SPC365

A preliminary analysis regarding Functional Mitral Regurgitation grading with Echocardiography and CMR: in search of similarities and resolving discordances.

Session: Comunicações Orais (Sessão 3) - Doença valvular
Speaker: Sérgio Maltês

Congress: CPC 2022
Topic: F. Valvular, Myocardial, Pericardial, Pulmonary, Congenital Heart Disease
Theme: 15. Valvular Heart Disease
Subtheme: 15.3 Valvular Heart Disease – Diagnostic Methods
Session Type: Comunicações Orais
FP Number: ---
Authors: Sérgio Maltês; Maria Rita Lima; Rita Reis Santos; Pedro Freitas; Pedro md Lopes; Liliana Marta; Sara Guerreiro; João Abecasis; António Ferreira; Regina Ribeiras; Maria João Andrade; Miguel Mendes

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><u>Background</u>: Functional mitral regurgitation (fMR) severity grading by 2D transthoracic echocardiography (TTE) can be a complex task, especially in patients where PISA assumptions are not met (eg. non-circular orifice or multiple jets). Cardiac magnetic resonance (CMR) can provide further insight on the hemodynamic burden of fMR by accurately determining mitral regurgitant fraction (RegFrac). Our goal was to investigate the concordance and disagreement between the two modalities in assessing fMR.</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><u>Methodology</u><span style="color:#222222">: Single-center prospective study of fMR patients performing same-day TTE and CMR from February to December 2021. MR severity was classified according to 2020 ACC consensus: grade I (mild; EROA &lt; 0.20cm<sup>2</sup>), grade II (moderate; EROA 0.20-0.29cm<sup>2</sup>), grade III (moderate-to-severe; EROA 0.30-0.39cm<sup>2</sup>) and grade IV (severe; EROA &ge; 0.40cm<sup>2</sup>). MR assessment by CMR was determined through regurgitant volume (RVol) and RegFrac quantification. A RegFrac </span>&ge;<span style="color:black">35% (recently shown as the best cut-off for prognostication) was considered hemodynamically significant.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><u><span style="color:#222222">Results</span></u><span style="color:#222222">: A total of&nbsp;36&nbsp;patients were included (age&nbsp;65 &plusmn; 14y; 74% male; mean left ventricle [LV] ejection fraction by TTE and CMR 35 &plusmn; 13% and 34 &plusmn; 11%, respectively). Mean RVol and EROA by TTE were 28 &plusmn; 11mL and 0.18 &plusmn; 0.8cm<sup>2</sup>. Mean RVol and Regfrac by CMR were 20 &plusmn; 13mL and 25 &plusmn; 12%, respectively. A moderate correlation between RVol by TTE and CMR was found (Pearson&rsquo;s R 0.58, p=0.001). According to TTE, there were 20 patients (56%) with grade I fMR, 12 patients (33%) with grade II fMR and 4 patients (11%) with grade III fMR. All patients considered to have mild (grade I) fMR by TTE had a RegFrac &lt;35% at CMR. However, amongst those with moderate and moderate-to-severe (grades II and III) fMR, there were 8 patients (50%) with hemodynamic significant fMR (RegFrac </span>&ge;35%)<span style="color:#222222"> at CMR &ndash; see figure 1.</span> <span style="color:black">Those with RegFrac </span>&ge;<span style="color:black">35% by CMR had higher indexed LV diastolic (165 </span><span style="color:#222222">&plusmn; 24 </span><span style="color:black">vs 139 </span><span style="color:#222222">&plusmn; 48</span><span style="color:black">mL</span><span style="color:#222222">/m<sup>2</sup></span><span style="color:black">) and systolic (116 </span><span style="color:#222222">&plusmn; 31</span><span style="color:black"> vs 95 </span><span style="color:#222222">&plusmn; 48</span><span style="color:black">mL</span><span style="color:#222222">/m<sup>2</sup></span><span style="color:black">) volumes and higher pulmonary artery systolic pressures (48 </span><span style="color:#222222">&plusmn; 14 </span><span style="color:black">vs 41 </span><span style="color:#222222">&plusmn; 16</span><span style="color:black">mmHg) when compared with patients whose RegFrac was &lt;35%</span>, &nbsp;even though <span style="color:black">statistically significance was not reached.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="background-color:white"><span style="font-family:Calibri,sans-serif"><u><span style="color:#222222">Conclusion</span></u><span style="color:#222222">: Using the criterion of RegFrac </span>&ge;<span style="color:black">35%, </span><span style="color:#222222">CMR re-classifies (half for each side) the patients with moderate and moderate-to-severe regurgitations by TTE. Recognizing, overcoming and resolving the disagreements between the techniques is the way forward to reach excellence.</span></span></span></span></p>