Carotid artery stenting in high-risk patients: midterm mortality analysis

Carotid artery interventions are predicated on early and late survival to prevent ischemic strokes. The technical feasibility of carotid artery stenting (CAS) has been established. Short-term results have been conflicting. Despite this, many practices have adopted CAS as an alterative to carotid endarterectomy in high-risk patients. Long-term protective benefits, however, are less established in high-risk patients. Midterm results following CAS in our high-risk protocol were analyzed to determine specific and all-cause mortality rates (beyond 30 days). We retrospectively evaluated a prospective carotid artery stent registry from October 2003 to February 2006. Demographics, high-risk indication, presence of carotid symptoms, prior history of cancer, periprocedural success, complications, as well as follow-up including readmission rate as well as specific etiology of death were recorded. Fifty patients with critical carotid stenosis (mean stenosis 90%) underwent CAS. This cohort met high-risk criteria due to physiologic reasons in 26 patients and anatomic factors in 22 cases. Two patients met both criteria. Indications were symptomatic disease in 14 (30%) and asymptomatic in 36 cases. The overall 30-day stroke, myocardial infarction, and death rate was 2%. No minor or major strokes were recorded within 30 days postprocedure. Overall average follow-up was 11-28 months. Stroke-free survival was 94% for all patients. Overall 1-year survival was 75% for all patients, significantly higher for the asymptomatic group (88%) (p < 0.01). Late mortality after 30 days was 11 cases (22%) at an average of 9 months post-CAS, ranging 3-13 months. No late mortality was due to ischemic stroke. Specific etiologies of mortality included end-stage cardiac disease (n = 1), recurrent or metastatic cancer (n = 2), acute cardiac event (n = 1), infectious complications (n = 3), and other (n = 3). Only symptomatic indication was predictive of late mortality. Clinicians may continue to cautiously offer CAS to asymptomatic high-risk patients given their anticipated longevity. Symptomatic patients, despite poor midterm survival, do achieve freedom from neurologic death following CAS.