Prediction of vascular risk after stroke - protocol and pilot data of the Prospective Cohort with Incident Stroke (PROSCIS)

Abstract

Rationale: Long-term risk of vascular disease is substantially increased after stroke with several models proposed to predict subsequent stroke and other vascular events after an index event. However, recent validation studies demonstrate limited predictive properties of available prognostic models.

Aims: We aim to determine prediction models of different complexity for the combined vascular end-point of stroke, myocardial infarction, and vascular death at three-years after first-ever stroke. An independent external validation of the developed models will be performed.

Design: Prospective observational hospital-based cohort study of patients after first-ever stroke.

Methods: The new predictive models will be developed using the following steps: (1) Development of a basic score based on clinical history data (e.g. hypertension, myocardial infarction, and atrial fibrillation); (2) Development of an advanced score including additional factors such as blood-based biomarkers and results of vascular imaging; (3) Comparing the models fit using different methods (discrimination, calibration); (4) Assessment of clinical utility of an advanced score using methods based on reclassification tables (e.g. net reclassification improvement, integrated discrimination improvement, decision curve analysis); and (5) Investigation of external validity.

Outcomes: Primary outcome is a combined vascular end-point composed of stroke, myocardial infarction, and vascular death at three-years after stroke. Furthermore, each component of the composite end-point will be investigated individually and the patterns and time points of risk transitions between vascular end-points and stroke sub-types will be determined.

Trial registration: ClinicalTrials.gov NCT01363856 NCT01364168.

Keywords: cohort study; first-ever stroke; prediction; stroke epidemiology; stroke-related outcomes.