No significant difference found at 5-year follow-up between bilateral and single CABG: The ART trial

1. At 5-years of follow-up, there were no significant differences in the rates of mortality and cardiovascular outcomes when comparing patients treated with bilateral or single internal-thoracic-artery coronary-artery bypass grafting (CABG).

2. There was a significantly higher rate of sternal wound complications observed in the bilateral group compared to the single group.

Evidence Rating: 1 (Excellent)

Study Rundown: One of the most commonly performed operations for the treatment of symptomatic multivessel coronary artery disease is CABG. The procedure involves an anastomosis of the left internal thoracic (mammary) artery (LIMA) to the left anterior descending (LAD) coronary artery. In cases where grafts are required, saphenous vein or radial artery grafts to bypass the other arteries may be used. The LIMA to LAD approach has resulted in over 90% patency rate at 10 years compared to 50% for vein grafts. This has resulted in the proposal to use a bilateral internal-thoracic-artery approach. However, the complexity of the procedure, higher risk of sternal wound complications, and lack of randomized evidence has hindered its popularity. Hence, the Arterial Revascularization Trial (ART) was initiated to compare the 10-year survival of bilateral compared to single artery grafting. At 5 years of follow-up, there were no significant differences between the two groups in the rates of mortality or cardiovascular events. There was a higher rate of sternal wounds in the bilateral group compared to the single group. The study is limited given that it is an interim analysis of a 10-year project.

Click to read the study, published today in NEJM

Relevant Reading: A meta-analysis of adjusted hazard ratios from 20 observational studies of bilateral versus single internal thoracic artery coronary artery bypass grafting

In-Depth [randomized controlled trial]: A total of 3102 patients were enrolled in this multicenter, randomized trial that took place at 28 cardiac surgical centers in 7 countries. Participants were randomly assigned to either single or bilateral internal-thoracic-artery grafting. The primary outcome was death from any cause at 10 years of follow-up. Secondary outcomes included a composite of death from any cause, myocardial infarction, or stroke, quality of life, rate of repeat revascularization, safety outcomes, and cost effectiveness.

This publication was an interim analysis performed at 5 years after follow-up. The rate of death was 8.7% in the bilateral group compared to 8.4% in the single group and there was no significant difference between the two groups (HR 1.04, 95%CI 0.81-1.32; p = 0.77). There was no significant difference between the two groups in the rate of death from any cause or myocardial infarction (HR 0.96; 95%CI 0.79-1.17; p = 0.69). However, the rate of sternal wound complication was significantly higher in the bilateral group at 3.5% compared to the single group at 1.9% (p = 0.005).

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