Abstract 13913: Value of Ischemia and Coronary Anatomy for Prognosis and Guiding Revascularization Among Patients With Stable Ischemic Heart Disease

Aims: To assess the value of ischemia versus coronary anatomy for prognosis and to guide revascularization. Methods: A total of 1764 patients who had rest-stress SPECT MPI and angiography (invasive or CT) were prospectively enrolled and followed for cardiac death/non-fatal MI. CAD prognostic index (CADPI) was used to quantify extent and severity of angiographic disease. Prognostic value was assessed using Cox models, adjusted for pre-test risk, known CAD, stressor, LVEF, %ischemia and infarct, CADPI, early (90 day) revascularization. Incremental prognostic value was evaluated using net reclassification indices (NRI). Results: Mean age was 69.7±9.5 years, 24.4% were women and 29.3% had known CAD. Ischemia was present in 90.9%; >10% in 28.4%. Non-obstructive, single, and multi-vessel disease was present in 256 (14.5%), 772 (43.8%) and 736 (41.7%) respectively. Early revascularization occurred in 579 (32.8%). Cardiac death/MI occurred in 148 (8.4%) over 4.6 year median follow-up. Both % ischemia and CADPI provided incremental prognostic value over pre-test clinical risk (p<0.001, Table ). In a model containing both ischemia and anatomy, ischemia was prognostic (HR per 1% ↑=1.06, 95% CI:1.02, 1.10,p=0.02), but CADPI was not (HR=1.01 (1.00, 1.02),p=0.07). Early revascularization modified the risk associated with %ischemia (interaction p=0.003, Figure ), but not with CADPI (interaction p=0.6). % Ischemia and SPECT variables added incremental prognostic value over clinical risk and CADPI (NRI=20.3%, 95%CI: 9%, 32%, p=0.01); however CADPI was not incrementally prognostic over pre-test risk, %ischemia and SPECT variables (NRI=3.1%, 95% CI: -5%, 15%, p=0.21; Table ). Conclusion: Ischemic burden provides independent and incremental prognostic value beyond CAD anatomy and identifies patients who benefit from early revascularization. Anatomic extent of disease has limited incremental benefit for prognosis and guiding revascularization beyond ischemia.