Auckland Transient Ischemic Attack Study (ATIAS)

Contact:

Dr Rita Krishnamurthi - rita.krishnamurthi@aut.ac.nz

Principle Investigator:  Professor Alan Barber


Named Investigators:

  • Prof Valery L Feigin
  • Dr Neil E Anderson
  • Dr Dean K Kilfoyle
  • Dr Edward Wong
  • Dr Rita V Krishnamurthi

Hypothesis:

*    That the incidence of transient ischemic attack (TIA) in Auckland is higher than other developed countries.


*    That the risk of stroke and cardiovascular disease following TIA in Auckland is greater than other developed countries.


*    That the ABCD2 stroke risk stratification score is less accurate at predicting adverse outcomes than originally reported.

Aim:

*    To determine the community-based incidence, outcome and risk factor profile of TIA in an ethnically mixed population.


*    To determine the accuracy of the ABCD2 stroke risk stratification score in a general practice, emergency department and specialist TIA clinic, and whether it requires modification.

Abstract of Research:


TIA can be simply defined as stroke-like symptoms and signs that resolve within 24 hours. About 25% of people with ischemic stroke have a preceding or warning TIA. Recent evidence highlights that the risk of stroke following TIA is greatest in the first 48 hours but may still be as high as 10% at 30 days and 20% at 90 days. Studies have shown that this risk of stroke can be reduced by up to 80% by rapid assessment, investigation and commencement of secondary prevention measures.


There have been few population based studies of the incidence and outcome of TIA. Most of these studies were performed over 10 years ago before there was widespread use of medications to lower cholesterol levels and blood pressure low and surgical intervention in patients with internal carotid artery stenosis. Even fewer TIA studies have looked at the effect of ethnicity on incidence and outcome.


We will test the hypotheses that the incidence of TIA is higher, and the outcome is worse, in Auckland than in other developed countries, and this may be explained by differences in our ethnically diverse population. We will also examine the accuracy of the ABCD2 stroke risk stratification score and determine if it should still be recommended in national and international stroke and TIA guidelines, or if (and how) it should be modified.


We will identify all patients with TIA between 1st March 2011 and 28th February 2012 who are aged 15 years or older and resident in Auckland, including those patients presenting to hospital or who are managed in the community. The patient identification processes of the fourth Auckland Regional Community Stroke study (ARCOS IV) will be utilised. All participants will be assessed at day 90 and 12 months.


Crude and age, ethnic, and sex standardized TIA incidence (first-ever events) and attack (all events) rates of stroke per 100 000 people will be determined. The incidence of stroke and other adverse cardiovascular events at 48 hours, 7 days, 90 days and 12 months will be determined. The ability of the ABCD2 score to discriminate between those who go on to have a stroke and those who do not, will also be determined.


This study has a high potential to play a central role in the planning of services and development of health policy in relation to TIA and stroke, within New Zealand and internationally, and be used to inform evidence-based recommendations for health care.


ATIAS concluded in September 2013.

Funded by:

  • The Auckland Medical Research Fund, and
  • The New Zealand Neurological Foundation