Abstract 12163: Prognostic Value of Stress Perfusion Computed Tomography in Comparison With Coronary Computed Tomographic Angiography in Patients With Known or Suspected Coronary Artery Disease

Abstract

Introduction: Contrast enhanced computed tomography (CT) with vasodilator stress can provide comprehensive assessment of coronary arterial stenosis and myocardial ischemia. However, no data are available regarding the prognostic value of stress perfusion CT examinations. We sought to determine whether stress perfusion CT has incremental prognostic value over coronary computed tomographic angiography (CCTA) in patients with known or suspected coronary artery disease (CAD).

Methods: We studied 114 subjects (76 men, age 66 ± 9 years) with known or suspected CAD who underwent stress perfusion CT and rest CCTA using 320 detector-row CT. CT images were visually analyzed by two blinded observers. Patients were followed up for the occurrence of cardiac events (cardiac death, nonfatal myocardial infarction, unstable angina requiring hospitalization, or revascularization > 3 months after the CT examination).

Results: During a median follow-up of 12 months, 8 cardiac events (1 cardiac death, 2 unstable angina, and 5 revascularizations) occurred. The annualized event rate for obstructive CAD (≧50% diameter stenosis, n=57) versus none or non-obstructive CAD (n=57) on CCTA was 9.5% versus 3.7% (P=0.03). On combined assessment of CCTA and stress perfusion CT, an excellent prognosis was noted in patients without obstructive CAD or perfusion defects with an annualized event rate of 0%, when compared with those with both obstructive CAD and perfusion defects (12.2%, P=0.005). Presence of perfusion defect was a significant predictor of cardiac events with an incremental prognostic value to CCTA (cox regression analysis, hazard ratio, 7.7; 95% confidence interval, 1.45-40.5; P=0.02).

Conclusion: The study result indicated that stress perfusion CT has additional value to CCTA by identifying patients at higher risk for subsequent events. Combined anatomical and functional assessment by CT may allow improved risk stratification in patients with known or suspected CAD.