Referral to coronary angiography post myocardial perfusion imaging

Abstract

Introduction: The current guidelines for CAD suggest that patients with moderate to severe ischemia should be referred for angiography and possible revascularization, while patients with mild ischemia can be safely treated medically. These recommendations are currently being tested in the ISCHEMIA trial. It is unclear how often patients with moderate to severe ischemia are referred to coronary angiography. The aim of this study is to identify the rate and predictors of referral to coronary angiography post MPI. Methodology: A retrospective cohort study included patients with suspected or known CAD who were referred to PET-CT imaging MPI due various clinical indications between May 2011 and March 2017. Ischemic burden was measured by the sum difference score. Moderate to severe ischemia was defined by summed stress score more than 7. Results: A total of 5060 patients were included. Approximately, one third of patients had prior coronary disease. The prevalence and extent of ischemia was higher among patients with previous coronary disease. Chest pain or shortness of breath was the most common indication for referral to MPI. Patients who had severe ischemia, nearly 70% of them were referred to coronary angiography within 90 days and 76.6% were referred to coronary angiography within one year. However patients with moderate ischemia were much less often referred to coronary angiography and less than half of these patients were referred to coronary angiography within 90 days. The independent predictors of referral to coronary angiography within 90 days among all patients were age, CAD, transient ischemic dilation and presence and degree of ischemia. Conclusion: This study found that the increase in patient’s age, Summed Different Score, Transient Ischemic Dilation, ischemia group, and having CAD can predict an increased in the coronary angiography referral, and CVA is a protective factor for referral to coronary angiography