Factors Associated With Implantable Cardioverter-Defibrillator Placement Among Us Veterans With Left Ventricular Ejection Fraction <= 35% At Least 40 Days After Acute Myocardial Infarction

Introduction: Implantable cardioverter defibrillators (ICD) reduce the risk of sudden cardiac death among patients with persistently low (≤35%) left ventricular ejection fraction (LVEF) at least 40 days following acute myocardial infarction (AMI). There are limited data about clinical factors associated with ICD placement following AMI. Hypothesis: We hypothesized that increasing age and number of comorbidities would decrease the odds of ICD placement post-AMI among patients with low (≤35%) LVEF, while revascularization for AMI would increase odds of ICD use. Methods: We used ICD-9 and 10 codes to identify all Veterans hospitalized for AMI from 2004-2017 and excluded Veterans with prior ICD and those who died during AMI hospitalization. We used a validated natural language processing algorithm to determine LVEF from echocardiograms performed 40-365 days post-AMI and identified patients with LVEF ≤35%. Using multivariable logistic regression, we examined the association of demographics, comorbidities, revascularization status for AMI, and prescription of guideline-directed medical therapy (GDMT) with the primary outcome of ICD placement 41-365 days post-AMI. Results: Of 10,447 Veterans eligible for an ICD, 1,966 (18.8%) received an ICD. Of 1,966 patients who received an ICD 7.1% died within 1-year, compared with 26.8% of patients who did not receive an ICD. In multivariable analysis, younger age, fewer comorbidities, revascularization during AMI hospitalization, and use of GDMT were associated with increased odds of receiving an ICD (Table). Eligible Black patients were less likely (OR 0.78, 95% CI 0.67-0.90) to receive an ICD than White patients. Conclusions: Many factors affect ICD placement among patients with reduced LVEF post-AMI. In particular, Black patients were less likely to receive ICDs than White patients. Future qualitative work could provide a deeper understanding of how patient and clinician factors influence decisions around ICD use.