SPC365

Functional mitral regurgitation: keeping coherence with the ASE grading guidelines, which proportionality concept best predicts prognosis in the real world?

Session: Comunicações Orais (Sessão 19) - Prémio Jovem Investigador - Investigação Clínica
Speaker: João Presume

Congress: CPC 2022
Topic: F. Valvular, Myocardial, Pericardial, Pulmonary, Congenital Heart Disease
Theme: 15. Valvular Heart Disease
Subtheme: 15.2 Valvular Heart Disease – Epidemiology, Prognosis, Outcome
Session Type: Comunicações Orais
FP Number: ---
Authors: João Presume; Pedro Lopes; Pedro Freitas; Francisco Albuquerque; Carla Reis; Eduarda Horta; Sara Guerreiro; Liliana Marta; Marisa Trabulo; João Abecasis; Maria João Andrade; Miguel Mendes; Regina Ribeiras

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif"><strong><u>Introduction:</u></strong></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif">While the proportionality concept of functional mitral regurgitation (fMR) has been proposed as a potential explanation for the different results of two landmark mitral edge-to-edge trials, it still remains to be established which is the best way to assess it. The aim of this study was to evaluate the prognostic value of two proportionality concepts and assess their ability to improve MR stratification proposed by the American Society of Echocardiography (ASE).</span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif"><strong><u>Methods:</u></strong></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif"><span style="font-family:Arial,Helvetica,sans-serif">We conducted a single-centre retrospective analysis in patients with reduced LVEF (&lt;50%) and at least mild fMR under optimal medical therapy. Proportionality status was calculated using the formulas proposed by: a) </span>Grayburn, <em>et al.</em> &ndash; disproportionate fMR defined as (<em><span style="font-family:&quot;Cambria Math&quot;,serif">EROA /&nbsp;</span></em><em><span style="font-family:&quot;Cambria Math&quot;,serif">LVEDV)</span></em>&nbsp;&ge; 0.15; b) Lopes, <em>et al.</em> &ndash; disproportionate fMR is present when measured EROA &gt; individualized EROA cut-off (determined as: (<span style="font-family:&quot;Cambria Math&quot;,serif">50% &times; LVEF &times; LVEDV)/</span><span style="font-family:&quot;Cambria Math&quot;,serif">Mitral VTI</span>). The primary endpoint was all-cause mortality. </span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif"><strong><u>Results:</u></strong></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif">A total of 572 patients (mean age 69&plusmn;12 years; 76% male) were included. Mean LVEF was 33&plusmn;9%, with a median LVEDV of 174 mL [136;220], and a median EROA of 14mm<sup>2</sup> [8;22]. During a mean follow-up of 4.1&plusmn;2.7 years, there were 254 (44%) deaths. FMR (ASE guidelines) was classified as grade I in 418 (73%) patients, grade II in 109 (19%), grade III in 33 (6%) and grade IV in 12 (2%). Considerable disagreement (p&lt;0.001) exists between the two formulas: 46 (48%) of the 96 patients with disproportionate fMR by Lopes&rsquo; formula were proportionate by Grayburn&rsquo;s; and 12 (19%) of the 62 patients with disproportionate fMR by Grayburn&rsquo;s were proportionate by Lopes&rsquo;.</span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif">Two different models were created to test each formula&rsquo;s prognostic impact. Each model was adjusted for multiple variables with prognostic value. While Lopes&rsquo; formula maintained independent prognostic impact (aHR 1.5 [95%CI 1.07-2.1], p=0.018), Grayburn&rsquo;s formula was not associated with all-cause mortality in multivariate analysis (aHR 1.0 [95%CI 0.67-1.5], p=0.998). </span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif">The distribution and mortality of ASE fMR classification was restratified according to each disproportionate formula - figure 1. Only Lopes&rsquo; formula was able to distinguish lower and higher risk subsets of patients.</span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif"><strong><u>Conclusion:</u></strong></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:Calibri,sans-serif">While two formulas exist to define fMR proportionality status, only the formula integrating LVEF at its core (Lopes&rsquo;s formula) maintained independent prognostic impact and was able to improve risk stratification of fMR severity according to the ASE. </span></span></p>