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