Mark F. Conrad, Shankha Mukhopadhyay, Michael J. Michalczyk, Arissa Opalacz, Glenn M. LaMuraglia, Richard P. Cambria
Vascular Surgery, Massachusetts General Hospital, Boston, MA.
OBJECTIVES: Although Level 1 evidence supports carotid endarterectomy (CEA) for stroke prevention in patients with asymptomatic severe (>70%) carotid stenosis (ASCAS), medical therapy has been promulgated by some as equally effective. The goal of this study is to determine the natural history of medically treated ASCAS.
METHODS: Patients with ASCAS were identified by Duplex (index study 2005-2006) and included if they were treated with medical therapy (for comorbidities or patient preference). Patients were excluded if they had a carotid intervention within 6mo of the index Duplex. Aspirin and statin use (including LDL) was recorded for each patient. The mean follow-up was 52 months. Study endpoints included: ipsilateral neurologic symptoms (INS)(stroke/tia) and death.
RESULTS: There were 126 carotid arteries in 115 points. Eighty-eight (70%) had severe (70-89%) and 38 (30%) had very severe (90-99%) stenoses (VSS). Demographics: age 73.5 years 5% chronic kidney disease (CKD), 86% were on statins (28% had LDL<100mg/dl) and 88% were on aspirin. Thirty-one (25%) patients developed INS during follow-up and most 23/31 (74%) occurred within 12 months of the initial DUS; 45% of INS were strokes. The 5-year actuarial freedom from INS was 70.1%+/-5%. Multivariate predictors of INS included: VSS (HR=3.23, CI=1.56-6.76; p=0.002), CKD (HR=6.25,CI=2.05-19.2; p=0.001), age (HR=0.94, CI=0.91-0.98; p=0.001). Forty-one (33%) patients underwent eventual carotid revascularization (32 CEA, 9 Stent); 56% were performed for INS and 44% for plaque progression. The 5-year actuarial survival was 69.8%+/-4.1%. Multivariate predictors of death included: Age (HR=1.06, CI=1.03-1.1; p=0.0001), COPD (HR=1.92, CI=1.08-3.41;p=0.03) and DM (HR=5.08, CI=2.86-9.01; p<0.0001). Neither statin nor aspirin use was protective in this cohort.
CONCLUSIONS: Medically managed patients with ASCAS develop INS early; especially those with >90% stenosis. The natural history of medically treated ASCAS and failure of aspirin/statins to prevent INS supports the continued role of CEA as first line therapy in these patients.
AUTHOR DISCLOSURES: R. P. Cambria: Nothing to disclose; M. F. Conrad: Nothing to disclose; G. M. LaMuraglia: Nothing to disclose; M. J. Michalczyk: Nothing to disclose; S. Mukhopadhyay: Nothing to disclose; A. Opalacz: Nothing to disclose.
Posted April 2013