Abstract 215: The Prognostic Significance of Subendocardial Myocardial Infarction in Patients Undergoing Carotid Endarterectomy or Carotid Artery Stent Placement
Background: The use of subendocardial myocardial infarction [MI] (non-ST-elevation or non-Q wave MI) as an endpoint following carotid endarterectomy (CEA) or carotid angioplasty and stent placement (CAS) within and outside clinical trials is debated.
Objective: To identify the frequency of subendocardial MI and impact on outcomes related to CEA or CAS in patients treated in a large national cohort.
Methods: We determined the frequency of subendocardial MI and associated in-hospital outcomes using data from the Nationwide Inpatient Survey (NIS) data files from 2002 to 2010. We ascertained the affect of subendocardial MI on in-hospital mortality and composite end point of stroke, cardiac events, and death after adjusting for potential confounders using multivariate analysis.
Results: Of the 1,083,688 patients who underwent CEA or CAS, 11341 (1%) developed subendocardial MI within the same hospitalization. The in-hospital mortality (6.2% versus 0.4%, p<0.0001) and neurological complications (6% versus 1.4%, p<0.0001) were significantly higher among patients who developed subendocardial MI. The hospitalization charges ($113,317 versus $29,160, p<0.0001) and mean [±SD] hospital days [12.2±9.0 versus 2.8±4.0 p<0.0001) were significantly higher among patients with subendocardial MI. After adjusting for age, gender, presence of hypertension, diabetes mellitus, hyperlipidemia, atrial fibrillation, congestive heart failure, and renal failure, subendocardial MI was associated with higher rates of in-hospital mortality (odds ratio [OR] 8.6, 95% confidence interval [CI] 7.0- 10.7)(p=<0.0001) and composite end point of stroke, cardiac events, and death (OR 14.6, 95% CI 13,0 - 16.5)(p=<0.0001).
Conclusions: Our results contradict the notion that subendocardial MI is a relatively benign entity after CEA or CAS. It remains unclear whether subendocardial MI is a marker or cause of high rates of adverse outcomes and resource utilization following CEA or CAS.
- © 2012 by American Heart Association, Inc.