Wearable Cardioverter Defibrillators in Patients with Recent Cardiac Surgery

Objectives: Patients with severely reduced left ventricular function are at a high risk to develop life-threatening ventricular arrhythmias. The European Society of Cardiology recommends a three months period with optimal medical therapy until the final decision about the implantation of an implantable cardioverter defibrillator (ICD) is made. To protect these patients from potentially lethal arrhythmias, a wearable cardioverter defibrillator (WCD) can be prescribed temporarily. In surgical patients with severely reduced left ventricular function no data are available yet about the clinical experience with wearable cardioverter defibrillators.

Methods: We retrospectively analyzed all surgical patients who were discharged at our department with a wearable cardioverter defibrillator. The WCD was prescribed for patients with a left ventricular ejection fraction (LVEF) of ≤35% or an explanted ICD. Age, sex and type of surgery as well as LVEF at time of prescription and in three months follow up, WCD-wearing time, recorded ventricular arrhythmias and WCD shocks were analyzed.

Results: A total of 100 patients were discharged with a wearable cardioverter defibrillator between 2012 and 2017. Mean age was 67 ± 10 years. 79 patients were male and 21 were female. Most of the patients (n = 60) had coronary artery bypass graft surgeries (CABG). Overall wearing time was 23.5 hours per day. The left ventricular ejection fraction was 29.0 ± 9 percent after surgery and improved significantly in the follow up echo to 36.6 ± 11 percent (p < 0.001). 5 patients were successfully defibrillated by the wearable cardioverter defibrillator while having episodes of ventricular tachycardia or ventricular fibrillation. Further 11 patients experienced non-sustained ventricular arrhythmias. An ICD was implanted in 24 patients after WCD wearing period.

Conclusion: A WCD is a feasible and save therapy in surgical patients. Recent sternotomy does not impair wearing time of a WCD. The LVEF improves significantly after three months and thus in several cases an ICD indication does not persist. Ventricular arrhythmias occur in a significant part of patients (16%) discharged with a WCD. A wearable cardioverter defibrillator can effectively protect patients against ventricular tachycardias and ventricular fibrillation after cardiac surgery.