Abstract
BackgroundThe ISCHEMIA trial is evaluating the impact of optimal medical therapy (OMT) versus OMT and revascularization among patients with moderate to severe ischemia. However, there is limited data on how patients with moderate or severe ischemia on stress testing are treated in contemporary medical practice.MethodsA cohort study that included patients with suspected or known CAD who were referred to PET-CT MPI imaging (positron emission tomography - Computed Tomography-myocardial perfusion imaging) for various clinical indications between May 2011 and March 2017. Demographic data and coronary artery disease risk factors were collected at the time of MPI. Moderate to severe ischemia was defined by summed difference score more than 7. Patients’ eligibility for the ISCHEMIA trial was studied.ResultsA total of 5,060 patients were included of which 3,195(63.1%), 449(8.9%), 537 (10.6%), 349(6.9%), 530(10.4%) had normal, scar but no ischemia, mild, moderate, or severe ischemia, respectively. Of the 879 patients with moderate to severe ischemia, 526 (59.8%) patients were referred to coronary angiography within 90 days while 353 (40.2%) patients were treated conservatively with medical therapy. Using Multivariate logistic regression analysis, the independent predictors of referral to coronary angiography within 90 days were age, prior CAD, the presence and degree of ischemia and transient ischemic dilation. Of the 879 patients with moderate to severe ischemia, only 295 patients (33.6%) had no exclusion criteria to the ISCHEMIA trial.ConclusionA significant proportion of patients with moderate to severe ischemia are being treated medically in contemporary medical practice. Only one third of these patients meet the inclusion criteria of the ISCHEMIA trial. This may limit the generalizability of the ISCHEMIA trial findings.