CT angiography for evaluation of coronary artery disease in inner-city outpatients: an initial prospective comparison with stress myocardial perfusion imaging

Abstract

To evaluate the utility of CT coronary angiography (CTA) for demonstrating coronary artery disease in inner-city outpatients, we prospectively compared CTA with stress SPECT myocardial perfusion imaging in an ethnically diverse, gender balanced population. All patients gave written informed consent for this IRB approved, HIPAA compliant study. Sixty-one patients completed both CTA and SPECT. About 67% were ethnic minorities, 51% were women. A stenosis of >or=70% on CTA was considered positive. Results were compared with perfusion defects on SPECT and correlated with clinical endpoints (hospital admissions, cardiovascular events, coronary interventions and deaths). CTA and SPECT data were compared with results of coronary angiography, when performed. There was moderate global agreement of 79% (48/61) between CTA and SPECT, kappa = 0.483 (SE +/- 0.13, P = 0.0001). With SPECT as the reference standard, CTA had sensitivity of 73% (11/15), specificity of 80% (37/46), negative predictive value of 90% (37/41) and positive predictive value of 55% (11/20). Positive SPECT was associated with positive CTA, (P < 0.0001, OR = 22). Eleven (18%) underwent subsequent cardiac catheterization, which was positive in 91% (10/11). CTA and SPECT had positive predictive values of 90 and 83% compared with catheterization. This study lends preliminary evidence to support to the utility of CTA as an alternative modality for the evaluation of CAD in an ethnically diverse, gender balanced inner-city outpatient population. Similar to more homogenous groups, CTA had a high negative predictive value and demonstrated disease occult to SPECT. Further study is necessary to evaluate the impact of CTA on patient outcomes.