Nuclear myocardial perfusion imaging in stable angina pectoris

Every day physicians balance clinical information with medical test results when confronted with symptomatic patients. Sometimes they find themselves in an apparently contradicting situation in which a patient has persistent complaints while his or her medical tests are normal. In this issue of the Netherlands Heart Journal, Yokota et al. addressed this matter in the setting of stable angina pectoris [1]. The authors performed a retrospective analysis of all patients who had undergone nuclear myocardial perfusion imaging in their centre and selected those with a normal scan but with persistent or worsening complaints that compelled the treating physician to order an invasive angiogram. Out of more than 11,000 patients, 229 fulfilled the study criteria. The authors reported that in this highly selected group of patients a fairly high percentage (34%) had significant coronary artery disease despite a normal perfusion scan, which was defined as >50% stenosis in the left main coronary artery or >70% stenosis for other segments. In the majority of cases, it concerned single-vessel disease (60%), while only a minority (17%) had left main coronary artery disease or three-vessel disease. Coronary revascularisation was performed in 90% and most of them were free of symptoms after 7 years of follow-up. The authors found that older age, male sex, typical angina and previous PCI are independent predictors for the presence of severe stenosis on invasive angiography following a normal myocardial perfusion scan. As the study was conducted in a ‘pre-FFR era’ there was a low rate of invasive functional testing, which in part might explain the discordancy.