P191 - LONG-TERM OUTCOMES OF ARTERIAL CONDUIT CONFIGURATIONS IN MULTIARTERIAL CORONARY ARTERY BYPASS GRAFTING

Background: Multiarterial grafting (MAG) in coronary artery bypass (CABG) has been associated with improved survival and graft patency. Despite this, MAG utilization remains low. Several possible configurations using the left internal thoracic artery (LITA) and the right internal thoracic (RITA) or radial (RAD) artery exist, however, equipoise remains with respect to ideal configurations. This uncertainty has led to complexity in operative planning and may be a factor limiting more widespread adoption of MAG.

METHODS AND RESULTS: 20,076 patients undergoing CABG in our province from Jan 2000 to Dec 2020 were considered. Those who received 2 arterial grafts were stratified into five groups by the conduits used, graft arrangement, and territories grafted. Free LITA or RITA grafts were excluded. A prospectively maintained cardiovascular outcomes database was linked with the Discharge Abstract Database and our provincial Vital Statistics for long-term outcomes. Unadjusted mortality and repeat revascularization were examined by Kaplan Meier analysis. Cox proportional hazards models were used to study adjusted outcomes and relevant pairwise comparisons.

5,647 patients met inclusion criteria with a median follow-up time of 9.1 years. Overall, 3,321 patients had a combination of one internal thoracic artery and a radial artery, and 2,326 had bilateral internal thoracic arteries. These were further stratified into 5 distinct configurations based on left-, or right-sided distal targets. After multivariable adjustment, graft configuration was not independently predictive of long-term mortality or repeat revascularization for any configuration studied (Figure). Adjusted pairwise comparisons demonstrated no significant difference in outcomes between configurations with RITA to Left anterior descending (LAD) compared to those with LITA to LAD. Additionally, there were equivalent long-term mortality and repeat revascularization between the use of LITA and RAD compared to LITA and RITA.


Conclusion: In this long-term series of over 5500 patients with MAG, the choice of graft configuration did not affect long-term survival or repeat revascularization. Importantly, the use of LITA and RAD, a technically simple configuration, yielded similar results to bilateral internal thoracic arteries. This has not previously been demonstrated in a large, long-term study. Also, configurations utilizing LITA or RITA to LAD yielded similar results. These data support MAG using the simplest strategy for the individual patient and may reduce complexity in the planning of these operations.