SPC365

Phase analysis of single-photon emission computerized tomography myocardial perfusion imaging (SPECT-MPI): closer to the root of left bundle branch block cardiomyopathy?

Session: Sessão de Posters 15 - Patologias diversas em Cardiologia
Speaker: Catarina Amaral Marques

Congress: CPC 2024
Topic: P. Other
Theme: 37. Miscellanea
Subtheme: 03.4 Nuclear Imaging
Session Type: Cartazes
FP Number: ---
Authors: Catarina Amaral Marques; Paula Soeiro; André Cabrita; Ana Isabel Pinho; Luís Santos; Cátia Oliveira; Helena Santos Moreira; Pedro Palma; Miguel Rocha; Rui André Rodrigues; Teresa Faria; Elisabete Martins

<p style="text-align:justify"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000"><strong>Introduction:</strong> Increasing relevance has been addressed to the need of a more comprehensive understanding of left ventricular dyssynchrony (LVdy). This is particularly true for patients (pts) with idiopathic left bundle branch block (iLBBB) and LBBB-cardiomyopathy (LBBB-CMP). LVdy markers are needed to predict LV dysfunction (LVD) development in iLBBB carriers, as well as to better select LBBB-CMP pts for cardiac resynchronization therapy (CRT). In this context, phase analysis (PA) has emerged as a promising tool, based on single-photon emission computerized tomography myocardial perfusion imaging (SPECT MPI). Our aim was to describe and explore the potential role of PA in a cohort of iLBBB and LBBB-CMP pts.&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span></span></span></p>

<p style="text-align:justify"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000"><strong>Methods:</strong> Tertiary care centre retrospective study of pts with iLBBB and LBBB-CMP who underwent gated SPECT MPI studies between 2011 to 2017 (n=30). The exams were performed according to a stress/rest protocol acquiring images with Tc 99m-tetrofosmin. Clinical and echocardiographic parameters were collected. Data was based on pts&rsquo; review of medical records and SPECT results, namely PA (SyncToolTM software) for LVdy evaluation. </span></span></span></p>

<p style="text-align:justify"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000"><strong>Results:</strong> Thirty pts were included: 40% female; mean age at first-ever LBBB report was 59 years-old; 43% and 57% were iLBBB carriers and LBBB-CMP pts, respectively. Median follow-up (FU) time was 8 years. Regarding SPECT data: median LV ejection fraction (LVEF) was 54%; 31% presented LVD; overall, pts presented with fixed small/moderate perfusion defects, mainly in the left anterior descending artery (LAD) territory (median summed stress score (SSS) and summed difference (SDS) of 11 and 1, respectively; median LAD-SSS and LAD-SDS of 8 and 1, respectively). &nbsp;</span></span></span></p>

<p style="text-align:justify"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000">Focusing PA data, histogram standard deviation (HSD) and bandwidth (HBD), as well as end-systolic (ES) and end-diastolic (ED) eccentricity values were evaluated (Table 1). ES and ED eccentricity values range between 0 and 1; lower values reflect a more normal/elliptical LV shape. All HSD and HBD summary values were higher than the described for presence of significant LVdy (HSD&gt;15.3&deg;; HBD&gt;35&deg;). &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span></span></span></p>

<p style="text-align:justify"><span style="font-size:medium"><span style="font-family:Calibri,sans-serif"><span style="color:#000000">Several PA variables pointed to significantly worse LVdy in LBBB-CMP pts (vs iLBBB carriers), as well as in pts who developed worse LVD during the FU. LVdy was also significantly worse in LBBB-CMP pts who later underwent CRT implantation (Table 1). </span></span></span></p>

<p><strong><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif">Conclusion:</span></span></strong><span style="font-size:12pt"><span style="color:#000000"><span style="font-family:Calibri,sans-serif"> Our SPECT results of a cohort of iLBBB and LBBB-CMP pts showed the typical perfusion defects associated with LBBB, as well as significant LVdy. Interestingly, our findings raise the question about a possible PA role in predicting LVD development in iLBBB pts, as well as identifying pts with higher risk for worse LVD development. It is also worth noting that higher LVdy was present in pts who later needed to implant CRT, suggesting a potential role of PA to further improve current CRT selection criteria. Additional and larger studies are needed to explore PA full potential.&nbsp; </span></span></span></p>