Abstract 18678: Symptoms Fail to Predict Ischemia and Cardiac Outcomes in Outpatient Diabetic Patients Referred for SPECT Myocardial Perfusion Imaging

Abstract

Introduction: Studies have shown a substantial prevalence of ischemic heart disease in asymptomatic diabetic patients. However, the relationship of symptoms to ischemia and events is unclear in the modern era of intensive medical management. We sought to identify the effect of symptoms on the prevalence of ischemia by SPECT myocardial perfusion imaging (MPI) and subsequent cardiac events in a cohort of outpatient, stable patients with diabetes referred for SPECT MPI.

Methods: The study cohort included 575 consecutive outpatients with diabetes who underwent quantitative, gated-SPECT MPI. Data was prospectively collected and compared using Chi-Square, Kaplan-Meier, and Cox proportional hazards analyses.

Results: The study population was at intermediate risk of coronary artery disease (CAD) or had known CAD (40.3%). There were no significant differences between the symptomatic patients and asymptomatic subgroup in the prevalence of ischemia (21.8% versus 22.3%, respectively, p=0.890) or significant (≥10%) left ventricular (LV) ischemia (5.1% versus 4.8%, respectively, p=0.876). Over a median 4.4 years of follow-up, the yearly rate of cardiac death/nonfatal myocardial infarction was moderate and similar between those with and without symptoms (2.3% versus 2.2%, p=0.854). Symptoms did not provide incremental prognostic benefit over clinical risk factors (p=0.230) in Cox modeling.

Conclusions: The presence of symptoms failed to predict any or significant ischemia or cardiac events in a consecutive cohort of stable, outpatient diabetic patients referred for SPECT MPI. These findings highlight the need for alternative and improved risk stratification strategies in diabetic patients.