Percutaneous intervention in unprotected left main coronary disease

A significant left main coronary artery (LMCA) stenosis is an important predictor of survival in patients with coronary artery disease. In the past, percutaneous coronary intervention (PCI) was generally restricted to patients with protected left main disease; and >50% stenosis of the LMCA was a contraindication to balloon angioplasty.
In the pre-stent era, results of left main balloon angioplasty were poor. For example, in one series, in-hospital mortality was 9.1% in the elective group and 50% in the acute group. The development of coronary stenting and effective antiplatelet therapy in the 1990s stimulated renewed interest in PCI for LMCA disease. A number of studies reported good outcomes for protected LMCA lesions, though results in haemodynamically unstable patients remained poor.
The figures for a number of studies of elective PCI for unprotected left main stenosis are also described. The best documented outcomes so far are one-year actuarial survival of 89% in high-risk patients and 98% in low-risk patients.
If severe calcification is obvious on angiography or ultrasound then debulking seems sensible. The data suggest that directional coronary atherectomy alone or with stenting may be associated with reduced restenosis rates.
The use of glycoprotein IIb/IIIa inhibitors and drug-eluting stents may further improve the outlook for patients with LMCA stenosis.