Abstract
1725
Objectives To investigate if any correlation exits between post stress fall in the LVEF and the reversibility of the perfusion defects in patients undergoing myocardial perfusion scintigarphy (MPS).
Methods A total of 137 patients who underwent myocardial perfusion MPS using Tc99m tetrofosmin as radiotracer were evaluated retrospectively. Automated LV function analysis software was used for calculation of post stress and rest LVEF from which Δ LVEF was calculated (Post stress LVEF - Rest LVEF). Summed stress scores, summed rest scores and summed difference scores were calculated for each patient by 2 experienced nuclear medicine physicians.
Results Of the 137 patients, 64 underwent adenosine stress, 22 dobutamine stress and 51 exercise (Treadmill) MPS. No correlation was observed between Δ LVEF and sum difference score (-0.05217) and summed stress score (-0.13509). Post stress LVEF was found to be negatively correlated to the summed stress score (-0.69278) whereas no significant correlation was observed between post stress LVEF and summed difference score (-0.14012). Negative correlation was observed between post stress LVEF and summed stress scores in patients who underwent adenosine stress MPS (-0.76063), exercise MPS (-0.58941) and dobutamine MPS (-0.65475). In patients undergoing dobutamine MPS negative correlation was observed between Δ LVEF and Summed Difference Score (-0.4006), between Δ LVEF and Summed Stress Scores (-0.67526).
Conclusions As a whole, fall in post stress LVEF is associated with more severe perfusion defects (highest with adenosine stress); however, the worsening of LVEF by stress is not correlated to the reversibility of the perfusion defects on myocardial perfusion imaging. In case of dobutamine stress whenever there is fall in LVEF post stress higher severity of defects is noted in these patients and a subset of these patients show higher reversibility. With further follow-up this data can be used in the prognostication of the patients.