Radiomic phenotype of epicardial adipose tissue in the prognosis of atrial fibrillation recurrence after catheter ablation in patients with lone atrial fibrillation.

Background: Epicardial adipose tissue (EAT) has been considered as one of the probable triggers of atrial fibrillation (AF). CT-rediomics is a perspective noninvasive method of assessment of EAT. We evaluate the radiomic phenotype of EAT in patients with lone AF in the prognosis of AF recurrence after catheter ablation. Methods: A total of 43 patients with lone AF referred for CA and 20 out-hospital patients without arrhythmia underwent multidetector computed tomography coronary angiography. Segmentation of EAT and extraction radiomic features were performed on calcium scoring series using by 3D-Slicer. Clinical follow-up was performed for 12 months period after the CA. Results: EAT in patients with lone AF had a distinct radiomic phenotype. Thus, 45 of 93 calculated radiomic features, volume and attenuation of EAT were significantly different between patients with lone AF and persons without any arrhythmia. In addition, 17 radiomic features were significantly different in subgroups with and without AF recurrence. Multivariate regression analysis demonstrated that only gray level nonuniformity normalized (GLSZM) was an independent predictor of AF recurrence (OR 1.0027, 95%CI 1.0009-1.0044, p = 0.002). ROC analysis data showed that GLSZM >1227.4 indicates high probability of AF recurrence during 12 months (sensitivity 89.4%, specificity 70.8%, AUC: 0.809; p = 0.001). Conclusion: The radiomic parameter GLSZM is associated with late AF recurrence after CA in patients with lone AF. In current study GLSZM was a stronger predictor of lone AF recurrence in multivariate analysis comparing with other established risk factors and EAT volume and attenuation.

The relationship between global cardiac and regional left atrial sympathetic innervation and epicardial fat in patients with atrial fibrillation.

AIM: To investigate the relationship between epicardial adipose tissue (EAT) volume and distribution and the parameters of global cardiac and regional left atrial (LA) sympathetic activity in patients with atrial fibrillation (AF). METHODS AND RESULTS: The data of the 45 consecutive patients scheduled for an index catheter ablation (CA) for AF were analyzed. Total and peri-atrial EAT volumes were measured by cardiac CT. Parameters of global cardiac sympathetic activity and discrete sympathetic regions around LA were assessed by 123I-mIBG SPECT/CT. The patients were followed up for AF recurrences assessment during 12 months after CA. A total of 133 (mean per patient 2.96 ± 1.07) discrete 123I-mIBG uptake areas (DUAs), corresponding to typical anatomical locations of LA ganglionated plexi (GP), were identified. Peri-atrial EAT volume was associated with the number of DUAs (regression estimate, 5.1 [95% CI, 0.3-9.9], p = 0.03). There was no statistically significant association between either total or peri-atrial EAT volumes and risks of AF recurrence. The washout rate (WR) was associated with reduced risk of AF recurrence (HR = 0.95; 95% CI 0.92-0.99; p = 0.01), while left ventricular (LV) myocardium 123I-mIBG summed defect score (SDS) was linked to increased hazards of AF recurrence (HR = 1.04; 95% CI 1.01-1.08; p = 0.03). CONCLUSION: Peri-atrial EAT volume is associated with regions of sympathetic activity corresponding to typical anatomical locations of LA GP. The WR was associated with reduced risk of AF recurrence while LV myocardial SDS was linked to increased hazards of AF recurrence.

The possible role of nuclear imaging in assessment of the cardiac resynchronization therapy effectiveness in patients with moderate heart failure.

BACKGROUND: The aim of the study was to elucidate the role of nuclear medicine imaging in the selection of candidates for cardiac resynchronization therapy (CRT) and in the evaluation of CRT effectiveness METHODS: We studied 28 patients (19 male and 9 female) with dilated cardiomyopathy (DCM) and heart failure (HF). Before implantation of CRT device, all patients underwent SPECT with (99m)Tc-MIBI at rest to evaluate the myocardial perfusion, (123)I-BMIPP to evaluate the myocardial metabolism, and gated cardiac blood-pool SPECT (GBPS) to assess the myocardial contractile function. Following CRT, all patients were examined with 99mTc-MIBI SPECT and GBPS 12 ± 3 months after the intervention. RESULTS: All patients after CRT were divided into three groups. The first group included 10 patients with LVEF increased by more than 10 % (hyperresponders), the 2nd group included 11 patients with an increase in EF of more than 5 % but less than 10 % (responders) and third group consisted of 7 males whose LVEF remained unchanged or worsened compared with pre-operative values (nonresponders). Prior to CRT, no statistically significant differences were found between groups in hemodynamic parameters (EF, EDV, ESV, SV), intra- and interventricular dyssynchrony, as well as in the midsize of perfusion defects. Following long-term CRT, we found increase in LVEF and decrease in average size of perfusion defects in groups of hyperresponders and responders (p < 0.05). Results of SPECT with (123)I-BMIPP, performed prior to CRT, showed that nonresponders had more pronounced disturbance of myocardial metabolism compared with the group of hyperresponders (20 vs. 14.7 %, p < 0.05). CONCLUSION: The radionuclide methods can be used as possible indicators in the evaluation effectiveness and selection of candidates on the CRT.