Risk Factors

Strong

Atrial fibrillation

Atrial fibrillation causes stasis in the left atrium, which increases the chance of thrombus formation in the left atrial appendage. Thrombus once formed inside the heart can embolise, creating TIA or stroke.

Valvular Disease

The mechanism of association is likely to be due to valve abnormality forming a thrombogenic focus in the heart and thus predisposing to embolic events.

Carotid Stenosis

Higher rates of stenosis (>70%) are associated with significantly increased risk compared with moderate stenosis (50% to 69%).

Congenital Heart Diseases

This may be due either to stasis, leading to increased risk of cardioembolic events, or via common risk factors for cerebrovascular disease and ischaemic heart failure. 

Hypertension

The most common risk factor for cerebrovascular disease.

Relative risk for TIA is approximately 2- to 5-fold in the presence of hypertension.[16} The higher the chronic BP elevation, the more this risk factor is important for cerebral ischaemia, forming a continuous risk association.

Mechanism is via increasing likelihood of atherosclerotic vascular disease.

Diabetes

Diabetes is a potent risk factor for atherosclerotic disease and has been reported to be present in up to one third of patients who present with cerebral ischaemia.[17] The presence of diabetes increases the risk for TIA by an odds ratio of 1.5 to 2.[16]

Diabetes is frequently associated with other atherosclerotic risk factors in the metabolic syndrome. It is recommended that the patient with diabetes be recognised to be at greater than average risk for cerebrovascular disease. As a result, patients with diabetes are felt to merit aggressive management of other modifiable risk factors.

Smoking

Alcohol

Strong association for heavy use only. The relationship between alcohol use and stroke is non-linear with higher risk with heavy use, but a relative protective effect with moderate alcohol intake.[18]

Moderate alcohol use may increase protective levels of high-density lipoprotein (HDL) and decrease platelet aggregation. Intake of >60 g of alcohol daily is associated with an increased risk of ischaemic stroke with an odds ratio of 1.6.[18]

Advanced age

TIAs are more common in middle age and in older people. Symptoms in a young patient increase the possibility of alternative diagnosis or a less common aetiology for ischaemia, such as congenital heart disease, paradoxical emboli, drug use, or hypercoagulability.

Weak

1. Hyperlipidaemia
2. patent foramen ovale
3.  inactivity
4. Obesity
5. Hypercoagulability