Coronary arteriography in the diagnosis results and prognosis analysis of suspected coronary artery disease in patients with normal SPET myocardial perfusion imaging.

OBJECTIVE Anatomic coronary artery disease (CAD) can be determined by coronary angiography (CAG) in patients with normal stress single photon emission tomography (SPET) myocardial perfusion imaging (MPI). Coronary angiography results of patients with negative exercise MPI and the prognosis of these patients (CAG-diagnosed CAD vs. non-CAD) were investigated in the current study. SUBJECTS AND METHODS Suspected CAD patients who had SPET-MPI and subsequent CAG studies were retrospectively reviewed from May 2002 to November 2006. Siemens Diacam SPET and Siemens Ecam SPET γ-cameras were used for the examination of rest/exercise technetium-99m methoxy isobutyl isonitrile ((99m)Tc-MIBI) myocardial imaging. Coronary angiography was performed with Philips arura angiography machine by the standard Judkins method. RESULTS In all, 6598 patients underwent clinically indicated rest/exercise (99m)Tc-MIBI SPET-MPI, and 133 patients underwent CAG despite negative MPI. Thirty one patients were diagnosed with CAD by CAG. Most of these lesions (66%) were located in distal vessels and most of these patients (68%) had 1 vessel disease. Age (P<0.01), hypertension (P<0.01), typical angina pectoris (P<0.01), high pretest likelihood of CAD (P<0.001), exercise induced angina (P<0.05), positive exercise ECG (P<0.01), and transient enlargement of scintigraphic left ventricular size (P<0.05) were significantly different between non-CAD and CAD groups. After median follow-up time of 53 ± 18 months, annualized cardiac event rate was 0.9% and 0.2% in CAD and non-CAD group, respectively (χ² = 1.22, P=0.27). CONCLUSION In all, 23% of 133 patients in our study we confirmed anatomic CAD by CAG, despite negative findings in SPET-MPI. Several clinical, stress, and MPI findings could be potential predictors. However, similar to non-CAD group, the CAG diagnosed CAD patients negative (99m)Tc-MIBI SPET-MPI exercise test had a good prognosis with annualized cardiac event rate less than 1.0%.