SPC365

Understanding the complex phenotype of hypertrophic cardiomyopathy: the role of systemic inflammation

Session: Posters (Sessão 4 - Écran 7) - Miocardiopatias hereditárias
Speaker: Inês Miranda

Congress: CPC 2023
Topic: F. Valvular, Myocardial, Pericardial, Pulmonary, Congenital Heart Disease
Theme: 17. Myocardial Disease
Subtheme: 17.7 Myocardial Disease - Other
Session Type: Pósters Electrónicos
FP Number: ---
Authors: Inês Pereira De Miranda; Filipa Gerardo; Mariana Passos; Inês Fialho; Carolina Mateus; Joana Lima Lopes; Marco Beringuilho; David Roque; Carlos Morais; João Bicho Augusto

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Arial"><span style="color:#000000"><strong>Background: </strong></span></span></span><span style="font-size:11pt"><span style="font-family:Arial"><span style="color:#000000">The pathophysiology of hypertrophic cardiomyopathy (HCM) involves a number of mechanisms that include endothelial dysfunction and myocardial fibrosis. Myocyte death can lead to local and systemic inflammation and perpetuate a positive feedback loop of necrosis/apoptosis and inflammation.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Arial"><span style="color:#000000"><strong>Objective: </strong></span></span></span><span style="font-size:11pt"><span style="font-family:Arial"><span style="color:#000000">We sought associations between (1) local myocardial lesion (troponin) and systemic inflammation in HCM, and (2) the effects of a systemic and local inflammation model to explain the phenotypic imaging complexity of HCM.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:'Times New Roman'"><span style="color:#000000"><strong>&nbsp;</strong></span></span></span><span style="font-size:11pt"><span style="font-family:Arial"><span style="color:#000000"><strong>Methods: </strong></span></span></span><span style="font-size:11pt"><span style="font-family:Arial"><span style="color:#000000">We included all consecutive HCM patients seen at our institution in a 10-year period. We collected data regarding demographic and clinical aspects, as well as systemic inflammation markers such as erythrocyte sedimentation rate (ESR), C-related protein, ferritin and albumin (the latter an inverse/negative marker of inflammation). High-sensitivity troponin levels were also measured, reflecting local inflammation/myocyte death. Finally, we analyzed the structural phenotype of HCM using echocardiography and cardiac MRI imaging. Multivariable regression models to predict the imaging phenotype were built using a backwards conditional input method.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Arial"><span style="color:#000000"><strong>Results: </strong></span></span></span><span style="font-size:11pt"><span style="font-family:Arial"><span style="color:#000000">A total of 106 HCM patients were included, 52 male (49%), with a mean age of 70&plusmn;16 years. No associations between inflammatory markers and left ventricular (LV) maximum wall thickness or LV mass were found. Among all systemic inflammation markers, only ESR showed a correlation trend with troponin (R=0.30, p=0.063). Multivariable regression models were consistent with a role of ferritin (systemic marker, beta coefficient 0.09 [0.03-0.15]], p=0.006) and troponin (local marker, beta coefficient 0.72 [0.19-1.24], p=0.014) on LV end-diastolic volume, with higher values of ferritin and troponin reflecting LV dilatation. Coincidentally, the same variables also generated the best prediction model for increased peak tricuspid regurgitation velocity (ferritin, beta 0.09 [95% CI 0.03-0.15], p=0.006, and troponin, beta 0.09 [95% CI 0.03-0.15], p=0.006)</span></span></span><span style="font-size:11pt"><span style="font-family:'Times New Roman'"><span style="color:#000000">.&nbsp;</span></span></span><span style="font-size:11pt"><span style="font-family:Arial"><span style="color:#000000">Ferritin was also consistent across all models to predict known markers of diastolic dysfunction: high septal e&rsquo; velocity (p=0.040), increased left atrial size (AP diameter, p=0.005) and peak tricuspid regurgitation velocity (p=0.006). No specific markers of myocardial fibrosis on cardiac MRI were found.</span></span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Arial"><span style="color:#000000"><strong>Conclusion: </strong></span></span></span><span style="font-size:11pt"><span style="font-family:Arial"><span style="color:#000000">Systemic inflammation, as measured by ferritin, is a marker of left ventricular relaxation impairment and LV dilatation in HCM patients, but not necessarily reflecting myocardial fibrosis. Inflammation is likely an early marker of disease and a potential target for treatment in HCM.</span></span></span></p>