Background and Purpose:
National AHA guidelines on carotid endarterectomy (CEA) for asymptomatic patients (Pts) stipulate that the long term benefit of surgery is dependent on having a ≤ 3% risk of perioperative death or stroke (D/S) due to the procedure. We developed and validated a multivariate model of risk of D/S within 30 days of CEA for asymptomatic disease and a clinical prediction rule based on the final model.
Methods:
We analyzed data from 6553 asymptomatic cases in the New York Carotid Artery Surgery (NYCAS) study, a population-based cohort of all Medicare beneficiaries having CEA in NY State from 1/98 to 6/99. Medical records were abstracted for: sociodemographics, neurological history, carotid imaging data, comorbidities, and D/S within 30 days. All events were adjudicated. Multivariate logistic regression with GEE was used to identify independent predictors of combined D/S. The final model was cross-validated with100 random splits. A CEA-8 Clinical Risk Score assigned 1 point to each risk factor except for disability which got 2 points.
Results:
The 6553 CEAs were performed by 435 surgeons in 157 hospitals. Mean age was 74 years, 3655 were male, 4152 had coronary artery disease (CAD), 873 valvular disease, 611 congestive heart failure (CHF), 1453 history of distant stroke or TIA, and 93 severe disability. Nearly all (6413) had 70-90% ipsilateral stenosis, and 2469 had ≥ 50% contralateral stenosis. The combined 30 day D/S rate was 3.0% (198 of 6553). Multivariable predictors of perioperative D/S were: female (OR, 1.5; 95% CI, 1.1-1.9), non-white (OR, 1.8; 1.1-2.9), severe disability (OR, 3.7; 1.8-7.7), CHF (OR, 1.6; 1.1-2.4), CAD (OR, 1.6; 1.2- 2.2), valvular heart disease (OR, 1.5; 1.1-2.3), distant history of stroke/TIA (OR, 1.5; 1.1- 2.0), and non-operated stenosis ≥50% (OR, 1.8; 1.3-2.3). The CEA-8 Risk Score stratified Pts from a D/S rate of 0.6% (3 of 509) to 10% (16 of 159).
Conclusions:
Several sociodemographic, neuroseverity, and comorbidity factors predicted risk of D/S in asymptomatic patients having CEA. A CEA-8 Risk Score of ≥ 4 identifies high risk Pts (predicted D/S rate of >7.5%) with 2.5 times the AHA guideline acceptable complication risk in asymptomatic Pts (≤ 3%).
Predicting Risk of Perioperative Death and Stroke After Carotid Endarterectomy in Asymptomatic Patients