Patient stratification in left main coronary artery disease--rationale from a contemporary perspective

Coronary artery disease involving the left main stem is of prognostic relevance. Current guidelines in the United States and Europe provide Class I recommendation for surgical revascularization in these patients (Level of evidence A). The guidelines are based on data from the Veterans Administration Cooperative Study, the European Coronary Surgery Study and the registry arm of the Coronary Artery Surgery Study - all trials dating back to the 1970s. Since then, no further randomized trials have addressed treatment strategies and associated outcomes in this patient subgroup, despite major advances in the treatment of coronary artery disease. In non-left main coronary artery disease current guidelines demand objective proof of ischemia prior to performing angioplasty or surgery. However, this concept has not been applied with respect to prognostic relevance in left main coronary artery disease in which case angiographic criteria remain the basis for treatment recommendations. Recently, several groups have investigated whether patient stratification to surgical or non-surgical therapy can be done safely according to the status of inducible ischemia on the basis of intracoronary pressure measurements. In this article, the characteristics and limitations of the three major trials will be reviewed and the validity and transferability of these data with respect to current clinical practice will be examined from a contemporary perspective. Furthermore, it will be discussed how recent data on functional and morphologic lesion assessment of left main disease by intracoronary pressure measurements and intravascular ultrasound may contribute to improved characterization of these patients and their respective treatment recommendations.