The assessment of ischaemic burden: thoughts on definition and quantification

Abstract

The most recent guidelines recommend some proof of ischaemia before invasive angiography or revascularization.1 This is based on multiple outcome studies, mainly from SPECT perfusion imaging,2 but also from stress echocardiography,3 or cardiovascular magnetic resonance (CMR) imaging either using adenosine stress first pass perfusion or dobutamine stress wall motion analysis.4,5 The majority of these studies show that patients without ischaemia have an excellent prognosis, while those with some grade of ischaemia have more events. Using invasive pressure measurements in the coronary arteries (FFR) to guide revascularization has convincingly demonstrated that patients without proof of ischaemia should not be revascularized.6 There is less data on the benefit of revascularizing patients with ischaemia, but there is increasing evidence that patients should be guided by the amount, rather than the pure presence of ischaemia.7 Most of these data stems from SPECT studies either assessing outcome from retrospective data or subgroup analyses in prospective trials. There is no prospective randomized trial assessing the amount of ischaemia a patient can tolerate without increasing the likelihood for a cardiac event or prospective randomized data on the benefit of revascularization in stable angina. Thus, the assessment and quantification of ischaemic …