An Unusual Cause of Recurrent Heart Failure
A 50-year-old female with a history of coronary artery disease (CAD) status post three-vessel coronary artery bypass grafts (CABG), ischemic cardiomyopathy (ejection fraction [EF] = 15%), left subclavian occlusion status post carotid to subclavian artery bypass, and type 2 diabetes mellitus presents for advanced heart failure therapy evaluation. In the past few months, she was admitted several times to her local hospital for heart failure exacerbations. Her inpatient evaluation identified reversible anterior ischemia on a nuclear perfusion study, but her coronary angiogram at the outside hospital did not reveal any new coronary stenosis. It was notable for patent bypass grafts, patent carotid to subclavian bypass, and no progression of the native coronary artery disease. After aggressive diuresis and ongoing optimal medical therapy, she was still limited from a functional standpoint. Her physicians elect to repeat her diagnostic cardiac catheterization. Initial angiography is performed via right femoral access. Angiogram of her native left coronary system revealed retrograde flow up the left internal mammary artery (LIMA) graft and to the left subclavian artery (Videos 1 and 2). Her native subclavian artery stenosis, proximal to the LIMA graft, is still present (Video 3). These findings explain the hypoperfusion of the anterior myocardium found on the nuclear study. Her final diagnosis is coronary steal syndrome.
Given this scenario, which of the following statements describes the best treatment approach for this patient's coronary steal syndrome?