Left ventricular function parameters in a Hispanic population: Comparison of planar and SPECT radionuclide ventriculography

Objectives LV function has major diagnostic and prognostic importance in CAD. The relationship between planar and SPECT 99mTc-RBC MUGA is well established. Overestimation of the LV ejection fraction by 7-10% in tomographic acquisition is most likely secondary to increased contrast resolution. Limited data is available comparing the diastolic function parameters between these methods. The goal of the study was to validate the LV function parameters in our Hispanic population and examine the potential gains from the transition to SPECT.

Methods Studies from 41 patients, available from 2009 and 2010, were retrospectively evaluated.

Results LVEF showed a good correlation between the acquisition techniques (r = 0.94) with an average difference of 3.8% from one method to the other. In terms of categorizing the results as normal or abnormal, this remained unchanged in 95% of the cases. Findings were statistically significant (p = 0.035). For the PFR, there was a moderate correlation between the techniques (r = 0.71), whereas the diagnosis remained unchanged in 89% of cases. The results were also statistically significant (p = 0.0004). Evaluation of the TPF values only demonstrated a weak correlation (r = 0.22) between the acquisition methods. Although the diagnosis remained the same in 68% of the cases, the results were not statistically significant (p = 0.089).

Conclusions Measurement of ventricular function with tomographic MUGA adds further benefit by improving contrast resolution, decreasing camera time, improving accuracy of interpretation and the overall reliability of the study. Systolic function results in our study were well below the 7-10% difference reported in the literature. Only a weak to moderate correlation was observed with the diastolic function parameters. Comparison with echocardiogram may be of benefit to evaluate which of these techniques results in more accurate diastolic function parameters