Validation of the Totaled Health Risks In Vascular Events (THRIVE) score for outcome prediction in endovascular stroke treatment.
BACKGROUND
We recently developed the Totaled Health Risks In Vascular Events (THRIVE) score to predict outcomes after endovascular stroke treatment. The THRIVE score, which incorporates age, National Institutes of Health Stroke Scale score, and three medical comorbidities (hypertension, diabetes mellitus, and atrial fibrillation), was developed using data from the Mechanical Embolus Removal in Cerebral Ischemia (MERCI) and Multi MERCI trials.


AIMS
We set out to perform external validation of the THRIVE score using data from the largest registry of endovascular stroke treatment performed to date, the Merci Registry.


METHODS
We compared the performance of the THRIVE score in two different data sets: the development cohort (the MERCI and Multi MERCI trials, n = 305) and a validation cohort (the Merci Registry, a prospective multicenter registry of patients undergoing endovascular stroke treatment, n = 1000). We examined the predictive utility of the THRIVE score across the range of clinical outcomes and used receiver-operator characteristics curve analysis to compare score performance in the two data sets.


RESULTS
The THRIVE score predicted good outcome, death, and the full range of the modified Rankin Scale in a similar fashion between the MERCI trials and the Merci Registry. Receiver-operator characteristics curve comparisons showed no statistically significant difference in the performance of the THRIVE score between the two data sets: for good outcome, the receiver-operator characteristics area under the curve was 0·293 for the MERCI trials and 0·266 for the Merci Registry (P = 0·47) and for death, the receiver-operator characteristics area under the curve was 0·692 for the MERCI trials and 0·717 for the Merci Registry (P = 0·48). The THRIVE score and vessel recanalization were also found to be independent and unrelated predictors of clinical outcome.


CONCLUSIONS
The THRIVE score reliably predicts outcomes after endovascular stroke treatment and may be useful as a clinical prognostic tool and to perform severity adjustments in stroke clinical research.