Abstract 16420: Double Internal Thoracic Artery Grafts are Associated to Better 10-year Outcomes After Coronary Artery Bypass Grafting

Abstract

Introduction: Few data on long-term follow-up of effectiveness and advantages related to the employ of double internal thoracic artery grafts (BITA) for coronary artery bypass grafting are available and the advantage of the employ of BITA have been recently questioned. Hypothesis: This observational cohort study was designed by the PRIORITY planning committee to evaluate 10-year follow-up of isolated CABG performed with and without BITA in order to evaluate the impact of BITA on long-term outcomes. Methods: The PRIORITY project was designed to evaluate the long-term outcomes of 2 large prospective multicenter cohort studies on CABG conducted between 2002-2004 and 2007-2008. Data on isolated CABG were linked to 2 administrative datasets. The primary endpoints were death and major adverse cardiac events (MACEs) at follow-up. Time-to-event data were analyzed using Kaplan-Meier estimates and Cox regression. Models generation was performed on the full dataset and the validation was performed with Montecarlo simulations. Results: The population consisted of 11021 patients who underwent isolated CABG; double thoracic internal artery grafts was employed in 23.5%. The median follow-up time was 7.9 years (interquartile range 7.4 - 10 years). After adjustment for potential confounding factors, BITA was significantly associated with better survival (HR 0.81, 95%CI 0.73-0.89, p < 0.001). Moreover, the employment of BITA reduced the incidence of MACEs at follow-up (adjusted HR 0.83, 95%CI 0.77-0.89, p < 0.001). In details, BITA was demonstrated to be a protective factor for acute myocardial infarction (adjusted HR 0.83, 95%CI 0.72-0.96, p = 0.001) and for rehospitalization for percutaneous cardiac intervention (PCI; adjusted HR 0.72, 95%CI 0.63-0.84, p < 0.001). Conclusions: The employment of double internal thoracic artery grafts for coronary artery bypass grafting has been associated to significant survival advantage at long-term. Moreover, it is a protective factor for acute myocardial infarction and rehospitalization for percutaneous cardiac intervention, reducing the hazard by 28%.