Abstract 15146: Superior Outcomes of Dual-Arterial Compared With Single-Arterial CABG Are Maintained in Low-Volume Centers in the Veterans Health Administration

Abstract

Introduction: A 2023 report of the STS Adult Cardiac Surgery Database (ACSD) demonstrated worse clinical outcomes with dual arterial CABG (DAG) compared to single arterial CABG (SAG) at low DAG volume centers (<30 DAG/year). It is unclear how generalizable these results are to low DAG volume centers in the Veterans Health Administration (VHA). Objective: We investigated outcomes of DAG with bilateral internal thoracic artery (BITA) or radial artery (RA) plus vein grafts (VG) compared to SAG using a left internal thoracic artery (LITA) graft plus VG in the VHA. Methods: This study analyzed data from 25,969 patients undergoing isolated CABG between 2005 and 2015 at 44 VHA hospitals (all performing<30 DAG/year). The primary outcome was 5-year mortality, and the secondary outcome was a composite of major adverse cardiac and cerebrovascular events (MACCE; all deaths, myocardial infarction, stroke, or repeat revascularization). Results: 1,261 patients (4.9%) received DAG (66.8% LITA plus RA/VG and 33.2% BITA/VG) and 24,708 patients (95.1%) had SAG. Median age and grafts per patient for DAG and SAG were 62 and 63 years and 3.0 and 3.0 grafts, respectively. At 5 years, mortality rates for DAG (10.6% [134 events]) were significantly lower vs. SAG (16.2% [4,011 events]). Similarly, MACCE were lower for DAG (22.0% [278 events]) vs. SAG (28.6% [7,078 events]). Kaplan-Meier analysis for all deaths showed a hazard ratio (HR) of 0.64 (95% CI: 0.54 to 0.76) favoring DAG (Figure). A covariate-adjusted Cox model for DAG vs SAG revealed adjusted HR of 0.70 (95% CI: 0.58 to 0.85) for all-cause mortality and 0.80 (95% CI: 0.70 to 0.91) for MACCE. Conclusions: In contrast to a recent STS-ACSD analysis, DAG in the VHA was associated with significantly improved 5-year survival and rates of MACCE compared to SAG. Additional studies are needed to understand the observed lack of negative DAG low-volume/outcome relationship in the VHA.