Cuantificación absoluta de la captación miocárdica de 99mTc-DPD en pacientes con amiloidosis cardiaca por depósitos de transtiretina (ATTR)

Purpose

To determine the diagnostic contribution of the absolute quantification of the myocardial deposit of ^99mTc-DPD in patients with cardiac amyloidosis due to transthyretin deposits (ATTR).

Materials and methods

SPECT/CT was performed on 41 patients with positive scintigraphic results for ATTR cardiac amyloidosis. The patients were divided into two groups (Perugini grades 2 and 3) and the SUVmax at the level of the bone and both ventricles and the percentage of dose calculated in these areas were calculated. Student's t-test was used to compare results and the area under the curve (AUC) was calculated to assess differential efficacy and establish discriminatory cut-off points between both groups of patients.

Results

Statistically significant differences were observed in all the study variables, with the exception of SUVmax bone. The differences with the greatest statistical power were observed in the variables SUVmax_RV and the percentage of dose in both ventricles (P < .001). The cut-off point obtained for the variable SUVmax_LV was 8.620 (sensitivity 87.9% and specificity 100%; AUC: 0.966), while that of the variable SUVmax_RV was 6.195 (sensitivity 81.8% and specificity 100%; AUC: 0.955).

Conclusions

The absolute quantification of myocardial uptake of ^99mTc-DPD in the SPECT/CT images of patients with suspected cardiac amyloidosis due to transthyretin deposits represents a new diagnostic tool that allows an adequate classification of patients, according to the visual grading scale of Perugini.