Ostial disease of the LAD and LCX is a challenge for the interventional cardiologist. Focal ostial stenting may result in incomplete lesion coverage, or plaque shift into the adjacent vessel, creating left main equivalent disease. The strategy of optimal treatment for the ostial lesions must be considered carefully before stenting. How should we treat ostial LAD disease then? Should the stent start just at the ostium of LAD, or should the stent be placed across the LCX starting from LM? Either way, one must be prepared for possible plaque shift into the ostium of LCX or LM distal part. Actually, in many cases plaque is located also in the LM and/or in the LCX ostium. Recently, a small IVUS study of distal left main lesions was published and plaque localised to either the LAD or LCX ostium and not involving the distal LMCA was seen in only 9.3% of LAD arteries and 17.1% of LCX arteries1
In our case, pre-procedure IVUS was performed, and it showed a pure ostial LAD de novo lesion. We found no significant plaque in LM or LCX ostium. Thus, stenting just from the ostium of LAD was chosen for our strategy. IVUS is practical, because pullback can be done from both LAD and LCX and the plaque location and involvement of the bifurcation can be easily demonstrated beforehand. In some cases IVUS may show a very large vessel diameter in LM, which is a contraindication for stenting.
We used the Cutting Balloon Microsurgical Dilatation Catheter (Boston Scientific) for the predilatation of the lesion. Previously, it has been observed, that predilatation with cutting balloon has reduced TLR rates in the ostial LAD lesions2
DES was chosen because it has been shown to be superior to bare metal stents in the ostial de novo lesions3 After predilatation, EES (Promus Element Everolimus Eluting Stent System) was successfully delivered into the target lesion and the stent was clearly seen, which gave us accuracy for the optimal stent location and deployment.
Case Study
A 59-year-old man with medical history of dyslipidaemia presented with stable angina (Canadian Cardiovascular Society Class 2) lasting one year and positive exercise stress test. The patient was observed to have elevated LDL-cholesterol levels (3.5mmol/l) despite having used a prescription of simvastatin (40mg/day).
Coronary angiography revealed a left anterior descending artery (LAD) with a severe stenosis in the proximal segment extending the ostium of LAD (Figure 1a and b). After discussion with the patient, a decision was made to proceed with percutaneous coronary intervention (PCI) and stenting. The left coronary artery was engaged with a 6F Q-Curve 3.5 guiding catheter (Mach I guide catheter; Boston Scientific) from the right radial approach. The LAD lesion was crossed with 0.014-inch guidewire (ChoICE Extra Support; Boston Scientific).
To determine whether the ostial plaque of LAD involved the distal left main coronary artery (LM) and the left-circumflex coronary (LCX) ostium, we decided to perform pre-intervention intravascular ultrasound (IVUS) using standard technique. IVUS images were recorded using the iLab ultrasound imaging system (Boston Scientific) after administration of 100–200mg of intra coronary nitroglycerin. The ultrasound catheter was advanced at least 5mm beyond the lesion and was pulled back to a point at least 5mm proximal to the lesion using motorized transducer pullback at 0.5mm/sec. The IVUS confirmed the severity of the lesion in LAD ostium (Figure 2a). However, the LCX oblique view showed that the ostium of the LCX appeared free of disease at IVUS (Figure 2b), as well as the distal part of LM was free of disease.
The decision was taken to predilate the LAD proximal lesion, and perform stenting with a drug-eluting stent (DES) starting at the ostium of the LAD. Subsequently, the lesion was dilated by Flextome cutting balloon Device 3.0/10mm (Boston Scientific), and successful implantation of everolimus-eluting (EES) Promus Element 4.0/16mm (Boston Scientific) stent was performed at 14atm, with an excellent final angiographic result (Figure 3a and b). The post-procedural IVUS confirmed that no plaque shift occurred towards the distal LM and LCX ostium.
The patient’s stay was uncomplicated and he was discharged home next day. The discharge medical regimen included clopidogrel 75mg/d for 12 months, aspirin 100mg/d indefinitely, and atorvastatin 40mg/d. The patient had been prescribed beta-blockade earlier, but it was discontinued for symptomatic bradycardia.
Content under the sole responsibility of the authors – does not reflect the opinion of Boston Scientist.
Matti Niemelä and Hannu Romppanen, Oulu University Hospital, Division of Cardiology, University of Oulu, Oulu, Finland.
References
1. Oviedo C. et al. Intravascular Ultrasound Classification of Plaque Distribution in Left Main Coronary Artery Bifurcations: Where Is the Plaque Really Located? Circul Cardiovasc Interv. 2010 Mar 2. [Epub ahead of print]
2. Dahm JB. et al. Directional atherectomy facilitates the interventional procedure and leads to a low rate of recurrent stenosis in left anterior descending and left circumflex artery ostium stenoses: subgroup analysis of the FLEXI-CUT study. Heart. 2006 Sep;92(9):1285–1289.
3. Tsagalou E. et al. Early outcome of treatment of ostial de novo left anterior descending coronary artery lesions with drug-eluting stents. Am J Cardiol. 2006 Jan 15;97(2):187–191.
Fig. 1. Right (A) and left (B) caudal coronary angiogram showing severe lesion of the proximal LAD extending to ostium.
Fig. 2. IVUS of the proximal LAD ostium shows significant fibrotic lesion with presence of calcium at the 11 o`clock position (A). An oblique view of LCX confirms, that there is not significant plaque visible at the ostium LCX (B).
Fig. 3. Final angiographic result of the LAD treated with EES showing an excellent result with no plaque shift towards distal LM and LCX ostium. Right caudal view (A); Left caudal view (B).
