SPC365

Microvascular dysfunction and myocardial fibrosis impact on left ventricular myocardial deformation in hypertrophic cardiomyopathy – per segment analysis by magnetic resonance imaging

Session: Comunicações Orais (Sessão 29) - Doenças do Miocárdio e Pericárdio 2 - Vários Tópicos
Speaker: Pedro Brás

Congress: CPC 2022
Topic: F. Valvular, Myocardial, Pericardial, Pulmonary, Congenital Heart Disease
Theme: 17. Myocardial Disease
Subtheme: 17.3 Myocardial Disease – Diagnostic Methods
Session Type: Comunicações Orais
FP Number: ---
Authors: Pedro Garcia Brás; Isabel Cardoso; Sílvia Aguiar Rosa; Boban Thomas; António Fiarresga; Miguel Mota Carmo; Gonçalo Branco; Ricardo Pereira; Mafalda Selas; Filipa Silva; Rui Cruz Ferreira; Luís Rocha Lopes

<p><span style="font-size:11pt"><span style="font-family:&quot;Calibri&quot;,sans-serif">Background: Left ventricular hypertrophy (LVH) and microvascular dysfunction are hallmarks of hypertrophic cardiomyopathy (HCM). We hypothesized that microvascular dysfunction contributes to LV myocardial deformation impairment. </span></span></p>

<p><span style="font-size:11pt"><span style="font-family:&quot;Calibri&quot;,sans-serif">Methods: Prospective evaluation of adult patients with HCM (patients with &ldquo;end-stage&rdquo; HCM, prior septal reduction therapy or epicardial coronary artery disease were excluded). All underwent a cardiac magnetic resonance (CMR) protocol (1.5-T), from which the following parameters were analysed: maximal LV wall thickness (MLVWT), T1 and T2 mapping, extracellular volume, late gadolinium enhancement (LGE) and stress perfusion assessment. Three-dimensional (3D) strain analysis was obtained by using feature-tracking from cine images. Results were stratified according to the <span style="background-color:white">16 American Heart Association segments. Multivariate regression analyses for longitudinal, circumferential and radial strain were performed.</span></span></span></p>

<p><span style="font-size:11pt"><span style="font-family:&quot;Calibri&quot;,sans-serif">Results: A total of 1200 myocardial segments were analysed (75 patients, <span style="color:black">63% male, age 54.6</span><span style="color:black">&plusmn;</span><span style="color:black">14.7 years) including </span><span style="color:black">61% with asymmetric septal LVH, 29% with apical LVH, 8% with concentric LVH, 28% exhibiting LV outflow tract obstruction Mean MLVWT was 20&plusmn;4.5mm.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:&quot;Calibri&quot;,sans-serif">Higher values of longitudinal strain (lower deformation) were found in segments with MLVWT &ge;15mm (&beta;-estimate: 2.31, 95% CI 0.91-3.70, p&lt;0.001) and in patients with obstructive HCM (&beta;-estimate: 2.44, 95% CI 1.15-3.72, p&lt;0.001]) (Table 1). No association was found between perfusion defects, LGE and longitudinal strain.</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:&quot;Calibri&quot;,sans-serif">Higher values of circumferential strain (lower deformation) were found in segments with MLVWT 12-14mm (&beta;-estimate: 2.31, 95% CI 1.36-3.25, p&lt;0.001), &ge;15mm (&beta;-estimate: 5.29, 95% CI 4.47-6.12, p&lt;0.001), with perfusion defects (&beta;-estimate: 2.75, 95% CI 2.0-3.5, p&lt;0.001), with LGE (&beta;-estimate: 2.49, 95% CI 1.77-3.22, p&lt;0.001) and in patients with obstructive HCM (&beta;-estimate: 1.25, 95% CI 0.44-2.06, p=0.003).</span></span></p>

<p><span style="font-size:11pt"><span style="font-family:&quot;Calibri&quot;,sans-serif">Lower radial strain values were found in segments with MLVWT 12-14mm (&beta;-estimate: -10.64, 95% CI -13.95 to -7.33, p&lt;0.001), MLVWT &ge;15mm (&beta;-estimate: -20.67, 95% CI -23.36 to -17.97, p&lt;0.001), with perfusion defects (&beta;-estimate: -10.60, 95% CI -13.08 to -8.13, p&lt;0.001), and with LGE (&beta;-estimate: -10.49, 95% CI &nbsp;-12.86 to -8.11) (Table 1).</span></span></p>

<p><span style="font-size:11pt"><span style="font-family:&quot;Calibri&quot;,sans-serif">Diabetes, hypertension, BMI &gt;25 kg/m<sup>2 </sup>and male gender were also associated with impaired myocardial deformation.</span></span><span style="font-size:11pt"><span style="font-family:&quot;Calibri&quot;,sans-serif"> No association was found between parametric mapping values and LV myocardial deformation. </span></span></p>

<p><span style="font-size:11pt"><span style="font-family:&quot;Calibri&quot;,sans-serif">Conclusion: In patients with HCM, 3D speckle tracking parameters for LV systolic function were particularly impaired in segments with LVH, microvascular dysfunction or fibrosis. LVH was associated with abnormal longitudinal, circumferential and radial strain while perfusion defects and LGE correlated with impaired circumferential strain and radial strain.</span></span></p>