Left main stem coronary disease: the case for percutaneous coronary intervention in a high risk patient with complex disease.

A lthough coronary balloon angioplasty is an established treatment for patients with coronary artery disease, the results of balloon angioplasty of unprotected left main coronary artery (LMCA) stenosis have been disappointing because of the high mortality rate in both in-hospital (9.1%) and follow up periods. Current in-hospital mortality after initial coronary artery bypass graft surgery (CABG) in unprotected LMCA without myocardial infarction (MI) is 2.3% in highly experienced centres. Therefore, the procedure has been controversial, and CABG has been considered the only effective treatment for this lesion. One reason for high in-hospital mortality in balloon angioplasty for unprotected LMCA was haemodynamic deterioration during balloon inflation that would lead to cardiogenic shock and/or fatal arrhythmia. Another reason was acute occlusion caused by recoil or dissection of the LMCA or left coronary arteries that would lead to fatal MI. The reason for high mortality at long term follow up derived from restenosis occurred mainly within six months after the procedure. In order to improve the results of percutaneous coronary intervention (PCI) in unprotected LMCA, other devices and procedures were mandatory instead of balloon angioplasty. Recently, directional coronary atherectomy (DCA) and coronary stenting have gradually been applied to this lesion. They can protect against acute occlusion in LMCA both during and after PCI, and attain larger post-minimal lumen diameter that can improve the late restenosis rate. Some studies have shown the feasibility, safety, and efficacy of PCI with these new devices in this lesion. Especially in CABG low risk patients, four institutions showed 0% of in-hospital mortality , results that were comparable with those achieved with CABG. Moreover, a multicentre registry has been conducted to analyse the procedure and has shown encouraging results for selected patients. In spite of better survival rates than CABG 15 in the selected patients (more than 95% within three years), 9 restenosis rates at follow up still remain about 20%. Therefore, PCI is not regarded as first choice for the treatment of unprotected LMCA stenosis. Drug eluting stents (DES), such as the sirolimus eluting stent (Cypher, Jonson & Jonson-Cordis, Miami, Florida, USA), have recently been reported to be effective in reducing restenosis rates in selected patients. Moreover, this stent has been increasingly used in PCI for unprotected LMCA with promising results, especially the low restenosis rate. However, before we apply this type of stent to all LMCA stenoses in the ‘‘real world’’ intervention, we must reconsider risks involved in undertaking PCI for this lesion.