Tsigkas et al Case report An asymptomatic 47-year-old male patient with a strong family history of coronary artery disease was admitted for coronary angiography due to a positive exercise stress test followed by a thallium scan which showed extensive ischemia of the anterior left ventricular wall. An echocardiogram revealed mild apical left ventricular hypokinesia with preserved global left ventricular ejection fraction. Coronary angiography showed a chronic total occlusion of the proximal part of the left anterior descending artery, along with a 40% stenosis of the left circumflex artery, and a normal right coronary artery. Beyond the proximal left anterior descending artery occlusion, the vessel was opacified through ipsilateral (Figure 1A) and mostly contralateral collaterals (Rentrop Grade 2),3 and appeared to have diffuse atheroma with at least three severe angiographic stenoses extending to its distal part (Figure 1B). This angiographic anatomy suggested that if percutaneous coronary intervention was selected as the initial therapeutic strategy, following a presumably successful treatment of the chronic total occlusion, multiple stents would be needed to restore full vessel patency. On the other hand, revascularization with coronary artery bypass grafting would require an extensive endarterectomy distal to the implantation of an arterial graft. Therefore, an attempt at percutaneous coronary intervention with a plan for referral for coronary artery bypass grafting if the former was unsuccessful was decided. Surprisingly, following successful stenting of the proximal left anterior descending artery occlusion with a paclitaxel-eluting stent, it became evident that, distal to the latter, the vessel had diffuse atherosclerosis, but without any other significant angiographic stenosis as the initial angiography had suggested (Figure 2). The patient had an Figure1 A) Right anterior oblique caudal view of left anterior descending artery. Total proximal occlusion of left anterior descending artery (white arrow). Arrowheads indicate mild ipsilateral collaterals from the obtuse marginal to the left anterior descending artery. B) straight right anterior oblique view of right coronary artery. Contralateral collaterals from the right coronary artery are feeding the distal part of the left anterior descending artery (white arrow), giving the impression of a narrow and multi-atheromatous vessel. Arrowheads show severe and diffuse atheroma in the left anterior descending artery. (Image courtesy of the Catheterization Laboratory at Patras University Hospital). 166 submit your manuscript | www.dovepress.com Dovepress Dovepress Figure 2 Right anterior oblique caudal (Panel A) and left anterior oblique; cranial (Panel B) projection of left anterior descending artery. After stent apposition, left anterior descending artery appears as a diffusely atheromatous vessel without critical stenosis. One more guide wire was used in order to protect the diagonal branch. (Image courtesy of the Catheterization Laboratory at Patras University Hospital). uneventful recovery and was discharged after three days. Follow-up at six months with an exercise treadmill test showed no electrocardiographic signs of ischemia and an excellent exercise tolerance. Discussion More than 30% of patients with significant coronary artery disease present with chronic total occlusions.4 In such patients, the existence of a collateral circulation supplying the myocardium distal to a severe stenosis or total occlusion may improve ventricular function, minimize the infarcted area, reduce the incidence of left ventricular aneurysm formation, and lead to improved survival compared with patients lacking a well developed collateral network.5 Additionally, the existence of the latter allows angiographic assessment of the involved vessel beyond the level of the chronic total occlusion. The extent of collateral flow is not always adequately estimated by coronary angiography, because there is a capacity for further dilatation in response to neurohumoral mediators.6 There are controversial opinions and results in the literature concerning the proper treatment of severe but asymptomatic coronary artery disease.7 Conversely, recanalization of chronic total occlusions, especially when the left anterior descending artery is involved, with percutaneous coronary intervention can reduce mortality and the need for bypass surgery,8 and even improve symptoms and prognosis.9 If coronary artery bypass grafting is selected as the initial therapeutic strategy, optimal visualization of the target vessel in its entire length through feeding collaterals is mandatory for deciding the feasibility of the former, but the surgeon should also construct a plan for the site of graft implantation, and the potential need for downstream endarterectomy. Obviously, close collaboration between cardiologists and surgeons is needed to balance the feasibility and risks of surgery versus percutaneous coronary Vascular Health and Risk Management 2011:7