Recurrent ventricular arrhythmias and mortality in cardiac arrest survivors with a reversible cause with and without an implantable cardioverter defibrillator: A systematic review

Background: Sudden cardiac arrest survivors with a reversible cause are not eligible for implantable cardioverter defibrillator (ICD) implantation. This study aims to evaluate the risk of recurrent ventricular arrhythmia in sudden cardiac arrest survivors with a reversible cause and evaluate if ICD implantation increases survival. Methods: We conducted a systematic review to identify studies evaluating ICD implantation in sudden cardiac arrest survivors with a reversible cause. Outcomes were mortality and appropriate device therapy. Sudden cardiac arrest patients were divided into 4 subgroups: due to acute myocardial infarction; due to coronary artery spasm; due to takotsubo cardiomyopathy; and studies with various reversible causes of cardiac arrest. Results: 27 studies were included, evaluating 11,402 patients. A total of 2570 patients received an ICD. Studies evaluating coronary artery spasm and with various reversible causes showed a relatively high rate of appropriate device therapy (17% and 20%) and described an increased survival in ICD patients. Takotsubo cardiomyopathy was associated with a low mortality and none of the ICD patients received appropriate device therapy. Studies evaluating acute myocardial infarction survivors reported inconsistent results, with high numbers of appropriate device therapy (12-66%), but the mortality-rate of patients with and without an ICD varied. Conclusion: This study shows that the recurrence risk of ventricular arrhythmia varies between different reversible causes of sudden cardiac arrest and should not be evaluated as one entity. Cardiac arrest survivors with a reversible cause can be at risk of recurrent ventricular arrhythmia and selected patients may benefit from ICD implantation.