SPC365

Assessing Proportionate and Disproportionate Functional Mitral Regurgitation with individualized thresholds outperforms the risk stratification proposed by current guidelines

Session: CO 06 - Valvulopatias
Speaker: Pedro M. Lopes

Congress: CPC 2021
Topic: B. Imaging
Theme: 03. Imaging
Subtheme: 03.1 Echocardiography
Session Type: Comunicações Orais
FP Number: ---
Authors: Pedro M. Lopes; Francisco Albuquerque; Pedro Freitas; Francisco Gama; Eduarda Horta; Carla Reis; João Abecasis; Marisa Trabulo; António m. Ferreira; Carlos Aguiar; Manuel Canada; Regina Ribeiras; Miguel Mendes; Maria j. Andrade
<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">Background:</span></span></span></strong> </span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">The clinical application of the concept of Proportionate and Disproportionate Functional Mitral Regurgitation (FMR) has been limited by the lack of a simple way to assess it.<strong> </strong>The aim of our study was<strong> </strong>to evaluate the prognostic value of an individualized method of assessing FMR Proportionality and to compare it with current established guidelines.</span></span></span></span></span></p>

<p style="text-align:justify">&nbsp;</p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">Methods: </span></span></span></strong></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">Patients with at least mild FMR and reduced left ventricular ejection fraction (LVEF &lt;50%) under </span></span></span><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif">guideline-directed medical therapy were <span style="color:black">retrospectively identified at a single-center. Considering regurgitant fraction &ge;50% as the threshold for hemodynamically significant FMR, an individualized theoretical regurgitant volume (RegVol) </span>cut-off can be derived by a simple equation that accounts for <span style="color:black">LV dilation and dysfunction (Figure panel A). Accordingly, the difference between the measured RegVol and the individual theoretical RegVol cut-off can be used to categorize FMR proportionality as non-severe, proportionate or disproportionate (Figure panel B). The discriminative ability (area under the ROC curve &ndash; AUC) of FMR proportionality status was compared against the European and American guidelines. </span>Integrated discrimination improvement (IDI) was used to ascertain if FMR disproportionality improves individual risk stratification provided by both guidelines. <span style="color:black">The primary endpoint was all-cause mortality.</span></span></span></span></span></p>

<p style="text-align:justify">&nbsp;</p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">Results: </span></span></span></strong></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">A total of 572 patients (median age 70 years; 76% male) were included. </span></span></span><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif">Median LVEF <span style="color:black">was 35% (IQR 28-40) </span>and <span style="color:black">LVEDV was 169 ml (IQR 132-215). </span>Disproportionate FMR was present <span style="color:black">in 109 patients (19%), Proportionate FMR </span>in <span style="color:black">148 patients (26%) and Non-Severe FMR in 315 patients (55%).</span> <span style="color:black">During a median follow-up of 3.8 years (IQR&nbsp;1.8-6.2), 254 patients died. The unadjusted mortality incidence per 100 persons-year (black line, Figure panel C) and the survival probability (Figure panel D) worsened as the degree of FMR disproportionality increased. &nbsp;On multivariable analysis, disproportionate FMR remained independently associated with all-cause mortality (adjusted HR: 1.79; 95%CI: 1.25-2.55; <em>P</em>=0.001). The FMR proportionality concept showed greater discriminative power (AUC 0.64; 95%CI: 0.60-0.68) than the American (</span>AUC 0.58; 95%CI: 0.55-0.62; <em>P</em> for comparison &lt;0.001<span style="color:black">) and European guidelines (AUC</span> 0.58; 95%CI: 0.55-0.62; <em>P</em> for comparison &lt;0.001<span style="color:black">). When added to any of these guidelines, FMR proportionality also improved risk stratification by reclassifying patients into lower and higher risk subsets&nbsp;</span>(IDI = 0.037 [<em>P</em>&lt;0.001] and 0.034 [<em>P</em>&lt;0.001], respectively).</span></span></span></span></p>

<p style="text-align:justify">&nbsp;</p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:black">Conclusions:</span></span></span></strong> </span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif">Disproportionate FMR assessed by an individualized method was independently associated with an increased risk of all-cause mortality. <span style="color:black">When added to the American and European guidelines, FMR proportionality also improved risk stratification by reclassifying patients into lower and higher risk subsets.</span></span></span></span></span></p>