How should I treat a patient with significant angina and a severe left anterior descending artery stenosis beyond the insertion of a left internal mammary artery jump graft (diagonal to LAD)

BACKGROUND: A 60-year-old man with a history of previous coronary artery bypass grafting (saphenous vein grafting [SVG] to native right coronary artery [RCA] and sequential left internal mammary artery [LIMA] jump grafting to his native first diagonal [D1] and left anterior descending [LAD] arteries), who had developed a previous ischaemic cerebrovascular accident following femoral angiography, re-presented with further ischaemic cardiac symptoms. INVESTIGATIONS: Physical examination, electrocardiography, biochemistry including high-sensitive troponin, echocardiography, and trans-radial angiography. DIAGNOSIS: Severe native 3 vessel disease including ostial occlusion of the LAD, distal left circumflex and obtuse marginal (LCX/OM) disease and proximal RCA occlusion; occluded SVG to RCA, and evidence of a critical stenosis in the mid LAD distal to the insertion of the tortuous LIMA jump graft (diagonal to LAD). TREATMENT: PCI to mid LAD lesion via LIMA jump graft from left trans-radial approach.