Beneficial effect of coronary artery bypass grafting as assessed by quantitative gated single-photon emission computed tomography

Abstract

The development of quantitative gated single-photon emission computed tomography (SPECT) has enabled the assessment of left ventricular perfusion, function and wall thickness in a single examination. Accordingly, the present study used gated SPECT to assess the benefit of coronary artery bypass grafting (CABG) in patients with coronary artery disease; 47 of those patients were evaluated before and 5 months after CABG. As a result of coronary revascularization, a significant improvement was observed in global ejection fraction (50±12→53± 11%; p<0.05). In 107 revascularized territories, the average regional reversible defect score (0.8±0.5→0.2±0.3; p<0.0001), average regional perfusion score at rest (0.6±0.6→0.3±0.4; p<0.0001), average regional wall motion score (0.9±0.7→0.7±0.5; p<0.05), and end-diastolic wall thickness (8.1±1.3→8.6±1.5 mm; p<0.0005) all improved significantly. Even in 34 non-revascularized territories, the average regional reversible defect score (0.5±0.7→0.2±0.5; p<0.03), average regional wall motion score (0.8±1.1→0.5± 1.0; p<0.03) and end-diastolic wall thickness (8.0±1.4→9.1±2.Omm; p<0.03) all improved significantly. These results indicate that improvement in myocardial ischemia, hibernation and left ventricular function with CABG can be assessed in detail with gated SPECT.