Myocardial perfusion imaging in patients with unprotected left main disease

BACKGROUND The management of patients with unprotected left main (LM) coronary artery disease remains challenging, with recent data casting a shadow of doubt on the safety of percutaneous coronary intervention. We aimed at describing the features of patients undergoing myocardial perfusion imaging (MPI) subsequently found to have LM disease. METHODS We queried our institutional database for subjects without prior revascularization or myocardial infarction (MI), who had undergone MPI followed by invasive coronary angiography within 6 months, comparing those with evidence of angiographically significant LM disease (i.e. diameter stenosis ≥50%) to those without significant coronary artery disease (CAD), or those with CAD not involving LM. Baseline, stress and imaging features were systematically collected and analyzed, and clinical outcomes (death, myocardial infarction, revascularization) sought. RESULTS We included a total of 74 patients with LM disease, which were compared with 70 without CAD, and 920 with significant CAD not involving LM. MPI was remarkably safe in all subjects, and significant differences were found for several features, but particularly so for ST change, rate pressure product, and left ventricular ejection fraction (all P