What are the non-surgical alternatives to an open-heart bypass?

Stenting. Coronary stent and/or angioplasty, if possible. Medical management, including beta-blockers and nitrates and/or ace inhibitors. There are also off-pump CABG for appropriate candidates as well as "minimally invasive" robot-assisted.
Several. Aortocoronary bypass is performed to allow blood to get to the heart around coronary blockages and involves using either venous or arterial conduits taken from another part of the body. Other options include treatment with medicines and adjustment of lifestyle, angioplasty(dilating lesion with balloon tipped catheter), atherectomy, or placement of stent.