Cardiac electrical device‐related bacterial infections: Prevention, diagnosis, and management

Significant developmentin modern cardiac (or cardiovascular) electrical devices (CIEDs), including permanent pacemakers, implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy, is contributing to the improvement in both the survival rate and quality of life in patients with cardiac arrhythmias and/or heart failure. The number of CIED implantations has increased significantly over the past decade based on clinical evidence. However, CIED-related bacterial infections remain one of the biggest and most serious complications of their use. In a study involving Medicare administrative data, the immediate post-procedural complications related to CIED implantations decreased between 2002 and 2005 [1]. This favorable trend may be because of operators’ experience, technological improvements, and device advances such as generator downsizing and/or the use of more sophisticated equipment [2]. Hence, focusing on device-related infections, the Nationwide Inpatient Sample discharge records demonstrated that the annual rate of CIED infections remained almost constant until 2004, but increased suddenly after 2005, with a rate of 1.53% in 2004 to 2.41% in 2008 (p<0.001) [3]. This study also revealed that the incidence of four major comorbidities (renal failure, respiratory failure, heart failure, and diabetes) in patients with CIED implantations similarly remained almost constant until 2004, but increased suddenly after 2005. This trend closely paralleled the increase in the rate of CIED infections. Combined with an aging population, rapid and widespread acceptance of ICD indication has been suggested as a possible cause of the increase in the rate of CIED infections. This is because the size of the ICD generator is larger, and candidates for ICD therapy are more likely to have additional comorbidities [3]. For superficial or incisional infections above the subcutaneous pocket without device involvement, removal of the CIED is not thought to be necessary [1]. However, even in cases with local pocket infections without any signs of systemic infection, complete removal of the entire system is recommended. Detailed managements based on each patient's condition are discussed in the following chapters in this special edition.co. Once a CIED-related infection occurs, each patient should be carefully and intensively evaluated. Early diagnosis and appropriate therapy certainly provide a beneficial effect on the patient's outcome. In one of the largest retrospective cohort studies involving data of 200,219 patients from the Medicare system, CIED-related infections were apparently associated with an increase in admissions and the long-term mortality (adjusted long-term mortality in patients with infections was 1.6- to 2.1-fold compared with those without infections) [6]. Mortality in patients with infections is reported to be in a wide range between 5% and 27% and is suggested to be higher in patients with device-related endocarditis and in those without device removal therapy [6]-[8]. The reported parameters associated with mortality are systemic embolization, moderate-to-severe tricuspid regurgitation, abnormal right ventricular function, and abnormal renal function [8]. CIED-related infections are increasing over time, and these result in high hospital admission and mortality rates. However, the development of several new technologies has contributed to controlling this challenging problem. In this special edition of the Journal of Arrhythmia featuring CIED-related infections, we aim to cover various aspects of this serious issue by inviting five experts in the field of CIEDs to be the main authors of each chapter. We deeply appreciate the efforts of all authors for providing manuscripts and hope that their excellent articles will maximize physicians’ performances in the management of patients with CIEDs.