Influence of prolapse volume in myxomatous mitral valve prolapse

Abstract

Myxomatous mitral valve prolapse (MMVP) is characterized by excessive leaflet tissue leading to a wide spectrum of mitral regurgitation (MR) ranging from trivial to complex severe incompetence. The prolapse volume (PV) below the prolapsing leaflets in end-systole was suspected to impact both chamber remodeling and MR grading in MMVP. Based on 157 consecutive patients (45 women; mean age 62 ± 15) referred for CMR assessment of MR, either from MMVP ( n = 91; 58%) or fibroelastic disease (FED) ( n = 66; 42%), we sought to study: – the interaction between PV and cardiac chamber geometry; – to study the impact of PV on MR quantification in MMVP. Despite similar left ventricular (LV) size, PV was larger in MMVP (11 ± 9 mL) than in FED (2 ± 2 mL). PV progressively increased with the severity of MR in MMVP but not in FED. Despite a low regurgitant volume (32 ± 18 mL), some MMVP patients with less than moderate MR exhibit significant cardiac chambers remodeling compared to 52 age and sex-matched controls. PV correlated significantly ( r = 0.52) with the LV dilatation in severe MR but also in less than moderate MR. In MMVP, PV > 14 mL was associated with a significant underestimation (Bias = −26 ± 32 mL) of regurgitant volume by PISA compared to CMR. In conclusion, in MMVP, PV may play a role in left cardiac chambers remodeling, even in patients without severe MR, and in discordant grading of MR between echocardiography and CMR.