Introduction The UK has one of the lowest implantable cardioverter defibrillator (ICD) implant rates in the western world. The majority of implants are for secondary prevention. It has been estimated that there are a minimum of 40 patients/million per year who satisfy current National Institute for Health and Clinical Excellence (NICE) criteria for primary prevention ICD alone. It is not known whether the low implant rate for primary prevention is due to failure to identify eligible patients in primary or secondary care, a lack of knowledge of ICD guidelines, failure to refer to implanting cardiologists, a lack of access or capacity in tertiary care, financial restrictions or patient choice to refuse treatment. This pilot study was designed to identify the stumbling blocks for potential primary prevention ICD recipients who might otherwise qualify for an ICD according to current NICE guidelines.
Methods A search was performed on the Oxford Radcliffe Hospitals echo and the British Cardiovascular Intervention Society (BCIS) databases for patients with an Oxfordshire postcode who had documentation of left ventricular ejection fraction (LVEF) recorded in the calendar year 2007. Patients less than 18 years were excluded. The search criteria included LVEF ⩽35%. In addition, the descriptive terms “severely impaired function” or “poor LVEF” were taken to indicate LVEF <30%. Medical notes were assessed for age, aetiology of heart disease, time from myocardial infarction, 12-lead ECG QRS duration, Holter or electophysiological studies, NYHA status and review by a cardiologist.
Results 215 patients with LVEF ⩽35% were identified from a database population of 3100 assessments and 30 patients were randomly sampled. The findings are summarised in the fig. Three patients already had an ICD. 11 patients were deemed not suitable. 12/16 had confirmed ischaemic heart disease. Five of 12 patients satisfied MADIT2 trial criteria and had QRS duration greater than 120 ms. Four of those five patients had seen a cardiologist yet none had discussed potential primary prevention ICD implants or had referral to an electrophysiologist. Seven of 12 patients were eligible for Holter monitor screening to look for non-sustained ventricular tachycardia, yet none had undergone monitoring or been referred for ventricular stimulation studies.
Conclusions In this pilot study, screening of an echo and BCIS database revealed that at least one sixth of patients with LVEF ⩽35% fulfilled NICE guidelines for primary prevention ICD, yet despite seeing cardiologists, none had been offered this therapy. Holter screening of potentially eligible patients is not being performed. A larger study is now underway to explore further the current barriers to the uptake of primary prevention ICD in the UK.