P1294 Distribution of infective lesions detected with radiolabeled leucocyte scintigraphy in carriers of various types of cardiac implantable electronic devices
Authors: Holcman K , Rubis P , Malecka B , Zabek A , Szot W , Boczar K , Lesniak-Sobelga A , Hlawaty M , Wisniowska-Smialek S , Stepien A , Podolec P , Kostkiewicz M 
Published: January 2020

Abstract

Funding Acknowledgements
Grant from the Jagiellonian University Medical College (K/DSC/004383)

Background
The rate of cardiac device-related infective endocarditis (CDRIE) is increasing disproportionately to the rising rate of device implantations. Hybrid technique of single photon emission tomography and computed tomography with technetium99m-hexamethylpropyleneamine oxime–labeled autologous leukocytes (99mTc-HMPAO-SPECT/CT) is a developing technique in patients with suspected endocarditis.

Purpose
The aim of this study was to evaluate distribution of both intracardiac and extracardiac inflammatory lesions detected with 99mTc-HMPAO-SPECT/CT in patients with suspected CDRIE depending on the type of carried cardiac implantable electronic device (CIED).

Methods
During years 2015-2018, we prospectively enrolled 103 consecutive patients with suspected CDRIE (70 males, 61 ± 18 y.o.). Patients undergone evaluation according to current ESC guidelines and subsequently 99mTc-HMPAO-SPECT/CT. Scans were classified as positive in the presence of abnormal tracer uptake involving cardiac or/and intravascular sections of device electrodes. Patients were divided to group 1 with implanted pacemakers (61 patients) and group 2 including 42 carriers of either an implantable cardioverter-defibrillator (ICD) or a cardiac resynchronization therapy device (CRT).

Results
Overall, in group 2 there was a higher prevalence of diabetes mellitus, coronary artery disease and heart failure (p &lt; 0.05). Moreover, group 2 had worse functional status with higher NYHA class (2.8 ± 0.9 vs. 1.7 ± 1, p = 0.001), NT-proBNP levels (5027 ± 5813 vs. 2320 ± 4279, p = 0.0004) and lower left ventricle ejection fraction (29 ± 12 vs. 54 ± 13, p = 0.0001). Both groups had comparable values of C-reactive protein, procalcitonin and white blood cells (p &gt; 0.05). The mean time since device implantation was 3.4 ± 3.8 years and on average patients had 1.9 implanted electrodes. Patients from group 2 presented more often with 99mTc-HMPAO-SPECT/CT positive for CDRIE (45% vs. 26%, p = 0.045). Frequency of lesions consistent with infection localized within the intravascular section of the electrode and the CIED lodge did not differ between groups (p &gt; 0.05). However, inflammatory foci in the vicinity of the intracardiac portion of the electrode were detected more often in group 2 (43% vs. 21%, p = 0.019). Overall, extracardiac inflammatory foci were found in 34% of patients, with most common localization in the gastrointestinal tract (13%) and musculoskeletal system (8%). Both prevalence and localization of extracardiac foci did not differ between groups (39% vs. 24%, p = 0.16).

Conclusions
Prevalence and localization of intracardiac inflammatory foci typical for CDRIE detected with 99mTc-HMPAO-SPECT/CT is different in patients with various types of CIEDs. Patients with implanted ICD or CRT have worse functional status and present more frequently with radiotracer uptake typical for CDRIE in 99mTc-HMPAO-SPECT/CT. Distribution of extracardiac inflammatory lesions does not differ between groups.