Incremental prognostic value of computed tomography in stroke: rationale and design of the IMPACTS study

This study was designed to determine the prognostic value of coronary computed tomography angiography (CCTA) in ischemic stroke patients and to identify any incremental risk stratification benefits of CCTA findings compared with coronary artery calcium scoring (CACS) and traditional Framingham risk scores (FRS) in ischemic stroke patients without chest pain. IMPACTS is a prospective, multicenter, observational cohort study in which at least seven centers in Korea will participate. All participants will be enrolled in this study after providing informed consent. Nine hundred total ischemic stroke patients without chest pain will be enrolled and will undergo CACS and CCTA. All participants will be followed-up for a minimum of 24 months to determine the endpoints. The primary endpoint will be occurrence of major adverse cardiovascular events (MACEs), defined as all-cause mortality, cardiovascular death, myocardial infarction, or cardiovascular events requiring hospitalization and revascularization either by percutaneous coronary intervention or by coronary artery bypass graft after 90 days of index testing during the follow-up period. Patient enrollment should be completed within 2.5 years. We plan to analyze and identify the CCTA predictors of MACEs. In addition, we will compare several models used to assess independent relationships between the variables and MACEs using a shared frailty model and therefore determine the incremental prognostic value of CCTA findings compared with either the CACS or FRS. The results of IMPACTS will provide valuable information for risk stratification with CCTA in ischemic stroke patients without chest pain.