Referral patterns for primary prophylaxis implantable cardioverter defibrillator therapy for an urban US population

Implantable cardioverter defibrillators (ICDs) have been demonstrated to improve survival for both primary and secondary prevention of sudden cardiac arrest. However, studies suggest that ICD therapy is underused in appropriate candidates. Sex and racial disparities in ICD use have been suggested. We sought to characterize the referral patterns of high-risk patients for the primary prophylaxis of sudden cardiac arrest at a tertiary academic medical center serving a diverse population in an urban US setting. Electronic hospital databases were retrospective reviewed for patients meeting criteria for prophylactic ICD implantation. We evaluated the association of gender, age, race, and primary language with the referral and subsequent implantation of an ICD. We identified 1,055 patients satisfying prophylactic ICD criteria: 600 men, mean age 62.6 years, 27.6% black, 19.3% white, 23.3% Hispanic, and 49.8% primary language of English. Of the 673 patients (63.7%) referred for ICD evaluation, 345 underwent implantation, 125 declined, and 203 had significant co-morbidities that precluded implantation. Gender, race, and primary language were not associated with referral for ICD or with decision to proceed with implantation. Patients of increased age were less likely to be referred for ICD and were more likely to refuse implantation. ICD therapy was not considered in 146 patients eligible for prophylactic implantation. In conclusion, referral rates for ICD consideration were higher at our institution than in previous reports. Nonetheless, 14% of appropriate patients were not considered. This argues for the importance of increased education for patients and referring physicians.