Abstract TP174: Incidence Rate of Transient Ischemic Attack and Subsequent Stroke Incidence Rates: a Meta-analysis

Abstract

Background and Purpose: Only a limited number of studies have examined the incidence of transient ischemic attack (TIA) along with the subsequent stroke incidence. There is no meta-analysis of the incident TIA along with the subsequent stroke incidence. The purpose of the present meta-analysis was to identify the annual incidence rate of TIA according to sex and age categories and the incidence rate of stroke after the onset of TIA. Methods: Using PubMed, we performed a systematic review and meta-analysis of prospective cohort studies of TIA published between 1985 and July 2015. The search was limited to English-language studies and reports showing the number of subjects according to sex and age categories. The incidence of stroke after TIA onset was calculated. Among 98 articles revealed by the PubMed search, eight studies of Western populations (1,422,037 men and 1,467,254 women) and the single study of a Japanese population met the inclusion criteria for the incidence of TIA. Among 115 articles by the PubMed search, 14 studies (8,763 patients with TIA) were included in our identification of the incidence rate of stroke after TIA search. Results: During the follow-ups, the incidence rates of TIA were 1.38 and 1.29 per 1,000 person-years in the Western men and women, respectively. The incidence rates of TIA in Western populations according to the age categories (<45, 45-54, 55-64, 65-74, 75-84, and ≥85 years old) were 0.05, 0.4, 1.1, 2.4, 4.8, and 5.2 per 1,000 person-years in the men and 0.03, 0.3, 0.7, 1.5, 3.7, and 5.4 per 1,000 person-years in the women, respectively. In the Japanese population, the incidence rates of TIA were 0.78 and 0.38 per 1,000 person-years in the men and women, respectively. The incidence rates of stroke which were all Western countries, were 3.8%, 6.3%, 9.7%, 10.5%, and 17.2% at 2 days, 1 week, and 1, 3, and 6 months after the onset of TIA, respectively. Conclusions: In this meta-analysis, the incidence rate of TIA in Western populations was 1.3 per 1,000 person-years, which is higher than that in Japanese population. One in 10 patients and one in 6 patients with TIA subsequently suffered from a stroke during a month and a half year, respectively. For stroke prevention, it is important that thorough care is provided for TIAs that occur during the acute phase.