Can double internal thoracic artery grafts affect 10-year outcomes after coronary artery bypass grafting?

Abstract Background The advantages of the employment of double internal thoracic artery grafts (BITA) for coronary artery bypass grafting have been recently questioned and no data on long-term follow-up are available. This observational retrospective 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 clarify and consolidate the contrasting literature. 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. Time-to-event distributions were separately analyzed accordingly to primary event-type (death, MACEs), using Kaplan-Meier estimates and Cox regression. Results The population consisted of 11021 patients who underwent isolated CABG that were divided into development and validation datasets; double thoracic internal artery grafts was employed in 24.6%. The median follow-up time was 8 years (interquartile range 7.6–10 years) and was 100% complete. After adjustment for potential confounding factors, BITA was significantly associated with better survival (HR 0.85, 95% CI 0.76–0.95, p=0.003). Moreover, the employment of BITA reduced the incidence of MACEs at follow-up (adjusted HR 0.87, 95% CI 0.80–0.94, p=0.001). In details, BITA was demonstrated to be a protective factor for acute myocardial infarction (adjusted HR 0.84, 95% CI 0.71–0.99, p=0.05) and for rehospitalization for percutaneous cardiac intervention (PCI; adjusted HR 0.82, 95% CI 0.70–0.96, p=0.013). Conclusions The employment of double internal thoracic artery grafts for coronary artery bypass grafting has been associated to survival advantage at 10-year. Moreover, it significantly decreased the incidence of acute myocardial infarction and rehospitalization for percutaneous cardiac intervention. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Italian Minister of Health