Experience and outcomes with carotid artery stenting: an analysis of the CHOICE study (Carotid Stenting for High Surgical-Risk Patients; Evaluating Outcomes Through the Collection of Clinical Evidence).

OBJECTIVES

This study sought to examine operator experience measured by time-related variables on outcomes with protected carotid artery stenting (CAS).

BACKGROUND

Studies on experience have focused on operator and institutional CAS volumes alone in the absence of a better metric.

METHODS

Using the CHOICE (Carotid Stenting for High Surgical-Risk Patients; Evaluating Outcomes Through the Collection of Clinical Evidence) multicenter prospective data from October 1, 2006 to June 1, 2012, 5,841 evaluable subjects were identified. Operator experience within this study was assessed using 5 variables for each operator: 1) baseline CAS volume; 2) time from first CAS to each subsequent CAS; 3) time between each CAS; 4) CAS volume in the institution; and 5) medical specialty (cardiology, surgery, or radiology/neurology). Institutional experience was determined by CAS volume within the study. Embolic protection device dwell time was used to assess technical performance, and 30-day death, stroke, or myocardial infarction composed the clinical outcome. Hierarchical logistic regression and linear mixed models were used.

RESULTS

Cardiologists (p < 0.001) along with operators with longer time interval from first CAS (p < 0.001) had reduced embolic protection device dwell times (technical performance). Increased time interval between CAS was the only independent predictor of 30-day death, stroke, or myocardial infarction (adjusted odds ratio: 1.05, 95% confidence interval: 1.02 to 1.09, p = 0.005). Prolonged embolic protection device dwell time was associated with 30-day death, stroke, or myocardial infarction (adjusted odds ratio: 1.08; 95% confidence interval: 1.01 to 1.17; p = 0.03).

CONCLUSIONS

The time interval between CAS procedures, specialty assignment, and time from first CAS are important measures of operator experience that may significantly affect technical performance and clinical outcome.