PURPOSE:To compare measurement of left ventricular ejection fraction (LVEF) by single photon computed tomographic myocardial perfusion imaging (MPI) versus coronary computed tomography angiography (CTA) in the same patients.
METHODS:MPI and CTA were performed in 292 patients because of chest pain or dyspnea a mean of 18 days between the 2 tests. Of the 292 MPI tests, 212 (73%) were sestamibi exercise stress tests, 78 (26%) were adenosine or dipyridamole sestamibi stress tests, and 2 (1%) were dobutamine sestamibi stress tests. The patients included 178 men and 114 women, mean age 66 ± 11 years.
RESULTS:The mean LVEF was 61 ± 12% for the MPI tests and 65 ± 11% for CTA (p <0.001). The LVEF was 50% or higher in 250 of 292 patients (86%) with MPI testing and in 266 of 292 patients (91%) with CTA (p <0.05). The LVEF was 36–49% in 31 of 292 patients (11%) with MPI testing and in 22 of 292 patients (8%) with CTA ( p not significant). The LVEF was 35% or less in 11 of 292 patients (4%) with MPI testing and in 4 of 292 patients (1%) with CTA (p not significant). Pearson correlation coefficient was R=0.67, p<0.001. A Bland-Altman plot showed that the upper and lower limits of agreement with 95% confidence interval were 38.5% and minus 22.5%, respectively, with 12 of 292 patients (4%) outside the 2-SD limits.
CONCLUSION:The resting LVEF is significantly higher in patients measured by CTA than in patients measured by stress testing when both tests are performed in the same patients.
CLINICAL IMPLICATIONS:These data clearly indicate in a large group of patients with known or suspected coronary artery disease in which measurements of LVEF by CTA and by MPI were performed an average of 18 days between the 2 tests that the LVEF is significantly higher when measured by CTA than when measured by MPI. LVEF values are not interchangeable between different methods of measurement.
DISCLOSURE:Archana Rajdev, No Financial Disclosure Information; No Product/Research Disclosure Information