Aortocoronary bypass graft failure is common and is associated with high morbidity and mortality. Failure of saphenous vein grafts is more common than failure of internal mammary artery grafts. Whether early graft angiography can reduce bypass graft failure remains unknown. The Cardiac CAtheterization for Bypass Graft Patency Rate Optimization (CABG-PRO) randomized-controlled pilot study is a phase III, double-blind, randomized-controlled pilot trial that will randomize 170 patients undergoing coronary artery bypass graft surgery to early (before dismissal) graft angiography vs. no early graft angiography. Coronary angiography will be performed at 12 months, to determine whether compared to no early graft angiography, early graft angiography will result in:

1. lower per patient angiographic bypass graft failure (in at least one graft) rates (defined as ≥75% diameter stenosis in at least one bypass graft) (primary efficacy endpoint)
2. lower per graft failure rates, per graft occlusion rates, and per patient bypass graft occlusion rates (in at least one bypass graft) (secondary endpoints)
3. lower incidence major adverse cardiac events (death, nonfatal myocardial infarction, nonfatal stroke, coronary revascularization, and composite of death/myocardial infarction) (secondary endpoint)

Intravascular ultrasonography and near-infrared spectroscopy will also be performed in at least one bypass graft at baseline (in the early graft angiography group only) and at 12-month angiographic follow-up to evaluate the structural bypass graft changes occurring after coronary artery bypass graft surgery (secondary endpoint).

Inclusion Criteria:

1. Age >18 years
2. Willing and able to give informed consent. The patients must be able to comply with study procedures and follow-up.
3. Undergoing clinically-indicated coronary artery bypass graft surgery

Exclusion Criteria:

1. Positive pregnancy test or breast-feeding
2. Coexisting conditions that limit life expectancy to less than 12 months or that could affect a patient's compliance with the protocol
3. Serum creatinine > 2.5 mg/dL or acute renal failure
4. Severe peripheral arterial disease limiting vascular access