Proportionality concept of mitral regurgitation-truly valid?

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main source(s): University Medical Centre Ljubljana, Slovenia. Background The results studies transcatheter mitral valve repair introduced a new conceptual framework that categorized regurgitation (MR) into proportionate (propMR) and disproportionate (dispropMR) according to the relationship between effective regurgitant orifice area (EROA) left ventricular (LV) end-diastolic volume (EDV). However, pathophysiological mechanisms behind these entities have not been well defined. Purpose To identify echocardiographic characteristics which could explain underlying mechanism dispropMR. Methods We retrospectively included 179 consecutive patients (age: 69±12 years, male: 132 [74%]) with HFrEF more than mild MR referred clinically indicated echocardiography. disproportional cut-off value specific for our group was calculated from theoretical line proportionality based on ratio EROA/EDV, considering clinical study group. Correspondingly, disproportionality 0.126. Potential factors might affect scheme were analysed: affecting EDV measurements (LV foreshortening) EROA calculation (dynamic variation flow rate (MRFR) different PISA approaches calculation: standard single-point method vs. serial method). Results In cohort, 55 (32%) had Patients dispropMR frequent LV foreshortened images propMR (31 (56.4%) 37 (32.7%); p = 0.003), resulting in smaller DispropMR substantial dynamic compared (Figure A), significant overestimation MRFR when using instantaneous (p 0.001). consistently overestimated by B). Consequently, 73% classified as either image or measurement. Conclusion Our suggest higher EROA/EDV be explained underestimation due foreshortening flow. data methodological limitations an important impact used definition proportionality. concept is questionable may support patients’ selection treatment strategies.