Figure 1.

Ventricular end-diastolic volume vs. effective regurgitant orifice area across various studies. The red line represents a theoretical threshold designed to differentiate between disproportionate and proportionate mitral regurgitation relative to left ventricular size (from Grayburn et al.¹³). It helps identify potential responders to transcatheter edge-to-edge repair , with patients below the line more likely to experience improvements in quality of life and symptom relief, along with reduced heart failure hospitalizations, while those above the line, in the absence of extreme left ventricular remodelling, may benefit from improved survival. However, this remains a hypothesis, and there could be other forms of relationships that warrant further exploration in future studies. Randomized trials are represented by circles (orange for severe mitral regurgitation, magenta for moderate mitral regurgitation with positive outcomes from transcatheter edge-to-edge repair, or mitral valve repair in the case of Surgical Treatment for Ischaemic Heart Failure, with the exception of MITRA-FR, shown in dark magenta). The blue squares denote non-randomized observational studies, demonstrating the prognostic impact of moderate mitral regurgitation (effective regurgitant orifice area ≥0.20 cm²; Grigioni et al.,³ Rossi et al.,¹⁸ Lancellotti et al.²⁰). The orange square represents a non-randomized study (Horii et al.²³) that showed no benefit from transcatheter edge-to-edge repair in the presence of significant left ventricular remodelling.