Catheter ablation for atrial fibrillation (AF) has established superiorityto medical therapy for the long-term maintenance of sinus rhythm and improvement in quality of life.Catheter ablation for AF and left atrial flutter (LAFL)is emerging as the most common ablation procedure performed in the U.S.with exponential growth observed in the past decade.³, ⁴ Despite the high frequency, there is little consensus on the postoperative management for these procedures. The standard remains inpatient admission and overnight monitoring. However, many practices have begun exploring alternative discharge strategies including outpatient AF ablation. ⁵While it would be more efficient and cost-effective to adopt a same-day discharge strategy for these types of procedures, concerns due to longer procedure times, left atrial lesion delivery, and heparinization have rendered the appropriate discharge strategy controversial.

There have been limited published data regarding same-day discharge for AF ablation procedures – with the majority consisting of historical case control studies or simple descriptive studies of clinical experience. Prior studies have either used non-randomized patient preference ⁶, historical control after institutional discharge strategy implementation⁷, ⁸, or observational longitudinal descriptions ⁹-¹¹.

With two high-volume electrophysiology centers simultaneously performing left atrial ablation differing primarily in post-procedure discharge strategies, we found a unique opportunity to compare outcomes between same-day (SD) and next-day (ND) post-ablation discharge with little variability to ablation strategy, operator experience, or patient factors. We analyzed acute outcomes of AF ablation and other left atrial ablation procedures in terms of complications and readmission rates to assess,in a temporally-parallelformat, the safety and feasibility of SD versus ND discharge strategy.

Consecutive patients undergoing AF, LAFL, or left atrial tachycardia ablationsinvolving transseptal puncture at two high-volume centers within the Emory Healthcare systembetween August 2017 and August 2019 were analyzed. Discharge strategy consisted of general practice guidelines within each hospital and were defined as: 1. ND, consisting of routine overnight stay in a telemetry floor with subsequent discharge the following morning after clinical assessment and groin check; and 2. SD, consisting of discharge after 2-4 hours of bedrest, clinical exam, and groin check. Ablation procedures followed accepted practice guidelines and consisted of predominantly cryo-ablation for paroxysmal AF andradiofrequency (RF) for persistent AF. Ultrasound either by intra-cardiac echo (ICE) or trans-esophageal echo (TEE) was used in the majority of cases and general anesthesia was used according to physician discretion.To specifically compare discharge practices, analysis excluded those who deviated from the institutional discharge strategy, but a separate intention to treat analysis was performed as well. The study was approved by the EmoryInstitutional Review Board.

All routine demographic data including gender, age, and body mass index as well as routine medical history was evaluated. Specificbaseline arrhythmia characteristics were also noted, includingAF subtype (paroxysmal, persistent, or permanent) and history of cardioversion or prior ablation. Procedural characteristics were also analyzed including anesthesia type, ablation type and location, procedure duration, and hemostasis method use.

The primary endpoint was defined as any clinical event that resulted in procedural abortion, a longer hospital stay than anticipated at either center, or readmission within 72 hours. Individual complications were categorized by type and classified as major or minor based on their clinical significance. Major complications included stroke, tamponade, phrenic nerve palsy, sinus node dysfunction, and esophageal perforation. Minor complications included access site issues, pericarditis, simple effusion, unstable labs or vitals, incomplete studies, and a few others.

Differences between groups were subjected to the Student’s t test or Wilcoxon rank sum test for normally and non-normally distributed continuous data, respectively, or the Fisher’s exact test for categorical variables. A 2-tailed P <.05 was considered significant. Continuous data are presented as mean ± standard deviation. We also performed multivariable regression to identify independent predictors of complications among the cohortthat included discharge strategy in an a priori fashion, as well as variables found to be associated with complications in univariateanalysis (p<0.05) as covariates. All analyses were performed using IBM SPSS ver. 26 (2019; IBM SPSS Statistics for Macintosh, Version 26.0. Armonk, NY: IBM Corp).

Our analysis using an intra-institutional comparison of SD versus ND discharge strategy represents a unique and more robust form of analyzing complication and readmission rates for patients undergoing left atrial ablation procedures. Our data indicate two important findings. First, there was no significant difference in complication rates or readmission ratesamong SD or ND discharge strategy when used as a general hospital-based approach. We feel this adds strength to the limited but growing evidence in favor of SD discharges for most AF and left atrial ablative procedures. Comparable rates of major complications are reported in large reviews¹²-¹⁶ and, while there is limited data from the U.S., other countries’ analyses introduced above reveal a lack of significant difference in these rates when patients are kept overnight. When examining a variable such as time of discharge, the importance of selection bias cannot be overstated, as those who do well would tend to have physicians choose to send the patient home sooner, and those in whom there was clinical concern would be expected to be monitored longer. This is why we chose to exclude those who deviated from the general discharge policy at the two comparator clinical sites. Importantly, when we chose to include the deviations from each site as an intention to treat, we continued to observe a non-significant difference in complication rate.

Secondly, multivariate analysis showed hypertension and procedure duration, not discharge strategy as inepedentpredictors of our primary endpoint. There were unavoidable differences in our patient demographic between the SD and ND hospitals that warrant mention and could confound our findings. Namely, a higher incidence of persistent AF, CHF, general anesthesia, and convergent/hybrid surgical procedures were observed in the ND cohort. Of these, procedure type, CHF, and sedation type were associated in univariate analysis with higher complication. However, multivariate analysis including these variables only identified hypertension and duration of procedure as significant predictors of complication. Gender has been identified as a risk marker for complication in other studies not examining discharge strategy for AF.¹⁷-²⁰ In our analysis we found a trend (P=0.06) toward higher univariate risk for complication, but this variable did not meet clinical significance. Other risk markers as outlined in [Table 2] are congruent with prior published studies.²¹

Complication and readmission rates among two high-volume medical centers within the same healthcare system adhering to either SD or ND discharge strategy do not significantly differ for left atrial ablation procedures. These data support a growing body of evidence in favor of SD discharge for this common procedure and the need for a prospective randomized trial.