Prognostic value of multislice computed tomography and gated single-photon emission computed tomography in patients with suspected coronary artery disease.

OBJECTIVES: This study was designed to determine whether multislice computed tomography (MSCT) coronary angiography has incremental prognostic value over single-photon emission computed tomography myocardial perfusion imaging (MPI) in patients with suspected coronary artery disease (CAD).

BACKGROUND: Although MSCT is used for the detection of CAD in addition to MPI, its incremental prognostic value is unclear.

METHODS: In 541 patients (59% male, age 59 +/- 11 years) referred for further cardiac evaluation, both MSCT and MPI were performed. The following events were recorded: all-cause death, nonfatal infarction, and unstable angina requiring revascularization.

RESULTS: In the 517 (96%) patients with an interpretable MSCT, significant CAD (MSCT > or =50% stenosis) was detected in 158 (31%) patients, and abnormal perfusion (summed stress score [SSS]: > or =4) was observed in 168 (33%) patients. During follow-up (median 672 days; 25th, 75th percentile: 420, 896), an event occurred in 23 (5.2%) patients. After correction for baseline characteristics in a multivariate model, MSCT emerged as an independent predictor of events with an incremental prognostic value to MPI. The annualized hard event rate (all-cause mortality and nonfatal infarction) in patients with none or mild CAD (MSCT <50% stenosis) was 1.8% versus 4.8% in patients with significant CAD (MSCT > or =50% stenosis). A normal MPI (SSS <4) and abnormal MPI (SSS > or =4) were associated with an annualized hard event rate of 1.1% and 3.8%, respectively. Both MSCT and MPI were synergistic, and combined use resulted in significantly improved prediction (log-rank test p value <0.005).

CONCLUSIONS: MSCT is an independent predictor of events and provides incremental prognostic value to MPI. Combined anatomical and functional assessment may allow improved risk stratification.