Abstract 14072: Long-Term Mortality Following 59253 Patients Who Underwent Coronary Artery Bypass Surgery in New South Wales, Australia: A Statewide Population-Linkage Study From 2001-2018

Abstract

Purpose: To describe changes in long-term mortality following coronary artery bypass graft (CABG) in New South Wales (NSW), Australia, from 2001-2018. Methods: Patients who underwent CABG were identified from the NSW Admission-Patient-Data-Collection registry linked to the NSW death registry and were stratified into six, 3-year groups. Changes in comorbidities and procedural techniques over time were determined. Primary outcome was death (end of follow-up: 31-December-2018). Secondary outcome was time to first percutaneous coronary intervention (PCI) post-CABG, with death as the competing event. Outcomes analyses using Cox regression were adjusted for baseline and procedural differences and geographical clustering. Results: A total 59253 patients underwent CABG during the study period. From 2001-03 to 2016-18, procedural numbers fell (11875 vs 7606); however patient complexity increased (Charlson comorbidity index [CCI]>0: 40% vs 55%) as did male patients (77% vs 83%). During a median (interquartile range) follow-up of 7.7yrs (3.8-12.1yrs), 16,484 (27.8%) patients died. Factors associated with increased long-term mortality included older age (>75 vs ≤60: hazard ratio [HR]=6.69, 95% confidence interval [CI]=6.33-7.08), female sex (HR=1.06, 95%CI=1.02-1.11), acute myocardial infarction (HR=1.86, 95%CI=1.80-1.92), atrial fibrillation (HR=1.38, 95%CI=1.29-1.47), valvular heart disease (HR=1.84, 95%CI=1.56-2.18), and CCI (per-1-score increase: HR=1.31, 95%CI=1.26-1.35). Multivariable survival analysis showed that, compared to 2001-03, the risk of death reduced from 2004-06 to 2016-18: HR=0.96, 95%CI=0.93-1.00 to HR=0.61, 95%CI=0.54-0.70, respectively. Multivariable time-to-PCI analysis with death as the competing event showed no significant difference over the years. Conclusion: Between 2001 and 2018, though CABG volume has decreased, proportionally more males and higher comorbid patients had CABG in recent years. Female sex and other major comorbidities were expectedly related to an increased association with mortality. Overall, mortality has fallen significantly over time, with no significant trend of PCI undertaken over time in these post CABG patients.