Abstract 12151: Health Care Disparities and Risk for Inappropriate Implantable Defibrillator Shocks
Objective: Inappropriate implantable defibrillator shocks (iShock) are estimated to occur in 8-40% of implantable defibrillator (ICD) recipients, representing 30-55% of ICD shocks. Common causes of iShock include atrial fibrillation (AF), other atrial tachyarrhythmias, or ICD lead malfunction. We tested the hypothesis that inadequate access to health care is a risk factor for iShock.
Methods: We prospectively analyzed 106 consecutive patients (pts) presenting with ICD shocks from one University and one public hospital from September 2011 through May 2013. Demographic, clinical, and device based data were collected. Interrogations were interpreted by two electrophysiologists blind to the pt history and demographics. In cases of disagreement a third electrophysiologist adjudicated the results. Insurance status was classified as uninsured/Medicaid or Medicare/private. Uni- and multivariate logistic regression analyses were performed.
Results: A total of 106 pts presented with ICD shocks. The mean age was 60 +/-13 years, 85 (80%) male, and 91 (87%) received the ICD for primary prevention indications. There were 50 pts (47%) with inappropriate shocks. Uninsured/Medicaid pts were more likely to present with iShock (23/36 vs. 27/70, p= .01). A history of AF was also associated with iShock (27/46 vs. 23/60, p=.04). In contrast, pts receiving anti arrhythmic drugs (AAD) were more likely to have appropriate shocks (28/41 vs 28/65, p=.01). On multivariate analysis, all three variables remained significant (Insurance: OR 2.5, 95% CI 1.02-5.9, p=.04; AF: 2.6, 1.1-5.9, p=.03; AAD: .4, .2-.9, p=.02). Pts with uninsured/Medicaid status had a longer interval between prior physician contact and ICD shock (mean 150±160 vs 84±129 days, p≤.05).
Conclusions: Uninsured/Medicaid pts were more likely to present with inappropriate shock than pts with Medicare or private insurance. The pts with Medicaid/uninsured status had a significantly longer interval from their prior physician contact to the shock, suggesting that these pts had inadequate follow-up compared to pts with Medicare or private insurance. Improved follow-up could prevent iShock by identifying the causes before the iShock occurs and enabling appropriate therapy to prevent it.
- © 2013 by American Heart Association, Inc.