Complications The main complications of balloon angioplasty and stent placement are Arterial dissection Bleeding caused by adjunctive anticoagulation Restenosis Standard complications of cardiac catheterization and coronary angiography Thrombosis and distal embolization Of all angiographic procedures, PCI has the highest risk of contrast nephropathy (due to increased contrast load and procedural time); this risk can be reduced by preprocedural hydration and possibly by use of a nonionic contrast agent or hemofiltration in patients with preexisting renal insufficiency.