Early and midterm outcomes of concomitant coronary artery bypass grafting for coronary artery disease in surgical repair of type A aortic dissection

Background: Type A aortic dissection (TAAD) is frequently complicated by concurrent coronary artery disease (CAD). This study aimed to evaluate the impact of concomitant coronary artery bypass grafting (CABG) for CAD on short- and mid-term outcomes following TAAD surgical repair.

Methods: A retrospective, post-hoc analysis was conducted from June 2019 to January 2024, involving 1,083 patients. Among them, 270 patients with CAD were stratified into two groups based on whether CABG for CAD was performed: the CABG and non-CABG groups. The inverse probability of treatment weighting (IPTW) was utilized to adjust for imbalanced characteristics. Kaplan-Meier survival analysis was employed to assess all-cause and midterm mortality.

Results: The overall cohort experienced six operative deaths (2.22%). After IPTW adjustment, the CABG group exhibited a significantly lower incidence of serious adverse events (2.5% vs. 8.3%, P=0.048) and operative mortality (0.5% vs. 4.6%, P=0.02) compared to the non-CABG group. The Kaplan-Meier all-cause survival curve initially showed improvement but deteriorated significantly later, revealing no significant difference between the groups (log-rank P=0.58). However, midterm mortality was significantly higher in the CABG group (log-rank P=0.01). Notably, a high incidence of graft occlusion was observed during follow-up period (42.67% at 3 years and 62.22% at 4 years), especially when the proximal graft was anastomosed to the prosthesis (P=0.02).

Conclusions: Concomitant CABG for CAD in TAAD patients lowers operative mortality but worsens midterm outcomes. The increased midterm mortality is mainly due to the high incidence of graft occlusion, which contributes to cardiovascular events and cardiac dysfunction. Due to the negative impact on long-term patency and prognosis, graft anastomosis to the prosthesis is not recommended.

Keywords: Type A aortic dissection (TADD); coronary artery disease (CAD); coronary artery bypass grafting (CABG); inverse probability of treatment weighting (IPTW)

 

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Key findings

• Coronary artery bypass grafting (CABG) for concurrent coronary artery disease (CAD) in type A aortic dissection (TAAD) patients shows better surgical outcomes but is associated with increased midterm mortality.

What is known and what is new?

• Concurrent CAD is frequently observed in patients with TAAD, but the impact of CABG for concurrent CAD in TAAD patients remains uncertain.

• This study demonstrates that CABG for concurrent CAD in TAAD patients reduces operative mortality but increases midterm mortality. A high incidence of graft occlusion is observed, particularly when the proximal end of the graft is anastomosed to the prosthesis.

What is the implication, and what should change now?

• The proximal end of the saphenous vein graft should be anastomosed to the native vessel tissue rather than to the prosthesis, as the latter negatively impacts long-term graft patency and patient prognosis.