Quantitative Definition of Severe Functional Mitral Regurgitation

Recent divergence between the American Heart Association/American College of Cardiology (AHA/ACC) and European Society of Cardiology/European Association for Cardio-Thoracic Surgery (ESC/EACTS) guidelines of the quantitative definition for severe functional mitral regurgitation (sFMR) introduced uncertainty, inconsistency, and continuing debate. According to the AHA/ACC guidelines, sFMR occurred in 17% by EROA, with a median EROA of 0.5 mm2 (IQR: 0.4 to 0.6 mm2), and in 13% by RegVol, with a median RegVol of 76 ml/beat (IQR: 69 to 101 ml/beat). According to the ESC/EACTS guidelines, sFMR occurred in 53% by EROA, with a median EROA of 0.4 mm2 (IQR: 0.2 to 0.4 mm2), and 40% according to RegVol, with a median RegVol of 51 ml/beat (IQR: 37 to 69 ml/beat).