Graft failure after CABG common and strongly associated with MI and death

The researchers reported, "Women and smokers have an increased risk of graft failure after CABG, although statins appear to be protective." They stated that graft failure is strongly associated with repeat revascularization, myocardial infarction, and an increased death risk.

Graft patency is the postulated mechanism for the benefits of CABG. However, systematic graft imaging assessment following CABG is rare, and contemporary data are scarce on the factors associated with graft failure and the association between clinical events and graft failure after CABG. Therefore, Mario Gaudino, Weill Cornell Medicine, New York, NY, and colleagues pooled individual patient data from RCTs (randomized clinical trials) with systematic CABG graft imaging to evaluate the graft failure incidence and its association with clinical risk factors.

The primary outcome was the composite of repeat revascularization or myocardial infarction occurring after CABG and before imaging. The association between graft failure and primary outcome was evaluated using a 2-stage meta-analytic approach. The researchers also evaluated the association between graft failure and myocardial infarction, repeat revascularization, or all-cause mortality after imaging.

A total of seven trials comprising 4413 patients were included. The mean age of the patients was 64.4±9.1 years; 82.4% were men, with 13 163 grafts (8740 saphenous vein grafts and 4423 arterial grafts).

The study revealed the following findings:

• The median time to imaging was 1.02 years (Q1; Q3: 1.00;1.03). Graft failure occurred in 33.7% of patients and 16.6% of grafts.
• Age (adjusted odds ratio [aOR], 1.08 [per 10-year increment, female sex (aOR, 1.27), and smoking (aOR, 1.20) were independently associated with graft failure, whereas statins were associated with a protective effect (aOR, 0.74).
• Graft failure was associated with an increased risk of myocardial infarction or repeat revascularization occurring between CABG and imaging assessment (8.0% in patients with graft failure versus 1.7% in patients without graft failure; aOR, 3.98).
• Graft failure was also associated with an increased risk of myocardial infarction or repeat revascularization occurring after imaging (7.8% versus 2.0%; aOR, 2.59).
• All-cause death after imaging occurred more frequently in patients with graft failure compared with patients without graft failure (11.0% versus 2.1%; aOR, 2.79).

"Our findings show that in contemporary practice, CABG graft failure remains common and is strongly associated with adverse cardiac events." the research team wrote. "There is a need for strategies to maximize graft patency to improve CABG outcomes, particularly for women who have a concerningly higher rate of failure compared with men."

"Due to its strong association with clinical outcomes, graft status may be useful as a surrogate outcome in clinical trials of patients undergoing CABG surgery," they concluded.

Reference:

Gaudino M, Sandner S, An KR, Dimagli A, Di Franco A, Audisio K, Harik L, Perezgrovas-Olaria R, Soletti G, Fremes SE, Hare DL, Kulik A, Lamy A, Peper J, Ruel M, Ten Berg JM, Willemsen LM, Zhao Q, Wojdyla DM, Bhatt DL, Alexander JH, Redfors B. Graft Failure After Coronary Artery Bypass Grafting and Its Association With Patient Characteristics and Clinical Events: A Pooled Individual Patient Data Analysis of Clinical Trials With Imaging Follow-Up. Circulation. 2023 Jul 7. doi: 10.1161/CIRCULATIONAHA.123.064090. Epub ahead of print. PMID: 37417248.