Abstract 16: Low Rates of Implantable Cardioverter-Defibrillator Use Among Medicare Patients with Low Ejection Fraction After Myocardial Infarction
Objective: Implantable cardioverter-defibrillators (ICDs) are a proven life-saving therapy for patients with low ejection fraction (EF) due to ischemic cardiomyopathy. Because ICDs are not recommended within 40 days of an acute myocardial infarction (MI), ICD consideration is potentially susceptible to errors of omission during the transition of care post-MI. This study examines ICD implantation rates within 1 year post-discharge among MI patients with low EF.
Methods: We identified Medicare patients with an EF ≤ 35% after an acute MI, treated at 441 ACTION Registry-GWTG hospitals between January 2007 and September 2010, excluding patients with prior ICD implantation. Using Medicare data, we examined the incidence of ICD implantation among survivors at 1 year post-discharge. A multivariable Cox model, stratified by discharging hospital, was used to determine patient characteristics associated with receiving an ICD within 1 year, accounting for death as a competing risk.
Results: Among 10,318 MI patients with EF ≤ 35%, 7,842 (76%) were alive at 1 year post-MI, of which 700 patients (8.9%) received an ICD in that year. The variation in 1-year ICD implantation rate by discharging hospital was significant (p=0.02), with the 90th percentile sites implanting 2.7 times more devices than the 10th percentile sites (8% vs. 3%). Patients that received an ICD were younger (median 74 vs. 77 years), more likely to be male (69% vs. 53%) and to have had a larger infarct (median peak troponin 80 vs. 51 times upper limit of normal) or ventricular tachycardia/fibrillation during the MI hospitalization (25% vs. 22%), but were less likely to have end stage renal disease (7% vs. 14%) than patients who did not receive an ICD (p<0.001 for all). Patients who saw a cardiologist within 2 weeks of discharge were more likely to receive an ICD at 1 year than patients who did not (12% vs. 8%, p<0.001). In the multivariable model, the factors significantly associated with ICD implantation within 1 year post-MI are shown in the Figure.
Conclusions: In US clinical practice, fewer than 1 in 10 Medicare patients with an EF ≤ 35% received an ICD within 1 year of an MI. This gap cannot be fully explained by EF recovery. Barriers to ICD implantation included sociodemographic and clinical factors, and they may be modified by transition of care practices.
Author Disclosures: S. Pokorney: B. Research Grant; Modest; AstraZeneca. G. Consultant/Advisory Board; Modest; Janssen Pharmaceuticals. A.L. Miller: None. A.Y. Chen: None. L. Thomas: None. G.C. Fonarow: G. Consultant/Advisory Board; Modest; Ortho McNeil. J.A. de Lemos: E. Honoraria; Modest; AstraZeneca. G. Consultant/Advisory Board; Modest; Sanofi Aventis, Daiichi Sankyo. S.M. Al-Khatib: None. E.D. Peterson: B. Research Grant; Significant; Eli Lilly & Company, Janssen Pharmaceuticals, American Heart Association. G. Consultant/Advisory Board; Modest; Boehringer Ingelheim, Bristol Myers Squibb, Janssen Pharmaceuticals, Pfizer, Genentech, Inc. T.Y. Wang: B. Research Grant; Significant; AstraZeneca, Gilead, Eli Lilly, The Medicines Company, Canyon Pharmaceuticals. E. Honoraria; Modest; AstraZeneca. G. Consultant/Advisory Board; Modest; Medco. G. Consultant/Advisory Board; Significant; American College of Cardiology.
- © 2014 by American Heart Association, Inc.