Underutilization of Implantable Cardioverter Defibrillator in Primary Prevention of Sudden Cardiac Arrest

The aim of this study was to evaluate the overall use of implantable cardioverter defibrillators (ICD) for primary prevention of sudden cardiac arrest (SCA), among eligible patients from an outpatient cardiology clinic and to determine what factors might contribute to underutilization of ICDs.

This report was a retrospective chart review of patients with ischemic or non-ischemic cardiomyopathy and left ventricular ejection fraction ≤ 35% from an outpatient cardiology practice from January 2005 to May 2008. These patients met the eligibility criteria for ICD implantation for primary prevention of SCA. A detailed review of medical records captured distribution of ICD implantation including future plans for ICD implant, patient preference against ICD use, presence of severe co-morbidities, and any other documented reasons/contraindications regarding ICD implantation.

Of the 275 patients who were eligible for ICD for primary prevention of SCA, 119 (43%) had an ICD implantation. ICDs were used in 84 (48%) eligible men and 35 (35%) eligible women (P 0.02). Among 156 (57%) patients who did not receive ICD, 79 (28%) had severe co-morbidities precluding them from having ICD. Twenty-six patients (10%) refused to have ICD implanted. The remaining 51 (19%) patient charts did not include any documentation regarding ICD use (future plan or contraindication).

ICDs are underutilized for primary prevention of SCA, with rates of use being lowest among eligible women. This underutilization exists even after accounting for patient preferences and presence of severe co-morbid conditions that might make an otherwise eligible patient not a suitable candidate for ICD implantation.