Study Design and Patient Population
The main objective of this multicenter retrospective observational study was to describe the safety outcomes following a cryoballoon ablation of AF in a SDD cohort compared to patients discharged via a standard-of-care route that encompassed an overnight hospitalization (ONS) for patient observation. At each hospital, the SDD cohort was comprised of consecutive patients discharged the same day as their cryoballoon ablation, and the ONS cohort was a pair-matched collection of patients at these centers (matching based on gender, age, BMI, and AF classification). The study was completed at three different US centers (Staten Island University Hospital a Northwell Health Hospital, Staten Island, NY; Mercy General Hospital/Dignity Health Heart and Vascular Institute, Sacramento, CA; and Spectrum Health Medical Center, Grand Rapids, MI) from January 2014 to March 2019. Subject inclusion criteria included any patient undergoing a cryoballoon ablation of atrial fibrillation at the three hospitals and willingness to complete in-office follow-up examinations. Patients who had a complication during the procedure were excluded from the analysis, as the decision to discharge home the same day was made by the operator after the procedure and was then based on clinical standards-of-care at each hospital with most patients not eligible for SDD. Institutional review board approval was granted at each hospital, and all patients gave informed consent for the data collection and the catheter ablation procedure. This project and the data collection activities conformed with the principles outlined in the Declaration of Helsinki. Data warehousing was hosted by the Staten Island University Hospital using REDCap (project-redcap.org). A subject-key system was used to de-identify patients which was not shared between hospitals in order to maintain the privacy of protected health information.