lower age, non-Caucasian ethnicity, contraceptive use in women aged under 55 and smoking for patients 55 and older. The research also found negative associations between antiplatelet (blood thinner) use before the stroke and higher Body Mass Index (BMI).

Ischaemic stroke occurs when a blood clot or other blockage cuts off blood supply to the brain and is the most common type of stroke. Lead author Dr Andre Rego said the study provides important insights on major risk factors for ischaemic stroke.

"Our findings underline the importance of testing and treating blood fat imbalances such as high cholesterol and triglyceride levels, as well as blood pressure and identifying and treating those with atrial fibrillation and type 2 diabetes", commented Dr Rego.

"Prior to our study, there was scarce clinical information about the frequency, patient profile and stroke mechanisms in patients with acute ischaemic stroke with previously undiagnosed major vascular risk factors. We hope that this study will help to identify potential stroke patients that require more intensive prevention techniques and surveillance in the future."