The role of coronary artery disease in lung transplantation
Authors: Luesebrink E , Gade N , Seifert P , Hoffmann S , Barton J , Veit T , Irlbeck M , Schneider C , Hatz R , Hagl C , Massberg S , Behr J , Milger-Kneidinger K , Orban M , Kneidinger N 
Published: November 2023

Abstract

Background
Coronary artery disease (CAD) is a common comorbidity in patients suffering from terminal lung disease and a recurrent problem in pre-transplant evaluation. While historically, CAD has been treated as a contraindication for lung transplantation, data from multiple small studies suggests that CAD in well selected patients might not be associated with a worse outcome. In its 2020 consensus document for the selection of lung transplant candidates, the International Society for Heart and Lung Transplantation states that CAD should not be considered an absolute contraindication but a potential marker for an unfavourable phenotype. However, data backing up this decision is limited and in parts inconclusive.

Purpose
This study aims to provide solid data on the relevance of pre-existing CAD in the setting of lung transplantation. Furthermore, defining cardiovascular risk factors and their effect in this unique population is required to support evidence-based risk stratification.

Methods
1003 patients receiving lung transplantation between January 2000 and August 2021 were included in this study. The median follow up was 3.24 years [1.30, 4.82]. Plaque formation in the coronary arteries was identified by coronary angiography in 230 patients. A relevant CAD defined by stenosis &gt;50% or previous percutaneous coronary intervention/coronary artery bypass graft was present in 104 patients.

Results
Baseline characteristics of the CAD group differed significantly from the non-CAD group in terms of Age at Transplantation [y] (60.28 [56.71, 63.24] vs. 53.96 [44.45, 59.85], p&lt;0.001), Sex [male] (74.0% vs. 52.3%, p&lt;0.001) and BMI [kg/m2] (24.13 [21.25, 27.41] vs 22.22 [19.37, 25.62], p&lt;0.001) as well as the abundance of cardiovascular risk factors including hypertension (67.3% vs 32.1%, p&lt;0.001) and smoking (67.3% vs 40.9%, p&lt;0.001). Therefore 1:1 propensity score matching was performed, resulting in 98 matched pairs. Matching variables, including demographics, cardiovascular risk factors, results from the right heart catheter and lung testing, were well balanced without significant differences between the groups. The primary endpoint overall survival was similar in the matched groups: HR=0.94, 95% CI 0.64-1.39, p=0.77. Graph 1 pictures the corresponding Kaplan – Meier curves. In addition, no significant differences in intrahospital mortality between patients with and without CAD (8.2% vs 5.1%, p=0.566) could be detected. Furthermore, there was no significant difference in the occurrence of myocardial infarction (6.1% vs 4.1%, p=0.745) or stroke (2.0% vs 5.1%, p=0.441) post transplantation.

Conclusion
The finding of this study provides further evidence indicating that CAD itself may not be associated with worse short – or long-term survival following lung transplantation. Careful evaluation and patient selection can allow patients suffering from CAD to successfully undergo lung transplantation without inferior survival.Survival Analysis