Abstract 12188: Utilization Rates of Primary Prevention Implantable Cardioverter-Defibrillators: A 2012 Calculation for a Midwestern Health Referral Region
Background: Database studies suggest that utilization rates (UR) of implantable cardioverter-defibrillators (ICD) for primary prevention of sudden cardiac death (PPSCD) are highly variable, with racial and gender discrepancies previously observed. However, because rates vary by referral regions and few studies have utilized comprehensive review of source documents (charts), the ICD UR in the community remains unclear. We sought to establish the ICD UR in central Indiana.
Methods and Results: We queried electronic medical records for patients with left ventricular ejection fraction (LVEF) ≤ 0.35 between June 2011 and May 2012, which returned 1863 unique patients. The ICD UR is defined by x/(x+y), where x=PPSCD ICD’s utilized and y=patients with Class I indication but without ICD implantation during the same time period. We found 1672 without (Cohort A) and 191 with (Cohort B) procedure code 37.94 (Implantation or replacement of ICD). To identify those patients eligible for ICD, we manually reviewed a stratified random sample of 300 patients from Cohort A and found only 137 (46%) patients to have a physician-confirmed LVEF ≤ 0.35. Among them, 48 (35 %) had class I indications for ICD, which adjusts to 193 in Cohort A overall after sampling correction. To identify patients with actual implanted ICDs, both cohorts were assessed. The review of 300 in Cohort A identified 8 patients with a new ICD implant for PPSCD, which extrapolates to 51 patients overall. Among Cohort B, 48 of 191 had a new ICD implant for PPSCD. Combined, 99 patients had a new ICD implant for PPSCD during the study period. The ICD UR was thus 34% overall (99/(193+99)); it was 43% for males (95% CI 28-58%), 16% for females (95% CI 11-21%), p=0.0003; 35% for whites (95% CI 21-49%), and 34% for blacks (95% CI 24-43%), p=0.44.
Conclusions: The ICD UR is 34% among patients meeting Class I indications. This UR suggests further opportunities to improve guideline compliance. Gender discrepancy in ICD UR was observed in the studied referral region, whereas a racial discrepancy was not observed. This study further illustrates that there may be substantial limitations in ICD UR calculations based on large electronic registries or repositories, without hands-on chart review.
- Heart failure
- Implantable cardioconvert defibrillator
- Ventricular defibrillation
- Sudden cardiac death
- © 2013 by American Heart Association, Inc.