Role of coronary revascularisation among patients receiving implantable defibrillators: a review

Patients with coronary artery disease (CAD) can present with spontaneous ventricular arrhythmias occurring outside the context of an acute coronary syndrome with no apparent identifiable reversible cause. In addition to secondary prevention medications, implantable cardiac defibrillator (ICD) remains the main therapeutic intervention to reduce the risk of subsequent mortality and morbidity. Investigations prior to ICD implantation may identify the presence of angiographically significant epicardial coronary stenoses in previously asymptomatic patients, alongside other arrhythmic substrates such as myocardial scar and impaired left ventricular systolic function. So does coronary revascularisation in these patients reduce the occurrence of appropriate ICD shocks in the long run? In this article we comprehensively review the literature to answer the primary question of whether coronary revascularisation reduces recurrent ventricular arrhythmia burden among patients with CAD receiving an ICD, with focus on those presenting with ventricular arrhythmias outside the context of acute coronary syndrome. With growing evidence of the adverse prognostic impact of appropriate ICD discharges and an ever-increasing number of ICD implants world-wide, we believe that this question is of paramount importance. We summarise the available evidence to draw conclusions about the appropriate management strategy and also highlight areas of uncertainty that require attention in future research.