Abstract 341: Population-level Insights Into 30-day Mortality in Medicare Beneficiaries After Inpatient and Outpatient Catheter Ablation for Atrial Fibrillation

Abstract

Background: Recent inpatient data abstracted from the National Inpatient Sample and/or National Readmissions Database have shown higher than expected (0.46%) 30-day mortality rates of AF ablation prior to 2016. AF ablation has been increasingly coded as an outpatient procedure and primarily as of late 2015. Prior studies did not include some of these outpatient ablation cases. As such, more complete data on mortality and health-disparity outcomes for combined inpatient and outpatient-coded AF ablation is lacking. The purpose of our study was to assess updated 30-day mortality rates following inpatient or outpatient AF ablation following coding changes with ICD-10. Patients were also stratified by demographics and geographic region. Method: Data were abstracted from the 2017 inpatient and outpatient Medicare institutional claims files. AF was identified based on primary or secondary ICD-10 diagnosis codes. Inpatient procedures were identified by matching a CPT code for AF ablation that occurred on the same day as a primary or secondary ICD-10-PCS code for AF ablation. Outpatient AF ablation was identified using the CPT code. AV nodal ablation or a pacemaker procedure on the same day as AF ablation were excluded. AF ablation had to occur within the first 11 months of the calendar year to allow 30-day mortality data for all patients. We used the Medicare Master Beneficiary Summary File to further stratify beneficiaries by sex, race, and ethnicity, and geographic region. Mortality rates are shown as frequency and percent, compared using the chi-square test. Results: In 2017, a total of 40,373 AF ablations (58% men) were identified, of which 30,539 (75.6%) were coded as outpatient. The mean age in years was 71.5 (SD = 7.1), and median age was 71 (21 to 100). In total, 294 patients died within 30 days of procedure (0.73%, 95% CI: 0.65% to 0.82%). The 30-day mortality rate was higher following inpatient coded procedures compared to outpatient coded procedures (2.34% vs. 0.21%, p < .001). Further, higher 30-day mortality rates were observed for male patients compared to female patients (0.83% vs. 0.59%, p = .006) as well as in non-white patients compared to white patients (1.32% vs. 0.69%, p < .001). Finally, 30-day mortality rates differed by region (South: 0.85%, Midwest: 0.81%, Northeast: 0.56%, and West: 0.51%; p = .007). Conclusion: Overall 30-day mortality post-AF ablation appears high, particularly following inpatient coded AF ablation. Most notably, it is significantly higher than the recent estimate of 0.46% mortality risk following AF ablation from primarily inpatient data. The findings of higher mortality in males, in the non-white population, and in certain regions of the US are notable. Further studies are needed to understand the factors impacting mortality.