THE IMPACT OF CARDIAC COMORBIDITY AFTER CAROTID ENDARTERECTOMY

Purpose: Myocardial infarction and other comorbidities contribute to c omplications after carotid endarterectomy (CEA). However, because the combined stroke and death rate after CEA is less than 5%, even relativ ely large series have small numbers of adverse events that preclude a detailed analysis of the association between the outcome and the patie nt factors, such as comorbidity and age. We sought to overcome this li mitation by studying patients who underwent CEA in a large random samp le of Medicare beneficiaries. Methods: me used a database that contain ed a 20% random sample of all Medicare beneficiaries to identify patie nts who underwent CEA between the years 1988 to 1990 (n = 22,165), and we followed these cases until 1992. With multivariate logistic regres sion and Cox proportional hazards regression models, we examined the i mpact of age, race, gender, geographic location, hospital characterist ics, and comorbidity, including acute myocardial infarction (AMI) and congestive heart failure (CHF), on the risk of stroke and death after CBA. Results: AMI and CHP had the greatest negative impact on the long -term survival rates (adjusted hazard ratio [HR]: 2.40, P <.0001, and 2.85, P <.0001, respectively). Other variables with a significant impa ct on the long-term survival rates were an age of >80 pears (HR, 2.16; P<.0001), an acute stroke (HR, 1.51; P <.0001), diabetes mellitus (DM ; HR, 1.52; P <.0001), and male sex (HR, 1.32; P <.0001). In addition, AMI, CHF, DM, and advanced age were associated with an increased risk of perioperative stroke and death. Conclusion: Patients with AMI, CHF , DM, and an age of >80 years have diminished perioperative and long-t erm survival rates after CEA. These results may alter the risk/benefit analysis for such patients, especially those with asymptomatic diseas e.