Abstract 2779: Stress Single Photon Emission Computed Tomography Predicts Mortality in Asymptomatic Patients (without Chest Pain Syndrome) with Moderate Coronary Heart Disease Risk
Background The ACCF/ASNC Appropriateness Criteria Report categorizes single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) as an uncertain indication for both the detection of coronary artery disease (CAD) and risk stratification in asymptomatic patients at moderate CAD risk (Framingham criteria). The goal of this study was to examine the diagnostic yield and prognostic ability of SPECT MPI in these patients.
Methods The Mayo Clinic Nuclear Cardiology database was used to identify 400 asymptomatic patients (66.3 ± 8.4 years, 67% men) without clinical evidence of CAD who were at moderate CAD risk and underwent 2-day stress SPECT MPI between March 1991 and June 1999. Stress SPECT images were categorized using the summed stress score (SSS). Mortality status was determined by a follow-up survey.
Results CAD risk factors included diabetes 29%, hypertension 58%, hyperlipidemia 60% and cigarette smoking 56%. Abnormal SPECT scans were present in 58%. SSS risk categories included low risk 62%, intermediate risk 21% and high risk 17%. Ten year survival by SSS risk categories (Figure 1⇓) was 58% for high risk scans (95% CI 42–79%), 67% intermediate risk (95% CI 53– 86%) and 87% low risk (95% CI 83–92%) including 90% (95% CI 85–95%) for patients with a normal SPECT scan (p < 0.001 by log rank).
Conclusions In this retrospectively identified group of asymptomatic patients at moderate CAD risk, stress SPECT MPI was effective for the detection and risk stratification of CAD. A majority of patients had abnormal SPECT scans. Annual mortality over 10 years was greater than 4% in patients with high risk scans versus 1% in patients with normal scans.