Prior and concomitant coronary artery revascularization and long-term survival on patients undergoing lung transplantation

R. Yanagida¹, M. Azuma², R. May², M. Abul. Kashem³, H. Kehara², S. Iturra-Urriola², R. Raman³, K. Krishan⁴, E. Leotta⁵, F. Cordova², N. Shigemura⁵, Y. Toyoda^6
1Temple University, Livingston, New Jersey ²Temple University, Philadelphia, Pennsylvania ³Department of Cardiothoracic Surgery at Temple University Hospital, Philadelphia, Pennsylvania ⁴Temple University Hospital, Philadelphia, Philadelphia, Pennsylvania ⁵Temple University Hospital, Philadelphia, Pennsylvania ⁶Temple University Hospital, Philadelphia, Pennsylvania

Purpose: Lung transplant candidacy for patients with coronary artery disease (CAD) have been studied, however, long term survival of these patients compared with those without CAD is not clear. This study reviewed the largest number of patients with CAD undergoing lung transplantation (LTx) and outcome associated with coronary artery revascularization.

Methods: A retrospective analysis of all single and double lung transplant patients from Feb-2012 to June-2023 at a single centered was performed (n = 1130). Significant CAD was defined by a fractional flow reserve < 0.8 or instantaneous wave-free ratio < 0.9. When patients were deemed anatomically not amenable to percutaneous coronary intervention (PCI), concomitant coronary artery bypass grafting (con-CABG) at time of lung transplantation was considered. All con-CABG procedures were performed on a beating heart without cardioplegic arrest. Patients were stratified into 4 groups: (1) LTx without revascularization, (2) Con-CABG, (3) Pre-operative CABG, and (4) Pre-operative PCI. Groups were compared for demographics, coronary artery revascularization, and survival outcomes using JMP pro version 17, where p-value < 0.05 was considered significant. Kaplan-Meier analysis and Cox proportional hazard model were performed to compare survival.

Results: Of 1130 patients who underwent LTx during the study period 77 patients received con-CABG, 40 had preoperative CABG, 107 preoperative PCI and 906 did not require revascularization. Patients who required coronary artery revascularization had greater incidence of restrictive lung disease than obstructive lung disease (p < 0.0001). Of 77 patients who had con-CABG single, 2, 3 and 4 vessel bypasses were performed on 41, 29, 4 and 3 patients, respectively. In patients who had con-CABG, median sternotomy was the most common approach (50%) followed by anterolateral thoracotomy (44.3%). The pre-operative CABG group had a higher proportion of single LTx than the others (p=0.007). The group without revascularization was younger than the other three groups (p < 0.0001) with con-CABG being second youngest. Among all the groups, there was no significant difference in lung allocation score, warm ischemic time and pump type. Incidence of postoperative myocardial ischemic events and stroke were similar among groups. Kaplan-Meier analysis demonstrated no significant difference in survival rates among the four groups (p=0.242). The Cox-regression only showed that prior PCI was statistically significant to survival rate (p=0.044).

Conclusion: In this largest study that included patients with CAD undergoing LTx our data showed no significant difference in long term survival among patients without CAD and selected patients with CAD who underwent coronary artery revascularization by the time of LTx or as con-CABG. Prior PCI was a risk factor for survival after LTx. Our data supports con-CABG as a viable option for lung transplant candidates with CAD who need LTx.

Identify the source of the funding for this research project: None.